TW201313920A - Hot-rolled steel sheet having high yield ratio and excellent low-temperature impact energy absorption and haz softening resistance and method for producing same - Google Patents

Hot-rolled steel sheet having high yield ratio and excellent low-temperature impact energy absorption and haz softening resistance and method for producing same Download PDF

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TW201313920A
TW201313920A TW101128765A TW101128765A TW201313920A TW 201313920 A TW201313920 A TW 201313920A TW 101128765 A TW101128765 A TW 101128765A TW 101128765 A TW101128765 A TW 101128765A TW 201313920 A TW201313920 A TW 201313920A
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steel sheet
energy absorption
less
ratio
hot
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TW101128765A
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Chinese (zh)
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TWI453287B (en
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Naoki Maruyama
Naoki Yoshinaga
Masafumi Azuma
Yasuharu Sakuma
Atsushi Itami
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Nippon Steel Corp
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
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    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
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    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
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    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
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    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
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Abstract

Provided is a hot-rolled steel sheet having a high yield ratio and excellent low-temperature impact energy absorption and HAZ softening resistance wherein the maximum tensile strength is 600 MPa or higher, and also provided is method for producing the same. The steel is formed from, by mass %, C: 0.04 to 0.09%, Si: 0.4% or less, Mn: 1.2 to 2.0%, P: 0.1% or less, S: 0.02% or less, Al: 1.0% or less, Nb: 0.02 to 0.09%, Ti: 0.02 to 0.07%, and N: 0.005% or less such that 2.0 Mn + 8 [%Ti] + 12 [%Nb] 2.6, with the remainder being Fe and inevitable impurities. The pearlite surface area percentage is 5% or less, and the total martensite and residual austenite surface area percentage is 0.5% or less, with the remainder being a ferrite and/or bainite metal structure. The average crystal grain size of the ferrite and bainite is 10 μm or smaller, the average grain size of phase-separated alloy carbonitride that contains Ti and Nb is 20 nm or less, and the yield ratio is 0.85 or greater.

Description

具優異低溫下之衝擊能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板及其製造方法 High-ratio ratio hot-rolled steel sheet with excellent impact energy absorption characteristics at low temperature and HAZ softening resistance and manufacturing method thereof 發明領域 Field of invention

本發明係有關於具優異低溫下之衝撃能量吸收特性及耐HAZ(Heat-Affected Zone：熱影響區)軟化特性的最大抗拉強度600MPa以上之高降伏比熱軋鋼板及其製造方法。本鋼板宜作為營建機具之弔桿、框的素材、或以彎曲成形為主體所成形的卡車或汽車之框、構件等的素材，甚至是作為管線之素材。 The present invention relates to a high-ratio ratio hot-rolled steel sheet having a maximum tensile strength of 600 MPa or more and a high tensile-resistance-resistant hot-rolled steel sheet having excellent latent energy absorption characteristics at low temperatures and HAZ (Heat-Affected Zone) softening characteristics, and a method for producing the same. The steel plate should be used as a material for the boom, frame of the construction machine, or a frame or member of a truck or a car formed by bending forming, or even as a material for the pipeline.

發明背景 Background of the invention

營建機具、卡車之框類係主要藉由彎曲加工成形熱軋鋼板，並藉由電弧熔接組裝該成形之零件。因此，使用於該等零件之素材，係要求優異之彎曲加工性與電弧熔接性。此外，因營建機具、卡車有於低溫環境化使用的情形，故特別追求於施加衝擊於卡車用之框等時，即使於低溫下仍未脆性地破壞，可充分地吸收衝撃能量的特性。 The frame of the building machine and the truck is mainly formed by bending a hot-rolled steel sheet and assembling the formed part by arc welding. Therefore, the materials used for these parts are required to have excellent bending workability and arc weldability. In addition, since the construction machine and the truck are used in a low-temperature environment, it is particularly desirable to apply the impact to the frame for a truck or the like, and the brittle energy can be sufficiently absorbed even if it is not brittlely broken at a low temperature.

衝撃能量吸收特性優異之鋼板，係於非專利文獻1及專利文獻1~2中揭示其技術。但，該等之鋼板具有包含殘留沃斯田鐵或麻田散鐵的組織，並且藉使鋼板之金屬組織最適化，達成優異之衝突特性。然而，如此之組織的鋼板有降伏應力低、或有彎曲成形性的問題。 The steel sheet having excellent energy absorption characteristics is disclosed in Non-Patent Document 1 and Patent Documents 1 to 2. However, these steel sheets have a structure containing residual Worthite iron or 麻田散铁, and the metal structure of the steel sheet is optimized to achieve excellent conflict characteristics. However, such a steel sheet has a problem that the relief stress is low or the bending formability is obtained.

又，專利文獻3中揭示了一種藉由進行冷軋，可高良率並穩定地製造具高衝撃能量吸收能之薄鋼板的方 法。然而，該方法中電弧熔接部之熱影響部(HAZ)的軟化大，除了未能得到充分之熔接接頭強度以外，於製造成本上亦不利。 Further, Patent Document 3 discloses a method for producing a thin steel sheet having high energy absorption energy at a high yield and stably by performing cold rolling. law. However, in this method, the softening of the heat-affected zone (HAZ) of the arc-welding portion is large, and it is disadvantageous in terms of manufacturing cost in addition to insufficient strength of the welded joint.

得到彎曲性優異之高降伏比的熱軋鋼板之方法，揭示有例如，專利文獻4~6所示之於鋼中使Ti、Nb等合金碳化物分散的方法。然而，活用有該等析出強化之鋼板的電弧熔接熱影響部之軟化大，有接頭強度下降的情形，並且，有於低溫下脆性破壞的情形、或衝撃能量吸收量變小的情形等問題。 In the method of obtaining a hot-rolled steel sheet having a high-ratio ratio, which is excellent in flexibility, for example, a method of dispersing alloy carbides such as Ti and Nb in steel as disclosed in Patent Documents 4 to 6 is disclosed. However, the arc-welding heat-affected zone of the steel sheet having such precipitation-strengthening has a large softening, and the joint strength is lowered, and there is a problem that the brittle fracture at low temperature or the amount of flushing energy absorption is small.

另一方面，抑制熔接熱影響部之軟化的技術方面，專利文獻7中揭示了一種藉由複合添加Mo與Nb或Ti以抑制HAZ軟化之方法，又，專利文獻8中揭示了一種藉由使成分最適化，以含有Ti之經析出強化的鋼來抑制HAZ軟化之方法。然而，該等方法中，於低溫下有於素材產生脆性破壞的情形、或衝撃能量吸收量變小的情形等問題。 On the other hand, in the technical aspect of suppressing softening of the heat affected portion of the fusion, Patent Document 7 discloses a method of suppressing softening of HAZ by adding Mo and Nb or Ti in combination, and Patent Document 8 discloses The composition is optimized to suppress the HAZ softening by using a precipitation-strengthened steel of Ti. However, in such methods, there are problems such as a case where the material is brittlely broken at a low temperature or a case where the amount of energy absorbed by the pumping is small.

專利文獻9中，揭示了一種藉由適當化自鋼片之粗軋延至完工軋延的軋延條件與之後的冷卻處理，以製造低溫韌性及熔接性優異之高強度電縫鋼管用熱軋鋼板的方法。該方法，雖可藉由控制鋼片之粗軋延及完工軋延下的再結晶，成為細粒之金屬組織，得到低溫韌性優異的鋼板，但未考量到控制合金碳氮化物之尺寸或分布。結果，因該等未能最適化，故有衝撃能量吸收特性下降的問題。 Patent Document 9 discloses a hot-rolled steel sheet for high-strength electric seam steel pipe which is excellent in low-temperature toughness and weldability by appropriately controlling the rolling conditions from the rough rolling of the steel sheet to the rolling and the subsequent cooling treatment. Methods. In this method, the steel sheet of the fine grain can be obtained by controlling the rough rolling of the steel sheet and the recrystallization under the completion rolling, thereby obtaining a steel sheet excellent in low temperature toughness, but the size or distribution of the controlled alloy carbonitride is not considered. . As a result, since these are not optimized, there is a problem that the energy absorption characteristics of the pumping are lowered.

專利文獻10中，揭示了一種藉由藉由適當化鋼片之粗軋延步驟下的軋縮率與保持時間及完工軋延條件，以 製造韌性及耐氫誘導破裂性優異之熱軋高張力鋼板的方法。該方法中之粗軋延步驟的最適化之目的係促進鋼之再結晶，但並未考量到控制合金析出物的尺寸或分布。結果，因該等未能最適化，故有衝撃能量吸收特性下降的問題。完工軋延條件方面，專利文獻10記載之方法中，未能控制合金析出物的尺寸或分布，有無法得到良好之衝撃吸收能量的問題。 Patent Document 10 discloses a reduction ratio, a holding time, and a finishing rolling condition in a rough rolling step by appropriately sizing a steel sheet, A method of producing a hot-rolled high-tensile steel sheet excellent in toughness and hydrogen-induced fracture resistance. The purpose of the optimization of the rough rolling step in this method is to promote recrystallization of the steel, but does not consider controlling the size or distribution of the alloy precipitate. As a result, since these are not optimized, there is a problem that the energy absorption characteristics of the pumping are lowered. In the method described in Patent Document 10, in the method described in Patent Document 10, the size and distribution of the alloy precipitates are not controlled, and there is a problem that a good absorbing energy cannot be obtained.

專利文獻11中，揭示了一種藉由於熔接熱影響部適當地分散析出粒子，以得到具優異之耐HAZ軟化特性的高強度熱軋鋼板之技術。然而，該技術係於電弧熔接中使細微之析出物分散於鋼板的HAZ部者，因鋼中之析出粒子尺寸未為最適化，結果，有鋼板之衝撃能量吸收特性不良的問題。 Patent Document 11 discloses a technique of appropriately dispersing precipitated particles by a heat-affected portion to obtain a high-strength hot-rolled steel sheet having excellent HAZ softening resistance. However, this technique is a technique in which fine precipitates are dispersed in the HAZ portion of the steel sheet during arc welding, and the size of the precipitated particles in the steel is not optimized, and as a result, there is a problem that the punching energy absorption characteristics of the steel sheet are poor.

先前技術文獻 Prior technical literature 專利文獻 Patent literature

專利文獻1：日本專利特開2007-284776號公報 Patent Document 1: Japanese Patent Laid-Open Publication No. 2007-284776

專利文獻2：日本專利特開2005-290396號公報 Patent Document 2: Japanese Patent Laid-Open Publication No. 2005-290396

專利文獻3：日本專利特開平10-58004號公報 Patent Document 3: Japanese Patent Laid-Open No. Hei 10-58004

專利文獻4：日本專利特開2009-185361號公報 Patent Document 4: Japanese Patent Laid-Open Publication No. 2009-185361

專利文獻5：日本專利特開2007-9322號公報 Patent Document 5: Japanese Patent Laid-Open Publication No. 2007-9322

專利文獻6：日本專利特開2005-264239號公報 Patent Document 6: Japanese Patent Laid-Open Publication No. 2005-264239

專利文獻7：日本專利特開2003-231941號公報 Patent Document 7: Japanese Patent Laid-Open Publication No. 2003-231941

專利文獻8：日本專利特開2001-89816號公報 Patent Document 8: Japanese Patent Laid-Open Publication No. 2001-89816

專利文獻9：日本專利特開2001-207220號公報 Patent Document 9: Japanese Patent Laid-Open Publication No. 2001-207220

專利文獻10：日本專利特開平10-298645號公報 Patent Document 10: Japanese Patent Laid-Open No. Hei 10-298645

專利文獻11：日本專利特開2008-280552號公報 Patent Document 11: Japanese Patent Laid-Open Publication No. 2008-280552

非專利文獻 Non-patent literature

非專利文獻1：新日鐵技術情報第378卷(2003)p.2 Non-Patent Document 1: Nippon Steel Technical Information, Vol. 378 (2003) p.2

發明概要 Summary of invention

本發明係有鑑於前述問題所作成者，其目的係提供具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性兩者的最大抗拉強度600MPa以上之高降伏比熱軋鋼板及其製造方法。 The present invention has been made in view of the above problems, and an object thereof is to provide a high-ratio ratio hot-rolled steel sheet having a maximum tensile strength of 600 MPa or more and excellent in both the pumping energy absorption property and the HAZ-resistant softening property at a low temperature, and a method for producing the same.

