KR20140002275A - Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet - Google Patents
Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet Download PDFInfo
- Publication number
- KR20140002275A KR20140002275A KR1020120070327A KR20120070327A KR20140002275A KR 20140002275 A KR20140002275 A KR 20140002275A KR 1020120070327 A KR1020120070327 A KR 1020120070327A KR 20120070327 A KR20120070327 A KR 20120070327A KR 20140002275 A KR20140002275 A KR 20140002275A
- Authority
- KR
- South Korea
- Prior art keywords
- less
- hot
- weight
- rolled steel
- steel sheet
- Prior art date
Links
Images
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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- 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
- B21B1/24—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 in a continuous or semi-continuous process
- B21B1/26—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 in a continuous or semi-continuous process by hot-rolling, e.g. Steckel hot mill
-
- 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
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
-
- 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
- C22C38/02—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
- C22C38/04—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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- 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
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)
- Heat Treatment Of Steel (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
본 발명은 열연강판 및 그 제조 방법에 관한 것으로, 보다 상세하게는 합금 성분 제어를 통하여, 충격 특성을 향상 시킬 수 있는 강도가 우수한 각관용 열연강판 및 그 제조 방법에 관한 것이다.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-rolled steel sheet and a method of manufacturing the same, and more particularly, to a hot-rolled steel sheet for each pipe having excellent strength capable of improving impact characteristics through alloy component control and a manufacturing method thereof.
건축 구조용 열연 강판은 산업의 고도화에 따른 건물의 고층화 또한 지진, 해일 등과 같은 자연 재해에 발생 빈도 증가로 인한 건축물의 안정성으로 인한 관심을 받고 있다. The hot-rolled steel sheet for architectural structure has attracted attention due to the stability of the building due to the increase in frequency of natural disasters such as earthquakes and tsunamis,
특히 내지진 강관의 경우 내진 성능이 우수해야 하며 용접 성능 또한 요구 되는 강종이며 주로 냉간 성형 제작으로 인해 큰 소성 변형에 의한 강도 상승과 연신율 및 인성의 저하, 이에 따른 충격 특성의 저하로 다른 열연 강판에 비해 높은 가공성 및 저항복비, 우수한 충격 특성이 요구 된다. Especially, the seismic steel pipe is required to have excellent seismic performance and welding performance, and it is mainly required to be manufactured by cold forming because of the increase in strength due to large plastic deformation, deterioration of elongation and toughness, It is required to have a high workability, low resistance and excellent impact properties.
따라서, 각관 제조시 강판 내의 고용 탄소 나 고용 질소는 전위 주위로 확산 하여 전위 이동를 방해 가공 경화에 의한 항복 강도 상승 및 취성-연성 천이 온도를 낮은 온도로 이동 시켜 열연 상태에서 보다 각관 제조 후 충격 특성이 저하 되는 문제점이 있다.
Therefore, in the manufacture of pipes, solid carbon and nitrogen in the steel plate diffuse around the dislocations to dislocate the dislocation movement. When the yield strength is increased by work hardening and the brittle-ductile transition temperature is moved to a lower temperature, There is a problem of deterioration.
관련 선행기술로는 대한민국 공개특허공보 제10-2012-0001010호(2012.01.04. 공개)가 있으며, 상기 문헌에는 복합조직을 갖는 고강도 열연강판 및 그 제조 방법이 개시되어 있다.
A related art is Korean Patent Laid-Open Publication No. 10-2012-0001010 (published on Jan. 14, 2012), which discloses a high strength hot-rolled steel sheet having a composite structure and a manufacturing method thereof.
본 발명의 목적은 티타늄, 니오븀 등의 합금성분 및 공정 제어를 통하여, 충격 특성이 우수한 각관용 열연강판 및 그 제조 방법을 제공하는 것이다.
An object of the present invention is to provide a hot-rolled steel sheet for each pipe having excellent impact characteristics through an alloy component such as titanium and niobium and process control, and a method for producing the same.
