TW200912014A

TW200912014A - Hot-rolled shape steel for ships and process for manufacturing the same

Info

Publication number: TW200912014A
Application number: TW097128385A
Authority: TW
Inventors: Tatsumi Kimura; Kazuhiko Shiotani; Shinichi Suzuki; Nobuo Shikanai; Kazutaka Kobayashi
Original assignee: Jfe Steel Corp
Priority date: 2007-07-27
Filing date: 2008-07-25
Publication date: 2009-03-16
Also published as: KR20130004605A; JP2009052136A; CN101772583B; CN101772583A; TWI391499B; JP5396758B2; KR101241935B1; KR20100023047A

Abstract

A hot-rolled shape steel for ships which is manufactured by heating a bloom containing by mass C: 0.03 to 0.25%, Si: 0.05 to 0.50%, Mn: 0.1 to 2.0%, P: 0.025% or below, S: 0.01% or below, Al: 0.005 to 0.10%, W: 0.01 to 1.0%, Cr: 0.01 to less than 0.20%, and N: 0.001 to 0.008% to a temperature of 1000 to 1350 DEG C, subjecting the resulting bloom to hot rolling wherein the cumulative rolling reduction at Ar3 or below is 10 to 80% and the rolling finishing temperature is (Ar3-30 DEG C) to (Ar3-180 DEG C), and then cooling the rolled steel by allowing it to stand and which has a microstructure composed of both ferrite containing worked ferrite and pearlite. Thus, a hot-rolled shape steel for ships which exhibits excellent corrosion resistance even when used in a severe corrosive atmosphere accompanied with corrosion due to seawater, e.g., ballast tanks of ships and which has strength corresponding to YP of 315MPa or above and is usable as longitudinal (lounge) or the like can be provided at a low cost.

Description

200912014 六、發明說明：【發明所屬之技術領域】 • 本發明係關於諸如：運煤船（coal ship)、礦砂專用船（〇re - carrier)、礦砂煤炭兩用船（ore coai carrier)、原油輪（crude oil tanker)、LPG 船（LPG carrier)、LNG 船（LNG carrier)、化學油輪（chemical tanker)、貨櫃船（container ship)、散裝船（bulk carrier)、木材運輸船（log carrier)、木屑運輸 ^ 船（chip carrier)、冷藏船（refrigerated cargo ship)、汽車運輸船（pure car carrier)、重載船（heavy load carrier)、 R0R0 船（rol卜on/r〇ll-0ff ship)、石灰石運輸船（limest〇ne carrier)、水泥運輪船（cementcarrier)等所使用的船舶用型鋼。本發明特別係關於在因海水導致嚴重腐蝕環境下的壓艙水櫃（ballast tank)之縱向肋骨（縱樑材）等所使用的船舶用熱軋型鋼、及其製造方法。此處，所謂「熱軋型鋼」係指利用熱軋成形為最終形狀的型鋼（此係以厚鋼板為素材的型鋼，將厚鋼板切斷為既定尺寸，亚施行溶接，而獲得型鋼的最終形狀）。此外，所謂「縱向肋骨（縱樑材）等所使用的船舶用熱軋_」，具體係指利用熱札進仃成形的諸如：等股角鋼（equal leg angle: AB)、不等邊 -肖鋼（聰_ leg angle : ABS)、不等邊不等厚角鋼（_ leg and thickness angle : NAB)、槽型鋼（channel “細：cb)、球緣角鐵（bulb plate : BP)、T 型鋼（τ-bar)等。 97128385 200912014 【先前技術】船舶的壓艙水櫃係在無載貨時’便注入海水而負責使船舶能穩定航行的功用。因而’壓餘水櫃將籠罩在非常嚴苛的腐蝕環境（corrosion eiwiromieiit)下。所以，就壓艙水櫃所使用鋼材的防蝕，通常將併用利用環氧樹脂塗料（ep〇xy paint)施行的防钱塗膜（anti-conOsion paint film)形成、以及電氣防餘（cathodic protection) °200912014 VI. Description of the invention: [Technical field to which the invention pertains] • The present invention relates to, for example, a coal ship, a sre-carrier, an ore coai carrier, and a crude oil. Crude oil tanker, LPG carrier, LNG carrier, chemical tanker, container ship, bulk carrier, log carrier, Chip carrier, refrigerated cargo ship, pure car carrier, heavy load carrier, R0R0 ship (rolb on/r〇ll-0ff ship), Ship steel for use in limestone transporters, cement carriers, etc. More particularly, the present invention relates to a hot-rolled steel for ship used for a longitudinal rib (longitudinal beam) of a ballast tank in a severely corrosive environment caused by sea water, and a method for producing the same. Here, the term "hot-rolled steel" refers to a section steel which is formed into a final shape by hot rolling (this is a section steel made of a thick steel plate, and the thick steel plate is cut into a predetermined size, and the steel is melted to obtain the final shape of the steel. ). In addition, "hot rolling" for ships used for longitudinal ribs (longitudinal beams), etc., specifically refers to the formation of equal-angle steels (equal leg angle: AB), etc. Steel (cone angle: ABS), unequal angle steel (_ leg and thickness angle: NAB), channel steel (channel "fine: cb", bulb plate (BP), T-shaped steel (τ-bar), etc. 97128385 200912014 [Prior Art] The ballast water tank of the ship is injected into the sea water when it is not loaded, and is responsible for the function of the ship to sail stably. Therefore, the 'pressure water tank will be shrouded in very severe Corrosion environment (corrosion eiwiromieiit). Therefore, the corrosion resistance of the steel used in the ballast tank is usually formed by an anti-conOsion paint film using epoxy paint (ep〇xy paint). And electrical protection (cathodic protection) °

但是，即使採取該等防_策，但壓齡_雜環境仍然處於嚴苛的狀態中。即，當在壓艙水射注人海水時，完全浸泡於海水中的部分，因為電氣防歸揮功能，而可抑制:虫二但是，壓艙水獅最上顧近，制係上甲板（卿打㈣）的背側，並未浸泡於海水中，僅有海水泡__狀態。因而，該:位的魏關料具魏。且，該雜糊场光導致鋼板溫度上升，而導致腐蝕環境更趨於嚴乃—万面，當麼艙水櫃中並未注人海水時，因為電氣_完全無翻，故附著的鹽分而遭受嚴重腐蝕。命細㈣麵她防崎膜壽，又了明係、，，勺1 〇年’屬於船舶壽命（約2〇年）的 =加目：實況係剩餘利年期間，得依賴施行諸如‘ 、Pair Paintlng)等處理，才能維持耐雜。彳日Θ 為㈣水櫃的縣環境係屬於非常嚴苛，因而=，因装，但仍頗難長時間持續維持效果。且，因為修補塗塗 97128385 ^ 200912014 。所以，期盼盡可負荷之耐蝕性優異窄空間中施彳τ作業’因㈣業環境並非良好能地延長需修補錄的_，且能減輕作業的鋼材開發。 _所以’就驗水櫃等在嚴苛腐鱗境下所使用鋼材本身的耐 I虫性提升技術便有數個提案。例如在日本專利特_ 48,921號公報（專利文獻υ中有揭不：在C : 0.2〇mass%以下的鋼中，添加耐錄改善元素〇 (element ^ impr〇ves erosion resistance)^ Cu ：〇·〇5〜0·50義％、W : 〇.〇卜未滿〇〇5_%，更添加 ο. 01 〜0. 2麵％之 Ge、Sn、pb、As、Sb、Bi、Te 及 Be 中工種或2種以上的耐蝕低合金鋼(anti_c町〇幻加_ all〇y steel)。此外，在日本專利特開昭48_〇5〇922號公報（專利文獻2)中有揭示：在c : 〇 2〇mass%以下的鋼材中，添加财餘性改善元素之 Cu : 0. 〇5〜〇. 5〇mass%、W : 〇. 〇5〜〇. 5mass%，更添加〇. 〇卜0· 2mass%之 Ge、Sn、Pb、As、Sb、Bi、Te 及 Be 中 1 種或2種以上的耐蝕性低合金鋼。又，在日本專利特開昭 48-05_號公報（專利文獻3)中有揭示··在c : Q. 15_热以下的鋼中，添加 Cu : 〇. 〇5〜未滿〇. 15mass%、W : 〇· 〇5〜〇· 5mass% • 的耐钱性低合金鋼。 ' 再者，在日本專利特開平07-034197號公報（專利文獻4)中有揭示.對在C : 0. 15mass%以下的鋼中，經添加耐蝕性改善元素之 P : 〇.〇3〜lOmass%、Cu : 0. l〜l.〇mass%、則： 97128385 5 200912014 0.2 l.Omass/。的低合金耐餘鋼材，施行諸如：瀝青環氧塗料 (tar epoxy paint)、純環氧塗料（卿^印阳加）、無溶劑型環氧塗料（epQXy Without solvent)、胺基甲酸乙醋塗料等防錄料的塗佈’而職經齡被覆的壓艙水櫃。該項技術係藉由提升鋼材本身的耐射生俾延長防#塗裝的壽命:實現在船舶使用期間的M年中可達免保養 (maintenance-free)化。再者’在日本專利特開平〇7'〇34196號公報（專利文獻5)有揭示：在C : 0. l5mass%以下的鋼，添加耐錄改善元素之以： 0. 2〜5廳s%，而提升耐敍性，俾實現船舶的免保養化。此外，在本專利特開平07-034270號公報（專利文獻6)中所提案的壓臉水櫃之祕方法，係將在㈡.15咖_下的鋼中，經添加耐健改善元素之^ 〇.2〜5mas__，使用為構成材料，且將壓餘水櫃㈣的氧氣纽設定為相對大氣中值的 0· 5以下之比率。 =者在日本專利特開平G7__3m4l號公報（專利文獻7)中有提案：在C:(Umass%以下的鋼中，藉由添加以： 0.5〜3_5mass%而提升耐錄’俾實現船舶的免保養化。此外，在曰本專觸開2._52號公報（專利文獻8)中所揭示的船舶用鋼材，係在㈡..Q. Q25mass%_中，藉錄加^ : m〇mass%，俾提升耐塗膜損傷性（paint,im resistance)，並減輕修補塗裝等保養費用。 97128385 200912014 再者’在日本專利特開2_'〇Π381號公報（專利文獻9)中所揭示的船舶用鋼’係在c : Q1〜G. 25_%的鋼中，藉由添加Cu : 01〜2. _ass%、Mg : M()㈣惠⑽咖％，俾在船舶外板、壓搶水櫃、貨油搶、煤炭船貨搶等的使用環境中能具有雜性。此外，在日本專利特開·4_2_4號公報（專利文獻ίο)中所揭示的鋼，係在c:請Μ 2随％的鋼中，藉由複合添加Mq、W及C：u，並限定不純物的p、s添加量，俾抑制在原油油财所發生的全面賴、局部賴情形。【發明内容】 (發明所欲解決之問題）然而，構成壓搶水櫃等的鋼材，通常施行鋅底漆However, even if such a defense policy is adopted, the age of the battery is still in a severe state. That is, when the ballast water is injected into the seawater, the part completely immersed in the seawater can be suppressed because of the electric anti-return function: the insect 2, but the ballast water lion is the closest to the upper deck. The back side of the hit (four)) is not soaked in the sea water, only the seawater bubble __ state. Therefore, the: Wei Guan material has Wei. Moreover, the miscellaneous field light causes the temperature of the steel sheet to rise, and the corrosive environment is more rigorous, that is, when the water is not filled in the tank, since the electric _ is completely unturned, the salt adheres. Suffered severe corrosion. Life fine (four) face her anti-seal film life, and the Ming system,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, Paintlng) and other treatments to maintain tolerance.彳日Θ The county environment system for (4) water tanks is very strict, so =, because it is installed, but it is still difficult to maintain the effect for a long time. And, because of the patch coating 97128385 ^ 200912014. Therefore, it is expected that the corrosion resistance of the load can be excellent. The operation of the 彳τ in the narrow space is because the (4) industry environment is not good enough to extend the need to repair the _, and can reduce the steel development of the operation. _ So there are several proposals for the resistance to insects in the water tanks used in the strict rust scales. For example, in Japanese Patent Publication No. 48,921 (the patent document υ 有 : 在在在在在在在在在在在在在在在在在在在钢钢钢钢钢钢钢钢钢钢钢钢钢钢钢钢钢钢钢钢钢钢钢 e 钢钢〇5~0·50%%, W: 〇.〇不未5_%, more added ο. 01 ～0. 2%% of Ge, Sn, Pb, As, Sb, Bi, Te and Be It is disclosed in Japanese Patent Laid-Open Publication No. SHO 48-〇5〇922 (Patent Document 2) that it is disclosed in the Japanese Patent Publication No. 48-〇5〇922 (Patent Document 2). : 〇2〇mass% or less of the steel, add the impurity improvement element of Cu: 0. 〇5~〇. 5〇mass%, W: 〇. 〇5~〇. 5mass%, add 〇. 〇卜0·2mass% of one or more types of corrosion-resistant low-alloy steels of Ge, Sn, Pb, As, Sb, Bi, Te, and Be. Further, Japanese Patent Laid-Open No. 48-05_ Document 3) Revealed · In the steel below c: Q. 15_ heat, add Cu: 〇. 〇5~ underfill 15. 15mass%, W: 〇· 〇5~〇· 5mass% • Resistance Money low alloy steel. 'Further, in Japanese patents Japanese Laid-Open Patent Publication No. Hei 07-034197 (Patent Document 4) discloses that, for a steel having a corrosion resistance of C: 0.15 mass% or less, P: 〇.〇3~lOmass%, Cu: 0. l~l.〇mass%, then: 97128385 5 200912014 0.2 l.Omass/. Low alloy residual steel, such as: tar epoxy paint, pure epoxy coating (Qing ^ Yin Yang Plus) , the application of anti-recording materials such as epQXy Without solvent and urethane formic acid coatings, and the age-covered ballast tank. This technology is to improve the resistance of the steel itself.俾俾俾 # 涂涂涂涂 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 196 It is revealed that in steels with C: 0. l5mass% or less, the addition of the resistance-improving elements is: 0. 2~5 halls s%, while improving the remarkability, and achieving the maintenance-free operation of the ship. In addition, in this patent The secret method of the pressure-faced water tank proposed in Japanese Laid-Open Patent Publication No. Hei 07-034270 (Patent Document 6) is a steel which will be under (2).15 coffee. , By adding resistance elements of the improved health ^ 〇.2~5mas__, New York set using oxygen constituent material, and (iv) of the water tank than the pressure value for the relative atmospheric · 0 ratio of 5 or less. In Japanese Patent Laid-Open Publication No. G7__3m4l (Patent Document 7), there is a proposal for the maintenance of the ship in C: (Umass% or less steel by adding: 0.5 to 3_5 mass% In addition, the steel material for ships disclosed in the Japanese Patent Publication No. 2._52 (Patent Document 8) is incorporated in (2)..Q. Q25mass%_, plus ^: m〇mass%,俾俾 paint paint paint paint paint paint paint 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 船舶Steel 'in the steel of c: Q1~G. 25_%, by adding Cu: 01~2. _ass%, Mg: M() (four) Hui (10) coffee%, smashing on the outer panel of the ship, pressing the water tank, The steel disclosed in Japanese Patent Laid-Open Publication No. Hei. No. 4-2_4 (Patent Document ίο) can be used in the environment of C: Μ 2 with % In steel, by adding Mq, W and C:u in combination, and limiting the amount of p and s added by impurities, 俾 suppresses the overall dependence on crude oil and oil. [Invention] [The problem to be solved by the invention] However, the steel material constituting the pressure grabbing water tank or the like is usually subjected to a zinc primer.