本發明人等詳細地調查關於可穩定地得到高降伏比之包含Ti等合金碳氮化物的鋼板之HAZ軟化與低溫下之衝撃能量吸收特性的影響因子。結果，觀察得知HAZ軟化量可藉由適當之Ti量、Nb量及Mn量抑制。 The inventors of the present invention investigated in detail the influence factors of the HAZ softening and the punching energy absorption characteristics at a low temperature of a steel sheet containing an alloy carbonitride such as Ti which can stably obtain a high derating ratio. As a result, it was observed that the amount of HAZ softening can be suppressed by an appropriate amount of Ti, amount of Nb, and amount of Mn.

又，發明人等接著致力地檢討提升低溫下之衝撃能量吸收特性的方法，首次觀察得知鋼板之金屬組織方面，藉由減少波來鐵之面積分率，並反而極力地排除以往認為有利於提升衝撃能量吸收能的殘留沃斯田鐵、麻田散鐵，且更加使分散於鋼中之含有Ti、Nb的合金碳氮化物與母相Fe之晶格匹配性及尺寸最適化，特別是，控制合金碳氮化物之經非整合析出的粒子之粒徑，以改善析出強化鋼中作為課題之低溫下的衝撃能量吸收特性。 In addition, the inventors continued to work hard to review the method of improving the energy absorption characteristics of the scouring energy at low temperatures. For the first time, it was observed that the metal structure of the steel sheet was reduced by reducing the area fraction of the iron, and instead it was strongly excluded from the past. The Worthite iron and the granulated iron which are used to enhance the energy absorption energy of the ramming energy, and the lattice matching and size of the alloy carbonitride containing Ti and Nb dispersed in the steel and the parent phase Fe are optimized, in particular, The particle size of the non-integrated precipitated particles of the alloy carbonitride is controlled to improve the punching energy absorption characteristics at a low temperature as a subject in the precipitation strengthened steel.

一般而言，於含有Nb、Ti之析出強化鋼中，雖控制析出物，以於與母相Fe具有特定之結晶方位關係的晶格匹配性佳的狀態下存在，但，此次，調查與低溫下之衝撃能量吸收特性的關係之結果，發現對母相Fe之晶格匹配性佳的析出狀態之合金碳氮化物不易成為產生裂縫的起點與傳播的障礙，另一方面，發現即使與母相Fe為非整合狀態的合金碳氮化物之尺寸較小，低溫下之衝撃能量吸收量仍下降。並未規定合金碳氮化物之對母相的晶格匹配性影響低溫下之衝撃能量吸收量的機構，但合金碳氮化物與母相Fe之晶格匹配性差時，將產生界面剝離或成為產生孔隙的起點，有促進延性破壞與脆性破壞任一者的可能。 In general, in the precipitation strengthened steel containing Nb and Ti, the precipitate is controlled so as to have a lattice matching property with a specific crystal orientation relationship with the parent phase Fe, but this time, investigation and As a result of the relationship between the energy absorption characteristics of the enthalpy at a low temperature, it was found that the alloy carbonitride which is in a precipitated state in which the lattice matching property of the parent phase Fe is excellent is not easily caused as a starting point and a propagation barrier of the crack. On the other hand, it is found that even with the mother The alloy carbonitride in which the phase Fe is in a non-integrated state is small in size, and the amount of rushing energy absorption at a low temperature is still decreased. The mechanism for the lattice matching of the alloy carbonitride to the parent phase affects the absorption energy of the punching energy at a low temperature is not specified, but when the lattice compatibility of the alloy carbonitride and the parent phase Fe is poor, interface peeling or generation occurs. The starting point of the pores has the potential to promote either ductile damage or brittle failure.

發明人等致力地檢討用以實現前述組織形態之製造製程、成分範圍，結果，完成兼具耐HAZ軟化特性與低溫下之能量吸收特性，且高降伏比及彎曲性良好的最大抗拉強度600MPa以上之熱軋鋼板及鍍敷鋼板。 The inventors of the present invention have deliberately reviewed the manufacturing process and the composition range for realizing the above-mentioned histological morphology, and as a result, completed the maximum tensile strength 600 MPa which has both HAZ softening resistance and energy absorption characteristics at low temperatures, and high drop ratio and flexibility. The above hot rolled steel sheets and plated steel sheets.

換言之，本發明之要旨係如以下所述。 In other words, the gist of the present invention is as follows.

(1)一種具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，係具有下述成分組成：以質量%計，含有：C：0.04~0.09%、Si：0.4%以下、Mn：1.2~2.0%、P：0.1%以下、S：0.02%以下、Al：1.0%以下、Nb：0.02~0.09%、Ti：0.02~0.07%、及N：0.005%以下，2.0≦Mn+8[%Ti]+12[%Nb]≦2.6，且剩餘部分具有由Fe及不可避免的不純物所構成；波來鐵之面積分率係5%以下，麻田散鐵及殘留沃斯田鐵之合計面積分率係0.5%以 下，且剩餘部分係由肥粒鐵及變韌鐵之1種或2種的金屬組織所構成；肥粒鐵及變韌鐵之平均結晶粒徑係10μm以下；含有Ti及Nb之經非整合析出的合金碳氮化物之平均粒子徑係20nm以下；降伏比係0.85以上，最大抗拉強度係600MPa以上。 (1) A high-ratio ratio hot-rolled steel sheet having excellent ramming energy absorption characteristics and HAZ softening resistance at a low temperature, having the following composition: in mass%, containing: C: 0.04 to 0.09%, Si: 0.4 % or less, Mn: 1.2 to 2.0%, P: 0.1% or less, S: 0.02% or less, Al: 1.0% or less, Nb: 0.02 to 0.09%, Ti: 0.02 to 0.07%, and N: 0.005% or less, 2.0 ≦Mn+8[%Ti]+12[%Nb]≦2.6, and the remaining part is composed of Fe and unavoidable impurities; the area fraction of Borne iron is 5% or less, Ma Tian loose iron and residual Voss The total area ratio of Tian Tiezhi is 0.5%. The remaining part is composed of one or two kinds of metal structures of ferrite iron and toughened iron; the average crystal grain size of ferrite iron and toughened iron is 10 μm or less; and the non-integration of Ti and Nb The precipitated alloy carbonitride has an average particle diameter of 20 nm or less; a drop ratio of 0.85 or more, and a maximum tensile strength of 600 MPa or more.

(2)如前述(1)記載之具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，其以質量%計，更含有V：0.01~0.12%。 (2) The high-ratio ratio hot-rolled steel sheet having excellent punching energy absorption characteristics and HAZ softening resistance at a low temperature as described in the above (1), further containing V: 0.01 to 0.12% by mass%.

(3)如申請專利範圍第1或2項記載之具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，其以質量%計，更含有合計為0.02~2.0%之Cr、Cu、Ni、Mo的1種或2種以上。 (3) The high-ratio ratio hot-rolled steel sheet having the excellent energy absorption characteristics at the low temperature and the HAZ softening resistance as described in the first or second aspect of the patent application, which is 0.02 to 2.0% by mass in total. One or two or more kinds of Cr, Cu, Ni, and Mo.

(4)如前述(1)~(3)中任1項記載的具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，其以質量%計，更含有0.0003~0.005%之B。 (4) The high-ratio ratio hot-rolled steel sheet having the excellent energy absorption characteristics at the low temperature and the HAZ softening resistance according to any one of the above items (1) to (3), further comprising 0.0003% by mass%. 0.005% of B.

(5)如前述(1)~(4)中任1項記載的具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，其以質量%計，更含有合計0.0003~0.01%之Ca、Mg、La、Ce的1種或2種以上。 (5) The high-ratio ratio hot-rolled steel sheet having excellent punching energy absorption characteristics and HAZ softening resistance at a low temperature according to any one of the above items (1) to (4), which is 0.003% by mass in total. ~0.01% of one or more of Ca, Mg, La, and Ce.

(6)一種具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鍍敷鋼板，係於前述(1)~(5)之任1項記載的高降伏比熱軋鋼板之表面施加有鍍敷或合金化鍍敷。 (6) A high-ratio ratio hot-rolled steel sheet having a high-ratio-ratio hot-rolled steel sheet having excellent ramming energy absorption characteristics and HAZ softening resistance at a low temperature, which is the high-ratio ratio hot-rolled steel sheet according to any one of the above items (1) to (5). The surface is coated with plating or alloying plating.

(7)一種具優異低溫下之衝撃能量吸收特性及耐 HAZ軟化特性的高降伏比熱軋鋼板之製造方法，係將由前述(1)~(5)之任1項記載的成分組成所構成之鋼片，進行下述步驟：加熱至1150℃以上；將經加熱之鋼片進行粗軋延，且於1000~1080℃間結束粗軋延，此時，於1150℃以下進行之粗軋延中最大的軋延間隔係45秒以下：粗軋延結束後，且歷時滿足下述式(1)之保持時間t1(秒)後，開始完工軋延；進行滿足下述式(2)的最終軋延溫度Tf之完工軋延；完工軋延後於3秒以內開始鋼片的水冷卻，接著以最低冷卻速度8℃/秒以上將鋼片冷卻至700℃以下，再於530~650℃之範圍內捲取。 (7) A punching energy absorption characteristic and resistance at an excellent low temperature A method for producing a high-ratio ratio HAZ softening property of a hot-rolled steel sheet, wherein the steel sheet comprising the component composition according to any one of the above items (1) to (5) is subjected to the following steps: heating to 1150 ° C or higher; The heated steel sheet is subjected to rough rolling and the coarse rolling is finished at 1000-1080 ° C. At this time, the maximum rolling interval in the rough rolling process below 1150 ° C is less than 45 seconds: after the rough rolling And after the holding time t1 (second) of the following formula (1) is satisfied, the completion rolling is started; the finishing rolling of the final rolling temperature Tf satisfying the following formula (2) is performed; after the rolling is completed, it is 3 seconds. The water of the steel sheet was started to be cooled, and then the steel sheet was cooled to 700 ° C or lower at a minimum cooling rate of 8 ° C /sec or more, and then taken up in the range of 530 to 650 ° C.

1000×([%Ti]+[%Nb])>t1………式(1) 1000×([%Ti]+[%Nb])>t1.........(1)

Tf>830+400([%Ti]+[%Nb])………式(2) Tf>830+400([%Ti]+[%Nb]).........(2)

(8)如(7)記載之高降伏比熱軋鋼板的製造方法，其中最終軋延溫度Tf係滿足下述式(3)。 (8) The method for producing a high-ramp ratio hot-rolled steel sheet according to (7), wherein the final rolling temperature Tf satisfies the following formula (3).

Tf>830+800([%Ti]+-[%Nb])………式(3) Tf>830+800([%Ti]+-[%Nb]).........(3)

(9)一種具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鍍敷鋼板之製造方法，係於將以前述(7)或(8)記載的製造方法所得之熱軋鋼板酸洗後，於Ac3溫度以下進行加熱，接著，浸漬於鍍敷浴中來鍍敷該鋼板表面。 (9) A method for producing a high-ratio ratio hot-rolled plated steel sheet having excellent latent energy absorption characteristics and HAZ softening resistance at a low temperature, which is the heat obtained by the production method according to (7) or (8) above After the pickled steel sheet is pickled, it is heated at a temperature equal to or lower than Ac3, and then immersed in a plating bath to plate the surface of the steel sheet.

(10)如(9)記載之具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鍍敷鋼板之製造方法，其係於前述鍍敷後進行鍍敷合金化處理。 (10) A method for producing a high-ratio ratio hot-rolled-plated steel sheet having excellent punching energy absorption characteristics and HAZ-resistant softening properties as described in (9), which is subjected to a plating alloying treatment after the plating.