상기 하나의 목적을 달성하기 위한 본 발명의 실시예에 따른 열연강판 제조 방법은 탄소(C) : 0.10~0.20 중량%, 실리콘(Si) : 0.25 중량% 이하, 망간(Mn) : 0.5~1.0 중량%, 인(P) : 0.02 중량% 이하, 황(S) : 0.005 중량% 이하, 질소(N) : 0.006 중량% 이하, 니오븀(Nb) :0.1 중량% 이하, 티타늄(Ti) : 0.1 중량% 이하 및 보론(B) : 0.1 중량% 이하 및 나머지 철(Fe)과 불가피한 불순물로 이루어지는 슬라브 판재를 820~860℃의 마무리 압연 온도(FDT) 조건으로 열간 압연하는 단계; 및Hot-rolled steel sheet manufacturing method according to an embodiment of the present invention for achieving the above object is carbon (C): 0.10 ~ 0.20% by weight, silicon (Si): 0.25% by weight or less, manganese (Mn): 0.5 ~ 1.0 weight %, Phosphorus (P): 0.02% or less, sulfur (S): 0.005% or less, nitrogen (N): 0.006% or less, niobium (Nb): 0.1% or less, titanium (Ti): 0.1% by weight Below and boron (B): hot rolling a slab plate made of 0.1 wt% or less and the remaining iron (Fe) and unavoidable impurities under a finish rolling temperature (FDT) condition of 820 to 860 ° C .; And
상기 열간 압연된 판재를 냉각하여, 권취 온도(CT) 600~650℃에서 권취하는 단계;를 포함하는 것을 포함하는 것을 특징으로 한다.
And cooling the hot-rolled sheet material and winding the sheet at a coiling temperature (CT) of 600 to 650 ° C.
상기 다른 목적을 달성하기 위한 본 발명의 실시예에 따른 열연강판은 탄소(C) : 0.10~0.20 중량%, 실리콘(Si) : 0.25 중량% 이하, 망간(Mn) : 0.5~1.0 중량%, 인(P) : 0.02 중량% 이하, 황(S) : 0.005 중량% 이하, 질소(N) : 0.006 중량% 이하, 니오븀(Nb) :0.1 중량% 이하, 티타늄(Ti) : 0.1 중량% 이하 및 보론(B) : 0.1 중량% 이하 및 나머지 철(Fe)과 불가피한 불순물로 이루어지는 것을 특징으로 한다.
Hot-rolled steel sheet according to an embodiment of the present invention for achieving the above another object is carbon (C): 0.10 ~ 0.20% by weight, silicon (Si): 0.25% by weight or less, manganese (Mn): 0.5 ~ 1.0% by weight, phosphorus (P): 0.02 wt% or less, Sulfur (S): 0.005 wt% or less, nitrogen (N): 0.006 wt% or less, niobium (Nb): 0.1 wt% or less, titanium (Ti): 0.1 wt% or less and boron (B): 0.1 wt% or less, and the remaining iron (Fe) and is characterized by consisting of inevitable impurities.
본 발명에 따른 열연강판 제조 방법은 티타늄 및 니오븀등의 합금성분 조절을 첨가하여, 충격 특성이 우수한 열연강판을 제조할 수 있다.
The hot-rolled steel sheet manufacturing method according to the present invention can produce a hot-rolled steel sheet having excellent impact properties by adding the control of alloy components such as titanium and niobium.
도 1은 본 발명의 실시예에 따른 열연강판 제조 방법을 나타낸 순서도이다.
도 2는 본 발명의 실시예 1에 따른 방법으로 각관 시뮬레이션 결과를 나타낸 것이다.
1 is a flowchart showing a method of manufacturing a hot-rolled steel sheet according to an embodiment of the present invention.
Fig. 2 shows the results of the pipe simulation in the method according to the first embodiment of the present invention.
