KR20160053776A - Steel wire rod having high strength and impact toughness, and method for manufacturing thereof - Google Patents
Steel wire rod having high strength and impact toughness, and method for manufacturing thereof Download PDFInfo
- Publication number
- KR20160053776A KR20160053776A KR1020150144758A KR20150144758A KR20160053776A KR 20160053776 A KR20160053776 A KR 20160053776A KR 1020150144758 A KR1020150144758 A KR 1020150144758A KR 20150144758 A KR20150144758 A KR 20150144758A KR 20160053776 A KR20160053776 A KR 20160053776A
- Authority
- KR
- South Korea
- Prior art keywords
- impact toughness
- manganese
- less
- strength
- present
- Prior art date
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 36
- 239000010959 steel Substances 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000004519 manufacturing process Methods 0.000 title abstract description 17
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 34
- 239000010936 titanium Substances 0.000 claims abstract description 25
- 239000000463 material Substances 0.000 claims abstract description 23
- 239000010703 silicon Substances 0.000 claims abstract description 22
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 22
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910052796 boron Inorganic materials 0.000 claims abstract description 18
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 18
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims abstract description 17
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 17
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 11
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000012535 impurity Substances 0.000 claims abstract description 8
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 5
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 5
- 239000011593 sulfur Substances 0.000 claims abstract description 5
- 239000011572 manganese Substances 0.000 claims description 68
- 238000001816 cooling Methods 0.000 claims description 39
- 229910000859 α-Fe Inorganic materials 0.000 claims description 34
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 31
- 229910052748 manganese Inorganic materials 0.000 claims description 31
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 21
- 238000005098 hot rolling Methods 0.000 claims description 18
- 229910000734 martensite Inorganic materials 0.000 claims description 18
- 239000011651 chromium Substances 0.000 claims description 10
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 6
- 229910052804 chromium Inorganic materials 0.000 claims description 6
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims description 5
- 239000011574 phosphorus Substances 0.000 claims description 5
- 238000003303 reheating Methods 0.000 claims description 5
- 229910002804 graphite Inorganic materials 0.000 claims description 2
- 239000010439 graphite Substances 0.000 claims description 2
- 239000000758 substrate Substances 0.000 claims 1
- 229910052799 carbon Inorganic materials 0.000 abstract description 17
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 abstract description 3
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 abstract 1
- 230000008569 process Effects 0.000 description 11
- 229910001563 bainite Inorganic materials 0.000 description 10
- 239000000203 mixture Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 8
- 230000015572 biosynthetic process Effects 0.000 description 7
- 230000007423 decrease Effects 0.000 description 5
- 230000003247 decreasing effect Effects 0.000 description 5
- 229910001566 austenite Inorganic materials 0.000 description 3
- 150000004767 nitrides Chemical class 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 238000005728 strengthening Methods 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910001567 cementite Inorganic materials 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 238000004453 electron probe microanalysis Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 238000005496 tempering Methods 0.000 description 2
- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 238000010622 cold drawing Methods 0.000 description 1
- 238000010273 cold forging Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- 230000003116 impacting effect Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052961 molybdenite Inorganic materials 0.000 description 1
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910001562 pearlite Inorganic materials 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/525—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
-
- 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
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
-
- 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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- 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
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- 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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
-
- 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
- B21B2001/225—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length by hot-rolling
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/002—Bainite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/008—Martensite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Heat Treatment Of Steel (AREA)
- Ropes Or Cables (AREA)
Abstract
Description
본 발명은 다양한 외부 부하 환경에 노출되는 산업기계, 자동차 등의 부품에 사용될 수 있는 강도와 충격 인성이 우수한 선재와 이를 제조하는 방법에 관한 것이다.
The present invention relates to a wire rod excellent in strength and impact toughness which can be used for parts such as industrial machines and automobiles exposed to various external load environments, and a method for manufacturing the wire rod.
최근, 환경오염의 주범으로 지목되고 있는 이산화탄소의 배출을 줄이기 위한 노력이 전세계적인 이슈가 되고 있다. 그 일환으로 자동차의 배기가스를 규제하는 움직임이 활발하며, 이에 대한 대책으로 자동차 메이커들은 연비 향상을 통해 이 문제를 해결해 나가려고 하고 있다. 그런데 연비 향상을 위해서는 자동차의 경량화 및 고성능화가 요구되므로, 이에 따른 자동차용 소재 또는 부품의 고강도 필요성이 증대되고 있다. 또한 외부 충격에 대한 안정성의 요구도 높아지고 있으므로, 충격인성도 소재 또는 부품의 중요한 물성으로 인식되고 있다.
Recently, efforts to reduce the emission of carbon dioxide, which is considered to be the main cause of environmental pollution, have become a global issue. As a part of this, there is a trend to regulate automobile exhaust gas. As a countermeasure, automakers are trying to solve this problem by improving fuel efficiency. However, in order to improve fuel efficiency, the weight and high performance of automobiles are required, and hence the necessity of high strength of automobile materials or parts is increasing. In addition, since the demand for stability against external impact is also increasing, impact toughness is also recognized as an important property of a material or part.
페라이트 또는 펄라이트 조직의 선재는 우수한 강도 및 충격 인성을 확보하는데 한계가 있다. 이들 조직을 갖는 소재는 통상 충격 인성은 높은 반면, 강도는 상대적으로 낮은 특징이 있으며, 강도를 높이기 위해서 냉간 신선을 행하게 되면 고강도를 얻을 수 있으나, 충격 인성은 강도 상승에 비례해 급격하게 저하되는 단점이 있다.
Ferrite or pearlite wire rods have limitations in securing excellent strength and impact toughness. The materials having these structures usually have high impact toughness, but are relatively low in strength. In order to increase the strength, high strength can be obtained by cold drawing, but impact toughness is rapidly decreased in proportion to the increase in strength. .
따라서, 일반적으로 우수한 강도와 충격 인성을 동시에 구현하기 위해서는 베이나이트 조직이나 템퍼드 마르텐사이트 조직을 이용하게 된다. 베이나이트 조직은 열간 압연한 강재를 사용하여 항온변태 열처리를 통해 얻을 수 있고, 템퍼트 마르텐사이트 조직은 담금질 및 뜨임 열처리를 통해 얻을 수 있다. 그러나, 통상의 열간 압연 및 연속 냉각 공정만으로 이러한 조직들은 안정적으로 얻을 수 없기 때문에 열간 압연된 강재를 사용하여 상기와 같은 추가적인 열처리 공정을 거쳐야만 한다.
Therefore, in order to realize excellent strength and impact toughness at the same time, a bainite structure or a tempered martensite structure is used. The bainite structure can be obtained by heat-induced transformation heat treatment using hot-rolled steel, and the tempered martensite structure can be obtained by quenching and tempering heat treatment. However, since such structures can not be stably obtained only by ordinary hot rolling and continuous cooling processes, additional heat treatment processes as described above must be performed using hot-rolled steel.
추가적인 열처리를 하지 않고도 고강도 및 우수한 충격 인성을 확보할 수 있다면, 소재로부터 부품 생산에 이르기까지 공정의 일부가 생략되거나 단순해질 수 있어 생산성을 향상시키고, 제조원가를 낮출 수 있는 장점이 있다.If high strength and excellent impact toughness can be ensured without additional heat treatment, a part of the process from the material to the part production can be omitted or simplified, thereby improving the productivity and lowering the manufacturing cost.
그러나, 추가적인 열처리 공정 없이 열간압연 및 연속 냉각 공정을 이용하여 베이나이트 또는 마르텐사이트 조직을 안정적으로 얻을 수 있는 선재는 아직 개발되지 못하고 있어, 이러한 선재 개발에 대한 요구가 대두되고 있다.
However, wire rods which can stably obtain bainite or martensite structure by using hot rolling and continuous cooling processes without additional heat treatment process have not yet been developed, and there is a demand for development of such wire rods.
본 발명은 추가 열처리 공정 없이 열간압연 및 연속 냉각 공정만으로 고강도와 우수한 충격 인성을 가질 수 있는 선재 및 이를 제조하는 방법을 제공하고자 하는 것이다. The present invention provides a wire rod which can have high strength and excellent impact toughness only by a hot rolling and a continuous cooling process without an additional heat treatment process, and a method of manufacturing the wire rod.