依據本發明之熱軋鋼板，藉由前述構成，可得到最大抗拉強度600MPa以上、耐HAZ軟化特性與低溫下之能量吸收特性，且彎曲加工性優異之高降伏比熱軋鋼板。依據以往之鋼板，有低溫下之使用及移動受限、無法得到充分之接頭強度的問題，但依據本發明之熱軋鋼板，可於寒冷地區使用，且藉由高強度化可薄化零件的板厚，可期待營建機具、汽車或卡車之輕量化效果。 According to the hot-rolled steel sheet of the present invention, the high-ratio ratio hot-rolled steel sheet having a maximum tensile strength of 600 MPa or more, HAZ softening resistance and energy absorption characteristics at low temperatures, and excellent bending workability can be obtained. According to the conventional steel sheet, there is a problem that the use and movement at a low temperature are limited, and sufficient joint strength cannot be obtained. However, the hot-rolled steel sheet according to the present invention can be used in a cold region, and the parts can be thinned by high strength. The thickness of the board can be expected to reduce the weight of the building equipment, car or truck.

又，依據本發明之具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的熱軋鋼板之製造方法，可製造最大抗拉強度600MPa以上、耐HAZ軟化特性與低溫下之衝撃能量吸收特性、及彎曲加工性優異之高降伏比熱軋鋼板。 Moreover, according to the method for producing a hot-rolled steel sheet having excellent punching energy absorption characteristics and HAZ softening resistance at a low temperature according to the present invention, it is possible to produce a maximum tensile strength of 600 MPa or more, a HAZ softening resistance, and a punching energy absorption property at a low temperature. And a high-ratio ratio hot-rolled steel sheet excellent in bending workability.

另外，於本發明中，低溫下之衝撃能量吸收優異係指，於沙丕衝撃試驗中-40℃中的衝撃能量吸收係70J/cm2以上。又，耐HAZ軟化性優異係指，於進行選擇可得良好珠狀之熔接電流、電壓、熔接速度，且熔接入熱係10000J/cm以下的電弧熔接時，熔接熱影響部(HAZ)之最軟化部的維克氏硬度(HVHAZ)與素材之維克氏硬度(HVBM)的差△HV(=HVBM-HVHAZ)係40以下。又，彎曲性優異係指，於90°V彎曲試驗中，以試驗片之板厚作為t、以未產生破裂之有限彎曲半徑作為rlim時，rlim/t係1.0以下。 Further, in the present invention, the excellent energy absorption at the low temperature means that the punching energy absorption system at -40 ° C in the sand blast test is 70 J/cm 2 or more. Further, the HAZ softening resistance is excellent, and the welding heat-affecting zone (HAZ) is the most preferable when the welding current, the voltage, and the welding speed are selected to obtain a good bead shape, and the arc is welded to a heat system of 10000 J/cm or less. The difference ΔHV (= HV BM - HV HAZ ) between the Vickers hardness (HV HAZ ) of the softened portion and the Vickers hardness (HV BM ) of the material is 40 or less. Further, in the 90°V bending test, when the thickness of the test piece is t and the finite bending radius at which cracking does not occur is r lim , r lim /t is 1.0 or less.

圖式簡單說明 Simple illustration

圖1係表示Mn+8Ti+12Nb與vE-40及△HV之關係的圖表。 Fig. 1 is a graph showing the relationship between Mn + 8Ti + 12Nb and vE - 40 and ΔHV.

圖2係表示Ti+Nb量對最終粗軋延~完工軋延開始為止 之保持時間t1與vE-40的關係所造成的影響之圖表。 Fig. 2 is a graph showing the effect of the amount of Ti+Nb on the relationship between the holding time t1 and the vE- 40 of the final rough rolling to the completion of the rolling.

圖3係表示表2所示之鋼種中本發明例及比較例之2種(A-7、B-6)的Ti+Nb之質量%與Tf(℃)的關係之圖表。 Fig. 3 is a graph showing the relationship between the mass % of Ti + Nb and the Tf (°C) of two types (A-7, B-6) of the present invention and the comparative examples in the steel types shown in Table 2.

用以實施發明之形態 Form for implementing the invention

以下，詳細地說明本發明。 Hereinafter, the present invention will be described in detail.

首先，說明限定本發明之具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板之鋼成分的理由。此處，關於成分之「%」係質量%之意。 First, the reason for limiting the steel composition of the high-ratio ratio hot-rolled steel sheet having the excellent energy absorption characteristics at the low temperature and the HAZ softening resistance of the present invention will be described. Here, the "%" of the component is the meaning of the mass%.

「C：0.04~0.09%」 "C: 0.04~0.09%"

C量小於0.04%時，確保最大抗拉強度600MPa以上係為困難。另一方面，大於0.09%時，因粗大且經非整合析出之含有Ti及Nb的合金碳氮化物增加，低溫下之衝撃能量吸收特性變低，故限制於0.04%~0.09%的範圍內。 When the amount of C is less than 0.04%, it is difficult to ensure a maximum tensile strength of 600 MPa or more. On the other hand, when it is more than 0.09%, the alloy carbonitride containing Ti and Nb which is coarse and precipitated by non-integration increases, and the energy absorption characteristics at the low temperature become low, so it is limited to the range of 0.04% to 0.09%.

「Si：0.4%以下」 "Si: 0.4% or less"

Si量大於0.4%時，有麻田散鐵或殘留沃斯田鐵殘留於鋼板組織內的情形，低溫下之韌性及衝撃能量吸收特性下降。因此，將其適當範圍設為0.4%以下。由確保彎曲成形性之觀點來看，以0.2%以下較佳。Si量之下限並未特別限定，但小於0.001%時，因製造成本增大，故0.001%係實質之下限。 When the amount of Si is more than 0.4%, there is a case where the granulated iron or the residual Worth iron remains in the steel sheet structure, and the toughness and the absorbing energy absorption characteristics at a low temperature are lowered. Therefore, the appropriate range is set to 0.4% or less. From the viewpoint of ensuring the bend formability, it is preferably 0.2% or less. The lower limit of the amount of Si is not particularly limited, but when it is less than 0.001%, the manufacturing cost increases, so 0.001% is a substantial lower limit.

「Mn：1.2~2.0%」 "Mn: 1.2~2.0%"

Mn係透過控制金屬組織以確保母材之強度所使用，更係有助於抑制熔接部的HAZ軟化之元素。小於1.2%時，波 來鐵之面積分率增加，低溫下之衝撃能量吸收特性下降，且因HAZ軟化量變大，故熔接接頭強度將相對於母材強度大幅地下降。於含有大於2.0%時，有形成硬質之麻田散鐵的情形，因低溫下之衝撃能量吸收特性下降，故將其適當範圍設為2.0%以下。由確保彎曲成形性之觀點來看，以1.8%以下較佳。 Mn is used to control the metal structure to ensure the strength of the base material, and is more effective in suppressing the HAZ softening of the welded portion. Wave less than 1.2% The area fraction of the incoming iron increases, and the energy absorption characteristics of the slag at a low temperature decrease, and since the HAZ softening amount becomes large, the strength of the welded joint is largely lowered with respect to the strength of the base material. When the content is more than 2.0%, there is a case where the hard rammed iron is formed, and since the energy absorption characteristics at the low temperature are lowered, the appropriate range is set to 2.0% or less. From the viewpoint of ensuring the bend formability, it is preferably 1.8% or less.

「P：0.1%以下」 "P: 0.1% or less"

P係用以確保鋼之強度。然而，於含有大於0.1%時，低溫韌性下降，且因未得低溫下之衝撃能量吸收特性，故將其適當範圍設為0.1%以下。下限並未特別限定，但小於0.001%時，因製造成本增大，故0.001%係實質之下限。 P is used to ensure the strength of steel. However, when the content is more than 0.1%, the low-temperature toughness is lowered, and since the energy absorption characteristics at the low temperature are not obtained, the appropriate range is made 0.1% or less. The lower limit is not particularly limited, but when it is less than 0.001%, the manufacturing cost increases, so 0.001% is the lower limit.

「S：0.02%以下」 "S: 0.02% or less"

S係影響衝撃能量吸收特性之元素。於含有大於0.02%時，即使控制金屬組織之面積分率與合金碳氮化物的平均粒子徑，仍未得到低溫下之衝撃能量吸收特性，故將其適當範圍設為0.02%以下。下限並未特別限定，但小於0.0003%時，因製造成本增大，故0.0003%係實質之下限。 The S system affects the elements of the energy absorption characteristics of the punch. When the content is more than 0.02%, even if the area fraction of the metal structure and the average particle diameter of the alloy carbonitride are controlled, the pumping energy absorption characteristics at a low temperature are not obtained, so the appropriate range is made 0.02% or less. The lower limit is not particularly limited, but when it is less than 0.0003%, the manufacturing cost increases, so 0.0003% is the lower limit.

「Al：1.0%以下」 "Al: 1.0% or less"

Al係用以脫氧及控制鋼板之金屬組織所使用。於大於1.0%時，因電弧熔接之熱影響部軟質化，未能得到充分之熔接接頭強度，故將其適當範圍設為1.0%以下。下限並未特別限定，但小於0.001%時，因製造成本增大，故0.001%係實質之下限。 Al is used to deoxidize and control the metal structure of the steel sheet. When the amount is more than 1.0%, the heat-affected zone of the arc welding is softened, and sufficient weld joint strength is not obtained. Therefore, the appropriate range is made 1.0% or less. The lower limit is not particularly limited, but when it is less than 0.001%, the manufacturing cost increases, so 0.001% is the lower limit.

「Nb：0.02~0.09%」 "Nb: 0.02~0.09%"

Nb係作為析出強化元素以調整鋼之強度，且用以控制熔接HAZ的軟化。小於0.02%時，未能發現熔接HAZ之軟化抑制效果，又大於0.09%時，因粗大且經非整合析出之含有Ti及Nb的合金碳氮化物增加，低溫下之衝撃能量吸收特性變低，故限制於0.02%~0.09%的範圍內。 Nb acts as a precipitation strengthening element to adjust the strength of the steel and to control the softening of the welded HAZ. When the amount is less than 0.02%, the softening inhibitory effect of the welded HAZ is not found, and when it is more than 0.09%, the alloy carbonitride containing Ti and Nb which is coarse and non-integrated precipitates increases, and the energy absorption characteristics at low temperature become low. Therefore, it is limited to the range of 0.02% to 0.09%.

「Ti：0.02~0.07%」 "Ti: 0.02~0.07%"

Ti係作為析出強化元素以調整鋼之強度，且用以抑制熔接HAZ的軟化。小於0.02%時，不易得到最大抗拉強度：600MPa以上。又大於0.07%時，因粗大且經非整合析出之含有Ti及Nb的合金碳氮化物增加，低溫下之衝撃能量吸收特性變低，故限制於0.02%~0.07%之範圍內。為穩定地得到降伏比0.85以上，以將0.03%設為下限為佳。 Ti is used as a precipitation strengthening element to adjust the strength of the steel and to suppress the softening of the welded HAZ. When it is less than 0.02%, it is difficult to obtain the maximum tensile strength: 600 MPa or more. When it is more than 0.07%, the alloy carbonitride containing Ti and Nb which is coarse and non-integrated precipitates increases, and the absorbing energy absorption property at a low temperature becomes low, so it is limited to the range of 0.02% to 0.07%. In order to stably obtain a drop ratio of 0.85 or more, it is preferable to set 0.03% as the lower limit.

「N：0.005%以下」 "N: 0.005% or less"

N係透過形成氮化物而有助於鋼板之金屬組織的結晶粒徑。然而，大於0.005%時，因粗大且經非整合析出之含有Ti及Nb的合金碳氮化物增加，低溫下之衝撃能量吸收特性變低，故限制於0.005%以下之範圍內。下限並未特別限定，但小於0.0003%時，因製造成本增大，故0.0003%係實質之下限。 The N system contributes to the crystal grain size of the metal structure of the steel sheet by forming a nitride. However, when it is more than 0.005%, the alloy carbonitride containing Ti and Nb which is coarse and precipitated by non-integration is increased, and the energy absorption characteristics at the low temperature are lowered, so it is limited to the range of 0.005% or less. The lower limit is not particularly limited, but when it is less than 0.0003%, the manufacturing cost increases, so 0.0003% is the lower limit.