본 발명의 이점 및 특징, 그리고 그것들을 달성하는 방법은 첨부되는 도면과 함께 상세하게 후술되어 있는 실시예들을 참조하면 명확해질 것이다. 그러나, 본 발명은 이하에서 개시되는 실시예들에 한정되는 것이 아니라 서로 다른 다양한 형태로 구현될 것이며, 단지 본 실시예들은 본 발명의 개시가 완전하도록 하며, 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자에게 발명의 범주를 완전하게 알려주기 위해 제공되는 것이며, 본 발명은 청구항의 범주에 의해 정의될 뿐이다. 명세서 전체에 걸쳐 동일 참조 부호는 동일 구성요소를 지칭한다.Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.
이하 첨부된 도면을 참조하여 본 발명의 바람직한 실시예에 따른 열연강판 및 그 제조 방법에 관하여 상세히 설명하면 다음과 같다.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a hot-rolled steel sheet according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
열연강판Hot-rolled steel sheet
본 발명에 따른 열연강판은 탄소(C) : 0.10~0.20 중량%, 실리콘(Si) : 0.25 중량% 이하, 망간(Mn) : 0.5~1.0 중량%, 인(P) : 0.02 중량% 이하, 황(S) : 0.005 중량% 이하, 질소(N) : 0.006 중량% 이하, 니오븀(Nb) :0.1 중량% 이하, 티타늄(Ti) : 0.1 중량% 이하 및 보론(B) : 0.1 중량% 이하를 포함한다. Hot rolled steel sheet according to the present invention is carbon (C): 0.10 ~ 0.20% by weight, silicon (Si): 0.25% by weight or less, manganese (Mn): 0.5 ~ 1.0% by weight, phosphorus (P): less than 0.02% by weight, sulfur (S): 0.005 wt% or less, nitrogen (N): 0.006 wt% or less, niobium (Nb): 0.1 wt% or less, titanium (Ti): 0.1 wt% or less and boron (B): 0.1 wt% or less do.
상기 성분들 이외에 나머지는 철(Fe)과 불가피한 불순물로 이루어진다.In addition to the above components, the remainder is composed of iron (Fe) and inevitable impurities.
이하, 본 발명에 따른 열연강판에 포함되는 각 성분의 역할 및 그 첨가량에 대하여 설명하면 다음과 같다.
Hereinafter, the role of each component included in the hot-rolled steel sheet according to the present invention and the addition amount thereof will be described.
탄소(C)Carbon (C)
탄소(C)는 강도를 확보하기 위하여 첨가되며, 용접성에 가장 큰 영향을 미치는 원소이다. Carbon (C) is added to secure strength and is the most influential element in weldability.
상기 탄소(C)는 본 발명에 따른 열연강판 전체 중량의 0.1~0.2 중량%로 첨가되는 것이 바람직하다. 만일, 탄소(C)의 첨가량이 0.1 중량% 미만일 경우에는 충분한 강도를 확보하는 데 어려움이 따를 수 있다. 반대로, 탄소(C)의 첨가량이 0.2 중량%를 초과할 경우에는 인성 저하를 야기할 수 있다.
The carbon (C) is preferably added in an amount of 0.1 to 0.2% by weight based on the total weight of the hot-rolled steel sheet according to the present invention. If the addition amount of carbon (C) is less than 0.1% by weight, it may be difficult to secure sufficient strength. On the other hand, if the addition amount of carbon (C) exceeds 0.2% by weight, the toughness may be lowered.
실리콘(silicon( SiSi ))
실리콘(Si)은 강도 확보에 기여하며, 또한 강 중의 산소를 제거하기 위한 탈산제 역할을 한다. Silicon (Si) contributes to securing strength and also acts as a deoxidizer to remove oxygen in the steel.
상기 실리콘은 본 발명에 따른 열연강판 전체 중량의 0.25중량% 이하로 첨가되는 것이 바람직하다. 실리콘의 첨가량이 0.25 중량%를 초과할 경우 용접성 및 도금성이 저하되는 문제점이 있다.
The silicon is preferably added to 0.25% by weight or less of the total weight of the hot rolled steel sheet according to the present invention. If the addition amount of silicon exceeds 0.25% by weight, there is a problem that the weldability and plating ability are deteriorated.