U (ZinC_Primer)、環氧樹脂塗料等的塗佈。上述專利文獻卜3 所揭示的技射’相關在該特财在下㈣錄並未進行充分的探討，财待更進—步進行探討的空間。再者’專敎獻4所揭㈣崎，為能提升底層金屬的耐钮 I便^ P 4的GUl^ss%，但是就熔接性 ⑽癒丨⑻找接部她（tQughness Qf _加㈣方面卻有問題。再者，專利文獻5及專利淼 ^ 文獻6所揭不的鋼材’因為Cr含有較多的0. 2〜5mass%，且專利文獻7你·4ε _ ^ J又獻7所揭不的鋼材則Cr含有較多的0. 5〜3. 5mass%，因而任一去沾者句有熗接性與熔接部韌性的問碭。此外，該等Cr含有量較客碉里旱乂夕的鋼材有製造成本提 97128385 200912014 問題。八=’她獻8 ___，因為g含有量較㈣ 3有置較高，因騎製造成本提高的問題。因=:=Γ9所揭示的鋼材，因為 η 不穩定、鋼材的機械特性亦未穩定的問題。 =專利細所揭示的鋼材，係屬為能在原油油槽内躲Μ的環境下使糊發㈣耐軸，但就㈣存在的壓艙水_之耐_丨不_。料，細上賴鋅底漆塗佈狀態下的耐歸尚未有探討。所以，就壓搶水櫃所使用方面，仍有尚待更進-步就耐純進行探討的空間。 -般’船舶係將厚鋼板（thickplates)、薄鋼板、型鋼、棒鋼等鋼材施行溶接而建造’對該鋼材的表面施行防韻塗裝。上述防韻塗裝普通係就-次防鱗（pHmary⑽阶赠㈣施行鋅底漆的塗佈’經小組裝後或大組裝後的二次塗裝（正式塗 )裝）（Secondary rust preventi〇n)則施行環氧樹脂塗裝。所以，船舶的鋼材表面大部分均將施行鋅底漆與環氧樹脂塗裝等雙層構造的防蝕塗裝。此外，熔接部因施行熔接時的熱導致辞底漆遭受燒磬（burned out)，因而就從熔接後起至正式塗裝期 •間的防銹對策，便採行利用鋅底漆施行修補塗裝（修補）（t〇uch-uP)。但是，當截至正式塗裝為止的期間係屬於較短的情況，亦有未施行修補塗裝。此外，在建造後，經長年使用後的船舶，有上述塗膜劣化情況，或者導致無法充分發揮防 97128385 8 200912014 銹塗膜機能的部分、以及塗膜剝落導致鋼板呈裸露狀態的部分存在。即，航行中的船舶鋼材表面，存在有：經施行鋅底漆與環氧樹脂塗裝等雙層塗裝的部分、僅施行環氧樹脂塗裝的部分、以及裸露狀態的部分等3種狀態。所以’為能達成提升船舶耐餘性之目的’必需屬於該等任一狀態均呈現優異耐蝕性的船舶用鋼材。但是，船舶所使用的厚鋼板，就從因使用鋼材量的減少而衍生的成本降低、以及確保安全性的觀點，將朝高強度化演進，而使用降伏應力YP(yield strength)達315MPa以上、且拉伸強度TS(tensile strength)達440MPa以上的高強度材。厚鋼板的情況，就強度與韌性的控制，一般係藉由調整控制軋延/ 加速冷卻製程（TMCP: Thermo-Mechanical Control Process) 的條件而達成。另一方面，壓艙水櫃的縱樑材等所使用鋼材中，尤其是不等邊不等厚角鋼、T型鋼等熱軋型鋼，在相較於相同船舶所使用厚鋼板等的情況下，因為前者的截面形狀、尺寸較為複雜，因而就強度與韌性的控制方法，便較難採用與厚鋼板相同的 TMCP。特別係因為型鋼係必需在考慮軋延途中的彎曲、翹曲之 ί月況下進行材質改造’因而為能成為降伏應力ΥΡ達以上的尚強度型鋼，便必需就型鋼的獨自製造方法進行檢討。緣疋，本發明之目的在於廉價提供：於船舶的壓艙水櫃等嚴 97128385 200912014 可腐_境下’不致受塗财在狀態所左右，均能發揮優里耐雌，可延長截至修補塗裝前的_，甚至可減輕修補塗穿作業，且耐蝴«縣有ΥΡ達謂㈣上強度的㈣型鋼。 (解決問題之手段）發明者等針對即使因海水所造成的嚴苛賴環境下，仍不受 Ο 表面狀態（塗贿在狀態）所左^，均可纽優異耐歸，並具有高強度的型鋼開發進行深人鑽研。結果發現下述事項，遂完成本發明。 •將W與Cr視為必要元素而添加，在其中更進一步藉由依適萬範圍含有Sb、Sn等提升耐餘性元素，便可獲得不管鋅底漆與環氧樹脂塗裝的雙層塗膜狀態、或環氧樹脂塗膜狀態、或裸露狀態等任何狀態下，均能呈現優異耐蝕性的船舶用熱軋型鋼；及 •就在不致妨礙生產性、熔接性等的情況下，達型鋼高強度化方面’利用（α + χ )二相域軋延（h〇t rolling during( 7" + a )region)而導入加工肥粒鐵（strain hardening ferrite)，將屬有效。即’本發明的耐蝕性優異船舶用熱軋型鋼，係具有由含：C : O. 03〜0· 25mass%、Si : 0. 05〜0. 50mass%、Μη : 〇. 1 〜2. Omass%、 P. 0. 025mass%以下、S: 0. Olmass%以下、A1: 0. 〇〇5〜0. lOmass%、 W : 0. 01〜1. Omass%、Cr : 0. Olmass%以上且未滿〇. 20mass%、N : 97128385 10 200912014 0. 001〜0. 008mass%，剩餘則為Fe與不可避免的不純物所構成之成分組成，且具有由含加工肥粒鐵的肥粒鐵、與珠粒鐵組織 • (pear 1 ite)所構成之微觀組織（microstructure)。 - 本發明之船舶用熱軋型鋼係除添加上述成分組成之外，最好更進一步含有屬於下述A〜E組中至少1組的成分。記 • A 組.伙 Sb . 0. 001 〜0· 3niass%及 Sn : 0. 001~0. 3inass%中 Ο 選擇1種或2種 • B 組：從 Cu : 0· 005〜0. 5mass%、Ni : 0· 005〜0. 25mass%、 Mo : 0· 〇1 〜〇. 5mass%及 Co : 0. 01〜1. Omass%中選擇 1 種或 2 種以上 • C 組：從 Nb : 0. 001 〜0· lmass%、Ti : 0. 〇〇1 〜〇. lmass%、Zr : 〇. 001〜0_ lmass%及V : 0. 002〜0. 2mass%中選擇1種或2種以上 • D 組：B : 0.0002〜0·003mass% ϋ • Ε 組：從 Ca: 0. 0002〜0. Olmass%、REM: 〇. 0002〜〇15mass% 及γ : 0. 0001〜0. lmass%中選擇1種或2種以上再者，本發θ月的船舶用熱軋型鋼，最好表面設有： •環氧樹脂塗膜； ' •鋅底漆塗膜；及 ' •鋅底漆塗膜與環氧樹脂塗膜中任一者。再者，本發明的船舶用熱軋型鋼之製造方法，係在進行上述 97128385 11 200912014 船舶用熱軋型鋼的製造之際，將具有上述組成的鋼素材加熱至 1000〜1350 C，然後，施行將Αι*3溫度（Ar3變態點）以下的累積軋細率5又為〜80%、將精軋溫度（finishing temperature)設 - 為（Ar3_30°c)〜（An_180°C)的熱軋，然後再放置冷卻（air cooling) ° 本發明的上述製造方法，最好An溫度以下的熱軋，係在將型鋼截面内的溫度差設為50°C以内實施。〇【實施方式】 (組成）發明者等為求開發出航行中船舶所使用鋼材，就所存在3種狀態（即’具有鋅底漆與環氧樹脂塗膜等雙層塗膜的狀態、僅環氧樹脂塗膜的狀態及裸露狀態），不管任何狀態下均呈現優異耐蝕性的船舶用熱軋型鋼，便施行以下的實驗。實驗室規格熔製經添加各種合金元素的鋼，經熱軋而形成板【i ’ 厚5mm的熱軋板。由該等熱軋板中採取5mmtxl00mmWx200mmL、或5賴tx50mmWxl50imnL的試驗片，對該試驗片表面施行珠粒噴擊（shotblasting)，經將表面的氧化鐵皮（scale :氧化被膜）與油分去除後’便製成經施行下述3種表面處理過的曝曬試驗 ' (exposure test)用試驗片。 •條件A :在試驗片表面上’形成辞底漆（膜厚約15/im)與瀝青環氧樹脂塗料（膜厚約l〇〇#m)等雙層被膜 •條件B:在試驗片表面上，形成瀝青環氧樹脂塗料（膜厚 97128385 12 200912014 約l〇〇#m)的單層被膜 •條件C:在試驗片表面僅施行珠粒噴擊的裸露狀態（無防蝕被膜） ' 然後，將該等試驗片在模擬實船壓艙水櫃的上甲板背側之腐钱環境條件下，施行腐姓試驗。具體而言，將（35。〇、5觀簡心溶液喷霧x2hr)—⑽。C、RH(相對濕度）5mass%x4hr)—(5〇 t、RH95maSS%x2hr)設為1循環，並乾濕重複施行132次循環 ' 的鹽水噴霧的腐蝕試驗。針對具有塗膜的條件驗片，在試驗前，便從塗膜利用美工刀+狀劃割出達原料生鐵表面之長別腿的到知傷痕（scratch) ’經試驗後’藉由測定到傷傷痕周圍所發生的塗膜膨潤面積（area of swelling)，而評估耐儀性。此外’相關未設有塗膜的條件c之試驗片，經試驗後，利用鹽〇酸施行除銹（加㈣，從經除鎮過的試驗片重量、與腐敍試: 則的試驗片重量差（減少量），計算出平均板厚減少量，而耐名虫性評仗。由上述腐賊驗的結果，針對依各合金元素所達成的耐钱性 =，、’健試驗片表面的每個塗膜條件整理如表ι所示。 ’十對、，、。果進行簡單說明： 1) 條件A(鋅底漆+瀝青擇耐肺提升最纽的元;：Γ錄的制麵）的情況：京係Cr，其次係W，接著係Sb 〇 2) 條件B(僅遞青環氧樹脂塗膜單層）的情況：耐健提 97128385 13 200912014 有效的兀素係w，其次係Sb、Sn。 3) 條件C(裸露狀態）的 w 障况.耐蝕性提升最有效的元素係 W ’其次係Sb、Sii。 4) 若複合添加w與c 條件A下的耐蝕性，將較單獨含有的情況更加提升’錢早獨條件B、C亦的3日 ’則不僅條件A，就連條仵β C亦均呈制_改善效果。 5) Μο的添加係條件Α、β、^下U (ZinC_Primer), epoxy resin coating, etc. The technical issue disclosed in the above-mentioned Patent Document 3 is not fully explored in the next (four) recording of the special wealth, and the space for further progress is discussed. In addition, the 'Specially Offered 4' (4) Kawasaki, in order to improve the resistance of the underlying metal, I will be able to improve the GUl^ss% of the P4, but the fusion (10) will be more (8) find the part of her (tQughness Qf _ plus (four) aspects However, the patent document 5 and the patent 淼^ document 6 are not disclosed in the steel 'because Cr contains more 0. 2~5mass%, and the patent document 7 you·4ε _ ^ J also offered 7 The amount of Cr is more than 0. 5~3. 5mass%, so there is a problem of the splicing and the toughness of the welded part. The steel of the eve has a manufacturing cost of 97128385 200912014. Eight = 'She offered 8 ___, because the content of g is higher than (4) 3, because of the increase in manufacturing cost of riding. Because ===Γ9 revealed the steel because η is unstable and the mechanical properties of the steel are not stable. The steels disclosed in the patents are made to be able to make a paste in the environment of hiding in the oil tank of the crude oil (4), but the ballast water exists in (4) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ There is still room for further research on the basis of resistance to pureness. - The general ship is made by welding thick steel plates (thickplates), thin steel plates, steel sections, steel bars and other steels to build 'the surface of the steel. The above-mentioned anti-rhyming coating is applied to the general anti-scale (pHmary (10) order gift (four) application of zinc primer] after small assembly or secondary assembly (formal coating) (Secondary rust preventi) 〇n) The epoxy resin is applied. Therefore, most of the steel surface of the ship will be coated with a double-layer structure such as zinc primer and epoxy resin coating. In addition, the heat of the welded portion is welded. As a result, the primer was burned out, so the rust-preventing measures from the time of welding to the official coating period were carried out by using a zinc primer to repair (repair) (t〇uch-uP) However, the period until the official painting is a short period of time, and there is also no repair coating. In addition, after the construction, the ship after years of use may have the above-mentioned coating film deterioration, or may not be able to Full play against 97128385 8 2 00912014 The part of the rust coating function and the part where the coating film peels off causes the steel plate to be exposed. That is, the surface of the ship's steel in navigation exists: double-coated with zinc primer and epoxy resin coating. In some cases, only the epoxy resin coating part and the bare state part are required. Therefore, 'for the purpose of improving the ship's durability', it is necessary for ships with excellent corrosion resistance in any of these states. Steel. However, the thick steel plate used in ships will evolve from high-strength from the viewpoint of cost reduction due to the reduction in the amount of steel used and safety, and the YP (yield strength) is 315 MPa. The above-mentioned high-strength material having a tensile strength TS (tensile strength) of 440 MPa or more. In the case of thick steel plates, the control of strength and toughness is generally achieved by adjusting the conditions of the TMCP (The Thermo-Mechanical Control Process). On the other hand, in the steel materials used for the vertical beam of the ballast tank, especially the hot-rolled steel such as unequal angle steel and T-shaped steel, compared with the thick steel plate used in the same ship, etc. Because the shape and size of the former are complex, it is difficult to control the strength and toughness of the same TMCP as the thick steel plate. In particular, since the steel profile must be materially modified in consideration of the bending and warping during rolling, and thus it is a strength steel that can become a relief stress, it is necessary to review the individual manufacturing method of the steel. The purpose of the present invention is to provide cheap: in the ballast water tank of the ship, etc. 97128385 200912014 can be rotted _ under the environment, not to be affected by the state of the state, can play the excellent and female, can be extended as the repair coating The former _ can even alleviate the repairing and coating work, and it is resistant to the butterfly (the county has the strength of the (four) type of steel. (Means for Solving the Problem) The inventor and others are aiming at the surface condition (the bribe is in the state), even if it is caused by the harsh environment caused by sea water, and it is excellent in resistance and has high strength. The development of steel sections is carried out in depth. As a result, the following items were found, and the cost invention was completed. • Add W and Cr as essential elements, and further increase the residual element by Sb, Sn, etc. in a suitable range, and obtain a double coating film regardless of zinc primer and epoxy resin coating. High-strength steel for ship that exhibits excellent corrosion resistance in any state, such as the state of the epoxy resin coating film or the bare state; and • high steel resistance without impeding productivity, weldability, etc. In terms of strength, it is effective to introduce a strain hardening ferrite by using (α + χ ) two-phase rolling (h〇t rolling during (7 " + a ) region). That is, the hot-rolled steel for ship having excellent corrosion resistance according to the present invention has a content of: C: O. 03 to 0. 25 mass%, Si: 0.05 to 0.50 mass%, Μη: 〇. 1 to 2. Omass %, P. 0. 025mass% or less, S: 0. Olmass% or less, A1: 0. 〇〇5~0. lOmass%, W: 0. 01~1. Omass%, Cr: 0. Olmass% or more Not full. 20mass%, N: 97128385 10 200912014 0. 001~0. 008mass%, the remainder is composed of Fe and inevitable impurities, and has fertilized iron containing processing iron The microstructure of the pearl 1 ite (pear 1 ite). In addition to the above-described component composition, the hot-rolled steel for ship of the present invention preferably further contains at least one component belonging to the following groups A to E.记• Group A. Group Sb. 0. 001 ～0·3niass% and Sn: 0. 001~0. 3inass% 中Ο Select 1 or 2 types • Group B: from Cu: 0· 005~0. 5mass% , Ni : 0· 005~0. 25mass%, Mo: 0· 〇1 〇 5. 5mass% and Co: 0. 01~1. One or more types of Omass% are selected • Group C: from Nb : 0 001 〜0· lmass%, Ti: 0. 〇〇1 〜〇. lmass%, Zr: 〇. 001~0_ lmass% and V: 0. 002~0. One or more of 2mass% are selected. Group D: B: 0.0002~0·003mass% ϋ • Ε Group: From Ca: 0. 0002~0. Olmass%, REM: 〇. 0002~〇15mass% and γ: 0. 0001~0. lmass% One or more types, the hot-rolled steel for ships of the present θ month, preferably with: • epoxy resin coating; ' • zinc primer coating; and ' • zinc primer coating and Either epoxy resin coating film. Further, in the method for producing a hot-rolled steel for ship according to the present invention, when the hot-rolled steel for ship is manufactured in the above-mentioned 97128385 11 200912014, the steel material having the above composition is heated to 1000 to 1350 C, and then累积ι*3 The temperature (Ar3 metamorphic point) below the cumulative rolling ratio 5 is again ~80%, and the finishing temperature is set to - (Ar3_30 °c) ~ (An_180 °C) hot rolling, and then Air cooling. In the above-described production method of the present invention, it is preferable that the hot rolling at an An temperature or lower is performed within a temperature difference of 50 ° C in the section of the steel section.实施实施实施组成组成组成组成组成组成组成组成组成组成组成发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明发明The following test was carried out on the hot-rolled steel for ships which exhibited excellent corrosion resistance in any state in the state of the epoxy resin coating film and the bare state. Laboratory specifications are melted by adding steel with various alloying elements and hot rolled to form a sheet [i ′] 5 mm thick hot rolled sheet. A test piece of 5 mmt x 100 mm W x 200 mm L or 5 Å tx 50 mm W x 150 imn L was taken from the hot-rolled sheets, and the surface of the test piece was subjected to shot blasting, and the surface of the scale (oxidized film) and the oil were removed. A test piece for performing an exposure test of the following three kinds of surface treatments was prepared. • Condition A: On the surface of the test piece, a double-layer film such as a primer (film thickness of about 15/im) and an asphalt epoxy resin coating (film thickness: about l〇〇#m) was formed. Condition B: On the surface of the test piece On the top, a single layer film of asphalt epoxy resin coating (film thickness 97128385 12 200912014 about l〇〇#m) is formed. Condition C: only the exposed state of the bead spray is applied to the surface of the test piece (no anti-corrosion film)' Then, The test strips were subjected to a rotten surname test under the conditions of rotten money on the back side of the upper deck of the simulated real ship ballast tank. Specifically, (35. 〇, 5 observations of a simple solution spray x 2 hr) - (10). C, RH (relative humidity) 5 mass% x 4 hr) - (5 〇 t, RH95 maSS% x 2 hr) was set to 1 cycle, and the wet and dry repeated spraying of the salt spray of 132 cycles ' was tested. For the conditional test piece with the coating film, before the test, the longest leg of the raw iron surface is cut out from the coating film by the utility knife + shape to the scratched 'study' The area of swelling around the scar was evaluated, and the resistance was evaluated. In addition, the test piece of condition c without the film coating is tested, and after the test, the rust is removed by using the salt acid (plus (4), the weight of the test piece after the removal of the test piece, and the test piece weight: The difference (reduction amount), the average plate thickness reduction is calculated, and the resistance to the insect resistance is evaluated. The result of the above-mentioned rot thief test, the resistance to money according to each alloy element =, 'the surface of the test piece The conditions of each coating film are as shown in Table ι. 'Ten pairs,,,. Fruits are briefly explained: 1) Condition A (Zinc Primer + Asphalt Selecting the most important element of lung resistance;: Γ 的制) The situation: Beijing-based Cr, followed by W, followed by Sb 〇 2) Condition B (only for the epoxy resin coating single layer): 耐健提97128385 13 200912014 Effective 兀素系w, followed by Sb , Sn. 3) Condition C (naked state) w. The most effective element for improving corrosion resistance is W' followed by Sb and Sii. 4) If the corrosion resistance under condition A is added in combination with c, it will be more improved than the case of 'individually alone. B and C are also 3 days'. Not only condition A, but also 仵β C is also present. System _ improve the effect. 5) 添加ο is added under conditions Α, β, ^