본 발명이 해결하고자 하는 과제는 이상에서 언급한 과제로 제한되지 않으며, 언급되지 않은 또 다른 과제들은 아래의 기재로부터 당업자에게 명확하게 이해될 수 있을 것이다.
The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.
본 발명의 일태양은 중량%로, 탄소(C): 0.05~0.15%, 실리콘(Si): 0.2% 이하, 망간(Mn): 3.0~4.0%, 인(P): 0.020% 이하, 황(S):0.020% 이하, 보론(B): 0.0010~0.0030%, 타이타늄(Ti): 0.010~0.030%, 질소(N): 0.0050% 이하, 알루미늄(Al): 0.010~0.050%, 나머지는 Fe 및 불가피한 불순물을 포함하고,One aspect of the present invention is a method of manufacturing a semiconductor device, comprising: 0.05 to 0.15% of carbon (C), 0.2% or less of silicon (Si), 3.0 to 4.0% of manganese (Mn) S: 0.020% or less, B: 0.0010-0.0030%, Ti: 0.010-0.030%, N: 0.0050% or less, Al: 0.010-0.050% Including unavoidable impurities,
미세조직은 면적분율로, 90% 이상의 베이니틱 페라이트와 나머지는 도상 마르텐사이트(M/A)를 포함하는 강도와 충격 인성이 우수한 선재를 제공한다.
The microstructure is an area fraction and provides a wire having excellent strength and impact toughness including 90% or more of bainitic ferrite and the remainder being molybdenite (M / A).
본 발명의 또다른 일태양은 중량%로, 탄소(C): 0.05~0.15%, 실리콘(Si): 0.2% 이하, 망간(Mn): 3.0~4.0%, 인(P): 0.020% 이하, 황(S):0.020% 이하, 보론(B): 0.0010~0.0030%, 타이타늄(Ti): 0.010~0.030%, 질소(N): 0.0050% 이하, 알루미늄(Al): 0.010~0.050%, 나머지는 Fe 및 불가피한 불순물을 포함하는 강재를 재가열하는 단계;Another aspect of the present invention is a method for producing a semiconductor device, which comprises 0.05 to 0.15% of carbon (C), 0.2% or less of silicon (Si), 3.0 to 4.0% of manganese (Mn) (B): 0.0010 to 0.0030%, Ti: 0.010 to 0.030%, nitrogen (N): 0.0050% or less, aluminum (Al): 0.010 to 0.050% Reheating a steel material containing Fe and unavoidable impurities;
상기 재가열된 강재를 열간 압연하는 단계;Hot rolling the reheated steel material;
상기 열간 압연 후, Bf~Bf-50℃의 온도범위까지 0.1~2℃/s의 속도로 냉각하는 단계; 및After the hot rolling, cooling to a temperature range of Bf to Bf-50 占 폚 at a rate of 0.1 to 2 占 폚 / s; And
상기 냉각된 강재를 공냉하는 단계를 포함하는 강도 및 충격 인성이 우수한 선재의 제조방법을 제공한다.
And air cooling the cooled steel material. The present invention also provides a method of manufacturing a wire rod excellent in strength and impact toughness.
상술한 구성에 따른 본 발명은, 열간 압연 및 연속 냉각 공정만을 이용하여 산업기계 및 자동차용 소재 또는 부품에서 요구되는 강도 및 충격 인성이 우수한 선재를 제공할 수 있다. The present invention according to the above-described structure can provide a wire rod excellent in strength and impact toughness required in industrial machinery and automobile materials or parts using only the hot rolling and the continuous cooling process.
또한, 종래의 추가적인 열처리 공정을 생략할 수 있어서, 전체 제조비용을 절감하는데 매우 유리하다.
In addition, since the conventional additional heat treatment process can be omitted, it is very advantageous to reduce the total manufacturing cost.
이하, 본 발명에 대해 상세히 설명한다. Hereinafter, the present invention will be described in detail.
먼저, 본 발명의 선재에 대해 상세히 설명한다. 본 발명의 선재는 중량%로, 탄소(C): 0.05~0.15%, 실리콘(Si): 0.2% 이하, 망간(Mn): 3.0~4.0%, 인(P): 0.020% 이하, 황(S): 0.020% 이하, 보론(B): 0.0010~0.0030%, 타이타늄(Ti): 0.010~0.030%, 질소(N): 0.0050% 이하, 알루미늄(Al): 0.010~0.050%, 나머지는 Fe 및 불가피한 불순물을 포함한다.
First, the wire material of the present invention will be described in detail. The wire material of the present invention preferably contains 0.05 to 0.15% of carbon (C), 0.2% or less of silicon (Si), 3.0 to 4.0% of manganese (Mn), 0.020% or less of phosphorus (P) (Ti): 0.010 to 0.030%, nitrogen (N): 0.0050% or less, aluminum (Al): 0.010 to 0.050%, the balance being Fe and unavoidable Impurities.
이하, 본 발명의 선재의 강 성분과 조성범위의 한정이유를 상세히 설명한다(이하, 중량%임).Hereinafter, the reasons for limiting the steel composition and the composition range of the wire of the present invention will be described in detail (hereafter referred to as weight%).
탄소(C): 0.05~0.15%Carbon (C): 0.05 to 0.15%
탄소는 강도를 확보하기 위한 필수적인 원소로서, 강중에 고용되거나 탄화물 또는 세멘타이트 형태로 존재한다. 강도의 증가를 위해 가장 손쉽게 할 수 있는 방법이 탄소 함량을 증가시켜 탄화물이나 세멘타이트를 형성시키는 일이지만, 반대로 연성과 충격 인성은 감소하기 때문에 일정한 범위내로 탄소의 첨가량을 조절할 필요가 있다. 본 발명에서는 C 함량을 0.05~0.15% 범위로 첨가함이 바람직한데, 이는 탄소 함량이 0.05% 미만이면 목표 강도를 얻기 힘들고, 0.15%를 초과하면 충격 인성이 급격히 감소할 수 있기 때문이다.
Carbon is an indispensable element for securing strength, which is either solid in steel or in the form of carbide or cementite. The easiest way to increase the strength is to increase the carbon content to form carbide or cementite. However, since the ductility and impact toughness decrease, it is necessary to control the addition amount of carbon within a certain range. In the present invention, it is preferable to add the C content in the range of 0.05 to 0.15% because if the carbon content is less than 0.05%, it is difficult to obtain the target strength, and if the carbon content is more than 0.15%, the impact toughness can be drastically reduced.
실리콘(Si): 0.2% 이하Silicon (Si): not more than 0.2%
실리콘은 알루미늄과 함께 탈산 원소로 알려져 있고, 강도를 향상시키는 원소이다. 실리콘은 첨가시 페라이트에 고용되어 강재의 고용 강화를 통한 강도 증가에 매우 효과가 큰 원소로 알려져 있다. 그러나, 실리콘 첨가에 의해 강도는 크게 증가하지만 연성과 충격 인성은 급격히 감소하기 때문에 충분한 연성을 필요로 하는 냉간 단조 부품의 경우 실리콘 첨가를 매우 제한하고 있다. 본 발명에서는 강도 하락을 최소화하면서, 우수한 충격 인성을 확보하기 위해서, 상기 실리콘의 함량을 0.2%이하로 포함한다. 실리콘 함량이 0.2%를 초과하면 목표 충격인성의 확보가 어려울 수 있기 때문이다. 보다 바람직하게는 0.1%이하로 포함한다.
Silicon, together with aluminum, is known as a deoxidizing element and is an element that improves strength. It is known that silicon is added to ferrite when added and is very effective in increasing the strength through solid solution strengthening of steel. However, the addition of silicon greatly increases the strength, but the ductility and impact toughness decrease sharply, so that the addition of silicon is very limited for cold forging parts that require sufficient ductility. In the present invention, the content of silicon is 0.2% or less in order to secure a good impact toughness while minimizing the strength drop. If the silicon content exceeds 0.2%, it may be difficult to secure the target impact toughness. And more preferably 0.1% or less.