망간(manganese( MnMn ))
망간(Mn)은 강속에 고용되어 있는 황(S)과 결합하여, 제조 공정 중에 불가피하게 형성되어 적열 취성을 유발하는 FeS 형성을 방지하며, MnS를 형성하여 고용 강화 효과 및 강의 강도를 증가시키는 역할을 한다.Manganese (Mn) is combined with sulfur (S) dissolved in the steel to prevent the formation of FeS which is inevitably formed during the manufacturing process to induce brittle brittleness and to form MnS to increase the solid solution strength and steel strength .
상기 망간은 본 발명에 따른 열연강판 전체 중량의 0.5~1.0 중량%로 첨가되는 것이 바람직하다. 망간이 첨가량이 0.5중량% 미만일 경우, 그 첨가 효과가 불충분하다. 반대로, 망간의 첨가량이 1.0중량%를 초과하는 경우, MnS를 과다하게 생성하여, 강의 가공성에 악영향을 미친다.
The manganese is preferably added in an amount of 0.5 to 1.0 wt% based on the total weight of the hot-rolled steel sheet according to the present invention. When the addition amount of manganese is less than 0.5% by weight, the effect of addition thereof is insufficient. On the other hand, when the addition amount of manganese exceeds 1.0% by weight, MnS is excessively produced, which adversely affects the workability of the steel.
인(P)In (P)
인(P)은 강의 제조시 편석되어 기계적 성질에 악영향을 미치며, 성형후 일정 시간이 지나면 파괴가 일어나는 지연파괴의 원인이 된다. Phosphorus (P) segregates during the manufacture of steel, which adversely affects the mechanical properties and causes a delayed fracture in which fracture occurs after a certain time after molding.
이에, 본 발명에서는 인의 함량을 본 발명에 따른 열연강판 전체 중량의 0.02 중량% 이하로 제한하였다.
Thus, in the present invention, the content of phosphorus was limited to 0.02% by weight or less of the total weight of the hot rolled steel sheet according to the present invention.
황(S)Sulfur (S)
황(S)은 망간과 결합하여 MnS와 같은 비금속 개재물을 형성한다. MnS 개재물이 다량 형성될 경우, 조관시 후크 크랙과 같은 용접부 결함을 발생할 수 있으며, 본 발명의 경우 망간 함량이 높기 때문에 가공성 확보 및 용접 결함을 방지하기 위해 황의 함량을 최소화할 필요가 있다.Sulfur (S) combines with manganese to form nonmetallic inclusions such as MnS. When a large amount of MnS inclusions are formed, weld cracks such as hook cracks may occur during the preparation. In the case of the present invention, since the content of manganese is high, it is necessary to minimize the content of sulfur in order to secure workability and prevent welding defects.
이에, 본 발명에서는 황의 함량을 본 발명에 따른 열연강판 전체 중량의 0.005 중량% 이하로 제한하였다.
Thus, in the present invention, the sulfur content is limited to 0.005% by weight or less of the total weight of the hot rolled steel sheet according to the present invention.
질소(N)Nitrogen (N)
질소(N)는 불가피한 불순물로써, 0.006 중량%를 초과하여 다량 함유될 경우 고용 질소가 증가하여 열연강판의 충격특성 및 연신율을 떨어뜨리고 용접부의 인성을 크게 저하시키는 문제점이 있다. Nitrogen (N) is an unavoidable impurity. If it is contained in an amount exceeding 0.006% by weight, the amount of nitrogen employed increases, which deteriorates the impact characteristics and elongation of the hot-rolled steel sheet and significantly deteriorates the toughness of the welded portion.
이에, 본 발명에서는 질소(N)의 함량을 열연강판 전체 중량의 0.006 중량% 이하로 제한하였다.
Thus, in the present invention, the content of nitrogen (N) was limited to 0.006% by weight or less of the total weight of the hot rolled steel sheet.