Ni、C〇係條件A、rir6W 焉微徒升，而Cu、 [表1]Ni, C 条件 condition A, rir6W 焉 micro-extra, and Cu, [Table 1]

撫效:¾) (有效専、— -------- h 下的耐蝕性將略微提升。以上述额(卿效果）升耐蝕性基本元素的；二:=將採用經複合添加入提耐締時’縣祕—a步要求成分設計。織，#再要錢時1種或2種的種或2_上。叫，便添力侧、 97128385 200912014 接著，針對本發明耐蝕性優異的船舶用熱軋型鋼所應具有的成分組成進行說明。 C . 0.03〜〇. 25mass% C係屬於提高鋼強度的有效元素，本發明中為能獲得所需強度’便必需含有〇〇3mass%以上。另一方面，若添加超過〇. 25mas热，熔接熱影響部（HAZ : Heat Affected Zone)的韌性降低。所以，c含有量設定為0.03〜0.25mass%範圍内。另外，就從利用後述加工肥粒鐵兼顧強度與韌性的觀點，c最好設定在〇·〇5〜0. 20mass%範圍内。 • Si · 〇. 05~0.50mass%Effect: 3⁄4) (effective 専, --------- h under the corrosion resistance will be slightly improved. With the above amount (Qing effect) rise the basic elements of corrosion resistance; two: = will be added by composite At the time of Tina, the county secret-a step requires component design. Weaving, #1 or 2 species or 2_ on the money. Call it, add force side, 97128385 200912014 Next, excellent corrosion resistance for the present invention The composition of the ship shall be described in terms of the composition of the hot-rolled steel. C. 0.03~〇. 25mass% C is an effective element for increasing the strength of steel. In the present invention, it is necessary to contain 〇〇3mass% in order to obtain the required strength. On the other hand, when the addition of more than 〇. 25mas heat, the toughness of the heat affected zone (HAZ: Heat Affected Zone) is lowered. Therefore, the c content is set in the range of 0.03 to 0.25 mass%. The viewpoint of the strength and toughness of the processed ferrite is considered to be in the range of 〜·〇5~0. 20mass%. • Si · 〇. 05~0.50mass%