망간(Mn): 3.0~4.0%Manganese (Mn): 3.0 to 4.0%
망간은 강재의 강도를 증가시키고, 경화능을 향상시켜 넓은 범위의 냉각속도에서 베이나이트 또는 마르텐사이트와 같은 저온조직의 형성을 용이하게 한다. 그러나 망간 함량이 3.0% 미만이면 경화능이 충분하지 못해 열간압연 후 연속냉각 공정으로 저온조직을 안정적으로 확보하기 곤란해 진다. 또한 4.0%를 초과하면 경화능이 너무 높아 공냉시에도 마르텐사이트 조직을 얻을 수 있기 때문에 적합하지 못하다. 이를 고려하여, 본 발명에서는 망간의 함량을 3.0~4.0%로 포함하는 것이 바람직하다.
Manganese increases the strength of the steel and improves the hardenability, facilitating the formation of low temperature structures such as bainite or martensite at a wide range of cooling rates. However, if the manganese content is less than 3.0%, the hardenability is not sufficient, and it becomes difficult to stably obtain the low-temperature structure by the continuous cooling process after the hot rolling. On the other hand, if it exceeds 4.0%, the curing ability is too high, which makes it impossible to obtain martensite structure even during air cooling. In consideration of this, it is preferable that the content of manganese in the present invention is 3.0 to 4.0%.
인(P): 0.020% 이하Phosphorus (P): not more than 0.020%
상기 인은 결정립계에 편석되어 인성을 저하시키고, 지연파괴 저항성을 감소시키는 주요 원인이므로, 가능한 포함되지 않는 것이 바람직하며, 이러한 이유로 본 발명에서는 그 상한을 0.020%로 한정한다.
Since phosphorus is segregated at grain boundaries to decrease toughness and reduce delayed fracture resistance, it is preferably not included as much as possible. For this reason, the upper limit of the present invention is limited to 0.020%.
황(S): 0.020% 이하Sulfur (S): not more than 0.020%
상기 황은 결정립계에 편석되어 인성을 저하시키고 저융점 유화물을 형성시켜 열간 압연을 저해하므로, 가능한 포함되지 않는 것이 바람직하다. 이러한 이유로 본 발명에서는 그 상한을 0.020%로 한정한다.
The sulfur is segregated in the grain boundaries to lower the toughness and form a low melting point emulsion to inhibit hot rolling, so that it is preferably not contained. For this reason, the upper limit of the present invention is limited to 0.020%.
보론(B): 0.0010~0.0030%Boron (B): 0.0010 to 0.0030%
상기 보론은 경화능을 향상시키는 원소로서, 오스테나이트 결정립계로 확산되어 냉각시 페라이트의 생성을 억제하고, 베이나이트 또는 마르텐사이트 형성을 용이하게 하는 원소이다. 그러나, 그 첨가량이 0.0010% 미만이면 첨가에 따른 효과를 기대할 수 없으며, 0.0030%를 초과하면 더 이상 효과 상승을 기대할 수 없음과 아울러 입계에 보론계 질화물의 석출로 인해 입계강도가 저하되어 열간 가공성을 저하시킬 수 있다. 따라서, 이러한 점을 고려하여, 본 발명에서는 보론의 첨가범위를 0.0010~0.0030%로 한다.
The boron is an element which improves the hardenability, diffuses into the austenite grain boundary system, inhibits the formation of ferrite upon cooling, and facilitates the formation of bainite or martensite. However, if the addition amount is less than 0.0010%, the effect of the addition can not be expected. If the addition amount exceeds 0.0030%, no further increase in the effect can be expected, and the grain boundary strength is lowered due to precipitation of boron nitride in the grain boundary, . Therefore, in consideration of this point, in the present invention, the addition range of boron is set to 0.0010 to 0.0030%.
타이타늄(Ti): 0.010~0.030%Titanium (Ti): 0.010 to 0.030%
상기 타이타늄은 질소와의 반응성이 가장 커서 제일 먼저 질화물을 형성한다. 타이타늄 첨가로 TiN을 형성하여 강중의 질소를 대부분 소진하게 되면 BN의 석출을 막아 붕소가 용해(soluble)된 상태로 존재할 수 있도록 도와 경화능 향상의 효과를 얻을 수 있다. 그러나, 그 첨가량이 0.010% 미만이면 첨가에 따른 효과가 미흡하고, 0.030%를 초과하면 조대한 질화물을 형성해 기계적 물성을 열위하게 할 수 있다. 이러한 점을 고려하여, 본 발명에서는 상기 타이타늄의 함량을 0.010~0.030%로 한다.
The titanium has the greatest reactivity with nitrogen and forms the first nitride. When TiN is formed by adding titanium, most of the nitrogen in the steel is exhausted, boron can be prevented from being precipitated, and boron can be present in a state of being soluble, so that the effect of improving hardenability can be obtained. However, if the addition amount is less than 0.010%, the effect of the addition is insufficient, and when the addition amount exceeds 0.030%, a coarse nitride is formed and the mechanical properties can be lowered. Considering this point, in the present invention, the content of the titanium is 0.010 to 0.030%.
질소(N): 0.0050% 이하Nitrogen (N): Not more than 0.0050%
상기 질소는 보론과 용해(soluble)된 상태로 유지되어, 경화능 향상 효과를 충분히 발휘하기 위해서, 가능한 포함되지 않아야 한다. 따라서, 본 발명에서는 그 함량이 0.0050% 이하로 것이 바람직하다.
The nitrogen is kept in a state of being soluble in boron and should not be contained as much as possible in order to sufficiently exhibit the effect of improving the hardenability. Therefore, in the present invention, the content thereof is preferably 0.0050% or less.
알루미늄(Al): 0.010~0.050%Aluminum (Al): 0.010 to 0.050%
알루미늄은 강력한 탈산 원소로서 강중의 산소를 제거해 청정도를 높일 뿐만 아니라, 강중에 고용된 질소와 결합하여 AlN을 형성함으로써, 충격 인성을 향상시킬 수 있다. 본 발명에서는 알루미늄을 적극적으로 첨가하지만 함유량이 0.010% 미만이면, 그 첨가 효과를 기대하기 어렵고, 0.050%를 초과하면 알루미나 개재물이 다량 생성되어 기계적 물성을 크게 저하시킬 수 있다. 이러한 점을 고려하여 본 발명에서는 알루미늄의 함량을 0.010~0.050%의 범위로 하는 것이 바람직하다.
Aluminum is a strong deoxidizing element which not only improves cleanliness by removing oxygen in steel, but also bonds with nitrogen dissolved in steel to form AlN, which can improve impact toughness. In the present invention, aluminum is positively added, but if the content is less than 0.010%, the effect of the addition is unlikely to be expected. If the content exceeds 0.050%, a large amount of alumina inclusions is produced, which may greatly deteriorate mechanical properties. Taking this into consideration, in the present invention, it is preferable that the aluminum content is in the range of 0.010 to 0.050%.
상기 조성 이외에, 추가적으로 크롬(Cr)을 0.3% 미만으로 포함할 수 있다. 상기 크롬은 망간과 유사하게 강재의 강도와 경화능을 증가시킨다. 크롬 함유량이 0.3% 이상이면 경화능 향상 및 고용강화 효과로 강도는 증가할 수 있지만, 오히려 충격 인성은 저하될 수 있다. 이를 고려하여, 본 발명에서는 크롬의 함량을 0.3% 미만으로 그 범위를 포함하는 것이 바람직하다.
In addition to the above composition, it may further contain less than 0.3% of chromium (Cr). The chromium increases the strength and hardenability of the steel similarly to manganese. If the chromium content is 0.3% or more, the strength can be increased due to the hardenability improvement and the solid solution strengthening effect, but the impact toughness may be lowered. In consideration of this, in the present invention, it is preferable that the content of chromium is less than 0.3%.
상기 조성 이외에 나머지는 Fe와 불가피한 불순물을 포함한다. 본 발명에서는 상기 언급된 합금 조성이외에 다른 합금의 추가를 배제하지 않는다.
In addition to the above composition, the balance includes Fe and unavoidable impurities. The present invention does not exclude the addition of alloys other than the alloy composition mentioned above.