니오븀(Niobium ( NbNb ))
니오븀(Nb)은 석출물 형성원소로서 강도 확보에 유효하게 작용한다. Niobium (Nb) acts effectively as a precipitate-forming element in securing strength.
상기 니오븀(Nb)은 강재 전체 중량의 0.1 중량% 이하의 함량비로 첨가하는 것이 바람직하다. 니오븀(Nb)의 함량이 0.1 중량%를 초과하는 경우, 니오븀(Nb) 함량 증가에 따른 강도와 저온인성은 더 이상 향상되지 않고, 용접성이 저하될 수 있다.
The niobium (Nb) is preferably added in an amount ratio of 0.1% by weight or less of the total weight of the steel. When the content of niobium (Nb) exceeds 0.1% by weight, strength and low temperature toughness as the content of niobium (Nb) increases are not improved any more, and weldability may be lowered.
티타늄(titanium( TiTi ))
티타늄(Ti)은 강력한 탄질화물 형성 원소로서, 고용탄소와 고용질소를 석출시켜 비시효성과 가공성을 향상시키는 역할을 한다. 특히, 티타늄(Ti)은 보론(B)이 질화 석출물로 석출되는 것을 방해하여 강 중에 보론이 고용 상태로 존재하게 함으로써, 보론이 강의 경화능을 향상시키는 역할을 한다.Titanium (Ti) is a strong carbonitride-forming element that precipitates solid carbon and solid nitrogen to improve non-vitrification and processability. In particular, titanium (Ti) prevents Boron (B) from being precipitated as a nitride precipitate, and boron is present in a solid state in the steel so that boron serves to improve the hardenability of the steel.
상기 티타늄(Ti)이 첨가될 경우, 그 함량은 강재 전체 중량의 0.1 중량% 이하로 첨가하는 것이 바람직하다. 티타늄(Ti)의 함량이 0.1 중량%를 초과할 경우에는 오스테나이트 고온역에서 석출하여 재가열된 오스테나이트의 결정립 성장을 억제하므로 오스테나이트의 결정립 미세화를 도모하나 NbC 이외에 TiC를 추가로 석출시켜 충격인성이 저하되는 문제점이 있다.
When the titanium (Ti) is added, the content is preferably added to 0.1% by weight or less of the total weight of the steel. When the content of titanium (Ti) exceeds 0.1% by weight, precipitation occurs at a high temperature of austenite to suppress grain growth of reheated austenite. Therefore, grain refinement of austenite is promoted, but TiC is precipitated in addition to NbC, Is lowered.
보론(B)Boron (B)
보론(B)은 니오븀 석출물 형성을 저하하여 석출물의 입계 내부에 형성을 유도한다. 따라서, 보론을 첨가함으로써, 가공 경화 및 적정량 이상의 니오븀 석출물에 의한 충격 특성을 저하시키는 역할을 한다.Boron (B) lowers the formation of niobium precipitates and induces the formation of precipitates inside the grain boundaries. Therefore, by adding boron, it plays a role of lowering the work hardening and the impact property by the niobium precipitate of a proper amount or more.
상기 보론(B)은 강재 전체 중량의 0.1 중량% 이하의 함량비로 첨가하는 것이 바람직하다. 보론(B)의 함량이 0.1 중량%를 초과하여 과다 첨가될 경우에는 보론 산화물의 형성으로 강재의 표면 품질을 저해하며, 고온강도 확보가 어려워지는 문제점이 있다.
The boron (B) is preferably added in an amount ratio of 0.1% by weight or less of the total weight of the steel. When boron (B) is added in an amount exceeding 0.1% by weight, boron oxide is formed, which hinders the surface quality of the steel and makes it difficult to secure high-temperature strength.
열연강판 제조 방법Hot-rolled steel sheet manufacturing method
이하, 본 발명에 따른 열연강판 제조 방법에 대하여 설명하기로 한다.Hereinafter, a method for manufacturing a hot-rolled steel sheet according to the present invention will be described.