Si係屬於脫氧劑（deoxidizing agent)，且為提高鋼強度而添加的元素，本發明中添加〇. 〇5mass%以上。但是，若添加超過0. 50mass%，因為鋼的韌性降低，因而便將Si的上限設為 0. 50mass%。 • Μη * 0. 1~2. Omass% Μη係屬於具有防止熱脆性sh〇rtness)、提高鋼強度效果的兀素，將添加〇· lmass%以上。但是，若Mn添加超過 2. Omass%，因為鋼的韌性與熔接性降低，因而上限設定為 2. Omass%。最好設定為〇. 5〜丨.6mass%範圍内。 • P : 0. 025mass%以下 P係屬於使鋼的母材韌性、熔接性及熔接部韌性降低的有害兀素，最好盡可能地減少。特別係若p含有量超過 97128385 15 200912014 0. 025mass%，則母材韌性（toughness)與炫接部勃性大幅降低。所以’ Ρ δ又疋在〇. 〇25mass%以下。最好〇. 〇i4mass%以下。 P雖亦可無添加，但就工業生產的現實狀況下，下限為 0. 005mass%左右。 • S : 0. Olmass%以下 S係屬於使鋼的韌性與熔接性降低的有害元素，因而最好盡可能減少，本發明中將設定在〇· 〇lmass%以下。s雖亦可無添 ( 加，但就工業生產的現實狀況下，下限為0. OOlmass%左右。 • A1 · 0. 005-0. lOmass% A1係屬於當作脫氧㈣添加的元素，必需添加請5贴沾% 以上。但是，若添加超過〇. 1〇mass%，將因原料生鐵的腐蝕而洛出A1，導致原料生鐵表面的pH降低，造成耐餘性降低，因而A1含有量的上限設定為〇. 1〇mass%。 • W ：〇.01-1.Omass% ϋ 说係如上述，亦可提升鋅底漆與環氧樹脂塗膜存在下的鋼耐錄’特別係在環氧樹脂塗膜存在下與裸露狀態下，具有明顯的耐錄提升效果。所以，在本發明中屬於提升耐餘性元素的最重要元素之—。上述效果係在添加W : oimass%以上才备顯現。但是’若添加量超過⑽^，則上述效果達餘和: 所以，W的含有量便設定為〇〇1~1〇難％範圍内。最好〇. 02〜0· 3maSS%範圍内。尤以〇· 2mass%以下為佳。 1具有上述提升耐祕效果的理由，係目下述情形： 97128385 16 200912014 •在因鋼板腐蝕所生成的鐵銹力备儿此仏 τ生成w〇4，因該wo/-的存在，亂化物離子對鋼板表面的侵人受抑制； •鋼板表面的陽極部等出請η 出見ΡΗ降低的部位’將生成難溶性The Si system is a deoxidizing agent and is an element added to increase the strength of the steel. In the present invention, 〇. 5 mass% or more is added. However, if the addition is more than 0.5% by mass, the upper limit of Si is set to 0.50 mass%. • Μη * 0. 1~2. Omass% Μη is a sputum that has the effect of preventing hot brittleness and improves the strength of steel. It will add 〇·lmass% or more. However, if the addition of Mn exceeds 2. Omass%, the upper limit of the steel is set to 2. Omass% because the toughness and weldability of the steel are lowered. It is best to set it to 〇. 5~丨.6mass%. • P: 0. 025 mass% or less P is a harmful element that reduces the toughness, weldability, and toughness of the weld metal of the steel, and is preferably reduced as much as possible. In particular, if the p content exceeds 97128385 15 200912014 0. 025 mass%, the toughness of the base material and the brittleness of the bristle portion are greatly reduced. So '’ δ is now 〇. 〇25mass% or less. Best 〇. 〇i4mass% or less. P may not be added, but in the actual situation of industrial production, the lower limit is about 0.005 mass%. • S: 0. Olmass% or less S is a harmful element that reduces the toughness and weldability of steel. Therefore, it is preferable to reduce it as much as possible. In the present invention, it is set to be less than 〇·〇lmass%. s although there is no addition (add, but in the actual situation of industrial production, the lower limit is about 0. OMlmass%. • A1 · 0. 005-0. lOmass% A1 is an element added as deoxidation (four), must be added Please stick more than 5%. However, if more than 〇.1〇mass% is added, A1 will be released due to corrosion of the raw material pig iron, resulting in a decrease in the pH of the raw iron surface, resulting in a decrease in the durability, so the upper limit of the A1 content. Set to 〇. 1〇mass%. • W : 〇.01-1.Omass% ϋ As mentioned above, it can also enhance the steel resistance of the zinc primer and epoxy resin coating. In the presence of the resin coating film, it has a remarkable resistance to recording improvement in the exposed state. Therefore, in the present invention, it is the most important element for improving the durability of the element. The above effect is manifested by adding W: oimass% or more. However, if the amount added exceeds (10)^, the above effects are satisfied: Therefore, the content of W is set to be within the range of 〇〇1~1〇%. It is preferably 〇. 02~0·3maSS%. Especially 〇·2mass% or less is preferred. 1The reason for the above-mentioned effect of improving the anti-mystery effect is as follows. Shape: 97128385 16 200912014 • In the rust force generated by corrosion of the steel plate, this 仏τ generates w〇4, because of the existence of the wo/-, the intrusion of the chaotic ions on the surface of the steel plate is suppressed; • The anode on the surface of the steel plate When the Ministry waits for η to see the reduced part, it will generate poor solubility.

FeW〇4’亦精由該FeW〇4的存在，如如— 抑制氟化物離子對鋼板表面的入等，而有效地抑制鋼的舰。此外，藉由動2—的防銹劑作用 (m itntKKi effect)，亦可抑制鋼的腐银。 •Cr:〇.Qlmass%以上、未滿〇.20mass% ^係屬於在辞底漆與環氧樹脂塗膜的存在下，顯現出優里而描性的成分，屬於本發明船_減_f的重要元素之上述耐錄提升效果推"依下述理由所造成。當鋅底漆存在情況，辞底漆中的Zn溶出於表面，而生成ZnQ、ZnCi2. 4Zn(0H)2等Zn系腐蝕生成物（如七⑽ pnxiuct)。Cr對該Zn系腐蝕生成物產生作用，推定具有更加提升因Zn系賴生成物所造成·生鐵防錄的作用。此種在鋅底漆存在下的Cr對耐蝕性提升效果，係在含有 O.Olmass%以上才會顯現。但是，若含有達〇 2〇觀%以上，炫接部祕便降低。所以，Gr含有量設定為請贿％以上且未滿0. 20mass%範圍内。最好0. 02〜〇. 15贴沾％範圍内。另外，如前述，若一起添加上述範圍内的Cr與w ,可獲得相乘效果，能無’塗膜種類财無設置均可獲得極良好的耐 97128385 17 200912014 蚀性。 • N ： 0. 001-0.008mass% N係對鋼的韌性屬有害成分。所以，為能提升韌性，N最好盡可能減少，設定在〇. 〇〇8mass%以下。但是，工業性頗難將n 降低至未滿〇. OOlmass%。因而’本發明中便將n含有量設定在 0. 001〜0. 008mass%範圍内。本發明的船舶用熱軋型鋼在更加提升耐蝕性之目的下，除上述成分之外，尚可添加下述成分。FeW〇4' is also refined by the presence of the FeW〇4, such as, for example, by inhibiting the influx of fluoride ions on the surface of the steel sheet, thereby effectively suppressing the steel ship. In addition, the rosin of the steel can also be suppressed by the action of the mit-protection agent (m itntKKi effect). •Cr: 〇.Qlmass% or more, less than 20.20mass% ^ belongs to the composition of the primer and the epoxy resin coating film, showing the excellent and characteristic composition, belonging to the ship of the invention _ reduction _f The above-mentioned resistance improvement effect of the important elements is caused by the following reasons. When the zinc primer is present, the Zn in the primer is dissolved on the surface to form a Zn-based corrosion product such as ZnQ, ZnCi2.4Zn(0H)2 (e.g., seven (10) pnxiuct). Cr acts on the Zn-based corrosion product, and it is presumed that it has an effect of further enhancing the anti-recording of the pig iron caused by the Zn-based product. Such an effect of improving the corrosion resistance of Cr in the presence of a zinc primer is manifested when it contains O.Olmass% or more. However, if it contains more than 2%, the seductive part will be reduced. Therefore, the Gr content is set to be more than 100% of the amount of bribes and less than 0.20mas%. The best is 0. 02~〇. 15 stickers are within the range of %. Further, as described above, when Cr and w in the above range are added together, a synergistic effect can be obtained, and excellent resistance can be obtained without any coating film type, and the corrosion resistance can be obtained. • N : 0. 001-0.008mass% N is a harmful component to the toughness of steel. Therefore, in order to improve the toughness, N is preferably reduced as much as possible, and is set at 〇. 〇〇8mass% or less. However, industrial nature is quite difficult to reduce n to less than 〇. OOlmass%. 008mass%范围内。 In the present invention, the n content is set in the range of 0. 001~0. 008mass%. In the hot-rolled steel for ship of the present invention, in addition to the above components, the following components may be added for the purpose of further improving the corrosion resistance.

Sb . 0· 〇〇1〜〇· 3mass%及 Sn : 0. 001-0. 3mass%中之 1 種戋 2 種Sb . 0· 〇〇1~〇· 3mass% and Sn: 0. 001-0. 1 of 3mass% 戋 2 species

Sb係不管在鋅底漆與環氧樹脂塗膜存在下、或環氧樹脂塗膜存在下、或裸露狀態等任何狀態下，均具有提升顺性的效果。而，Sn係在環氧樹脂塗膜存在下與裸露狀態下具有提升耐錄的效果。Sb、Sn的上収果係可料因為鋼板表面的陽極部等pH降低部位的腐钱情形受抑制的緣故所致。該等效果係Sn、Sb均含有達〇. __似上才會顯現。但是，若添加超過〇.3maSS%，因為母材韌性與HAZ部韌性降低，因而2 別最好設定添加在範圍内。另外，尤以％與 Sn二者均有添加為佳。 ' • Cu ： 0.005^0.5mass% > Ni ：〇.〇〇5~〇.25mass% > Mo : 0· 01 0· 5mass极 Co . G. G1 〜1. Gmass%中之！種或 2 種以上The Sb has an effect of improving the compliance regardless of the presence of the zinc primer and the epoxy resin coating film, or the presence of the epoxy resin coating film, or the bare state. However, Sn has an improved recording resistance in the presence of an epoxy resin coating film and in a bare state. The upper fruits of Sb and Sn are expected to be caused by the suppression of the money in the pH-reduced portion such as the anode portion on the surface of the steel sheet. The equivalent fruit systems Sn and Sb all contain up to 〇. __ appears to appear. However, if more than 〇.3maSS% is added, the toughness of the base metal and the toughness of the HAZ portion are lowered, so it is preferable to add it to the range. In addition, it is preferable to add both % and Sn. ' • Cu : 0.005^0.5mass% > Ni : 〇.〇〇5~〇.25mass% > Mo : 0· 01 0· 5mass Extreme Co . G. G1 ~1. Gmass%! Species or more

Cu、Ni、Mo及Go係具有提升在辞底漆與環氧塗膜存在下、及裸露狀態下的鋼耐健’ @ M〇甚至在環氧塗膜存在下亦具 97128385 18 200912014 性提升效果。所以，當欲更加提升_性時，該等元素 :可辅助性含有。CU、Ni、Mq、c。的上述效果係可認為藉由使鐵錄粒子微細化的作用所產生。此外，t Μ。的情況，可切為藉由鐵財生成祕、抑細_子侵人於鋼板表蚊事亦具有貢獻。該等效果係在Cu、Ni含有達〇. 005mass%以上、M〇含有達 O.Glmass%以上、C。含有達以上才會顯現。但是， °即使添加Cu :超過〇. 5咖％、Ni :超過〇. 25maSS%、Mo :超過0. 5mass%、Co :超過1. 〇mass%，因該項效果已達飽和，而不利於經濟效益。所以，Cu、Ni、Mo及c〇最好分別依上述範圍内添加。再者，本發明的熱軋型鋼在為能提高強度、提升韌性的情況下，除上述成分之外，尚可含有下述成分。 • Nb : 0.001 〜0. lmass%、Ti : 0.001 〜〇. lmass%、Zr : 0. 001〜0. lmass%及V : 0. 002〜0. 2mass%中之1種或2種以上 Nb、Ti、Zr及V均係屬於提高鋼強度的元素，可配合必要強度而選擇添加。為能獲得此種效果，Nb、Ti、Zr分別最好添加0. OOlmass%以上，V則最好添加〇. 002mass%以上。但是，若Nb、Ti、Zr添加超過〇. lmass%，且v添加超過0. 2mass%，反而導致韌性降低，因而Nb、Ti、Zr、V的添加最好以上述值為上限。較佳的上限係0· 04mass%。該等元素中’就從熔接部動性的觀點，最好為Ti，次佳者係Nb ° 97128385 19 200912014 • B : 0.0002〜0.003mass% B係屬於提高鋼強度的元素’可視需要含有。為能獲得上述效果，最好添加0.0002mass%以上。但是，若添加超過 0. 003mass% ’反而導致韌性降低。所以，b最好依 0· 0002〜0. 003mass%範圍内添加。 • Ca : 0.0002〜0. Olmass%、REM : 〇·〇〇〇2〜0.015mass%及 Y : 0. 0001〜0. lmass%中之1種或2種以上Cu, Ni, Mo and Go have improved steel resistance in the presence of primer and epoxy coating, and under bare state. @@〇 Even in the presence of epoxy coating, 97128385 18 200912014 . Therefore, when you want to improve _ sex, these elements: can be auxiliary. CU, Ni, Mq, c. The above effects are considered to be caused by the action of refining the iron-recorded particles. In addition, t Μ. In the case of the case, it is also possible to contribute to the formation of mosquitoes by the iron and silver. These effects are such that Cu and Ni contain up to 005 mass% or more, and M 〇 contains up to O.Glmass% or more and C. It will only appear if it contains more than one. However, even if Cu is added: more than 〇. 5%, Ni: more than 〇. 25maSS%, Mo: more than 0. 5mass%, Co: more than 1. 〇mass%, because the effect is saturated, not favorable Economic benefits. Therefore, Cu, Ni, Mo, and c〇 are preferably added in the above ranges, respectively. Further, in the case of improving the strength and improving the toughness, the hot-rolled steel of the present invention may contain the following components in addition to the above components. • Nb: 0.001 to 0. lmass%, Ti: 0.001 〇. lmass%, Zr: 0. 001~0. lmass% and V: 0. 002~0. One or more of 2mass% or more than Nb, Ti, Zr and V are all elements which increase the strength of the steel and can be added in accordance with the necessary strength. In order to obtain such an effect, Nb, Ti, and Zr are preferably added at a ratio of 0. OOlmass% or more, and V is preferably added at a level of 002 mass% or more. However, if Nb, Ti, and Zr are added in excess of 〇.lmass%, and v is added in excess of 0.2 mass%, the toughness is lowered. Therefore, it is preferable to add Nb, Ti, Zr, and V to the above value. A preferred upper limit is 0·04 mass%. Among these elements, 'from the viewpoint of the dynamic part of the welded portion, it is preferably Ti, and the second best is Nb ° 97128385 19 200912014 • B : 0.0002 to 0.003 mass% B is an element which increases the strength of the steel. In order to obtain the above effects, it is preferable to add 0.0002 mass% or more. However, if the addition exceeds 0.003 mass%, the toughness is lowered. Therefore, b is preferably added in the range of 0·0002~0. 003mass%. • Ca: 0.0002~0. Olmass%, REM: 〇·〇〇〇2~0.015mass% and Y: 0. 0001~0. One or more of lmass%