「2.0≦Mn+8[%Ti]+12[%Nb]≦2.6」 "2.0≦Mn+8[%Ti]+12[%Nb]≦2.6"

「Mn+8[%Ti]+12[%Nb]」係與低溫下之衝撃能量吸收特性及利用熔接之HAZ軟化特性相關的各元素之貢獻比例的合計。如圖1所示，針對Ti、Nb相異之11鋼種，繪圖出作為衝撃能量吸收特性的指標之vE-40與作為HAZ軟化量之指 標的△HV之關係時，於本參數之值小於2.0時，未能得到充分之耐HAZ軟化特性(即，△HV>40)，且變得不易得到最大抗拉強度600MPa以上，大於2.6時，粗大且經非整合析出之含有Ti及Nb的合金碳氮化物增加，低溫下之衝撃能量吸收特性變低(即，vE-40<70J/cm2)。因此，將其適當範圍限制於2.0~2.6之範圍。 "Mn + 8 [% Ti] + 12 [% Nb]" is a total of the ratio of the contribution of each element related to the energy absorption characteristics at low temperature and the HAZ softening characteristics by welding. As shown in Fig. 1, for the 11 steel grades with different Ti and Nb, the relationship between vE- 40, which is an index of the energy absorption characteristics of the pumping, and ΔHV, which is an index of the softening amount of the HAZ, is plotted. The value of this parameter is less than 2.0. At the time, sufficient HAZ softening resistance (ie, ΔHV>40) is not obtained, and it becomes difficult to obtain a maximum tensile strength of 600 MPa or more, and when it is more than 2.6, coarse and non-integrated precipitated alloy carbon containing Ti and Nb The nitride increases, and the energy absorption characteristics at the low temperature become low (i.e., vE - 40 &lt; 70 J/cm 2 ). Therefore, the appropriate range is limited to the range of 2.0 to 2.6.

於本發明中，鋼成分除了前述各必須元素以外，亦可更選擇性地含有如以下所示之元素。 In the present invention, the steel component may further contain an element as shown below in addition to the above-mentioned essential elements.

「V：0.01~0.12%」 "V: 0.01~0.12%"

V亦可用以調整鋼之強度。然而，V之含量小於0.01%時，並無該效果，又，大於0.12%時，進行脆化，低溫下之衝撃能量吸收特性下降。因此，將其適當範圍限定為0.01~0.12%。 V can also be used to adjust the strength of steel. However, when the content of V is less than 0.01%, this effect is not obtained, and when it is more than 0.12%, embrittlement is carried out, and the energy absorption characteristics at the low temperature are lowered. Therefore, the appropriate range is limited to 0.01 to 0.12%.

「合計0.02~2.0%之Cr、Cu、Ni、Mo的1種或2種以上」 "A total of 0.02 to 2.0% of one, two or more types of Cr, Cu, Ni, and Mo"

Cr、Cu、Ni、Mo亦可用以控制鋼之組織。然而，該等元素之1種或2種以上的合計含量小於0.02%時，即使添加仍無前述效果，又，大於2.0%時，沃斯田鐵殘留，低溫下之衝撃能量吸收特性下降。因此，將該等元素之合計量的適當範圍限定為0.02~2.0%。 Cr, Cu, Ni, Mo can also be used to control the structure of steel. However, when the total content of one or two or more of these elements is less than 0.02%, even if it is added, the effect is not obtained, and when it is more than 2.0%, the Worthite iron remains, and the energy absorption characteristics at the low temperature are lowered. Therefore, the appropriate range of the total amount of these elements is limited to 0.02 to 2.0%.

「B：0.0003~0.005%」 "B: 0.0003~0.005%"

B亦可用以控制鋼板組織。然而，B量小於0.0003%時，未能顯現該效果，又，大於0.005%時，形成麻田散鐵，低溫下之衝撃能量吸收特性下降。因此，將其適當範圍限制 為0.0003~0.005%。 B can also be used to control the steel sheet structure. However, when the amount of B is less than 0.0003%, the effect is not exhibited, and when it is more than 0.005%, the granulated iron is formed, and the absorbing energy absorption property at a low temperature is lowered. Therefore, limit its appropriate range It is 0.0003~0.005%.

「合計0.0003~0.01%之Ca、Mg、La、Ce的1種或2種以上」 "Total one or two or more of Ca, Mg, La, and Ce of 0.0003 to 0.01%"

Ca、Mg、La、Ce亦可用以鋼之脫氧。然而，該等元素之1種或2種以上的合計量小於0.0003%時，並無該效果，又，大於0.01%時，於低溫下脆性破壞，衝撃能量吸收特性下降。因此，將其適當範圍限制為0.0003~0.01%。 Ca, Mg, La, and Ce can also be used for deoxidation of steel. However, when the total amount of one or two or more of these elements is less than 0.0003%, this effect is not obtained, and when it is more than 0.01%, brittleness is destroyed at a low temperature, and the energy absorption characteristics of the punching force are lowered. Therefore, the appropriate range is limited to 0.0003 to 0.01%.

另外，前述成分之剩餘部分係Fe及不可避免的不純物，但本實施形態中之鋼成分並未特別限定其他元素，亦可適當地含有用以調整強度的各種元素。 In addition, the remainder of the above-mentioned components is Fe and unavoidable impurities. However, the steel component in the present embodiment is not particularly limited to other elements, and various elements for adjusting the strength may be appropriately contained.

接著，說明本發明之熱軋鋼板的金屬組織。 Next, the metal structure of the hot-rolled steel sheet of the present invention will be described.

本發明之熱軋鋼板係以肥粒鐵及變韌鐵作為主相，剩餘部分亦可包含波來鐵與麻田散鐵與殘留沃斯田鐵中之任一種或二種以上。 In the hot-rolled steel sheet according to the present invention, the ferrite-grained iron and the toughened iron are used as the main phase, and the remainder may include any one or two or more of the white iron and the granulated iron and the residual Worth iron.

「波來鐵之面積分率」 "The area ratio of the Bora iron"

於含有Nb及Ti之析出強化鋼中，波來鐵之面積分率大於5%時，因低溫下變得容易脆性破壞，且衝撃能量吸收特性下降，故將其上限限制為5%。由確保彎曲性之觀點來看，3%以下係較佳之範圍。另外，下限並未特別限定，但對衝撃能量吸收特性來說，波來鐵之面積分率接近零較佳。 In the precipitation-strengthened steel containing Nb and Ti, when the area fraction of the ferritic iron is more than 5%, the brittle fracture is easily broken at a low temperature, and the enthalpy energy absorption property is lowered. Therefore, the upper limit is limited to 5%. From the viewpoint of ensuring flexibility, 3% or less is preferred. Further, the lower limit is not particularly limited, but in terms of the energy absorption characteristics of the enthalpy, the area fraction of the ferritic iron is preferably near zero.

「麻田散鐵與殘留沃斯田鐵之合計面積分率」 "The combined area ratio of Ma Tian loose iron and residual Worth Tin"

於含有Nb及Ti之析出強化鋼中，麻田散鐵與殘留沃斯田鐵之合計面積分率大於0.5%時，因低溫下變得容易脆性破壞，且衝撃能量吸收特性下降。因此，將合計面積分率 之上限限制為0.5%。另外，下限並未特別限定，但對衝撃能量吸收特性來說，麻田散鐵與殘留沃斯田鐵之合計面積分率接近零較佳。 In the precipitation-strengthened steel containing Nb and Ti, when the total area fraction of the granulated iron and the residual Worthite iron is more than 0.5%, the brittleness is easily broken at a low temperature, and the absorbing energy absorption characteristics are deteriorated. Therefore, the total area fraction will be The upper limit is limited to 0.5%. Further, the lower limit is not particularly limited, but in terms of the energy absorption characteristics, the total area fraction of the granulated iron and the residual Worth iron is close to zero.

「剩餘部分之金屬組織係肥粒鐵及變韌鐵的1種或2種」 "The remaining part of the metal structure is one or two of fertilized iron and toughened iron."

各別之面積分率並未特別限制，但由確保彎曲加工性之觀點來看，以包含10%以上之變韌鐵面積分率為佳。 The respective area fractions are not particularly limited, but from the viewpoint of ensuring the bending workability, it is preferable to include a toughness iron area fraction of 10% or more.

「肥粒鐵與變韌鐵之平均結晶粒徑」 "The average crystal grain size of ferrite iron and toughened iron"

肥粒鐵與變韌鐵之平均結晶粒徑係與脆化具相關關係的因子。平均粒徑大於10μm時，即使控制含有Nb與Ti之合金碳氮化物的平均粒子徑，因仍有無法確保低溫下之衝撃能量吸收特性的情形，故將其上限限制為10μm。8μm以下係可確保較穩定之衝撃能量吸收特性的較佳條件。下限並未特別限定，但小於2μm時，因製造成本大幅地增加，故2μm係實質之下限。 The average crystal size of fermented iron and toughened iron is a factor related to embrittlement. When the average particle diameter is more than 10 μm, even if the average particle diameter of the alloy carbonitride containing Nb and Ti is controlled, since the enthalpy energy absorption characteristics at a low temperature cannot be ensured, the upper limit is limited to 10 μm. Below 8 μm, a better condition for ensuring a more stable absorbing energy absorption characteristic is ensured. The lower limit is not particularly limited, but when it is less than 2 μm, the manufacturing cost is greatly increased, so 2 μm is a substantial lower limit.

於本發明中，鋼板之金屬組織的觀察係依據JIS G 0551，可藉由光學顯微鏡進行。觀察面係於研磨鋼板後，以硝太蝕劑腐蝕液蝕刻。 In the present invention, the observation of the metal structure of the steel sheet can be carried out by an optical microscope in accordance with JIS G 0551. The observation surface is etched with a nitric oxide etching solution after grinding the steel sheet.

肥粒鐵、變韌鐵、波來鐵、麻田散鐵之面積分率係藉由光學顯微鏡或掃描電子顯微鏡(SEM)使用經攝影之組織照片，可藉由計點法或影像解析測定。殘留沃斯田鐵之面積分率係藉由X射線繞射法測定。 The area fraction of fertilized iron, toughened iron, ferritic iron, and granulated iron is measured by optical microscopy or scanning electron microscopy (SEM) using photographs of photographs, which can be determined by counting or image analysis. The area fraction of the residual Worthite iron is determined by X-ray diffraction.

於本發明中，變韌鐵係包含上部變韌鐵、下部變韌鐵、粒狀變韌鐵之任一者。又，波來鐵係包含波來鐵及 疑似波來鐵。 In the present invention, the toughened iron system includes any of upper toughened iron, lower toughened iron, and granular toughened iron. Also, the Bora iron system contains Bora and Suspected to come to the iron.

結晶粒徑可藉由利用光學顯微鏡之觀察或利用EBSD法之結晶方位解析測定。此處，「結晶粒徑」係JIS G 0551記載的平均結晶粒徑d。 The crystal grain size can be determined by observation using an optical microscope or by crystal orientation analysis using an EBSD method. Here, the "crystal grain size" is the average crystal grain size d described in JIS G 0551.

「含有Ti及Nb之經非整合析出的合金碳氮化物之平均粒子徑」 "Average particle diameter of alloyed carbonitrides containing non-integrated precipitates of Ti and Nb"

含有Ti及Nb之合金碳氮化物的粒徑與作為母相組織之肥粒鐵或變韌鐵的晶格匹配性，係與低溫下之衝撃能量吸收特性相關的重要因子。一般而言，於析出強化鋼中，將與母相組織之晶格匹配性佳的細微合金碳氮化物作為細微粒子析出係眾所周知，為改善低溫韌性與改善衝撃能量吸收特性，控制與母相組織之晶格匹配性差的合金碳氮化物粒子係為重要。使晶格匹配性變差之經非整合析出的合金碳氮化物之平均粒子徑大於20nm時，因低溫下之衝撃能量吸收特性下降，故將其適當範圍限定為20nm以下。由得到較優異之衝撃能量吸收特性的觀點來看，10nm以下係較佳之範圍。下限並未特別限定，但由可解析析出物之結晶方位的尺寸來看，2nm係實質之下限。 The lattice matching of the alloy carbonitride containing Ti and Nb with the ferrite iron or toughened iron as the parent phase structure is an important factor related to the energy absorption characteristics at the low temperature. In general, in the precipitation strengthened steel, a fine alloy carbonitride having good lattice matching with the mother phase structure is known as fine particle precipitation, and the low temperature toughness and the improvement of the energy absorption characteristics of the punching are controlled, and the parent phase structure is controlled. Alloy carbonitride particles having poor lattice matching properties are important. When the average particle diameter of the non-integrated precipitated alloy carbonitride which deteriorates the lattice matching property is more than 20 nm, the pumping energy absorption property at a low temperature is lowered, so that the appropriate range is limited to 20 nm or less. From the viewpoint of obtaining superior punching energy absorption characteristics, a range of 10 nm or less is preferable. The lower limit is not particularly limited, but the lower limit of 2 nm is substantially determined by the size of the crystal orientation of the extractable material.