한편, 본 발명에서는 상기 망간(Mn), 타이타늄(Ti), 보론(B) 및 질소(N)의 함량이 하기 관계식 1을 만족하도록 함유됨이 바람직하다. In the present invention, it is preferable that the content of manganese (Mn), titanium (Ti), boron (B) and nitrogen (N)
[관계식 1][Relation 1]
Mn+5(Ti-3.5N)/B ≥ 5.0Mn + 5 (Ti-3.5N) / B? 5.0
단, 상기 관계식 1에서 망간(Mn), 타이타늄(Ti), 보론(B) 및 질소(N)는 각각 해당원소의 중량기준 함량을 의미한다.
In the above relational expression 1, manganese (Mn), titanium (Ti), boron (B) and nitrogen (N) refer to the content by weight of the corresponding element, respectively.
본 발명에서 망간은 경화능을 높여서 냉각속도가 상대적으로 작은 경우에도 베이니틱 페라이트가 용이하게 생성되도록 돕는다. 그리고, 타이타늄은 질소와 결합하여 질화물을 형성하고, 보론이 강중에 충분히 고용되게 함으로써 페라이트 생성을 억제하고 베이니틱 페라이트가 용이하게 생성되게 한다. In the present invention, manganese improves the hardenability and thus facilitates the production of bainitic ferrite even when the cooling rate is relatively small. Then, the titanium is combined with nitrogen to form a nitride, and the boron is sufficiently solved in the steel, thereby suppressing the ferrite formation and allowing the bainitic ferrite to be easily produced.
본 발명의 발명자들은 위와 같은 점에 착안하여 연구와 실험을 거듭한 결과, 상기 망간, 타이타늄, 보론 및 질소의 관계가 중량% 기준으로 Mn+5(Ti-3.5N)/B ≥ 5.0 를 만족했을 때, 보다 우수한 강도와 충격 인성을 가지는 베이티닉 페라이트 조직의 선재를 제공할 수 있음을 인지하고, 상기 관계식 1을 도출하게 된 것이다.
The inventors of the present invention have conducted research and experiments on the above points and have found that the relationship between manganese, titanium, boron, and nitrogen satisfies Mn + 5 (Ti-3.5N) / B? It is possible to provide a wire rod of a bainitic ferrite structure having more excellent strength and impact toughness at the time of welding.
또한, 본 발명에서 상기 망간(Mn) 및 실리콘(Si)의 함량은 하기 관계식 2를 만족하도록 함유되는 것이 바람직하다.In the present invention, the content of manganese (Mn) and silicon (Si) is preferably contained so as to satisfy the following relational expression (2).
[관계식 2][Relation 2]
Mn/Si ≥ 18Mn / Si? 18
단, 상기 관계식 2에서 망간(Mn) 및 실리콘(Si)은 각각 해당원소의 중량기준 함량을 의미한다.In the formula 2, manganese (Mn) and silicon (Si) mean the content by weight of the corresponding element, respectively.
본 발명에서 망간은 경화능을 높여서 냉각속도가 상대적으로 작은 경우에도 베이나이트가 쉽게 생성되도록 돕는다. 그리고 실리콘은 강중에 고용되어 강도는 증가시키지만 충격인성은 떨어뜨리는 단점이 있다. In the present invention, manganese improves the hardenability and helps to easily produce bainite even when the cooling rate is relatively small. Silicon is employed in steel to increase strength, but it has a disadvantage in that impact toughness is lowered.
본 발명자들은 상기 점에 착안하여 연구와 실험을 거듭한 결과, 상기 망간과 실리콘의 관계가 중량% 기준으로 Mn/Si ≥ 18를 만족했을 때, 보다 우수한 강도와 충격인성을 가지는 베이니틱 페라이트 조직의 선재를 제공할 수 있음을 확인하고 본 조성성분 관계식을 제시하는 것이다.
As a result of extensive research and experimentation, the present inventors have found that when the relationship between manganese and silicon satisfies Mn / Si ≥ 18 on a weight% basis, the bainitic ferrite structure having a better strength and impact toughness It is confirmed that the wire can be provided and the relationship of the constituent components is presented.
한편, 본 발명의 선재는 임의의 단면 영역에서 망간의 최대 농도[Mnmax]와 최소 농도[Mnmin]의 비가 하기 관계식 3을 만족하는 것이 바람직하다.On the other hand, in the wire rod of the present invention, the ratio of the maximum concentration [Mn max ] and the minimum concentration [Mn min ] of manganese in an arbitrary cross-sectional area preferably satisfies the following relational expression
[관계식 3][Relation 3]
[Mnmax]/[Mnmin] ≤ 3[Mn max ] / [Mn min ] 3
본 발명에서 망간은 경화능을 높여서 냉각속도가 상대적으로 작은 경우에도 베이니틱 페라이트가 쉽게 생성되도록 돕지만, 국부적으로 망간이 편석되어 있으면 마르텐사이트가 쉽게 생성될 수 있고, 망간이 고갈된 영역에서는 페라이트가 형성될 수 있어 미세조직이 불균일해지고, 충격 인성이 열위해질 수 있다.In the present invention, manganese improves hardenability and helps to easily produce bainitic ferrite even when the cooling rate is relatively small. However, when manganese is locally segregated, martensite can be easily produced. In the region where manganese is depleted, ferrite The microstructure may become uneven and the impact toughness may become dull.
본 발명자들은 상기 점에 착안하여 연구와 실험을 거듭한 결과, 상기 선재의 임의의 단면 영역에서 망간의 최대 농도와 최소 농도의 비가 3 이하일 때 우수한 강도와 충격 인성을 가지는 베이니틱 페라이트 조직의 선재를 제공할 수 있음을 확인하고 본 관계식을 제시하는 것이다.
As a result of extensive research and experimentation, the present inventors have found that when a ratio of the maximum concentration and the minimum concentration of manganese in an arbitrary cross-sectional area of the wire is 3 or less, the wire rod of bainitic ferrite structure having excellent strength and impact toughness And to present this relationship.
이하, 본 발명의 미세조직에 대해 상세히 설명한다. Hereinafter, the microstructure of the present invention will be described in detail.
본 발명의 선재의 미세조직은 90 면적% 이상의 베이니틱 페라이트와 잔부 도상 마르텐사이트(Martensite Austenite constituent, M/A)를 포함하는 것이 바람직하다. 한편, 베이나이트는 탄소함량이나 형태(morphology)에 따라 다양한 용어로 불릴 수 있다. 통상적으로 중탄소(약 0.2~0.45wt%) 이상에서는 상부/하부 베이나이트(upper/lower bainite)로 불린다. 그러나, 0.2% 이하의 저탄소 범위에서는 온도 영역에 따라 베이니틱(bainitic) 페라이트, 침상(acicular) 페라이트, 그래뉼라(granular) 페라이트 등으로 불린다. 본 발명에서는 저탄소 영역이어서, 베이니틱 페라이트 조직을 포함한다.
The microstructure of the wire of the present invention preferably contains 90% by area or more of bainitic ferrite and martensite austenite constituent (M / A). On the other hand, bainite can be called various terms depending on the carbon content and morphology. Normally, it is called upper / lower bainite above medium carbon (about 0.2 ~ 0.45 wt%). However, in the low-carbon range of 0.2% or less, it is called bainitic ferrite, acicular ferrite, granular ferrite and the like depending on the temperature range. In the present invention, it is a low carbon region and includes a bainitic ferrite structure.
본 발명의 선재의 미세조직은 베이니틱 페라이트가 90 면적% 이상을 포함하고 있으므로, 우수한 강도와 충격 인성을 확보할 수 있다. 베이니틱 페라이트가 아닌 통상의 페라이트가 상분율이 많아지게 되면 충격 인성 측면에서는 유리할 수 있으나, 강도의 저하를 막을 수 없으므로, 바람직하지 않다.
Since the microstructure of the wire of the present invention contains 90% or more by area of bainitic ferrite, excellent strength and impact toughness can be secured. If the phase fraction of normal ferrite other than bainitic ferrite is increased, it may be advantageous in terms of impact toughness, but it is not preferable because the decrease in strength can not be prevented.