Ca、REM及Y均係屬於具有提升溶接熱影響部之韌性效果的元素，可視需要選擇添加。該項效果係在以：〇〇〇〇2mass%以上、REM : 0. 0002mass%以上、Y ·· 〇. 0001mass%以上的添加時才旎獲得。但是，若添加Ca :超過〇. 〇imass%、rem :超過 0. 015maSs%、Y :超過〇. lmass%，反而導致韌性降低，因而Ca、 REM、Y的添加最好分別以上述值為上限。本發明的船舶用熱軋型鋼中，除上述以外的成分便係以及不可避的不純物。但，在不妨礙本發明效果的範圍内，並非排除含有除上述以外的成分。 (微觀組織）接者’針對本發明高強度且耐錄優異的船舶用熱軋型鋼之微觀組織進行說明。、船舶用鋼板，特別係降伏應力YP達315MPa以上的言強产严鋼板’-般將經減少碳當量並賦予聽接性的鋼素用組合控制軋延與控制冷卻的TMCP，形成曰 •"取弟2相的硬質變韌 97128385 20 200912014 鐵組織(bainite)，而達高強度化。然後，當要求低溫韋刃性的情況、或要求厚板化時，便藉由將上述控制軋延與控制冷卻的仏牛最佳化因應。所以，此情況，鋼板的微觀組織通常係肥粒 . 鐵+變勒鐵組織。另方面，船舶用熱軋型鋼的情況，多數情況係短邊與長邊的見度、厚度不同（例如截面非呈矩形的不等邊不等厚角鋼等），必然在軋延時或冷卻時將發生溫度不均勻情形。特別係 ( δ使用採用控制冷卻（加速冷卻）的強度調整時，殘留應力呈不均勻，誘發扭轉、彎曲、翹曲等，導致尺寸精度降低。因而，將軋延後的形狀矯正負荷便將增加。所以，導入第2相的硬質 i：早刃鐵組織俾達高強度化的方法便頗難適用於熱軋型鋼。此現象可謂就諸如軋延τ型鋼等全盤的船舶用熱軋型鋼均如此。所以’就船舶用熱軋型鋼便要求在未施行軋延後的加速冷卻 I月况下’可達降伏應力γρ:3i5MPa以上、且拉伸強度TS:440MPa 以上的高強度。因而，便必需利用尋常熱軋組織的肥粒鐵+珠粒鐵組織達高強度化。利用肥粒鐵+珠粒鐵組織實現高強度化的手段’係可考慮例如：增加第2相的珠粒鐵分率之方法、將肥粒鐵組織更加細粒化的方法、將肥粒鐵施行固溶強化或析出強化而硬的方法、或者在（7 )二相域中施行熱軋而將部分肥粒鐵形成高差排密度之加工肥粒鐵的方法等。上述方法中，將肥粒鐵細粒化的方法雖有利於使ΥΡ上升，但因為TS的上升較小，因而僅依靠該手法尚無法達充分的高 97128385 21 200912014 強度化。此外，增加珠粒鐵分率的方法必需添加大量的c，但因為過度添加c將導致嫁接性降低，因而最好避免。另外，添加固洛強化7L素或析出強化元素而將肥粒鐵強化的方法，因合金元素的大量添加而導致炼接性降低、或導致素材成本提高。另-方面’加工肥粒鐵的活用係將c或合金S素的添加抑制至最小極限，便可在維持炼接性的狀態下，提升γρ與TS。即，利用加工肥粒鐵的方法係經熱軋後，在未施行㈣冷卻（加速冷卻）的If況下’便可達兩強度化，因而將可在抑制船舶用熱軋型鋼製造時特有問題的軋延、冷卻時的彎曲、龜曲等情況發生之情形下，達高強度化。所以，本發明中，就船舶用熱乳型鋼的高強度化手段，便採用將鋼的微觀組織形成含有加工肥粒鐵的肥粒鐵+珠粒鐵組織之方法。其中，上述加工肥粒鐵的分率係就面積率，最好佔鋼組織整體的10〜。理由係若加工肥粒鐵的分率未滿1⑽，便热法獲得充分的鋼強化，反之，若超過7〇%，則不僅強度上升已達飽和，絲因U + τ)二相域軋延時的荷重增加而導致軋輕割損風險提高。另外’上述加工肥粒鐵係經導入由在An變態點以下的U + 二相域中，施行熱軋而形成的加工應變之肥粒鐵，通常將呈爲平化的加工肥粒鐵微量化，並將在微觀組織中的所佔面積定量化’便可測定其分率。微觀組織的測定位置最好係板厚最厚部位處的板厚1/4處。另外，含加工肥粒鐵的肥粒鐵，最好整體的面積率佔鋼組織 97128385 22 200912014 整體的10%〜70%左右。剩餘則為珠粒鐵組織，但除肥粒鐵•珠粒鐵以外的組織（即變韋刃鐵等），亦可依面積率計存在⑽以下。 . (表面處理） . 如泊所述，本發明的船舶用熱軋型鋼表面最好設定為： •無塗膜（裸露狀態） •僅環氧樹脂塗膜單層塗膜 •辞底漆與ί展氧樹脂塗震的雙層塗膜〇中之任—狀態。但，並非禁止除此以外的其他表面處理。特別係可自由將鋅底漆及/或環氧樹脂塗膜取代改用其他代替品。裸露狀態的情況’表面亦可保持熱軋狀態，但亦可利用珠粒喷擊等將氧化層與油層去除。不論環氧樹脂塗膜與鋅底漆的種類，均可使用本說明書中所說明物質、或其他周知物。另外，環氧樹脂塗臈最好使用瀝青環氧塗料樹脂。〇 (製造方法）其次，針對上述具有含加工肥粒鐵之肥粒鐵+珠粒鐵組織的船舶用熱軋型鋼，就其製造方法進行說明。當知行本發明船舶用熱軋型鋼之製造時，首先利用諸如轉 - 爐、電氣爐等普通周知設備熔製具有上述成分組成的鋼，接 - 著’最好利用諸如連續鑄造法、錠塊鑄造法等普通周知方法，形成鋼板坯、小截面方鋼坯、中鋼胚等鋼素材。另外，經熔製後，亦可施行諸如盛鋼桶精煉、真空脫氣等處理。 97128385 23 200912014 接著’將上述鋼素材裝入加熱爐中，經施行再熱後，施行熱 #L ’便形成具有所需尺寸、纽織及特性的船舶用熱軋型鋼。此夺鋼素材的再熱溫度必需設定在 1_〜135GC範H内。加熱溫度未滿1GQ(rc ’則變形阻力變大’較難施彳了熱軋。反之，若超過135Qt：的加熱，則成為表面傷痕的發生肇因、科致氧化鐵皮損失（scale loss)、燃料原單位增加。最好設定在11〇〇〜13〇(rc範圍内。接著，熱軋必需將在Αη溫度以下的累積軋縮率設為 10〜80%。若全軋延溫度在Αη溫度以上，便將成為鋼的微觀組織未含加工肥粒鐵者，而無法確保必要的強度、韌性。同樣的，若ΑηΜ度以下的累積軋縮率未滿ι〇%，因為加工肥粒鐵的生成里較少，因而強韌化效果較小。反之，若超過8〇%的軋縮率，則軋延荷重增加，導雜延趨於_，或者因軋延的軋道次數增加導致生產性降低。所以，將Αγ3溫度以下的累積軋縮率設為10〜80%。最好10〜60%範圍内。另外，Αη溫度以下的軋延係只要至少1軋道以上實施便可’亦可為複數軋道。此處所謂溫度以下的累積軋縮率」係指相對Αη溫度下的軋延材截面積 (Α)，經軋延結束後的軋延材截面積（Β)之截面減面率，依下式表示： (Ail溫度以下的累積札縮率[%] )=(Α-Β)/Αχΐ〇0 再者，上述熱軋係必需依照精軋溫度：（Ar3_3〇°c)〜（^ C)的條件實施。理由係精乳溫度若超過，& 97128385 24 200912014 (充細舰縣，狄，若未滿 έ 變形阻力增加，導致軋延荷重增加’造成軋延趨於困難。心取再者，上述熱軋中η 熱軋型錮㈣ ’取好將An溫度以下的軋延，在船舶用、面内各部位之溫度差設定在5(TC以内。例如在船舶用熱軋型鋼中，Ca, REM, and Y are all elements that have the toughness effect of improving the heat affected zone of the fusion, and may be added as needed. This effect is obtained when: 〇〇〇〇 2mass% or more, REM: 0. 0002mass% or more, Y ·· 〇. 0001mass% or more. However, if Ca: exceeds 〇. 〇imass%, rem: more than 0. 015maSs%, Y: exceeds 〇. lmass%, which causes a decrease in toughness, so the addition of Ca, REM, and Y is preferably the upper limit of the above value. . In the hot-rolled steel for ship of the present invention, components other than the above are unavoidable impurities. However, the components other than the above are not excluded insofar as they do not impair the effects of the present invention. (Microstructure) The present invention is described with respect to the microstructure of the hot-rolled steel for ship which is high in strength and excellent in recording resistance. Steel plate for ships, in particular, a steel sheet with a tensile stress YP of 315 MPa or more, which is a steel sheet that has been reduced in carbon equivalent and imparts kinetic resistance to TMCP, which is controlled by rolling, controlled cooling, and controlled cooling. The younger brother of the 2 phase of the hard tough 97128385 20 200912014 iron structure (bainite), and the high strength. Then, when a low-temperature blade is required or a thick plate is required, the above controlled rolling and controlled cooling of the calf are optimized. Therefore, in this case, the microstructure of the steel sheet is usually fat. Iron + modified iron structure. On the other hand, in the case of hot-rolled steel for ships, in most cases, the visibility and thickness of the short side and the long side are different (for example, the non-equal thickness of the unequal section of the rectangular section is not rectangular), and it is necessary to delay or cool the rolling. Temperature unevenness occurs. In particular, when the intensity of δ is controlled by controlled cooling (accelerated cooling), the residual stress is uneven, and torsion, bending, warpage, etc. are induced, resulting in a decrease in dimensional accuracy. Therefore, the shape correcting load after rolling is increased. Therefore, the introduction of the hard phase i of the second phase: the method of high-strength of the early-edge iron structure is difficult to apply to hot-rolled steel. This phenomenon can be said to be the same for hot-rolled steel for ships such as rolling τ steel. Therefore, in the case of hot-rolled steel for ships, it is required to have a high strength of up to the undulation stress γρ: 3i5 MPa or more and a tensile strength TS: 440 MPa or more under the accelerated cooling I month without rolling. The high-strength of the ferrite iron + bead iron structure of the ordinary hot-rolled structure is utilized. The means for achieving high strength by using the ferrite iron + bead iron structure can be considered, for example, to increase the bead iron fraction of the second phase. The method, the method of finely granulating the ferrite grain iron structure, the hardening strengthening or precipitation strengthening hard method of the ferrite iron, or the hot rolling in the (7) two-phase domain to form part of the ferrite iron Height difference In the above method, the method of fine-graining the ferrite-grained iron is advantageous for raising the enthalpy, but since the rise of TS is small, it is not possible to reach a sufficient height by only relying on this method. 21 200912014 Strength. In addition, the method of increasing the iron fraction of beads must add a large amount of c, but it is best to avoid the excessive grafting of c, which is best avoided. In addition, the addition of Guluo 7L or precipitation strengthening elements is added. The method of strengthening the ferrite and iron is caused by a large amount of alloying elements, which leads to a decrease in the refining property or an increase in the cost of the material. The other aspect of the processing of the ferrite is to suppress the addition of c or alloy S to the minimum limit. Γρ and TS can be improved while maintaining the refining property. That is, the method of processing the ferrite can be used to achieve two conditions after hot rolling without the (four) cooling (accelerated cooling). When the strength is increased, it is possible to increase the strength in the case of rolling, stretching, and tortuosity which are particularly problematic in the production of hot-rolled steel for ship production. Therefore, in the present invention, The method of high-strength of hot-type milk steel for ship uses a method of forming a microstructure of steel into a ferrite-rich iron + bead iron structure containing processed ferrite, wherein the fraction of the processed ferrite is based on an area ratio. It is best to account for 10% of the overall steel structure. The reason is that if the fraction of processed ferrite is less than 1 (10), the thermal method obtains sufficient steel strengthening. On the contrary, if it exceeds 7〇%, the strength rises to saturation. The risk of light cutting is increased due to the increased load of the U + τ) two-phase rolling delay. In addition, the above-mentioned processing fertilizer iron is introduced into the U + two-phase domain below the An transformation point, and the processing strain of the ferrite iron formed by hot rolling is usually flattened and processed. And quantify the area occupied in the microstructure to determine its fraction. The measurement position of the microstructure is preferably 1/4 of the thickness at the thickest portion of the plate thickness. In addition, the grain size of the ferrite-containing iron containing the processed ferrite is preferably about 10% to 70% of the overall steel structure of 97128385 22 200912014. The rest is the bead iron structure, but the structure other than the ferrite iron • bead iron (ie, Wei Wei, etc.) may also exist below (10) depending on the area ratio. (Surface treatment). As described in the poise, the surface of the hot-rolled steel for ship of the present invention is preferably set to: • no coating film (naked state) • only epoxy resin coating single-layer coating film • reprimand and ί Oxygen-coated resin coated double-layer coating film in the state - state. However, other surface treatments other than this are not prohibited. In particular, it is possible to freely replace the zinc primer and/or epoxy coating with other alternatives. In the case of the bare state, the surface may be kept in a hot rolled state, but the oxide layer and the oil layer may be removed by bead blasting or the like. The materials described in the present specification or other known materials can be used regardless of the type of the epoxy resin coating film and the zinc primer. Further, it is preferable to use an asphalt epoxy coating resin for epoxy resin coating. 〇 (Manufacturing Method) Next, the method for producing the hot-rolled steel for ships having the ferrite-rich iron + bead iron structure containing the processed ferrite iron will be described. When knowing the manufacture of the hot-rolled steel for ship of the present invention, firstly, a steel having the above composition is melted by a conventionally known device such as a rotary-furnace or an electric furnace, and it is preferable to use, for example, a continuous casting method or an ingot casting. A well-known method such as a method forms a steel material such as a steel slab, a small-section square billet, and a medium steel billet. In addition, after melting, it can also be processed such as steel drum refining and vacuum degassing. 97128385 23 200912014 Then, the above-mentioned steel material was placed in a heating furnace, and after reheating, heat #L ' was applied to form a hot-rolled steel for ship having a desired size, texture and characteristics. The reheat temperature of this steel material must be set within the range of 1_~135GC. When the heating temperature is less than 1 GQ (r', the deformation resistance becomes large, it is difficult to apply hot rolling. On the other hand, if it exceeds 135 Qt: heating, it causes the occurrence of surface flaws, the scale loss of the iron oxide scale, The original unit of fuel is increased. It is preferably set in the range of 11 〇〇 to 13 〇 (rc). Next, the hot rolling must be set to a cumulative rolling reduction of 10 to 80% below the temperature of Αη. If the full rolling temperature is at Αη temperature Above, it will become the steel microstructure without the processing of ferrite, and can not ensure the necessary strength and toughness. Similarly, if the cumulative rolling reduction below ΑηΜ is less than 〇%, because of the processing of ferrite Less generation, so the toughening effect is smaller. Conversely, if the rolling reduction exceeds 8〇%, the rolling load increases, the miscibility tends to _, or the productivity is increased due to the number of rolling passes. Therefore, the cumulative rolling reduction ratio below the Αγ3 temperature is 10 to 80%, preferably 10 to 60%. Further, the rolling system below the Αη temperature can be carried out by at least one pass or more. For the number of rolling passes, here is the cumulative rolling below the temperature The rate refers to the cross-sectional area of the rolled web at a temperature of Αη (Α), and the cross-sectional area of the cross-section of the rolled web after rolling (Β) is expressed by the following formula: (accumulation below Ail temperature) Reduction ratio [%] ) = (Α - Β) / Αχΐ〇 0 In addition, the above-mentioned hot rolling system must be carried out in accordance with the conditions of the finishing rolling temperature: (Ar3_3 〇 ° c) ~ (^ C). Exceeded, & 97128385 24 200912014 (Filling Ship County, Di, if not full of deformation resistance increases, resulting in increased rolling load load, resulting in rolling delays tend to be difficult. Heart-to-heart, above-mentioned hot-rolling η hot-rolled 锢(4) 'When the temperature below An temperature is taken, the temperature difference between the ship and the surface is set to 5 (TC). For example, in hot-rolled steel for ships,