此處「經非整合析出之合金碳氮化物」係指於作為母相組織的肥粒鐵或變韌鐵中係未整合析出之狀態，且於鄰接的肥粒鐵或變韌鐵之間未具有下述之結晶方位關係(Baker-Nutting之方位關係)者。 Here, the "non-integrated precipitated alloy carbonitride" refers to a state in which the ferrite iron or the toughened iron as the mother phase structure is not integrated and precipitated, and is not adjacent to the ferrite iron or the toughened iron. It has the following crystal orientation relationship (Baker-Nutting orientation relationship).

(100)MX//(100)Fe (100)MX//(100)Fe

(010)MX//(011)Fe (010)MX//(011)Fe

(001)MX//(0-11)Fe(注：-1係表示作為於1之上附有輥之記號)此處，M表示Ti、Nb，不計Ti、Nb之占有分率。又，X表示C、N，不計C、N之占有分率。於添加有V或Mo時，有於M中含有V或Mo的情形。 (001) MX / / (0-11) Fe (Note: -1 is a symbol with a roll attached to 1) Here, M represents Ti and Nb, and does not count the occupied fraction of Ti and Nb. Further, X represents C and N, and the fraction of C and N is not counted. When V or Mo is added, there is a case where V or Mo is contained in M.

另外，經非整合析出之合金碳氮化物的結晶方位解析及平均粒子徑之測定係使用穿透式電子顯微鏡(TEM)進行。首先，將鋼片試料薄膜化至可透射電子束的程度，再以TEM進行析出物及其周圍之母相Fe間的結晶方位解析，接著，測定經判定為非整合析出物之析出物中由大之徑者依序20個的平均粒子徑。此處，析出物之粒子徑係作為假定為粒子截面積與等值之圓的等值圓直徑測定。 Further, the crystal orientation analysis and the average particle diameter of the alloy carbonitride precipitated by non-integration were measured using a transmission electron microscope (TEM). First, the steel sheet sample is thinned to the extent that the electron beam can be transmitted, and the crystal orientation analysis between the precipitate and the parent phase Fe is performed by TEM, and then the precipitate determined to be a non-integrated precipitate is measured. The Big Path is followed by an average particle diameter of 20 pieces. Here, the particle diameter of the precipitate is measured as an equivalence circle diameter assumed to be a particle cross-sectional area and an equivalent circle.

「降伏比係0.85以上」 "The ratio of the drop is 0.85 or more"

降伏比小於0.85時，有低溫下之衝撃能量吸收特性下降的情形，又彎曲加工性亦下降。因此，將降伏比之下限限制為0.85。 When the drop ratio is less than 0.85, there is a case where the pumping energy absorption property at a low temperature is lowered, and the bending workability is also lowered. Therefore, the lower limit of the drop ratio is limited to 0.85.

另外，本發明中使用rlim/t作為彎曲加工性之評價基準。此處，t係試驗片之板厚，rlim係90°V彎曲試驗中未產生破裂的有限彎曲半徑，以rlim/t計1.0以下記為彎曲加工性優異。0.5以下係較佳之範圍。上限並未特別限定，但大於1.1時，因有彎曲加工性下降的可能性，故1.1以下係較佳之範圍。 Further, in the present invention, r lim /t is used as a criterion for evaluation of bending workability. Here, a test piece of sheet thickness t based, r lim 90 ° V bending test system is not a limited bend radius of the rupture, to r lim / t from 1.0 hereinafter referred to as excellent in bending workability. 0.5 or less is a preferred range. The upper limit is not particularly limited, but when it is more than 1.1, there is a possibility that the bending workability is lowered. Therefore, 1.1 or less is preferable.

「最大抗拉強度：600MPa以上」 "Maximum tensile strength: 600MPa or more"

最大抗拉強度小於600MPa時，因無助於汽車、卡車、建設機械等構件之輕量化，故於本發明中以最大抗拉強 度：600MPa以上的鋼板作為前提。 When the maximum tensile strength is less than 600 MPa, the maximum tensile strength is exceeded in the present invention because it does not contribute to the weight reduction of components such as automobiles, trucks, and construction machinery. Degree: Steel plate of 600 MPa or more is premised.

接著，詳細地說明製造方法。 Next, the manufacturing method will be described in detail.

於熱軋之前，將本發明中規定之成分的鋼片加熱至1150℃以上，使存在於鋼片之合金碳氮化物為固溶狀態係為必要。加熱溫度小於1150℃時，不易得到最大抗拉強度600MPa以上的強度，又，粗大之合金碳氮化物未能充分地熔解，結果，因殘留粗大之合金碳氮化物，故低溫下之衝撃能量吸收特性下降。因此，將鋼片之加熱溫度限定為1150℃以上。上限並未特別限定，但大於1300℃時，因效果飽和，故其係實質之上限。 Before the hot rolling, the steel sheet of the component specified in the present invention is heated to 1150 ° C or higher, so that the alloy carbonitride present in the steel sheet is in a solid solution state. When the heating temperature is less than 1150 ° C, it is difficult to obtain a maximum tensile strength of 600 MPa or more, and the coarse alloy carbonitride is not sufficiently melted. As a result, due to the residual alloy carbonitride, the absorbing energy absorption at a low temperature is obtained. The characteristics are declining Therefore, the heating temperature of the steel sheet is limited to 1150 ° C or higher. The upper limit is not particularly limited, but when it is more than 1300 ° C, since the effect is saturated, it is the upper limit of the substance.

將經前述加熱之鋼片粗軋延作為粗輥。該粗軋延需於1000℃~1080℃之間結束。結束溫度小於1000℃時，沃斯田鐵中析出粗大之合金碳氮化物，低溫下之衝撃能量吸收特性下降，另一方面，1080℃以上時，沃斯田鐵結晶粒粗大化，於完工軋延、冷卻、捲取後之變態後組織中，未能得到肥粒鐵及變韌鐵之10μm以下的平均結晶粒徑，低溫韌性劣化，衝撃能量吸收特性下降。又，於1150℃以下進行粗軋延中，各軋縮道次間之保持時間係對非整合之合金碳氮化物的平均粒子徑造成影響之重要參數。本發明之方法中，粗軋延係進行通常3~10次左右的軋縮，以進行5~10次之軋縮較佳，但於1150℃以下進行的各軋延間之最大保持時間t0為45秒以上時，合金碳氮化物將粗大化至對衝撃能量吸收特性造成影響的程度。因此，將各軋縮道次間之保持時間限制為45秒以內。以30秒以內較佳。 The previously heated steel sheet was roughly rolled to a coarse roll. The rough rolling is required to end between 1000 ° C and 1080 ° C. When the end temperature is less than 1000 ° C, the coarse alloy carbonitride is precipitated in the Worthite iron, and the energy absorption characteristics of the punching at low temperature are lowered. On the other hand, when the temperature is above 1080 ° C, the Worthite iron crystal grain is coarsened, and the rolling is completed. In the microstructure after cooling and coiling, the average crystal grain size of 10 μm or less of the ferrite iron and the toughened iron was not obtained, and the low temperature toughness was deteriorated, and the energy absorption characteristics of the punching were lowered. Further, the rough rolling is performed at 1150 ° C or lower, and the holding time between each rolling reduction is an important parameter which affects the average particle diameter of the non-integrated alloy carbonitride. In the method of the present invention, the rough rolling is carried out usually for 3 to 10 times, and the rolling is preferably performed 5 to 10 times, but the maximum holding time t0 between each rolling at 1150 ° C or lower is Above 45 seconds, the alloy carbonitride will coarsen to the extent that it affects the energy absorption characteristics of the crucible. Therefore, the holding time between each rolling reduction is limited to 45 seconds. It is preferably within 30 seconds.

接著，將粗輥進行完工軋延作為軋延材。 Next, the coarse roll is subjected to completion rolling as a rolled material.

自粗軋延結束後至完工軋延開始為止之時間(t1)係對合金碳氮化物之平均粒子徑與變態後的肥粒鐵及變韌鐵之結晶粒徑造成影響的重要參數。如圖2所示，Ti與Nb之合計量越多，因衝撃能量吸收特性(vE-40)自良好(OK)移動至不良(NG)之保持時間t1(圖中箭頭)增加。自良好(OK)移動至不良(NG)之保持時間t1(秒)大致對應於1000×([%Ti]+[%Nb])。如此，自粗軋延結束後至完工軋延開始為止之保持時間t1(秒)為1000×([%Ti]+[%Nb])秒以上時，於沃斯田鐵中析出粗大之合金碳氮化物，沃斯田鐵結晶粒粗大化，於完工軋延、冷卻、捲取後之變態後組織中無法得到肥粒鐵及變韌鐵為10μm以下的平均結晶粒徑，低溫韌性劣化，且衝撃能量吸收特性下降。700×([%Ti]+[%Nb])>t1秒係較佳之範圍。藉此，將保持時間t1(秒)規定於下述式(1)。 The time from the end of the rough rolling to the start of the rolling (t1) is an important parameter affecting the average particle diameter of the alloy carbonitride and the crystal grain size of the deformed ferrite iron and the toughened iron. As shown in Fig. 2, the more the total amount of Ti and Nb is combined, the increase in the holding time t1 (arrow in the figure) from the good (OK) movement to the bad (NG) due to the rushing energy absorption characteristic (vE - 40 ). The hold time t1 (second) from good (OK) to bad (NG) roughly corresponds to 1000 × ([%Ti] + [% Nb]). Thus, when the holding time t1 (sec) from the end of the rough rolling to the start of the rolling is 1000 × ([% Ti] + [% Nb]) seconds or more, the coarse alloy carbonitride is precipitated in the Worthite iron. The coarse grain of the Worthite iron crystal grain can not obtain the average crystal grain size of the ferrite iron and the toughened iron below 10 μm in the microstructure after the completion of the rolling, cooling and coiling, and the low temperature toughness is deteriorated, and the punching energy is deteriorated. The absorption characteristics are degraded. 700 × ([% Ti] + [% Nb]) > t1 second is a preferred range. Thereby, the holding time t1 (second) is defined in the following formula (1).

1000×([%Ti]+[%Nb])>t1………式(1) 1000×([%Ti]+[%Nb])>t1.........(1)

又，於熱完工軋延中，因最終軋延溫度Tf將對合金碳氮化物之平均粒子徑與變態後之肥粒鐵及變韌鐵的結晶粒徑造成影響，故於本發明中係重要之條件，對應於Ti及Nb含量變化。 Moreover, in the hot rolling, the final rolling temperature Tf affects the average particle diameter of the alloy carbonitride and the crystal grain size of the deformed ferrite iron and the toughened iron, which is important in the present invention. The conditions correspond to changes in Ti and Nb content.

最終軋延溫度Tf為830+400×([%Ti]+[%Nb])以下時，可知無相對於母相之晶格匹配性的粗大之合金碳氮化物析出，低溫下之衝撃能量吸收特性下降。因此，設定為使最終軋延溫度Tf滿足以下之式(2)。 When the final rolling temperature Tf is 830+400×([%Ti]+[%Nb]) or less, it is understood that there is no coarse alloy carbonitride precipitated with respect to the matrix phase of the mother phase, and the punching energy absorption property at a low temperature. decline. Therefore, it is set so that the final rolling temperature Tf satisfies the following formula (2).