도 1은 본 발명의 실시예에 따른 열연강판 제조 방법을 나타낸 순서도이다. 1 is a flowchart showing a method of manufacturing a hot-rolled steel sheet according to an embodiment of the present invention.
도 1을 참조하면, 본 발명에 따른 열연강판 제조 방법은 열간압연 단계(S110) 및 냉각/권취 단계(S120)를 포함한다. 또한, 본 발명에 따른 열연강판 제조 방법은 상기 열간압연 단계(S110) 이전에 슬라브 재가열 단계(S105)를 더 포함할 수 있다.
Referring to FIG. 1, the hot rolled steel sheet manufacturing method according to the present invention includes a hot rolling step (S110) and a cooling / winding step (S120). Further, the method of manufacturing a hot-rolled steel sheet according to the present invention may further include a step of re-heating the slab (S105) before the hot-rolling step (S110).
슬라브 재가열Reheating slabs
슬라브 재가열 단계(S105)는 반제품 상태의 슬라브 판재의 재가열을 통하여, 주조시 편석된 성분 및 석출물을 재고용한다. The slab reheating step (S105) reuses the segregated components and precipitates through the reheating of the slab plate in the semi-finished product state.
슬라브 재가열은 1150~1300℃의 온도에서 대략 1~3시간동안 실시되는 것이 바람직하다. 슬라브 재가열 온도가 1150℃ 미만이면 슬라브 판재의 온도가 낮아 압연 부하가 커지는 문제점이 있다. 반대로, 슬라브 재가열 온도가 1300℃를 초과하면 오스테나이트 결정립이 조대화되어, 강도 확보가 어려운 문제점이 있다.
The slab reheating is preferably performed at a temperature of 1150 to 1300 캜 for about 1 to 3 hours. If the reheating temperature of the slab is less than 1150 DEG C, there is a problem that the rolling load becomes large because the temperature of the slab plate is low. On the other hand, when the slab reheating temperature exceeds 1300 DEG C, the austenite grains are coarsened, which makes it difficult to secure strength.
열간압연Hot rolling
열간압연 단계(S110)에서는 슬라브 판재를 열간압연한다. In the hot rolling step (S110), the slab plate is hot-rolled.
열간압연 단계(S110)에서 마무리 압연 온도(FDT)는 820~880℃인 것이 바람직하다. 마무리 압연 온도가 880℃를 초과하는 경우, 권취 온도와의 편차가 증가하여 온도 제어가 어려운 문제점이 있다. 반대로, 마무리 압연 온도가 820℃ 미만인 경우, 열간압연시 압연 부하가 증가될 수 있다.
The finishing rolling temperature (FDT) in the hot rolling step (S110) is preferably 820 to 880 ° C. When the finishing rolling temperature exceeds 880 DEG C, there is a problem that the deviation from the coiling temperature increases and the temperature control becomes difficult. Conversely, when the finishing rolling temperature is lower than 820 占 폚, the rolling load upon hot rolling can be increased.
냉각/Cooling/ 권취Coiling
냉각/권취 단계(S120)에서는 열간압연된 판재를 냉각하여 권취한다.In the cooling / winding step (S120), the hot rolled plate is cooled and wound.
본 발명에서, 권취 온도(Coiling Temperature :CT)는 600~650℃인 것이 바람직하다. 권취 온도가 650℃를 초과할 경우에는 충분한 강도를 확보하는 데 어려움이 따를 수 있다. 반대로, 권취 온도(CT)가 600℃ 미만일 경우에는 열연강판의 경도가 과다하게 높아질 수 있으며, 연신율이 감소할 수 있다.
In the present invention, the coiling temperature (CT) is preferably 600 to 650 ° C. If the coiling temperature exceeds 650 DEG C, it may be difficult to ensure sufficient strength. On the other hand, when the coiling temperature (CT) is less than 600 ° C, the hardness of the hot-rolled steel sheet may become excessively high and the elongation rate may decrease.