計對長邊與短邊的板厚有差異之不等邊不、予鋼，最好相對板厚較薄的長邊側，將板厚較厚的短邊側 :軋^機錢均施行水冷’俾將長邊側與短邊綱溫度差抑制 50 C以内。^溫度差超過5〇。〇，則不僅短邊側與長邊側的強度動性特性變動變大，·延後的冷卻步驟巾，彎曲情形變大，造成施行矯正時所需要的負擔變大，導致生產性降低。將紐邊側與長邊側的溫度差抑制在50°C以内的手段，最好使用在粗軋機（rougher rolling miu)前後所配置的冷卻設備，進行冷卻控制的方法。具體而言，最好利用上述冷卻設備，將板厚較厚的短邊側施行重點式水冷，而解除溫度差的方法。此時的水冷係可就軋延機前後僅在前面實施、或僅在後面實施、或前後二處均有實施，且配合施行軋延的型鋼尺寸、要求精度，亦可重複施行複數次。另外，施行水冷時的水量密度，最好設定在lm3/m · min以上。型鋼的截面内溫度差，係利用輻射溫度計測定翼板與腹板 (參照實施例）的表面溫度’再從所獲得的最高溫度與最低溫度差進行求取。 97128385 25 200912014 接著熱軋之後的冷卻並無特別的限制，最好採行放置冷卻。藉此，便可減輕因軋延後的冷卻不均勻所造成的彎曲、翹曲等型鋼形狀變化狀況，可減輕在軋延後對產品施行矯正的負擔。 - 放置冷卻時的冷卻速度雖將依板厚而異，但將設定在〇. 4〜1. 〇 C/s左右。在上述冷卻速度範圍内將冷卻進行加減速的處置 (強制冷卻、保溫等），因為實質上將如同放置冷卻，因而並未特別排除使用。 c [實施例]It is considered that the difference between the thickness of the long side and the short side is not equal to that of the steel. It is better to use the long side with a thinner plate thickness and the shorter side of the thicker plate: the machine is water-cooled. '俾The temperature difference between the long side and the short side is suppressed within 50 C. ^ The temperature difference exceeds 5 〇. In other words, not only the fluctuation in the dynamic characteristics of the short side and the long side is increased, but also the cooling step of the delay is increased, and the burden required for performing the correction is increased, resulting in a decrease in productivity. In the means for suppressing the temperature difference between the front side and the long side to be within 50 ° C, it is preferable to use a cooling device disposed before and after the rougher rolling mill to perform cooling control. Specifically, it is preferable to use a cooling device as described above to perform a critical type of water cooling on the short side of the thick plate to release the temperature difference. The water cooling system at this time may be carried out only before and after the rolling mill, or only at the rear, or both at the front and the back, and may be repeatedly applied in combination with the size and required precision of the rolled steel. Further, it is preferable to set the water density at the time of water cooling to be lm3/m·min or more. The temperature difference in the cross section of the section steel was measured by the radiation thermometer to determine the surface temperature of the flap and the web (refer to the example), and then the difference between the highest temperature and the lowest temperature obtained was obtained. 97128385 25 200912014 There is no particular restriction on the cooling after hot rolling. It is best to place it for cooling. Thereby, it is possible to reduce the shape change of the steel such as bending and warpage caused by the uneven cooling after rolling, and it is possible to reduce the burden of correcting the product after rolling. - The cooling rate at the time of cooling will vary depending on the thickness of the plate, but it will be set at 〇. 4~1. 〇 C/s or so. The treatment for accelerating and decelerating the cooling in the above-described cooling rate range (forced cooling, heat preservation, etc.) is not particularly excluded since it is substantially cooled as it is placed. c [Examples]

、利用真轉解爐或轉舰製具有表2(表2_i及表2_2)所示成分组成的鋼’並形成中鋼胚，將該中鋼胚裝入加熱爐中，經施3加熱後，再依照表3(表3-1及表3—2)所示條件施行熱軋， ^製得表3所錢面尺寸的料邊不等厚角鋼（MB)及軋延τ 型鋼、。另外，表3中，相關不等邊不等厚角鋼（_，將長邊側記為「腹板」’將短邊側記為「翼板」。針對不錢不等厚角鋼從短邊採取】IS1A號拉伸試驗片，針腦細申—蝴拉娜等厚角鋼將料 TS、伸展E1)。此外，針對不等邊不入施行氣職·2嶋m的熱輸衝擊試驗片（2魏‘接卿），並從HAZ中央處採取夏不氏中的吸收能量缺口試驗片）’測定在—2crc夏风衝擊試驗再者針對不等邊不等厚角鋼將從短邊， 97128385 而針對T型鋼則從 26 200912014 翼板採取組織觀察用試料，利用顯微鏡依倍率200倍觀察板厚 1/4處的組織。所觀察到的組織中，將依二相域軋延所生成的扁平化加工肥粒鐵施行微量，且利用影像解析將在微觀組織中，所佔的面積定量化，便求得加工肥粒鐵的分率。〇 97128385 27 200912014 [表 2-1], using a true transfer furnace or a rotary ship made of steel having the composition shown in Table 2 (Table 2_i and Table 2_2) and forming a medium steel embryo, the medium steel embryo is placed in a heating furnace, and after heating 3, Then, hot rolling is carried out according to the conditions shown in Table 3 (Table 3-1 and Table 2-3), and the thickness of the surface of Table 3 is not equal to the thick angle steel (MB) and the rolled τ steel. In addition, in Table 3, the relevant unequal unequal angle steel (_, the long side is referred to as "web"" and the short side is referred to as "wing". For the non-constant unequal angle steel from the short side] IS1A No. tensile test piece, needle-brained---------------------------------------------------------------------- In addition, for the heat transfer impact test piece (2 Wei 'Ji Qing), which is not required to perform the qi 2·m, and take the absorption energy gap test piece in Xiabu from the center of HAZ) The 2crc summer wind impact test is based on the unequal thickness of the unequal angle steel from the short side, 97128385 for the T-shaped steel from the 26 200912014 wing plate for the observation of the tissue, using the microscope to observe the plate thickness 1/4 at 200 times the magnification Organization. In the observed structure, the flattened processing fertilized iron produced by rolling in the two-phase domain is subjected to a trace amount, and the area occupied by the microstructure is quantified by image analysis, and the processed ferrite is obtained. The rate of division. 〇 97128385 27 200912014 [Table 2-1]

鋼 No. 化學成分（mass%)(其一）備註 C Si Μη Ρ S A1 W Cr N 1 0. 13 0.25 1. 25 0. 009 0. 002 0. 030 0. 05 0. 01 0. 0034 發明例 2 0. 10 0. 32 1. 32 0. 013 0. 003 0. 029 0. 20 0. 08 0. 0028 發明例 3 0. 11 0.40 1. 20 0. 010 0. 005 0. 030 0. 08 0. 12 0. 0035 發明例 4 0. 09 0.24 1. 28 0. 009 0. 002 0. 018 0. 18 0. 18 0.0028 發明例 5 0. 12 0. 11 0. 93 0. 014 0. 009 0. 025 0. 10 0. 05 0. 0025 發明例 6 0. 14 0. 30 0. 65 0. 014 0. 010 0. 045 0. 15 0. 05 0. 0030 發明例 7 0. 12 0.32 1. 33 0. 010 0.005 0.018 0.03 0. 03 0. 0015 發明例 8 0. 08 0.20 1. 15 0. 005 0. 001 0. 040 0.05 0. 05 0. 0043 發明例 9 0. 06 0. 15 1. 57 0. 015 0. 003 0. 025 0.15 0. 12 0.0022 發明例 10 0. 10 0. 27 1. 26 0. 012 0. 005 0. 030 0. 07 0. 08 0. 0031 發明例 11 0. 12 0. 28 1. 18 0. 015 0. 002 0. 030 0. 12 0. 07 0. 0045 發明例 12 0. 12 0. 23 1. 22 0. Oil 0. 004 0. 025 0. 06 0. 04 0. 0033 發明例 13 0. 11 0. 34 1. 38 0. 014 0. 003 0. 021 0. 13 0. 12 0.0040 發明例 14 0. 13 0.25 1.25 0. 015 0. 005 0. 021 _ _ 0.0031 比較例 15 0. 13 0.20 1. 31 0. 008 0. 005 0. 035 0. 07 — 0. 0030 比較例 16 0. 12 0.25 1.26 0. 015 0. 007 0. 033 — 0. 06 0. 0028 比較例 17 0. 13 0. 15 1. 01 0. 015 0. 005 0. 022 0·『0 0. 33 0. 0028 比較例Steel No. Chemical composition (mass%) (1) Remarks C Si Μ Ρ A S A1 W Cr N 1 0. 13 0.25 1. 25 0. 009 0. 002 0. 030 0. 05 0. 01 0. 0034 Invention Example 2 0. 10 0. 32 1. 32 0. 013 0. 003 0. 029 0. 20 0. 08 0. 0028 Invention Example 3 0. 11 0.40 1. 20 0. 010 0. 005 0. 030 0. 08 0. 12 0. 0035 Invention Example 4 0. 09 0.24 1. 28 0. 009 0. 002 0. 018 0. 18 0. 18 0.0028 Invention Example 5 0. 12 0. 11 0. 93 0. 014 0. 009 0. 025 0. 10 0. 05 0. 0025 Invention Example 6 0. 14 0. 30 0. 65 0. 014 0. 010 0. 045 0. 15 0. 05 0. 0030 Invention Example 7 0. 12 0.32 1. 33 0. 010 0.005 0.018 0.03 0. 03 0. 0015 Inventive Example 8 0. 08 0.20 1. 15 0. 005 0. 001 0. 040 0.05 0. 05 0. 0043 Inventive Example 9 0. 06 0. 15 1. 57 0. 015 0. 003 0. 025 0.15 0. 12 0.0022 Invention Example 10 0. 10 0. 27 1. 26 0. 012 0. 005 0. 030 0. 07 0. 08 0. 0031 Invention Example 11 0. 12 0. 28 1. 18 0. 015 0. 002 0. 030 0. 12 0. 07 0. 0045 Inventive Example 12 0. 12 0. 23 1. 22 0. Oil 0. 004 0. 025 0. 06 0. 04 0. 0033 Inventive Example 13 0. 11 0. 34 1. 38 0. 014 0. 003 0. 021 0. 13 0. 12 0.0040 Inventive Example 14 0. 13 0.25 1.25 0. 015 0. 005 0. 021 _ _ 0.0031 Comparative Example 15 0. 13 0.20 1. 31 0. 008 0. 005 0. 035 0. 07 — 0. 0030 Comparative Example 16 0. 12 0.25 1.26 0. 015 0. 007 0. 033 — 0. 06 0. 0028 Comparative Example 17 0. 13 0. 15 1. 01 0. 015 0. 005 0. 022 0·『0 0. 33 0. 0028 Compare example