한편, 상기 도상 마르텐사이트는 주상인 베이니틱 페라이트 결정립계를 따라 형성되며, 그 분율이 높을 경우에는 강재의 강도가 높아질 수 있으나, 충격 인성이 나빠질 수 있기 때문에, 가능한 그 분율을 낮게 관리하는 것이 바람직하다. 이를 고려하여, 본 발명에서는 상기 도상 마르텐사이트의 분율이 면적%로, 10% 이하(다시 말해, 주상인 베이니틱 페라이트 조직을 90% 이상)으로 관리하는 것이 바람직하다. 이러한 본 발명 선재의 미세조직을 얻기 위해서는 본 발명에서는 강재를 열간압연한 후, 냉각시 냉각종료 온도와 냉각속도를 조절함으로써, 효과적으로 달성할 수 있다. On the other hand, the on-road martensite is formed along the bainitic ferrite grain boundaries of the main phase. When the fraction is high, the strength of the steel material can be increased, but impact toughness may be deteriorated. Therefore, . In view of this, in the present invention, it is preferable to control the fraction of the present invention martensite to 10% or less (that is, 90% or more of the main phase bainitic ferrite structure) in terms of area%. In order to obtain the microstructure of the wire rod of the present invention, the present invention can be effectively achieved by adjusting the cooling end temperature and the cooling rate in hot rolling the steel material.
한편, 상기 도상 마르텐사이트(M/A)의 결정립도는 5㎛ 이하인 것이 바람직하다. 상기 도상 마르텐사이트(M/A)의 결정립도가 5㎛를 초과할 경우에는 베이니틱 페라이트 기지와 접하는 계면의 면적이 커지기 때문에 충격 인성이 열위해질 수 있다.
On the other hand, the grain size of the amorphous martensite (M / A) is preferably 5 탆 or less. If the crystalline martensite (M / A) has a grain size of more than 5 mu m, impact toughness may be impaired because the area of the interface contacting the bainitic ferrite base becomes large.
다음으로, 본 발명의 선재를 제조하는 방법에 대해 상세히 설명한다.Next, a method for manufacturing the wire rod of the present invention will be described in detail.
본 발명의 선재의 제조방법은, 상술한 조성을 갖는 강을 마련한 후, 이를 재가열하는 공정; 상기 재가열된 강재를 열간 압연하는 단계; 상기 열간 압연한 후, Bf~Bf-50℃의 온도범위까지 0.1~2℃/s의 속도로 냉각하는 공정; 및 상기 냉각된 강재를 공냉하는 공정;을 포함한다.
A method of manufacturing a wire rod according to the present invention comprises the steps of: preparing a steel having the above composition and reheating the steel; Hot rolling the reheated steel material; After the hot-rolling, a step of cooling to a temperature range of Bf to Bf-50 占 폚 at a rate of 0.1 to 2 占 폚 / s; And air cooling the cooled steel material.
먼저, 본 발명에서는 상술한 조성성분을 갖는 강재를 마련한 후, 이를 재가열 한다. 본 발명에서 채용할 수 있는 재가열 온도 범위는 1000~1100℃ 범위를 이용하면 좋다. First, in the present invention, a steel material having the above-mentioned composition components is prepared and reheated. The reheating temperature range that can be employed in the present invention may be in the range of 1000 to 1100 占 폚.
상기 강재의 형태는 특별히 한정되지 않으나, 통상적으로는 블룸(bloom)이나 빌렛(billet) 형태인 것이 바람직하다.
The shape of the steel material is not particularly limited, but is preferably in the form of a bloom or a billet.
이어, 상기 재가열된 강재를 열간 압연하여 선재를 제조한다. 상기 열간 압연의 마무리 열간 압연 온도는 특별히 한정되지 않으나, 850~950℃ 범위로 관리하는 것이 바람직하다.
Next, the reheated steel is hot-rolled to produce a wire rod. The finish hot rolling temperature of the hot rolling is not particularly limited, but is preferably controlled in the range of 850 to 950 占 폚.
상기 열간 압연된 강재는 냉각처리되는데, 상기 냉각은 Bf~Bf-50℃의 온도범위까지 0.1~2℃/s의 냉각속도로 냉각하는 것이 바람직하다. 냉각 종료 온도가 Bf를 초과하면 충분한 양의 베이니틱 페라이트 조직을 확보하기 어렵고, Bf-50℃ 미만이면 강재가 충분히 식어 취급은 용이하나, 생산성을 떨어뜨리기 때문에 냉각종료온도는 Bf~Bf-50℃의 온도범위로 하는 것이 바람직하다. 상기 Bf는 오스테나이트에서 베이나이트 또는 베이니틱 페라이트로의 상변태가 종료되는 온도를 의미한다.
The hot-rolled steel is subjected to cooling treatment, and the cooling is preferably carried out at a cooling rate of 0.1 to 2 占 폚 / s to a temperature range of Bf to Bf-50 占 폚. If the cooling end temperature exceeds Bf, it is difficult to secure a sufficient amount of bainitic ferrite structure. If Bf-50 deg. C or less, the steel material is sufficiently cooled to facilitate handling, but the productivity is lowered. Is preferably set to a temperature range of < RTI ID = 0.0 > Bf means the temperature at which the phase transformation from austenite to bainite or bainitic ferrite is terminated.
본 발명에서는 열간 압연 후 연속 냉각을 수행하여 베이니틱 페라이트 조직을 확보함으로써 우수한 강도와 충격 인성을 확보한다. 이에, 기존에 행했던 담금질 및 템퍼링과 같은 열처리를 생략할 수 있어, 추가 공정을 요하지 않아 제조원가 측면에서 매우 유리한 장점이 있다.
In the present invention, continuous cooling is performed after hot rolling to secure a bainitic ferrite structure to secure excellent strength and impact toughness. Accordingly, it is possible to omit the heat treatment such as quenching and tempering which has been performed in the prior art, and there is an advantage that it is very advantageous from the viewpoint of the manufacturing cost because no additional process is required.
또한, 본 발명에서는 냉각 개시 온도에서부터 냉각 종료 온도까지의 구간을 0.1~2℃/s의 냉각속도로 냉각함이 바람직하다. 상기 냉각속도가 0.1℃/s 미만이면 초석 페라이트의 형성이 많아지고, 2℃/s 초과하게 되면, 마르텐사이트의 형성이 많아져 강도와 충격 인성을 열위하게 만들기 때문에, 본 발명에 냉각속도는 0.1~2℃/s로 관리하는 것이 바람직하다.In the present invention, it is preferable to cool the zone from the cooling start temperature to the cooling end temperature at a cooling rate of 0.1 to 2 占 폚 / s. If the cooling rate is less than 0.1 ° C / s, the formation of pro-eutectoid ferrite becomes excessive. If the cooling rate exceeds 2 ° C / s, the formation of martensite is increased to weaken the strength and impact toughness. To 2 [deg.] C / s.
상술한 바와 같이 냉각구간에서 냉각 속도 확보를 통하여, 면적분율 90% 이상의 베이니틱 페라이트를 갖는 강도와 충격 인성이 우수한 선재를 얻을 수 있다.
As described above, a wire material having bainitic ferrite having an area fraction of 90% or more and excellent in impact strength and impact toughness can be obtained through securing the cooling rate in the cooling section.
이하, 본 발명의 실시예에 대해 상세히 설명한다. 하기 실시예는 본 발명의 이해를 위한 것일 뿐, 실시예에 의해 본 발명을 한정하는 것은 아니다.Hereinafter, embodiments of the present invention will be described in detail. The following examples are for the purpose of understanding the present invention and are not intended to limit the scope of the present invention.
(실시예)(Example)
하기 표 1의 조성 성분을 갖는 용강을 주조한 후, 이를 1100℃로 재가열한 후 직경 15mm로 선재 압연한 후, 표 2의 냉각속도로 Bf 온도 이하인 300℃까지 냉각한 이후 공냉하여 선재를 제조하였다. 한편, 베이나이트 상변태 종료 온도인 Bf는 Dilatometer를 이용하여 측정하였고, 화학조성이 따라 다소 차이가 나며, 300~350℃의 범위를 보였다.
After casting molten steel having the composition shown in the following Table 1, it was reheated at 1100 占 폚 and then subjected to wire rolling at a diameter of 15 mm, followed by cooling to 300 占 폚 below the Bf temperature at the cooling rate shown in Table 2, . On the other hand, Bf, which is the end temperature of the bainite phase transformation, was measured using a dilatometer. The temperature varied from 300 to 350 ° C depending on the chemical composition.