실시예Example
이하, 본 발명의 바람직한 실시예를 통해 본 발명의 구성 및 작용을 더욱 상세히 설명하기로 한다. 다만, 이는 본 발명의 바람직한 예시로 제시된 것이며 어떠한 의미로도 이에 의해 본 발명이 제한되는 것으로 해석될 수는 없다. Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.
여기에 기재되지 않은 내용은 이 기술 분야에서 숙련된 자이면 충분히 기술적으로 유추할 수 있는 것이므로 그 설명을 생략하기로 한다.
Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.
1. One. 열연시편의Hot-rolled specimen 제조 Produce
표 1에 기재된 조성으로 진공 용해로에서 용해하여 잉곳을 제조한 후, 표 1에 기재된 조건을 바탕으로 열간 압연하여 실시예 1~3 및 비교예 1에 따른 시편을 제조하였다. The ingot was dissolved in a vacuum melting furnace in the composition shown in Table 1, and then hot-rolled under the conditions shown in Table 1 to prepare specimens according to Examples 1 to 3 and Comparative Example 1. [
[표 1] (단위 : 중량%) [Table 1] (unit:% by weight)
2. 기계적 특성 평가2. Evaluation of mechanical properties
표 2 및 3은 실시예 1~3 및 비교예 1에 따라 제조된 시편들에 대한 기계적 물성 평가 결과 및 충격 시험 결과를 나타낸 것이다.Tables 2 and 3 show the results of mechanical property evaluation and impact test on the specimens prepared according to Examples 1 to 3 and Comparative Example 1. [
[표 2][Table 2]
도 2는 본 발명의 실시예 1에 따른 방법으로 각관 시뮬레이션 결과를 나타낸 것이다. Fig. 2 shows the results of the pipe simulation in the method according to the first embodiment of the present invention.
굽힘시험은 굽힘시험기를 이용하여 굽힘반경이 40mm일 경우, 곡률부에는 19.6% 하중이 인가되었다. 또한, 각관 시뮬레이션은 변형율을 5%에서 20%까지 5%씩 증가 시키면서 충격 시험을 하였다. 이때, 하중은 곡률부에서부터 54mm지점에 인가하였다.The bending test was carried out using a bending tester, and a bending radius of 40 mm was applied to the curvature portion with a load of 19.6%. In addition, the pipe test was performed by increasing the strain rate from 5% to 20% in 5% increments. At this time, the load was applied to the point 54 mm from the curvature portion.
[표 3] [Table 3]
표 3을 참조하면, 실시예 1 내지 3에 따라 제조된 시편의 경우, 충격에너지(CVN)가 240J 이상으로 충격 특성이 매우 우수하였다.Referring to Table 3, in the case of the specimens prepared according to Examples 1 to 3, the impact characteristics (CVN) of 240 J or more were excellent.
반면, 비교예 1의 경우, 보론, 티타늄 및 니오븀이 첨가되지 않은 결과, 충격 에너지(CVN)이 150J 정도에 불과하였다.
On the other hand, in the case of Comparative Example 1, the impact energy (CVN) was only about 150 J as a result of not adding boron, titanium and niobium.
따라서, 위의 실험 결과를 토대로, 실시예 1~3에 따라 제조된 시편들은 보론, 티타늄 및 니오븀을 첨가하여, 충격특성이 우수한 것을 알 수 있다.
Based on the above experimental results, it can be seen that the specimens prepared according to Examples 1 to 3 have excellent impact properties by adding boron, titanium and niobium.
이상에서는 본 발명의 실시예를 중심으로 설명하였지만, 당업자의 수준에서 다양한 변경이나 변형을 가할 수 있다. 이러한 변경과 변형이 본 발명의 범위를 벗어나지 않는 한 본 발명에 속한다고 할 수 있다. 따라서 본 발명의 권리범위는 이하에 기재되는 청구범위에 의해 판단되어야 할 것이다.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Such changes and modifications are intended to fall within the scope of the present invention unless they depart from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.