Tf>830+400([%Ti]+[%Nb])………式(2) Tf>830+400([%Ti]+[%Nb]).........(2)

該關係式(2)係由後述之表2的鋼種與最終軋延溫度Tf之關係求得。圖3係表示表2所示之鋼種中本發明例及比較例之2種(A-7、B-6)的Ti+Nb之質量%與Tf(℃)的關係。此處，可知以「a([%Ti]+[%Nb])」部分之係數a為400時，即，式(2)以-40℃下之衝撃吸收能量vE-40為70J/cm2以上作為界線。 This relational expression (2) is obtained from the relationship between the steel grade of Table 2 to be described later and the final rolling temperature Tf. Fig. 3 is a graph showing the relationship between the mass % of Ti + Nb and the Tf (°C) of two types (A-7, B-6) of the present invention and the comparative examples in the steel types shown in Table 2. Here, it can be seen that when the coefficient a of the portion "a([%Ti]+[%Nb])") is 400, that is, the formula (2) has a pumping energy vE -40 at -40 ° C of 70 J/cm 2 . The above is the boundary.

係數a為800的情形，即，Tf>830+800([%Ti]+[%Nb])………式(3)時，相較於係數a為400的情形，自-40℃下之衝撃吸收能量vE-40為70J/cm2以上的界線稍微偏離。但，係數a為400~800之領域中，因至完工軋延開始為止之等待時間變長，開始析出合金碳氮化物的可能性變高，故以依據係數a為800之式(3)控制Tf為佳。 The case where the coefficient a is 800, that is, when Tf>830+800 ([%Ti]+[%Nb])...(3), compared to the case where the coefficient a is 400, from -40 ° C The boundary of the absorbing energy vE- 40 of 70 J/cm 2 or more is slightly deviated. However, in the field where the coefficient a is from 400 to 800, the waiting time until the start of the rolling is long, and the possibility of starting the precipitation of the alloy carbonitride becomes high, so it is controlled by the formula (3) according to the coefficient a of 800. Tf is better.

最終軋延溫度Tf之上限並未特別限定，但肥粒鐵及變韌鐵之結晶粒徑有變粗大的傾向，故以970℃以下較佳。 The upper limit of the final rolling temperature Tf is not particularly limited, but the crystal grain size of the ferrite iron and the toughened iron tends to be coarse, so that it is preferably 970 ° C or lower.

最終軋延後立刻進行軋延材之水冷卻。自最終軋延結束至空氣冷卻開始為止之時間係透過γ之粒徑與合金碳氮化物的平均粒子徑，對低溫下之母材韌性及衝撃能量吸收特性造成影響。最終軋延後之空氣冷卻時間大於3秒時，因有衝撃能量吸收特性下降的傾向，故於3秒以內開始水冷卻。下限並未特別限定，但一般之設備來說，實質係0.2秒以上。 Immediately after the final rolling, the water of the rolled and rolled material is cooled. The time from the end of the final rolling to the start of the air cooling is such that the particle diameter of γ is transmitted and the average particle diameter of the alloy carbonitride affects the toughness and the absorbing energy absorption characteristics of the base material at a low temperature. When the air cooling time after the final rolling is more than 3 seconds, the pumping energy absorption characteristics tend to decrease, so that water cooling starts within 3 seconds. The lower limit is not particularly limited, but in general, the device is substantially 0.2 seconds or longer.

最終軋延後之空氣冷卻，緊接著冷卻軋延材作成熱軋鋼板。該冷卻係控制金屬組織的重要步驟。以最低冷卻速度8℃/秒以上進行冷卻至700℃以下。 The air after the final rolling is cooled, and then the rolled and rolled material is cooled to form a hot rolled steel sheet. This cooling is an important step in controlling the metal structure. Cooling to 700 ° C or lower is carried out at a minimum cooling rate of 8 ° C /sec or more.

冷卻之停止溫度大於700℃時，於粒界上容易析出粗大之合金碳氮化物，又，容易形成波來鐵，並且，肥粒鐵之結晶粒徑變大，低溫下之衝撃能量吸收特性下降。另一方面，於至700℃之最低冷卻速度小於8℃/秒時，容易於粒界上析出粗大之合金碳氮化物，又，容易形成波來鐵，並且，肥粒鐵之結晶粒徑變大，低溫下之衝撃能量吸收特性下降。 When the cooling stop temperature is greater than 700 ° C, coarse alloy carbonitride is easily precipitated on the grain boundary, and the Borne iron is easily formed, and the crystal grain size of the ferrite iron becomes large, and the energy absorption characteristics at the low temperature are lowered. . On the other hand, when the minimum cooling rate to 700 ° C is less than 8 ° C / sec, it is easy to precipitate coarse alloy carbonitride on the grain boundary, and it is easy to form ferrite, and the crystal grain size of the ferrite iron is changed. The absorption energy absorption characteristics of the large and low temperature are reduced.

此處，最低冷卻速度8℃/秒以上係指自空氣冷卻結束溫度至700℃之溫度間的冷卻速度經常不低於8℃/秒之意。因此，係指例如，於該溫度區間內不進行空氣冷卻之意。如此，本發明中，係如以往地，於利用水冷卻之冷卻過程途中不進行空氣冷卻。 Here, the minimum cooling rate of 8 ° C /sec or more means that the cooling rate between the air cooling end temperature and the temperature of 700 ° C is often not lower than 8 ° C / sec. Therefore, it means, for example, that air cooling is not performed in this temperature range. As described above, in the present invention, as in the related art, air cooling is not performed in the middle of the cooling process by water cooling.

冷卻停止溫度以680℃以下較佳，又，最低冷卻速度以15℃/秒以上較佳。最低冷卻速度之上限並未特別限定，但大於80℃/秒時，不易於熱軋捲料內均一地冷卻，捲料內之強度變動變大。因此，以80℃/秒以下為佳。 The cooling stop temperature is preferably 680 ° C or less, and the minimum cooling rate is preferably 15 ° C / sec or more. The upper limit of the minimum cooling rate is not particularly limited, but when it is more than 80 ° C / sec, it is not easy to uniformly cool the hot rolled coil, and the strength variation in the coil becomes large. Therefore, it is preferably 80 ° C / sec or less.

接著，捲取經冷卻之熱軋鋼板。捲取溫度係530~650℃。捲取溫度小於530℃時，有形成麻田散鐵或殘留沃斯田鐵的情形，低溫下之韌性下降與衝撃能量吸收特性下降變得顯著。又，大於650℃時，波來鐵之面積分率變多，低溫下之韌性下降與衝撃能量吸收特性下降變得顯著。 Next, the cooled hot rolled steel sheet is taken up. The coiling temperature is 530~650 °C. When the coiling temperature is less than 530 ° C, there is a case where the granulated loose iron or the residual Worth iron is formed, and the decrease in toughness at low temperature and the decrease in the absorbing energy absorption characteristic become remarkable. Further, when the temperature is more than 650 ° C, the area fraction of the ferritic iron increases, and the toughness at low temperature and the decrease in the absorbing energy absorption characteristics become remarkable.

亦可將如此所得之熱軋鋼板再加熱(退火)。此時，再加熱之溫度大於Ac3溫度時，析出粗大之合金碳氮化物，低溫下之衝撃能量吸收特性下降。因此，將再加熱溫度之適當範圍限制為Ac3溫度以下。加熱方法並未特別指定，可以爐加熱、感應加熱、通電加熱、高頻加熱等方法進行。 The hot rolled steel sheet thus obtained may also be reheated (annealed). At this time, when the temperature of the reheating is higher than the temperature of Ac3, the coarse alloy carbonitride is precipitated, and the energy absorption characteristics of the punching at a low temperature are lowered. Therefore, the appropriate range of the reheating temperature is limited to the Ac3 temperature or lower. The heating method is not specifically specified, and may be carried out by furnace heating, induction heating, electric heating, high frequency heating, or the like.

加熱時間並未特別限定，但於550℃以上之加熱保持時間大於30分鐘時，為得到590MPa以上之抗拉強度，最高加熱溫度以700℃以下為佳。 The heating time is not particularly limited, but when the heating retention time at 550 ° C or higher is more than 30 minutes, in order to obtain a tensile strength of 590 MPa or more, the maximum heating temperature is preferably 700 ° C or less.

另外，再加熱(退火)亦可於捲取熱軋鋼板後，溫度回復至室溫之前進行。 Further, reheating (annealing) may be performed after the hot rolled steel sheet is taken up and the temperature is returned to room temperature.

表皮道次軋延或校平軋延因有助於矯正形狀、改善時效性、疲勞特性，故亦可於酸洗後或酸洗前進行。於進行表皮道次軋延時，軋縮率之上限以3%為佳。因大於3%時，將損及鋼板的成形性之故。又，酸洗亦可視目的進行。 Epidermal rolling or leveling rolling can be performed after pickling or before pickling because it helps to correct shape, improve timeliness and fatigue characteristics. For the epitaxial rolling reduction, the upper limit of the rolling reduction ratio is preferably 3%. When it is more than 3%, the formability of the steel sheet is impaired. Also, pickling can also be carried out according to the purpose.

接著，說明本發明之熔融鍍鋅鋼板及其製造方法。 Next, a hot-dip galvanized steel sheet of the present invention and a method for producing the same will be described.

本發明之熔融鍍鋅鋼板係於前述之本發明的熱軋鋼板之表面設有鍍敷層或合金化鍍敷層的鋼板。 The hot-dip galvanized steel sheet according to the present invention is a steel sheet provided with a plating layer or an alloyed plating layer on the surface of the hot-rolled steel sheet according to the present invention.

將藉由前述方法所得之熱軋鋼板酸洗後，使用連續鍍鋅設備或連續退火鍍鋅設備，加熱鋼板，施行熔融鍍敷，於熱軋鋼板之表面形成鍍敷層。 After pickling the hot-rolled steel sheet obtained by the above method, the steel sheet is heated and subjected to hot-plating using a continuous galvanizing apparatus or a continuous annealing galvanizing apparatus to form a plating layer on the surface of the hot-rolled steel sheet.

鋼板之加熱溫度大於Ac3溫度時，因產生鋼板之抗拉強度下降與低溫下之衝撃能量吸收特性下降，故將加 熱溫度的適當範圍限制為Ac3溫度以下。因加熱溫度越接近Ac3，抗拉強度將急遽地下降，材質差異變大，故Ac3-30℃以下係較佳之加熱溫度範圍。 When the heating temperature of the steel sheet is higher than the Ac3 temperature, the tensile strength of the steel sheet is lowered and the energy absorption characteristic of the punching material at a low temperature is lowered, so The appropriate range of thermal temperature is limited to less than the Ac3 temperature. As the heating temperature is closer to Ac3, the tensile strength will drop sharply and the material difference will become larger. Therefore, Ac3-30 °C or lower is a preferred heating temperature range.

此外，於施行熔融鍍敷後，進行鍍鋅合金化處理，亦可作為合金化熔融鍍鋅層。 Further, after the hot-plating is performed, the galvanization alloying treatment is performed, and the alloyed hot-dip galvanized layer can also be used.

另外，鍍敷種類不僅限定為鍍鋅，只要加熱溫度之上限為Ac3溫度，亦可為其他鍍敷種類。 Further, the plating type is not limited to galvanizing, and the other temperature may be other plating types as long as the upper limit of the heating temperature is Ac3.

又，於本發明中熱軋之前的製造方法並未特別限定。換言之，於利用豎爐、轉爐、電爐等熔製後，接著以各種之2次精煉進行成分調整以成為目的之成分含量。接著，除了通常之連續鑄造、利用鑄錠法之鑄造以外，亦可以薄扁鋼胚鑄造等方法鑄造。原料亦可使用廢料。於利用連續鑄造得到扁鋼胚時，亦可直接將高溫鑄片送至熱軋機，亦可於冷卻至室溫後於加熱爐再加熱後進行熱軋。 Further, the production method before hot rolling in the present invention is not particularly limited. In other words, after being melted by a shaft furnace, a converter, an electric furnace or the like, the composition is adjusted in various secondary refinings to achieve the desired component content. Next, in addition to the usual continuous casting and casting by the ingot casting method, it can also be cast by a method such as thin flat steel blank casting. Waste materials can also be used as raw materials. When the flat steel blank is obtained by continuous casting, the high temperature cast piece may be directly sent to the hot rolling mill, or may be hot rolled after being cooled to room temperature and then heated in the heating furnace.