이렇게 제조된 선재를 미세조직을 분석하여 표 2에 나타내었으며, 인장강도와 충격 인성을 측정하여 표 2에 나타내었다. 상기 선재의 미세조직 중 도상 마르텐사이트(M/A)의 면적 분율과 결정립도는 화상 분석기(Image Analyzer)를 이용하여 측정하였고, 망간의 농도는 EPMA(Electron Probe Micro-Analysis)를 이용하여 측정하였다.
Table 2 shows the tensile strength and impact toughness of the wire rod thus manufactured, and Table 2 shows the tensile strength and impact toughness. The area fraction and grain size of graphite martensite (M / A) in the microstructure of the wire were measured using an image analyzer and the concentration of manganese was measured using EPMA (Electron Probe Micro-Analysis).
그리고, 상온 인장시험은 crosshead speed를 항복점까지는 0.9mm/min, 그 이후로는 6mm/min의 속도로 실시하여 측정하였다. 또한 충격 시험은 시편에 충격을 가하는 striker의 edge부 곡률이 2mm이고, 시험 용량이 500J인 충격시험기를 이용하여 상온에서 실시하여 측정하였다.
The room temperature tensile test was carried out at a crosshead speed of 0.9 mm / min until the yield point and then at a rate of 6 mm / min. The impact test was carried out at room temperature using an impact tester with an edge curvature of 2 mm and a test capacity of 500 J of the striker impacting the specimen.
(상기 표 1에서 관계식 1은 Mn+5(Ti-3.5N)/B, 관계식 2는 Mn/Si이며, 나머지는 Fe와 불가피한 불순물임)
(Relation 1 in Table 1 is Mn + 5 (Ti-3.5N) / B, Relation 2 is Mn / Si, and the remainder is Fe and unavoidable impurities)
(℃/s)Cooling rate
(° C / s)
(%)M / A fraction
(%)
(MPa)The tensile strength
(MPa)
(J)Impact toughness
(J)
(상기 표 2에서 관계식 3은 [Mnmax]/[Mnmin]임)(In the above Table 2, the relation 3 is [Mn max ] / [Mn min ]
상기 표 1 및 2에 나타난 바와 같이, 본 발명의 강조성 및 제조방법을 만족하는 발명예 1 내지 11은 모두 90 면적% 이상의 베이니틱 페라이트가 얻어짐을 알 수 있으며, 기계적 물성 또한 600~700MPa의 인장강도와 150~200J의 우수한 충격 인성을 나타냄을 알 수 있다. As shown in Tables 1 and 2, Examples 1 to 11 satisfying the stress and the manufacturing method of the present invention all show that bainitic ferrite of 90% or more of area is obtained, and the mechanical properties are also tensile of 600 to 700 MPa Strength and excellent impact toughness of 150 to 200J.
발명예 8은 실리콘의 함량이 0.1 중량% 이하로서, 충격 인성이 더욱 향상되는 것을 확인할 수 있다. 상기 발명예들 중에서 망간과 타이타늄과 보론과 질소의 관계식 1(Mn+5(Ti-3.5N)/B ≥ 5.0) 및 망간과 실리콘의 관계식 2(Mn/Si ≥ 18)을 모두 만족하는 발명예 2, 3, 5, 7, 6, 9 및 11은 그렇지 않은 경우와 비교할 때, 충격인성이 더욱 우수해지는 것을 알 수 있다. In the case of Inventive Example 8, it is confirmed that the content of silicon is 0.1 wt% or less, and impact toughness is further improved. Among the inventions described above, the inventors of the present invention have found that when manganese, titanium, boron and nitrogen satisfy the relationship 1 (Mn + 5 (Ti-3.5N) / B? 5.0) 2, 3, 5, 7, 6, 9, and 11 show that the impact toughness is further improved as compared with the case where it is not.
즉, 상기 발명예들 중에서 관계식 1(Mn+5(Ti-3.5N)/B ≥ 5.0) 및/또는 관계식 2(Mn/Si ≥ 18)를 만족하지 않는 발명예 1, 4, 6 및 10은 충격인성이 다소 열위해지는 것을 알 수 있다.
That is, the inventive examples 1, 4, 6 and 10 which do not satisfy the relationship 1 (Mn + 5 (Ti-3.5N) / B? 5.0) and / or the relation 2 It can be seen that impact toughness is somewhat dull.
이에 반하여, 비교예 12는 탄소 함량이 높아져 인장 강도는 우수하나, 충격 인성은 열위해지는 것을 확인할 수 있는데, 이는 탄소가 M/A상에 고용되어 안정한 M/A상을 증가되었기 때문이다. 비교예 13은 실리콘 함량이 본 발명의 범위를 벗어난 경우로서, 실리콘 또한 탄소와 유사하게 그 첨가량이 많아짐에 따라 기지에 고용량이 증가하고 결국 고용강화의 효과를 나타내게 된다. 즉, 실리콘 첨가량이 0.25% 수준에서도 인장 강도는 매우 커지지만 그와 함께 충격 인성은 급격히 감소하게 된다. 비교예 14는 망간 및 보론의 첨가량이 적어 강재의 경화능을 떨어뜨리기 때문에 냉각조건을 만족하더라도 페라이트와 베이니틱 페라이트 조직이 혼립되어 인장 강도가 감소한 것을 확인할 수 있다.
On the other hand, in Comparative Example 12, it was confirmed that the carbon content was high and the tensile strength was excellent, but the impact toughness was inferior because carbon was incorporated in the M / A phase to increase the stable M / A phase. Comparative Example 13 is a case where the silicon content is out of the range of the present invention. As the addition amount of silicon and carbon is increased, the amount of silicon in the base increases and ultimately the effect of strengthening employment is exhibited. That is, even when the amount of silicon added is 0.25%, the tensile strength becomes very large, but the impact toughness decreases sharply. In Comparative Example 14, the addition amount of manganese and boron was so small that the hardenability of the steel was lowered, so that even when the cooling conditions were satisfied, the ferrite and bainitic ferrite structure were mixed and the tensile strength was reduced.
한편, 비교예 15는 강조성 성분은 본 발명의 범위를 만족하나 제조공정에서 냉각속도가 빨라짐에 따라 마르텐사이트가 형성되어 강도는 증가하지만, 충격인성은 나빠짐을 보여주고 있다. 비교예 16은 그 강조성 성분은 본 발명의 범위를 만족하나, 제조공정에서 냉각속도가 느린 경우로서, 페라이트가 형성되어 강도는 감소한 것을 보여주고 있다.
On the other hand, in Comparative Example 15, the stress-sensitive component satisfies the range of the present invention, but as the cooling rate is increased in the manufacturing process, martensite is formed and the strength is increased, but the impact toughness is poor. The comparative example 16 shows that the reinforcing component satisfies the range of the present invention, but the ferrite is formed and the strength is decreased when the cooling rate is slow in the manufacturing process.
또한, 비교예 17은 타이타늄의 첨가량이 적은 경우로서, solute 보론량이 감소하기 때문에 경화능이 감소하고, 냉각속도도 작을 경우 초석 페라이트 석출량이 많아져 인장강도는 감소한 것을 보여주고 있다. In Comparative Example 17, the amount of titanium added was small, and the solute boron amount was decreased, so that the hardenability decreased. When the cooling rate was small, the amount of pro-eutectoid ferrite precipitated increased and the tensile strength decreased.
아울러, 비교예 18은 망간이 많이 첨가될 경우, 상대적으로 경화능이 너무 커지기 때문에 발명에서 제시한 냉각속도로 냉각하더라도 마르텐사이트가 생성되어 강도가 증가한 반면, 충격인성이 떨어지는 것을 나타내고 있다. 그리고, 강중에 망간이 편석되어 있기 때문에 국부적으로 불균일한 조직의 형성으로 인해서도 충격인성이 열위해지고 있음을 보여준다.
In Comparative Example 18, when manganese was added in a large amount, martensite was generated even when cooled at the cooling rate proposed in the present invention because the curing ability was too large, and the strength was increased, while the impact toughness was lowered. Also, since the manganese is segregated in the steel, it is shown that the impact toughness is becoming weak due to the formation of local uneven texture.