97128385 28 200912014 [表 2-2] 鋼 No. 化學成分（mass%)(其二）備註 Sb Sn Cu、Ni、Mo、Co V、Nb、Ti、Zr B Ca、REM、Y 1 — — 一 — — — 發明例 2 0. 10 — — — — — 發明例 3 0.09 0.04 — — — — 發明例 4 — — Cu : 0. 25、 Ni : 0. 15 — — — 發明例 5 — — — Nb : 0. 012 — — 發明例 6 — — — — 0. 0010 一發明例 7 — — — — — Ca ： 0.0018 發明例 8 0. 08 — Mo : 0. 08 V : 0. 030、 Ti ： 0.Oil — — 發明例 9 0. 05 0. 03 Cu : 0· 22、 Ni : 0. 13、 Co : 0. 11 Zr ： 0. 011 — REM ： 0. 050 發明例 10 0. 05 — — Nb : 0. 018、 Ti ： 0.008 — Y ·· 0· 010 發明例 11 0. 05 0. 08 — V ： 0. 030 — Ca : 0.0020 發明例 12 0.09 0. 03 — Nb : 0· 010、 Ti ： 0. 010 — — 發明例 13 0. 11 0. 03 — Ti ： 0. 012 — — 發明例 14 — — — 一 — — 比較例 15 — — — 一 — — 比較例 16 — — — — 一 — 比較例 17 — — — — — — 比較例97128385 28 200912014 [Table 2-2] Steel No. Chemical composition (mass%) (Part 2) Remarks Sb Sn Cu, Ni, Mo, Co V, Nb, Ti, Zr B Ca, REM, Y 1 — — — – Inventive Example 2 0. 10 — — — — — Inventive Example 3 0.09 0.04 — — — — Inventive Example 4 — — Cu : 0. 25, Ni : 0. 15 — — — Inventive Example 5 — — — Nb : 0 012 - Inventive Example 6 — — — — 0. 0010 Inventive Example 7 — — — — — Ca : 0.0018 Inventive Example 8 0. 08 — Mo : 0. 08 V : 0. 030, Ti : 0.Oil — - Invention Example 9 0. 05 0. 03 Cu : 0· 22, Ni : 0. 13, Co : 0. 11 Zr : 0. 011 — REM : 0. 050 Invention Example 10 0. 05 — — Nb : 0. 018, Ti : 0.008 — Y ·· 0· 010 Inventive Example 11 0. 05 0. 08 — V : 0. 030 — Ca : 0.0020 Inventive Example 12 0.09 0. 03 — Nb : 0· 010, Ti : 0. 010 - Inventive Example 13 0. 11 0. 03 - Ti : 0. 012 - - Inventive Example 14 - - - One - Comparative Example 15 - - - One - Comparative Example 16 - - - - One - Comparative Example 17 - — — — — - Comparative example

29 97128385 200912014 [表 3-1 ]29 97128385 200912014 [Table 3-1]

軋延編號鋼 No. An溫度 (°C) 種類截面尺寸中鋼胚加熱溫度 (°C) 備註腹板長x翼板長 (mxm) 腹板厚 (mm) 翼板厚（m) A 1 788 NAB 400x100 12. 5 18. 0 1200 發明例 B 2 791 NAB 400x100 12.5 18.0 1180 發明例 C 3 799 NAB 400x100 12.5 18.0 1250 發明例 D 4 783 NAB 400x100 12.5 18. 0 1200 發明例 E 5 798 NAB 350x100 12.5 17. 0 1200 發明例 F 6 830 NAB 300x90 13. 0 16. 0 1250 發明例 G 7 786 NAB 300x90 13. 0 16. 0 1230 發明例 Η 8 808 NAB 250x90 13. 0 16. 0 1280 發明例 I 9 772 NAB 400x100 12. 5 18. 0 1250 發明例 J 10 777 NAB 400x100 12. 5 18. 0 1200 發明例 K 11 795 NAB 400x100 12. 5 18. 0 1200 發明例 L 14 788 NAB 400x100 12. 5 18. 0 1200 比較例 Μ 15 782 NAB 400x100 12. 5 18. 0 1230 比較例 N 16 789 NAB 400x100 12. 5 18. 0 1250 比較例 0 17 798 NAB 400x100 12. 5 18. 0 1220 比較例 P 3 799 NAB 300x90 13.0 16. 0 1200 發明例 Q 3 799 NAB 400x100 12. 5 18. 0 1200 比較例 R 3 799 NAB 400x100 12.5 18.0 1300 比較例 S 3 799 NAB 250x90 13.0 16.0 1200 發明例 T 3 799 NAB 200x90 8. 0 14. 0 1100 發明例 U 1 788 T型 300x125 11.0 19. 0 1280 發明例 V 3 799 T型 300x125 11.0 19. 0 1320 發明例 W 4 808 T型 300x125 12.0 22. 0 1300 發明例 X 9 772 T型 300x125 12.0 25. 0 1320 . 發明例 Y 12 775 T型 400x100 12.5 18. 0 1250 發明例 Z 13 770 T型 400x100 12. 5 18. 0 1250 發明例 a 12 788 T型 400x100 12.5 18. 0 1250 發明例 97128385 30 200912014 [表 3-2]Rolling numbered steel No. An temperature (°C) Steel preform heating temperature (°C) of type cross section size Remarks web length x wing length (mxm) web thickness (mm) wing thickness (m) A 1 788 NAB 400x100 12. 5 18. 0 1200 Inventive Example B 2 791 NAB 400x100 12.5 18.0 1180 Inventive Example C 3 799 NAB 400x100 12.5 18.0 1250 Inventive Example D 4 783 NAB 400x100 12.5 18. 0 1200 Inventive Example E 5 798 NAB 350x100 12.5 17 0 1200 Inventive Example F 6 830 NAB 300x90 13. 0 16. 0 1250 Inventive Example G 7 786 NAB 300x90 13. 0 16. 0 1230 Invention Example 8 808 NAB 250x90 13. 0 16. 0 1280 Invention Example I 9 772 NAB 400x100 12. 5 18. 0 1250 Inventive Example J 10 777 NAB 400x100 12. 5 18. 0 1200 Inventive Example K 11 795 NAB 400x100 12. 5 18. 0 1200 Inventive Example L 14 788 NAB 400x100 12. 5 18. 0 1200 Comparative Example 15 782 NAB 400x100 12. 5 18. 0 1230 Comparative Example N 16 789 NAB 400x100 12. 5 18. 0 1250 Comparative Example 0 17 798 NAB 400x100 12. 5 18. 0 1220 Comparative Example P 3 799 NAB 300x90 13.0 16. 0 1200 Inventive Example Q 3 799 NAB 400x100 12. 5 18. 0 1200 Comparative Example R 3 799 NAB 400x100 12.5 18.0 1300 Comparative Example S 3 799 NAB 250x90 13.0 16.0 1200 Inventive Example T 3 799 NAB 200x90 8. 0 14. 0 1100 Inventive Example U 1 788 T Type 300x125 11.0 19. 0 1280 Invention Example V 3 799 T Type 300x125 11.0 19. 0 1320 Inventive Example W 4 808 T-type 300x125 12.0 22. 0 1300 Inventive Example X 9 772 T-type 300x125 12.0 25. 0 1320 . Invention Example Y 12 775 T-type 400x100 12.5 18. 0 1250 Invention Example Z 13 770 T-type 400x100 12. 5 18. 0 1250 Inventive Example a 12 788 T Type 400x100 12.5 18. 0 1250 Invention Example 97128385 30 200912014 [Table 3-2]

累積軋縮率過大’導致軋延荷重超過基準，而中止軋延接著，針對各個熱軋型鋼，就不等邊不等厚角鋼將從短邊，而就τ型鋼則從翼板採取5mmtxl〇〇mmWx2〇〇^L或5丽碰舰w xl5〇mmL的試驗片，對試驗片表面施行珠粒喷擊後，施行以下條件A〜C的表面處理，便形成耐餘性試驗片。 <表面處理條件> 97128385 31 200912014 •條件A :在_表面上，形成鋅底漆(膜厚約15_)斑遞青環氧樹脂塗料(膜厚約2QMm)的雙層_ - •條件B ·在試驗片表面上’形成⑽環氧樹脂塗料（膜厚約200/im)的單層被膜 •條件C:試驗片表面維持著珠粒喷擊狀態的防蝕被膜）片，從塗膜上 80mm刮傷傷If the cumulative rolling reduction is too large, the rolling load exceeds the reference, and the rolling is stopped. Then, for each hot-rolled steel, the unequal thickness of the steel will be from the short side, and the τ steel will take 5 mmtxl from the wing. A test piece of mmWx2〇〇^L or 5 Libeng ship w xl5〇mmL was subjected to bead blasting on the surface of the test piece, and subjected to surface treatment of the following conditions A to C to form a residual test piece. <Surface treatment conditions> 97128385 31 200912014 • Condition A: On the _ surface, a double layer of zinc primer (film thickness about 15 Å) plaque-green epoxy coating (film thickness about 2QMm) is formed _ - • Condition B · On the surface of the test piece, 'form a single layer film of (10) epoxy resin coating (film thickness about 200 / im) • Condition C: the surface of the test piece is maintained with the anti-corrosion film of the bead spray state), 80 mm from the coating film Scratch

另外’對已形成塗膜的上述條件A與B之試驗方利用美1刀—字狀_㈣原料生鐵表面之長痕0 依如上述所製得試驗片，之後將安裝於實船的驗水插上甲板背側’並施行2年期間的曝曬試驗。該曝曬試驗的賴環境係平均在歸水櫃㈣人海水的觸約2G日、未裝入海水的 d間約20日’依此為1循環，並重複施行該循環。曝曬試驗的耐錄評估係依如下述實施。相關設有塗膜的條件A與B之試驗片’觀在嗎傷痕所發生的塗膜膨潤面積。此外’相關未設置塗膜的條件c之試驗片，經試驗後，施行除錄，從經除的試驗片質量、與試驗前的試驗片質量差 (減少I) ’計算出平均板厚減少量。根肋等結果，以未特別含有耐錄提升元素的Να 12鋼為基準⑽），計算出相對於該基準的各試驗片比，並施行耐蝕性評估。表4所不係上述拉伸試驗、衝擊試驗、微觀組織調査及耐蝕性式驗的結果。由雜性試驗的結果巾得知，滿足本發明成分 97128385 32 200912014 組成的發明例No. 1〜13鋼’不管條件A〜C，相對底鋼板（N〇. l4) 的塗膜膨潤面積及板厚減少量均在50%以下，具有良好的耐餘 • 性。相對於此，未滿足本發明成分組成的No. 14〜17鋼，即使 . 耐蝕性較底鋼板（No. 14)提升，但相對底鋼板的比率有出現超過50%的實驗條件，且熔接部的韌性大幅降低。此外，微觀組織係就含有加I肥粒鐵的崎鐵+絲鐵喊（除軋延編號q 以外）可獲传本發明所所期待的充分強度，且彎曲、翹曲等形狀變化亦較輕微，生產性亦極良好。 j延編號㈣型鋼（Αη溫度以下的熱軋中，型鋼截面内的溫 t '……的清’兄）’雖特性值有達目標，但彎曲、龜曲卻產勺、女。In addition, the test side of the above conditions A and B for which the coating film has been formed utilizes the long trace of the surface of the raw iron on the surface of the original 1 knife-shaped _ (4). The test piece prepared as described above is then installed in the water test of the actual ship. Insert the back side of the deck' and perform an exposure test for 2 years. In the exposure test, the average environment was about 2 days between the water supply cabinet (4) and the seawater without the seawater, and the cycle was repeated for about 20 days. The evaluation of the tolerance of the exposure test was carried out as follows. The test piece of the conditions A and B which are provided with the coating film is used to observe the swelling area of the coating film which occurs in the flaw. In addition, the test piece of the condition c without the coating film is applied, and after the test, the recording is performed, and the average plate thickness reduction is calculated from the quality of the removed test piece and the difference in the quality of the test piece before the test (reduction I). . As a result of the root ribs, the ratio of each test piece to the standard was calculated based on the Να 12 steel which did not particularly contain the resistance-enhancing element (10)), and the corrosion resistance was evaluated. Table 4 does not show the results of the above tensile test, impact test, microstructure investigation and corrosion test. From the results of the hybrid test, it was found that the invention No. 1 to 13 of the composition of the composition of the present invention 97128385 32 200912014 'different conditions A to C, the coating film swelling area and the plate relative to the bottom steel plate (N〇. l4) The thickness reduction is less than 50%, and has good durability. On the other hand, No. 14 to 17 steel which does not satisfy the composition of the present invention, even if the corrosion resistance is higher than that of the bottom steel plate (No. 14), the ratio of the bottom steel plate is more than 50%, and the welded portion is present. The toughness is greatly reduced. In addition, the microstructure of the microstructure contains the iron-iron + wire iron with the addition of I-fertilizer iron (except for the rolling number q) to obtain the sufficient strength expected by the present invention, and the shape changes such as bending and warping are also slight. The productivity is also very good. j extension number (four) section steel (in the hot rolling below the Αη temperature, the temperature in the section of the section steel t '...clear brothers'' has a characteristic value, but the bending and tortoises produce spoons and women.