[實施例] [Examples]

以下，利用實施例更加說明本發明。 Hereinafter, the present invention will be further described by way of examples.

藉由以下之方法製造具有表1所示的化學成分之A~AC的鋼。首先，藉由鑄造製作鋼片後，以表2-1及表2-2所示之熱軋條件及退火鍍敷條件將鋼片再加熱、粗軋延作為粗輥。接著，將粗輥完工軋延作為4mm板厚之軋延材後冷卻，再捲取作為熱軋鋼板。 Steel having A to AC having the chemical compositions shown in Table 1 was produced by the following method. First, after the steel sheets were produced by casting, the steel sheets were reheated and roughly rolled as the coarse rolls under the hot rolling conditions and the annealing conditions shown in Table 2-1 and Table 2-2. Next, the rough roll was rolled and rolled into a rolled material of 4 mm thickness, and then cooled, and then coiled as a hot rolled steel sheet.

表1中之化學組成的表示係質量%。又，表1中，Ac3(℃)係藉由以下之式所算出的值。 The chemical composition in Table 1 is expressed in mass%. Further, in Table 1, Ac3 (°C) is a value calculated by the following formula.

Ac3=910-210[%C]+45[%Si]-30[%Mn]+700[%P]+40[%Al]+400[%Ti]+32[%Mo]-11[%Cr]-20[%Cu]-15[%Ni] Ac3=910-210 [%C]+45[%Si]-30[%Mn]+700[%P]+40[%Al]+400[%Ti]+32[%Mo]-11[%Cr]-20[% Cu]-15[%Ni]

式中，%C、% Si、% Mn、% P、% Al、% Ti、% Mo、% Cr、%Cu、% Ni係分別表示C、Si、Mn、P、Al、Ti、Mo、Cr、Cu及Ni之鋼中的含量。 In the formula, %C, % Si, % Mn, % P, % Al, % Ti, % Mo, % Cr, %Cu, % Ni represent C, Si, Mn, P, Al, Ti, Mo, Cr, respectively. , the content of steel in Cu and Ni.

表1中之鋼的化學組成係對應於其鋼No.之英文字母大寫相同的表2中之鋼No.的鋼之化學組成。 The chemical composition of the steel in Table 1 corresponds to the chemical composition of the steel of Steel No. in Table 2 in which the English letters of the steel No. are capitalized.

表2中之「SRT」係顯示扁鋼胚加熱溫度(℃)。「RFT」係顯示粗軋延結束溫度(℃)。「t0」係顯示於1150℃以下進行之各粗軋延間的最大保持時間(秒)。「t1」係顯示自粗軋延結束至完工軋延開始為止之時間(秒)。「Tf」係顯示最終完工軋延溫度(℃)。「t2」係顯示最終完工軋延後的空氣冷卻時間(秒)。「CRmin」係顯示自空氣冷卻後至SCT間之最低冷卻速度(℃/秒)。「SCT」係顯示水冷卻停止溫度(℃)。「CT」係顯示捲取溫度(℃)。 The "SRT" in Table 2 shows the flat steel embryo heating temperature (°C). "RFT" shows the rough rolling end temperature (°C). "t0" shows the maximum holding time (seconds) between each rough rolling step performed at 1150 ° C or lower. "t1" shows the time (in seconds) from the end of the rough rolling to the start of the rolling. "Tf" shows the final finishing rolling temperature (°C). "t2" shows the air cooling time (seconds) after the final completion rolling. "CRmin" shows the lowest cooling rate (°C/sec) from air cooling to SCT. "SCT" shows the water cooling stop temperature (°C). "CT" shows the coiling temperature (°C).

鋼A-12~14、C-2係熔融鍍鋅鋼板，係於酸洗熱軋鋼板後，於連續退火鍍鋅生產線上，以表2所示之退火溫度退火，接著進行鍍鋅地製造。 The steel A-12-14 and C-2 hot-dip galvanized steel sheets are subjected to pickling hot-rolled steel sheets, and are annealed at an annealing temperature shown in Table 2 on a continuous annealing galvanizing line, followed by galvanizing.

另外，以450℃作為鍍鋅浸漬溫度，又經進行鍍鋅合金化處理者係以500℃作為合金化溫度地進行。 Further, 450 ° C was used as the galvanizing immersion temperature, and the galvannealing treatment was carried out at 500 ° C as the alloying temperature.

首先，進行經製作之鋼板的金屬組織、合金碳氮化物之觀察。 First, observation of the metal structure and alloy carbonitride of the produced steel sheet was carried out.

如前述，鋼板之金屬組織的觀察，係依據JIS G 0551，藉由光學顯微鏡對L截面進行。又，各組織的面積分率係使用組織照片，於L截面之1/4t厚度(板厚為t時自鋼板表面1/4t之位置)的領域中，藉由計點法或影像解析測定。肥粒鐵及變韌鐵之結晶粒徑的測定係依據JISG0552，算出標稱粒徑之值。 As described above, the observation of the metal structure of the steel sheet was carried out by an optical microscope on the L cross section in accordance with JIS G 0551. Further, the area fraction of each of the tissues was measured by a point method or a video analysis in the field of a 1/4 t thickness of the L section (a position of 1/4 t from the surface of the steel sheet when the thickness of the sheet was t). The measurement of the crystal grain size of the ferrite iron and the toughened iron is based on JIS G0552, and the value of the nominal particle diameter is calculated.

含有Ti及Nb之經非整合析出的合金碳氮化物之結晶方位解析及平均粒子徑的測定，係藉由將鋼片試料薄膜化至可透射電子束的程度，並使用穿透式電子顯微鏡(TEM)，觀察20個以上之合金碳氮化物地進行。 The crystal orientation analysis and average particle diameter of the non-integrated precipitated alloy carbonitride containing Ti and Nb are determined by thinning the steel sheet sample to the extent that it can transmit electron beams and using a transmission electron microscope ( TEM), observation was carried out by observing more than 20 alloy carbonitrides.

接著，以電弧熔接製作搭接接頭，以測定熔接熱影響部(HAZ)之軟化量。熔接之環境氣體係以CO2：100%進行，入熱量係於5000~8000J/cm之範圍進行。熔接後進行截面之研磨，進行母材、及熔接熱影響部(HAZ)的維克氏硬度試驗，指出係0以下。於表3顯示以上之測定結果。另外，表3中之「F」係肥粒鐵、「B」係變韌鐵、「A」係殘留沃斯田鐵、「M」係麻田散鐵、「P」係波來鐵，「d(F,B)」係肥鐵及變韌鐵之平均結晶粒徑(μm)、「dMCN」係經非整合析出之合金碳氮化物的平均粒子徑(nm)、「△HV」係表示將熔接熱影響部之最軟化部的維克氏硬度作為HVHAZ、將素材之維克氏硬度作為HVBM時，HVBM與HVHAZ的差。 Next, a lap joint was produced by arc welding to measure the softening amount of the heat affected portion (HAZ). The fused ambient gas system is carried out with CO 2 : 100%, and the heat input is carried out in the range of 5000 to 8000 J/cm. After the welding, the cross section was polished, and the Vickers hardness test of the base material and the heat affected zone (HAZ) was carried out, and it was indicated that the system was 0 or less. The above measurement results are shown in Table 3. In addition, in Table 3, "F" is the ferrite iron, "B" is a toughened iron, "A" is a residual Worthite iron, "M" is a Ma Tian loose iron, and "P" is a boehmite, "d (F, B) is the average crystal grain size (μm) of ferrite and toughened iron, and the average particle diameter (nm) of "d MCN " which is a non-integrated alloy carbonitride, and "△HV" When the Vickers hardness of the softened portion of the heat-affected zone is HV HAZ and the Vickers hardness of the material is HV BM , the difference between HV BM and HV HAZ is obtained.

接著，評價鋼板之強度特性、低溫下之衝撃能量吸收特性與彎曲性。 Next, the strength characteristics of the steel sheet, the punching energy absorption characteristics at low temperature, and the bendability were evaluated.

鋼板之強度特性係藉由以下之方法評價。首先，將供試材加工成JIS Z 2201記載的5號試驗片。之後，依據JIS Z 2241記載之方法對該5號試驗片進行抗拉試驗，求出抗拉最高強度(TS)、降伏強度(YS)、及延伸(EI)。 The strength characteristics of the steel sheet were evaluated by the following methods. First, the test piece was processed into a test piece No. 5 described in JIS Z 2201. Thereafter, the No. 5 test piece was subjected to a tensile test in accordance with the method described in JIS Z 2241, and the tensile maximum strength (TS), the fall strength (YS), and the elongation (EI) were determined.

低溫下之衝撃能量吸收特性係藉由沙丕衝撃試驗評價。依據JIS2202製作板厚3mm之2mmV凹口試驗片，將試驗片冷卻至-40℃後，進行沙丕衝撃試驗，計測該衝撃能量吸收值(J/cm2)。 The energy absorption characteristics of the scouring energy at low temperatures were evaluated by the sand blast test. A 2 mm V notch test piece having a thickness of 3 mm was produced in accordance with JIS2202, and the test piece was cooled to -40 ° C, and then subjected to a sand blast test to measure the rush energy absorption value (J/cm 2 ).

彎曲試驗係藉由JISZ224之V槽塊(V block)法(彎 曲角度：90°)進行，以試驗片之板厚作為t，計測未產生破裂的有限彎曲半徑rlim。 The bending test was carried out by the V block method (bending angle: 90°) of JIS Z224, and the plate thickness of the test piece was taken as t, and the finite bending radius r lim where no crack occurred was measured.

於表3顯示以上之測定結果。另外，如前述，表3中之「vE-40」係沙丕衝撃吸收值(J/cm2)，「rlim/t」係有限彎曲半徑rlim除以板厚的值。將rlim/t為0.5以下者作為◎、大於0.5、1.0以下之範圍內者作為○、大於1.0者作為×。 The above measurement results are shown in Table 3. Further, as described above, "vE - 40 " in Table 3 is the absorption value (J/cm 2 ) of the sand shovel, and "r lim /t" is the value of the finite bending radius r lim divided by the thickness. The case where r lim /t is 0.5 or less is ◎, and the range of more than 0.5 and 1.0 or less is ○, and more than 1.0 is ×.

鋼A-2係扁鋼胚加熱溫度於適當範圍外，故抗拉強度小於600MPa，又低溫下之衝撃能量吸收特性低的比較例。 The steel A-2 series flat steel embryo heating temperature is outside the appropriate range, so the tensile strength is less than 600 MPa, and the comparative energy absorption characteristics at low temperature are low.

鋼A-3~4、鋼B-3~4係粗軋延結束溫度於適當範圍外，故低溫下之衝撃能量吸收特性低的比較例。 A comparison example in which the steel A-3~4 and the steel B-3~4 series have a rough rolling end temperature outside the appropriate range, so that the pumping energy absorption characteristics at low temperatures are low.

鋼A-6、鋼B-3係自粗軋延結束至完工軋延開始為止之時間於適當範圍外，故低溫下之衝撃能量吸收特性低 的比較例。 The steel A-6 and steel B-3 are out of the proper range from the end of the rough rolling to the start of the rolling, so the low energy absorption characteristics at low temperature are low. Comparative example.

鋼A-7~8、鋼A-10、鋼B-6~8係完工軋延之條件及完工軋延後的冷卻條件於適當範圍外，故低溫下之衝撃能量吸收特性低的比較例。 Steel A-7~8, steel A-10, steel B-6~8 are the conditions for completion rolling and the cooling conditions after finishing rolling are outside the appropriate range, so the comparative energy absorption characteristics at low temperature are low.

鋼A-11、鋼B-10係完工軋延後之水冷卻停止溫度及熱軋鋼板的捲取溫度於適當範圍外，故低溫下之衝撃能量吸收特性低的比較例。 Steel A-11 and steel B-10 are comparative examples in which the water cooling stop temperature after completion rolling and the coiling temperature of the hot-rolled steel sheet are outside the appropriate range, so that the pumping energy absorption characteristics at low temperatures are low.