Claims (12)
미세조직은 면적분율로, 90% 이상의 베이니틱 페라이트와 나머지는 도상 마르텐사이트(M/A)를 포함하는 강도와 충격 인성이 우수한 선재.
(Si): not more than 0.2%, manganese (Mn): not more than 3.0 to 4.0%, phosphorus (P): not more than 0.020%, sulfur (S): not more than 0.020% 0.0010 to 0.0030% of boron (B), 0.010 to 0.030% of titanium (Ti), 0.0050% or less of nitrogen (N), 0.010 to 0.050% of aluminum (Al), and Fe and unavoidable impurities,
The microstructure is an area fraction, and has excellent strength and impact toughness including 90% or more of bainitic ferrite and the remainder martensite (M / A).
상기 선재는 크롬(Cr): 0.3% 미만을 추가적으로 포함하는 강도와 충격 인성이 우수한 선재.
The method according to claim 1,
Wherein the wire rod further includes a chromium (Cr) content of less than 0.3% and is excellent in impact toughness.
상기 망간(Mn), 타이타늄(Ti), 보론(B) 및 질소(N)의 함량은 하기 관계식 1을 만족하는 강도와 충격 인성이 우수한 선재.
[관계식 1]
Mn+5(Ti-3.5N)/B ≥ 5.0
The method according to claim 1,
The content of manganese (Mn), titanium (Ti), boron (B) and nitrogen (N) satisfies the following relational expression 1 and excellent impact toughness.
[Relation 1]
Mn + 5 (Ti-3.5N) / B? 5.0
상기 망간(Mn) 및 실리콘(Si)의 함량은 하기 관계식 2를 만족하는 강도와 충격 인성이 우수한 선재.
[관계식 2]
Mn/Si ≥ 18
The method according to claim 1,
The content of manganese (Mn) and silicon (Si) satisfies the following relational expression (2) and is excellent in impact toughness.
[Relation 2]
Mn / Si? 18
상기 선재는 임의의 단면에서 망간의 최대 농도[Mnmax]와 최소 농도[Mnmin]의 비가 하기 관계식 3을 만족하는 강도와 충격 인성이 우수한 선재.
[관계식 3]
[Mnmax]/[Mnmin] ≤ 3
The method according to claim 1,
Wherein the wire rod has excellent strength and impact toughness satisfying the following relational expression 3 in the ratio of the maximum concentration [Mn max ] and the minimum concentration [Mn min ] of manganese in an arbitrary section.
[Relation 3]
[Mn max ] / [Mn min ] 3
상기 도상 마르텐사이트(M/A)의 결정립도는 5㎛ 이하인 강도와 충격 인성이 우수한 선재.
The method according to claim 1,
The graphite martensite (M / A) has a grain size of 5 탆 or less and excellent impact toughness.
상기 재가열된 강재를 열간 압연하는 단계;
상기 열간 압연 후, Bf~Bf-50℃의 온도범위까지 0.1~2℃/s의 속도로 냉각하는 단계; 및
상기 냉각된 강재를 공냉하는 단계
를 포함하는 강도와 충격 인성이 우수한 선재의 제조방법.
(Si): not more than 0.2%, manganese (Mn): not more than 3.0 to 4.0%, phosphorus (P): not more than 0.020%, sulfur (S): not more than 0.020% (B): 0.0010 to 0.0030%, titanium (Ti): 0.010 to 0.030%, nitrogen (N): 0.0050% or less, aluminum (Al): 0.010 to 0.050%, and the balance being Fe and unavoidable impurities Reheating the substrate;
Hot rolling the reheated steel material;
After the hot rolling, cooling to a temperature range of Bf to Bf-50 占 폚 at a rate of 0.1 to 2 占 폚 / s; And
Air cooling the cooled steel
And a method of producing the wire.
상기 강재는 크롬(Cr): 0.3% 미만을 추가적으로 포함하는 강도와 충격 인성이 우수한 선재의 제조방법.
The method of claim 7,
Wherein the steel material further comprises less than 0.3% of chromium (Cr), and is excellent in impact toughness.
상기 망간(Mn), 타이타늄(Ti), 보론(B) 및 질소(N)의 함량은 하기 관계식 1을 만족하는 강도와 충격 인성이 우수한 선재의 제조방법.
[관계식 1]
Mn+5(Ti-3.5N)/B ≥ 5.0
The method of claim 7,
Wherein the content of manganese (Mn), titanium (Ti), boron (B), and nitrogen (N) satisfy the following relational expression 1 and the impact toughness is excellent.
[Relation 1]
Mn + 5 (Ti-3.5N) / B? 5.0
상기 망간(Mn) 및 실리콘(Si)의 함량은 하기 관계식 2를 만족하는 강도와 충격 인성이 우수한 선재의 제조방법.
[관계식 2]
Mn/Si ≥ 18
The method of claim 7,
Wherein the content of manganese (Mn) and silicon (Si) satisfy the following relational expression (2) and the impact toughness is excellent.
[Relation 2]
Mn / Si? 18
상기 재가열 온도는 1000~1100℃로 행하는 강도와 충격 인성이 우수한 선재의 제조방법.
The method of claim 7,
Wherein the reheating temperature is in the range of 1000 to 1100 占 폚.
상기 열간 압연의 마무리 열간 압연은 850~950℃의 온도범위에서 행하는 강도와 충격 인성이 우수한 선재의 제조방법.The method of claim 7,
Wherein the finish hot rolling of the hot rolling is excellent in strength and impact toughness in a temperature range of 850 to 950 占 폚.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US15/516,783 US20170298471A1 (en) | 2014-11-03 | 2015-11-02 | Wire rod having enhanced strength and impact toughness and preparation method for same |
| CN201580059619.2A CN107075648B (en) | 2014-11-03 | 2015-11-02 | Intensity and the excellent wire rod and its manufacturing method of impact flexibility |
| PCT/KR2015/011650 WO2016072679A1 (en) | 2014-11-03 | 2015-11-02 | Wire rod having enhanced strength and impact toughness and preparation method for same |
| MX2017005038A MX2017005038A (en) | 2014-11-03 | 2015-11-02 | Wire rod having enhanced strength and impact toughness and preparation method for same. |
| JP2017523479A JP6488008B2 (en) | 2014-11-03 | 2015-11-02 | Wire material excellent in strength and impact toughness and method for producing the same |
| DE112015004992.4T DE112015004992T5 (en) | 2014-11-03 | 2015-11-02 | ROLLED WIRE WITH IMPROVED STRENGTH AND IMPACT AND MANUFACTURING METHOD THEREFOR |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20140151494 | 2014-11-03 | ||
| KR1020140151494 | 2014-11-03 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20160053776A true KR20160053776A (en) | 2016-05-13 |
| KR101714903B1 KR101714903B1 (en) | 2017-03-10 |
Family
ID=56023559
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020150144758A KR101714903B1 (en) | 2014-11-03 | 2015-10-16 | Steel wire rod having high strength and impact toughness, and method for manufacturing thereof |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US20170298471A1 (en) |
| JP (1) | JP6488008B2 (en) |
| KR (1) | KR101714903B1 (en) |
| CN (1) | CN107075648B (en) |
| DE (1) | DE112015004992T5 (en) |
| MX (1) | MX2017005038A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20180067894A (en) * | 2016-12-13 | 2018-06-21 | 주식회사 포스코 | High strength wire rod having excellent impact toughness and method for manufacturing the same |
| KR102175586B1 (en) * | 2019-06-04 | 2020-11-06 | 주식회사 포스코 | Non-heat treated wire rod having excellent drawability and impact toughness and method for manufacturing thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101858851B1 (en) | 2016-12-16 | 2018-05-17 | 주식회사 포스코 | High strength wire rod having excellent ductility and method for manufacturing same |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6439326A (en) * | 1987-08-05 | 1989-02-09 | Kobe Steel Ltd | Production of steel wire for non-tempered high-strength spring |
| JPH10298704A (en) * | 1997-02-27 | 1998-11-10 | Sumitomo Metal Ind Ltd | High strength and high toughness free-cutting non-heat treated steel |
| JP2008196045A (en) * | 2007-01-17 | 2008-08-28 | Jfe Steel Kk | Manufacturing method of steel for high strength reinforcement |
| KR20110000395A (en) * | 2009-06-26 | 2011-01-03 | 현대제철 주식회사 | Steel sheet having ultra-high strength, and method for producing the same |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6018729B2 (en) * | 1976-10-20 | 1985-05-11 | 住友金属工業株式会社 | Manufacturing method of medium-low carbon high tensile strength wire rod |
| JPS61124524A (en) * | 1984-11-22 | 1986-06-12 | Sumitomo Metal Ind Ltd | Manufacture of bar steel for steel reinforced concrete |
| JPS6487746A (en) * | 1987-06-19 | 1989-03-31 | Kobe Steel Ltd | Ultra-high-strength extra fine wire |