97128385 33 200912014 [表4]97128385 33 200912014 [Table 4]

軋延編號鋼 No. 微觀組織 (肥粒鐵+ i未粒鐵）中，有無含加工肥粒鐵加工肥粒鐵分率 (%) 拉伸特性夏丕氏衝擊特性vE (-20 °C)(J) 2年期間的曝曬試驗結果* 備註 YS (MPa) TS (MPa) El (%) 母材熔接部試驗片的處理條件 A B C A 1 有 15 349 464 33 272 126 46 47 43 發明例 B 2 有 60 420 540 28 205 183 36 43 42 發明例 C 3 有 20 353 469 32 303 110 40 38 38 發明例 D 4 有 30 375 496 35 331 220 39 36 36 發明例 E 5 有 50 330 430 37 285 135 30 33 34 發明例 F 6 有 65 349 445 35 183 140 42 43 41 發明例 G 7 有 70 441 554 31 150 136 45 49 48 發明例 Η 8 有 70 376 478 34 165 243 40 43 40 發明例 I 9 有 20 375 488 35 363 200 34 41 38 發明例 J 10 有 25 369 480 35 306 154 40 42 39 發明例 K 11 有 20 374 487 35 310 126 33 41 40 發明例 L 14 有 15 356 463 36 342 143 100 100 100 比較例 Μ 15 有 50 430 546 30 290 140 58 90 95 比較例 N 16 有 35 376 490 32 286 131 60 53 45 比較例 0 Π 有 35 416 543 31 258 Μ 39 30 28 比較例 P 3 有 45 431 545 29 327 無法測定發明例 Q 3 0 307 432 40 352 無法測定比較例 R 3 無法測定無法測定比較例 S 3 有 70 440 553 31 245 無法測定發明例 T 3 有 20 362 478 34 245 無法測定發明例 U 1 有 20 356 460 34 251 138 45 42 45 發明例 V 3 有 50 371 511 31 228 130 38 35 40 發明例 w 4 有 50 381 508 30 255 168 40 35 35 發明例 X 9 有 70 388 520 28 322 208 34 38 38 發明例 Y 12 有 35 351 536 30 244 188 40 45 39 發明例 z 13 有 40 363 528 31 342 209 40 38 40 發明例 a 12 有 20 348 470 33 270 126 46 47 43 發明例氺：試驗片條件A、B :塗膜膨潤面積（相對底鋼板（No. 14、L 鋼）的比）；試驗片條件C :板厚減少量（相對底鋼板（No. 14、L鋼）的比） (產業上之可利用性) 根據本發明，將可廉價提供高強度，且即使在因海水所造成 34 97128385 200912014 嚴苛腐餘環境下’仍具有優異性的船舶用熱軋型鋼外，本發明的型鋼因為耐錄優異，因而對截至船舶修，為止的期間延長、及減輕修補塗裝的作業負荷_大貢獻。巢另外，本發明的船舶用熱軋型鋼特別係在因海水所告崎下將_異耐祕，因而經由船舶修補期間::腐 7助於船舶本體的壽命延長。此外，亦屬於能類似 Ο 腐鱗境下㈣他錢__伽。在類似Rolling number steel No. Microstructure (fertilizer iron + i ungranulated iron), with or without processing fertilizer, iron processing fertilizer, iron content (%), tensile properties, Charpy impact characteristics vE (-20 °C) (J) Exposure test results during 2 years* Remarks YS (MPa) TS (MPa) El (%) Processing conditions for test pieces of base metal welded joints ABCA 1 15 349 464 33 272 126 46 47 43 Inventive example B 2 60 420 540 28 205 183 36 43 42 inventive example C 3 20 353 469 32 303 110 40 38 38 invention example D 4 having 30 375 496 35 331 220 39 36 36 invention example E 5 having 50 330 430 37 285 135 30 33 34 Inventive Example F 6 There are 65 349 445 35 183 140 42 43 41 Inventive Example G 7 70 441 554 31 150 136 45 49 48 Inventive Example 8 There are 70 376 478 34 165 243 40 43 40 Inventive Example I 9 There are 20 375 488 35 363 200 34 41 38 Invention Example J 10 There are 25 369 480 35 306 154 40 42 39 Invention Example K 11 There are 20 374 487 35 310 126 33 41 40 Invention Example L 14 There are 15 356 463 36 342 143 100 100 100 Comparison Example 15 There are 50 430 546 30 290 140 58 90 95 Comparative Example N 16 There are 35 376 490 32 286 131 60 53 45 Compare Example 0 Π There are 35 416 543 31 258 Μ 39 30 28 Comparative Example P 3 There are 45 431 545 29 327 Unable to measure the invention Example Q 3 0 307 432 40 352 Unable to measure Comparative Example R 3 Unable to measure Unable to measure Comparative Example S 3 Yes 70 440 553 31 245 Unable to measure invention Example T 3 20 362 478 34 245 Unable to measure invention Example U 1 20 356 460 34 251 138 45 42 45 Invention Example V 3 50 371 511 31 228 130 38 35 40 Invention Example w 4 There are 50 381 508 30 255 168 40 35 35 invention example X 9 has 70 388 520 28 322 208 34 38 38 invention example Y 12 has 35 351 536 30 244 188 40 45 39 invention example z 13 has 40 363 528 31 342 209 40 38 40 Inventive Example a 12 There are 20 348 470 33 270 126 46 47 43 Inventive Example: Test piece conditions A, B: film swelling area (ratio of bottom steel plate (No. 14, L steel)); test piece conditions C: thickness reduction (ratio of bottom steel plate (No. 14, L steel)) (industrial availability) According to the present invention, high strength can be provided at low cost, and even if it is caused by sea water, 34 97128385 200912014 a ship that still has superiority in a harsh environment In addition to the hot-rolled steel, the steel of the present invention contributes greatly to the durability of the ship as long as it is repaired, and the work load of the repair coating is reduced. In addition, the hot-rolled steel for ship of the present invention is particularly resistant to seawater, and therefore, during the repair period by the ship: the rot 7 contributes to the life of the ship body. In addition, it belongs to the same Ο 腐鳞 ( (4) his money __ 伽. Similar in

L 97128385 35L 97128385 35

Claims

200912014 VII. Application scope of claim: 1. A hot-rolled steel for ship, which has the following composition components: & C. 〇.〇3~〇25mass%, Si: 0.05~0.50mass%, Μη: 〇 1 〜2, 〇mass%, Ρ: 〇. 〇25mass% or less, S: 0. Olmass% or less, Α1: 〇· 005~G. lGmass%, w: 0. G Bu 1. Gmass%, Cr: G. Glmass% or more and less than 0. 20mass%, N: 〇. 〇〇1~〇. 〇〇8mass%, the remainder is composed of Fe and unavoidable impurities, and has iron oxide containing processed fertilizer The microstructure of the ferrite iron and the bead iron structure. 2. For hot-rolled steels for ships of the first application of the patent scope, in addition to the above-mentioned composition, 'except from Sb: 0. 001 to 〇.3mass% and Sn: 〇. 〇〇. 0. 3mass% Choose one or two of them. 3. For hot-rolled steels for ships of the first scope of the patent application, in addition to the above-mentioned composition, 'still contains from Cu: 0. 005~0. 5mass%, Ni: 〇. 005~0· 25mass%, M〇: 〇.01~5mass% and Co: 0.01~1.Qmass% One or two or more selected. 4. In the case of the hot-rolled steel for ships of the second paragraph of the patent application, in addition to the above-mentioned composition, it also contains from Cu: 0. 005~0. 5mass%, Ni: 〇. 005~0. 25mass%, Mo: 〇.01~0.5mass% and Co: 0.01~1.Omass% One or two or more selected. 5. For the hot-rolled steel for ships of the first application of the patent scope, in addition to the above composition, it also contains from Nb: 0. 001~0. lmass%, Ti: 97128385 36 200912014 〇· 001 〇〇 1_S%, Zr: 〇· 001~0 Imass% and v: 〇. 〇〇2 〇· 2 or more of 2 legs. 6', for example, the hot-rolled steel for ships of the second application of the patent scope, wherein, in addition to the above-mentioned composition of the knife, 'from Nb: 0. 001~0. lmass%, Ti: 〇_ 001 ~ (Umass% , Zr: 〇〇1~〇. and v: 〇〇2~〇. One or more of the two halls s%. 7. For the hot-rolled steel for ships of the third application of the patent scope, In addition to the above composition, 'still contains from Nb: 0. 001~0. lmass%, Ti: 〇· 〇〇1 〇 l lmass%, Zr: 〇· 〇〇 0 0. lmass% and V: 0. 002~0. 2mass0/〇1 or more than one selected. 8. For hot-rolled steel for ships of the fourth application scope of the patent application, in addition to the above composition, 'still contains Nb: 0. 001 〜1. lmass%, Ti: 0. 001-0. lmass% ' Zr : 0. 〇〇l~〇. lmass%AV : 0. 002-0. 2mass% one or more of 2 or more. The hot-rolled steel for ship according to any one of claims 1 to 8, wherein 'except for the above composition, B: 0. 0002~0. 003mass%. 10. Ship hot-rolled steel of any of 1 to 8 'In addition to the above composition, it also contains one or two selected from Ca: 0.0002~0. 〇lmass%, RM: 〇0〇02邛.〇i5mass% and Y: 0. 0001~0. lmass% 11. For the hot-rolled steel for ships of the ninth application, in addition to the above composition, it also contains from Ca: 0. 0002~0· Olmass%, REM: 97128385 37 200912014 0. 0002 ~0. 015mass% and Υ : 〇· oooi~〇. The choice of imass% is more than 2 kinds of genus. If you apply for a full-time 丨丨 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 The surface is provided with an epoxy resin coating. Axis 9 Nacaqing Table (4) Γ 14. For the hot-rolled steel of the scope of application (4), it is applied to the oxyresin coating film. 15·If the patent application _ u hot rolling Steel, which is coated with oxyresin. 16. For hot-rolled steel of any of items 1 to 8 of the patent period, 1 is a zinc primer coating on the surface. /, you 17. The hot-rolled steel of the application of the patent model _9 is based on the surface of the primer coating film. ^ 18. For example, the hot-rolled steel of the patent scope 帛1〇 is provided with a bottom on the surface. Coating. 19. The hot-rolled section steel of claim 11 is provided with a zinc primer coating film on the surface. 20. The hot-rolled steel according to any one of claims 1 to 8, which is provided with a zinc tree-touching coating film on the surface. 21. 21. A method for manufacturing hot-rolled steel for ships, which is a method for manufacturing hot-rolled niobium steel of the ammonium alloy according to items 1 to 11 of the patent application, and kneading the steel material to 1000 to 1350 ° C, 97128385 38 200912014 Then, hot rolling is performed by setting the cumulative rolling reduction ratio below An temperature to 10 to 80%, and setting the finishing rolling temperature to (Ar3-30 °C) to (Ar3-180 °C), and then cooling it. . The method of producing a hot-rolled steel for ship according to claim 21, wherein the hot rolling at the An temperature or lower is performed within a temperature difference of 50 °C in the section of the steel. 97128385 39 200912014 IV. Designation of Representative Representatives: (1) The representative representative of the case is: No (2) Simple description of the symbol of the representative figure: No. 5. If there is a chemical formula in this case, please disclose the chemical formula that best shows the characteristics of the invention: No 97128385