鋼A-12、鋼B-11係熱軋鋼板之捲取溫度於適當範圍外，故抗拉強度小於600MPa，低溫下之衝撃能量吸收特性低的比較例。 In the comparative example in which the coiling temperature of the steel A-12 and the steel B-11 hot-rolled steel sheet is outside the appropriate range, the tensile strength is less than 600 MPa, and the punching energy absorption property at a low temperature is low.

鋼A-15係退火溫度為Ac3溫度以上，故低溫下之衝撃能量吸收特性低的比較例。 The steel A-15 series annealing temperature is equal to or higher than the Ac3 temperature, so that the pumping energy absorption characteristics at low temperatures are low.

鋼F-1、Q-1、S-1、AB-1、AC-1係Mn量、Ti量、Nb量之值於適當範圍外，故HAZ軟化量大的比較例。其中，鋼F-1、Q-1、AC-1之抗拉強度小於600MPa。 Steel F-1, Q-1, S-1, AB-1, and AC-1 are comparative examples in which the amount of Mn, the amount of Ti, and the amount of Nb are outside the appropriate range, so that the HAZ softening amount is large. Among them, the tensile strength of steel F-1, Q-1 and AC-1 is less than 600 MPa.

鋼G-1係C量於適當範圍外，故強度小於600MPa，且HAZ軟化量大的比較例。 The steel G-1 is a comparative example in which the amount of C is outside the appropriate range, so that the strength is less than 600 MPa and the HAZ softening amount is large.

鋼H-1、I-1、K-1、AB-1係C量、Si量、Mn量於適當範圍外，故存在麻田散鐵或殘留沃斯田鐵，低溫下之衝撃能量吸收特性低，且彎曲性亦差的比較例。 Steel H-1, I-1, K-1, and AB-1 are outside the appropriate range of C, Si, and Mn. Therefore, there is a loose iron or a residual Worth iron in the field, and the energy absorption characteristics at low temperature are low. And a comparative example in which the flexibility is also poor.

鋼J-1係Mn量於適當範圍外，故存在波來鐵，低溫下之衝撃能量吸收特性低的比較例。 In the case where the amount of Mn of the steel J-1 is outside the appropriate range, there is a comparative example in which the iron is present and the energy absorption characteristics at the low temperature are low.

鋼M-1、O-1係S量及P量過大，故低溫下之衝撃能量吸收特性低的比較例。 Steel M-1 and O-1 are comparative examples in which the amount of S and the amount of P are too large, so that the energy absorption characteristics at low temperatures are low.

鋼E-1、R-1、T-1、U-1係Ti量、Nb量、N量於適當範圍外，故存在粗大之合金碳氮化物，低溫下之衝撃能量吸收特性低的比較例。 Steel E-1, R-1, T-1, and U-1 are Ti, Nb, and N in an appropriate range, so there is a coarse alloy carbonitride, and the comparative energy absorption characteristics at low temperature are low. .

鋼P-1係Al量過大，故HAZ經軟質化之比較例。 The steel P-1 is a comparative example in which the amount of Al is too large, so that the HAZ is softened.

相對於此，任一本發明例之降伏比為0.85以上、最大抗拉強度為600MPa以上，且，顯示具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的特性。 On the other hand, in any of the examples of the present invention, the lodging ratio was 0.85 or more, and the maximum tensile strength was 600 MPa or more, and the characteristics of the punching energy absorption property and the HAZ softening resistance at an excellent low temperature were exhibited.

圖1係表示Mn+8Ti+12Nb與vE-40及△HV之關係的圖表。 Fig. 1 is a graph showing the relationship between Mn + 8Ti + 12Nb and vE - 40 and ΔHV.

圖2係表示Ti+Nb量對最終粗軋延~完工軋延開始為止之保持時間t1與vE-40的關係所造成的影響之圖表。 Fig. 2 is a graph showing the effect of the amount of Ti+Nb on the relationship between the holding time t1 and the vE- 40 of the final rough rolling to the completion of the rolling.

圖3係表示表2所示之鋼種中本發明例及比較例之2種(A-7、B-6)的Ti+Nb之質量%與Tf(℃)的關係之圖表。 Fig. 3 is a graph showing the relationship between the mass % of Ti + Nb and the Tf (°C) of two types (A-7, B-6) of the present invention and the comparative examples in the steel types shown in Table 2.

Claims (10)

一種具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，其特徵在於具有下述成分組成：以質量%計，含有：C：0.04~0.09%、Si：0.4%以下、Mn：1.2~2.0%、P：0.1%以下、S：0.02%以下、Al：1.0%以下、Nb：0.02~0.09%、Ti：0.02~0.07%、及N：0.005%以下，2.0≦Mn+8[%Ti]+12[%Nb]≦2.6，且剩餘部分係由Fe及不可避免的不純物所構成；波來鐵之面積分率係5%以下，麻田散鐵及殘留沃斯田鐵之合計面積分率係0.5%以下，且剩餘部分係由肥粒鐵及變韌鐵之1種或2種的金屬組織所構成；肥粒鐵及變韌鐵之平均結晶粒徑係10μm以下；含有Ti及Nb之經非整合析出的合金碳氮化物之平均粒子徑係20nm以下；降伏比係0.85以上；最大抗拉強度係600MPa以上。 A high-ratio ratio hot-rolled steel sheet having excellent ram energy absorption characteristics and HAZ softening resistance at a low temperature, characterized by having the following composition: in mass%, containing: C: 0.04 to 0.09%, Si: 0.4% Hereinafter, Mn: 1.2 to 2.0%, P: 0.1% or less, S: 0.02% or less, Al: 1.0% or less, Nb: 0.02 to 0.09%, Ti: 0.02 to 0.07%, and N: 0.005% or less, 2.0≦ Mn+8[%Ti]+12[%Nb]≦2.6, and the remainder is composed of Fe and unavoidable impurities; the area fraction of the Borne iron is 5% or less, the granulated iron and the remaining Worthfield The total area fraction of iron is 0.5% or less, and the remainder is composed of one or two kinds of metal structures of ferrite iron and toughened iron; the average crystal grain size of ferrite iron and toughened iron is 10 μm or less. The non-integrated precipitated alloy carbonitride containing Ti and Nb has an average particle diameter of 20 nm or less; a drop ratio of 0.85 or more; and a maximum tensile strength of 600 MPa or more. 如申請專利範圍第1項之具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，其以質量%計，更含有V：0.01~0.12%。 The high-ratio ratio hot-rolled steel sheet having the excellent energy absorption characteristics at the low temperature and the HAZ softening resistance according to the first aspect of the patent application is further contained in a mass percentage of V: 0.01 to 0.12%. 如申請專利範圍第1或2項之具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，其以質量%計，更含有合計為0.02~2.0%之Cr、Cu、Ni、Mo的1種或2種以上。 The high-ratio ratio hot-rolled steel sheet having the excellent energy absorption characteristics at the low temperature and the HAZ softening resistance, as in the first or second aspect of the patent application, contains, in mass%, Cr and Cu in total of 0.02 to 2.0%. One or two or more of Ni and Mo. 如申請專利範圍第1至3項中任1項的具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，其以質量%計，更含有0.0003~0.005%之B。 The high-ratio ratio hot-rolled steel sheet having excellent punching energy absorption characteristics and HAZ softening resistance at an excellent low temperature according to any one of claims 1 to 3, which contains 0.0003 to 0.005% of B in mass%. . 如申請專利範圍第1至4項中任1項的具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板，其以質量%計，更含有合計為0.0003~0.01%之Ca、Mg、La、Ce的1種或2種以上。 The high-ratio ratio hot-rolled steel sheet having the excellent energy absorption characteristics at the low temperature and the HAZ softening resistance according to any one of the first to fourth aspects of the patent application, which is 0.003% to 0.01% by mass in total. One or two or more of Ca, Mg, La, and Ce. 一種具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鍍敷鋼板，其特徵在於，其係於申請專利範圍第1至5項中任1項的高降伏比熱軋鋼板之表面施加有鍍敷或合金化鍍敷。 High-ratio ratio hot-rolled plated steel sheet having excellent energy absorption characteristics at low temperature and HAZ softening resistance, which is characterized by high-ratio ratio hot rolling of any one of items 1 to 5 of the patent application scope Plating or alloying plating is applied to the surface of the steel sheet. 一種具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板之製造方法，其特徵在於，其係將由申請專利範圍第1至5項中任1項的成分組成所構成之鋼片，進行下述步驟：加熱至1150℃以上；將經加熱之鋼片進行粗軋延，且於1000~1080℃間 結束粗軋延，此時，於1150℃以下進行之粗軋延中最大的軋延間隔係45秒以下；粗軋延結束後，且歷時滿足下述式(1)之保持時間t1(秒)後，開始完工軋延；進行滿足下述式(2)的最終軋延溫度Tf之完工軋延；完工軋延後於3秒以內開始鋼片的水冷卻，接著以最低冷卻速度8℃/秒以上將鋼片冷卻至700℃以下，再於530~650℃之範圍內捲取；1000×([%Ti]+[%Nb])>t1………式(1)，Tf>830+400([%Ti]+[%Nb])………式(2)。 The invention relates to a method for manufacturing a high-ratio ratio hot-rolled steel sheet with excellent energy absorption characteristics at low temperature and HAZ softening resistance, which is characterized in that it is composed of the components of any one of items 1 to 5 of the patent application scope. Steel sheet, the following steps are carried out: heating to above 1150 ° C; the heated steel sheet is coarsely rolled and stretched between 1000 and 1080 ° C When the rough rolling is completed, the maximum rolling interval in the rough rolling process performed at 1150 ° C or lower is 45 seconds or less; after the end of the rough rolling, the holding time t1 (second) satisfying the following formula (1) is satisfied. After that, the completion of the rolling is started; the completion rolling is performed to satisfy the final rolling temperature Tf of the following formula (2); after the completion of the rolling, the water cooling of the steel sheet is started within 3 seconds, followed by the minimum cooling rate of 8 ° C / sec. The above steel sheet is cooled to below 700 ° C, and then coiled in the range of 530 ~ 650 ° C; 1000 × ([% Ti] + [% Nb]) > t1 ... ... (1), Tf > 830 + 400 ([%Ti]+[%Nb]).........Formula (2). 如申請專利範圍第7項之高降伏比熱軋鋼板之製造方法，其中最終軋延溫度Tf係滿足下述式(3)：Tf>830+800([%Ti]+[%Nb])………式(3)。 The method for manufacturing a high-ratio ratio hot-rolled steel sheet according to item 7 of the patent application, wherein the final rolling temperature Tf satisfies the following formula (3): Tf>830+800 ([%Ti]+[%Nb])... ... (3). 一種具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鍍敷鋼板之製造方法，其特徵在於，其係於將以申請專利範圍第7或8項的製造方法所得之熱軋鋼板酸洗後，於Ac3溫度以下進行加熱，接著，浸漬於鍍敷浴中來鍍敷該鋼板表面。 A method for producing a high-ratio ratio hot-rolled plated steel sheet having excellent latent energy absorption characteristics and HAZ softening resistance at a low temperature, which is obtained by the manufacturing method of claim 7 or 8 After the hot-rolled steel sheet is pickled, it is heated at a temperature equal to or lower than Ac3, and then immersed in a plating bath to plate the surface of the steel sheet. 如申請專利範圍第9項之具優異低溫下之衝撃能量吸收特性及耐HAZ軟化特性的高降伏比熱軋鋼板之製造方法，其係於前述鍍敷後更進行鍍敷合金化處理。 A method for producing a high-ratio-ratio hot-rolled steel sheet having excellent latent energy absorption characteristics and HAZ softening resistance at a low temperature according to the ninth application of the patent application, which is subjected to a plating alloying treatment after the plating.
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JP5354130B2 (en) 2013-11-27
MX2014001501A (en) 2014-05-12
CN103732776A (en) 2014-04-16
WO2013022043A1 (en) 2013-02-14
RU2562582C1 (en) 2015-09-10
CA2843588A1 (en) 2013-02-14
US20140178712A1 (en) 2014-06-26
CA2843588C (en) 2018-02-20
KR20140026574A (en) 2014-03-05
MX349893B (en) 2017-08-18
CN105648311A (en) 2016-06-08
EP2743364B1 (en) 2016-07-27
CN103732776B (en) 2016-06-08
ES2589640T3 (en) 2016-11-15

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