| JP2002003998A (en) * | 2000-06-20 | 2002-01-09 | Daido Steel Co Ltd | Wire rod and its manufacturing method |
| DE10109136A1 (en) * | 2001-02-26 | 2002-09-12 | Cytotools Gmbh | Using inhibitor of thrombospondin-1 interaction for promoting wound healing, also for treating living skin replacements, inhibits apoptosis of wound-repair cells |
| JP4777112B2 (en) * | 2006-03-30 | 2011-09-21 | 新日本製鐵株式会社 | Manufacturing method of high strength wire rod with excellent weldability |
| JP5030200B2 (en) * | 2006-06-05 | 2012-09-19 | 株式会社神戸製鋼所 | High strength steel plate with excellent elongation, stretch flangeability and weldability |
| KR100797327B1 (en) * | 2006-10-11 | 2008-01-22 | 주식회사 포스코 | Steel wire rod for high strength and high toughness spring having excellent cold workability, method for producing the same and method for producing spring by using the same |
| KR101018131B1 (en) * | 2007-11-22 | 2011-02-25 | 주식회사 포스코 | High strength and low yield ratio steel for structure having excellent low temperature toughness |
| CN101619420A (en) * | 2009-07-29 | 2010-01-06 | 马鞍山钢铁股份有限公司 | 10.9-grade chromium-containing non-quenched and tempered cold-heading steel and rolling method of hot finished rod thereof |
| KR101253852B1 (en) * | 2009-08-04 | 2013-04-12 | 주식회사 포스코 | Non-heat Treatment Rolled Steel and Drawn Wire Rod Having High Toughness and Method Of Manufacturing The Same |
| JP5540764B2 (en) * | 2010-02-24 | 2014-07-02 | Ｊｆｅスチール株式会社 | Manufacturing method for steel for rebar |
| JP5521705B2 (en) * | 2010-03-30 | 2014-06-18 | Ｊｆｅスチール株式会社 | Steel material for high-strength reinforcing bars and method for producing the same |
| JP5537248B2 (en) * | 2010-05-06 | 2014-07-02 | 株式会社神戸製鋼所 | Machine structural steel, manufacturing method thereof, and machined part manufacturing method using machine structural steel |
-
2015
- 2015-10-16 KR KR1020150144758A patent/KR101714903B1/en active IP Right Grant
- 2015-11-02 DE DE112015004992.4T patent/DE112015004992T5/en active Pending
- 2015-11-02 US US15/516,783 patent/US20170298471A1/en not_active Abandoned
- 2015-11-02 JP JP2017523479A patent/JP6488008B2/en not_active Expired - Fee Related
- 2015-11-02 CN CN201580059619.2A patent/CN107075648B/en not_active Expired - Fee Related
- 2015-11-02 MX MX2017005038A patent/MX2017005038A/en unknown
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6439326A (en) * | 1987-08-05 | 1989-02-09 | Kobe Steel Ltd | Production of steel wire for non-tempered high-strength spring |
| JPH10298704A (en) * | 1997-02-27 | 1998-11-10 | Sumitomo Metal Ind Ltd | High strength and high toughness free-cutting non-heat treated steel |
| JP2008196045A (en) * | 2007-01-17 | 2008-08-28 | Jfe Steel Kk | Manufacturing method of steel for high strength reinforcement |
| KR20110000395A (en) * | 2009-06-26 | 2011-01-03 | 현대제철 주식회사 | Steel sheet having ultra-high strength, and method for producing the same |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20180067894A (en) * | 2016-12-13 | 2018-06-21 | 주식회사 포스코 | High strength wire rod having excellent impact toughness and method for manufacturing the same |
| WO2018110850A1 (en) * | 2016-12-13 | 2018-06-21 | 주식회사 포스코 | High-strength wire rod having superior impact toughness and manufacturing method therefor |
| KR101879068B1 (en) * | 2016-12-13 | 2018-07-16 | 주식회사 포스코 | High strength wire rod having excellent impact toughness and method for manufacturing the same |
| EP3556885A4 (en) * | 2016-12-13 | 2019-10-30 | Posco | High-strength wire rod having superior impact toughness and manufacturing method therefor |
| KR102175586B1 (en) * | 2019-06-04 | 2020-11-06 | 주식회사 포스코 | Non-heat treated wire rod having excellent drawability and impact toughness and method for manufacturing thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6488008B2 (en) | 2019-03-20 |
| MX2017005038A (en) | 2017-07-19 |
| JP2017538034A (en) | 2017-12-21 |
| CN107075648B (en) | 2018-09-21 |
| US20170298471A1 (en) | 2017-10-19 |
| CN107075648A (en) | 2017-08-18 |
| KR101714903B1 (en) | 2017-03-10 |
| DE112015004992T5 (en) | 2017-07-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2423344B1 (en) | High strength, high toughness steel wire rod, and method for manufacturing same | |
| KR102178711B1 (en) | Non-heat treated wire rod having excellent strength and impact toughness and method for manufacturing thereof | |
| KR102164112B1 (en) | High-strength steel sheet having excellent ductility and low-temperature toughness and method for manufacturing thereof | |
| KR101714903B1 (en) | Steel wire rod having high strength and impact toughness, and method for manufacturing thereof | |
| KR101879068B1 (en) | High strength wire rod having excellent impact toughness and method for manufacturing the same | |
| KR101736590B1 (en) | Non heat treated wire rod having excellent high strength and method for manafacturing thereof | |
| KR101726081B1 (en) | Steel wire rod having excellent low temperature inpact toughness and method for manufacturing the same | |
| KR102175586B1 (en) | Non-heat treated wire rod having excellent drawability and impact toughness and method for manufacturing thereof | |
| KR101676112B1 (en) | Wire having high strength, and method for manufacturing thereof | |
| KR101676115B1 (en) | Wire rod having high strength and impact toughness, and method for manufacturing thereof | |
| KR101736602B1 (en) | Wire rod having excellent impact toughness and method for manafacturing the same | |
| KR101676113B1 (en) | Wire rod having high strength, and method for manufacturing thereof | |
| KR101676111B1 (en) | Wire having high strength and method for manufacturing thereof | |
| KR20160078844A (en) | Steel sheet having excellent resistance to hydrogen induced cracking, and method of manufacturing the same | |
| KR101714905B1 (en) | Steel wire rod having high impact toughness, and method for manufacturing thereof | |
| KR101675677B1 (en) | Non-heated hot-rolled steel sheet and method of manufacturing the same | |
| KR102560057B1 (en) | High yield ratio and high strength steel sheet having excellent bendability and the method for manufacturing the same | |
| KR101696097B1 (en) | Non heat treated wire rod having excellent high strength and impact toughness and method for manafacturing the same | |
| KR102448753B1 (en) | Non-heat treated steel with improved machinability and toughness and the method for manufacturing the same | |
| KR101676116B1 (en) | Wire rod having high strength, and method for manufacturing thereof | |
| KR101639895B1 (en) | Wire rod having high strength and impact toughness and method for manufacturing thereof | |
| KR20160063565A (en) | Wire rod having high strength, and method for manufacturing thereof | |
| KR101676110B1 (en) | Wire rod having high strength and impact toughness, and method for manufacturing thereof | |
| KR101620738B1 (en) | Wire rod having high strength and impact toughness and method for manufacturing thereof | |
| KR101676114B1 (en) | Wire rod having high strength and impact toughness, and method for manufacturing thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant | ||
| FPAY | Annual fee payment |
Payment date: 20200303 Year of fee payment: 4 |