S105 : 슬라브 재가열 단계
S110 : 열간압연 단계
S120 : 냉각/권취 단계 S105: Slab reheating step
S110: Hot rolling step
S120: cooling / winding step
Claims (4)
상기 열간 압연된 판재를 냉각하여, 권취하는 단계;를 포함하는 것을 특징으로 하는 각관용 열연강판 제조 방법.
Carbon (C): 0.10 to 0.20 wt%, Silicon (Si): 0.25 wt% or less, Manganese (Mn): 0.5 to 1.0 wt%, Phosphorus (P): 0.02 wt% or less, Sulfur (S): 0.005 wt% Or less, nitrogen (N): 0.006% by weight or less, niobium (Nb): 0.1% by weight or less, titanium (Ti): 0.1% by weight or less and boron (B): 0.1% by weight or less and the remaining iron (Fe) and unavoidable impurities Hot-rolling the slab plate material having a finish rolling temperature (FDT) of 820 to 860 ° C .; And
And cooling and winding the hot-rolled plate material.
상기 열연 강판 제조 방법은
상기 열간 압연 전에, 상기 슬라브 판재를 1150~1300℃의 온도에서 재가열하는 단계를 더 포함하는 것을 특징으로 하는 각관용 열연강판 제조 방법.
The method of claim 1,
The hot-rolled steel sheet manufacturing method
Further comprising the step of reheating the slab sheet at a temperature of 1150 to 1300 占 폚 before the hot rolling.
상기 권취는 600~650℃에서 실시되는 것을 특징으로 하는 각관용 열연강판 제조 방법.
The method of claim 1,
Wherein the coiling is carried out at 600 to 650 占 폚.
0℃ 충격에너지 240J 이상을 갖는 것을 특징으로 하는 각관용 열연강판. Carbon (C): 0.10 to 0.20 wt%, Silicon (Si): 0.25 wt% or less, Manganese (Mn): 0.5 to 1.0 wt%, Phosphorus (P): 0.02 wt% or less, Sulfur (S): 0.005 wt% Or less, nitrogen (N): 0.006% by weight or less, niobium (Nb): 0.1% by weight or less, titanium (Ti): 0.1% by weight or less and boron (B): 0.1% by weight or less and the remaining iron (Fe) and unavoidable impurities It consists of
0 DEG C impact energy of 240 J or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020120070327A KR101412327B1 (en) | 2012-06-28 | 2012-06-28 | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020120070327A KR101412327B1 (en) | 2012-06-28 | 2012-06-28 | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20140002275A true KR20140002275A (en) | 2014-01-08 |
| KR101412327B1 KR101412327B1 (en) | 2014-06-25 |
Family
ID=50139371
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020120070327A KR101412327B1 (en) | 2012-06-28 | 2012-06-28 | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR101412327B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016105002A1 (en) * | 2014-12-24 | 2016-06-30 | 주식회사 포스코 | Low-temperature steel sheet with excellent surface processing quality and method for manufacturing same |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20100047015A (en) * | 2008-10-28 | 2010-05-07 | 현대제철 주식회사 | Hot-rolled steel sheet having ultra-high strength, and method for producing the same |
-
2012
- 2012-06-28 KR KR1020120070327A patent/KR101412327B1/en active IP Right Grant
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016105002A1 (en) * | 2014-12-24 | 2016-06-30 | 주식회사 포스코 | Low-temperature steel sheet with excellent surface processing quality and method for manufacturing same |
| CN107109602A (en) * | 2014-12-24 | 2017-08-29 | Posco公司 | The excellent steel plates for low temperature service of suface processing quality and its manufacture method |
Also Published As
| Publication number | Publication date |
|---|---|
| KR101412327B1 (en) | 2014-06-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR20140118313A (en) | Hot-rolled steel and method of manufacturing the same | |
| KR101505279B1 (en) | Hot-rolled steel sheet and method of manufacturing the same | |
| KR101412327B1 (en) | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet | |
| KR101546138B1 (en) | Hot-rolled steel sheet and manufacturing method of the same | |
| KR101505301B1 (en) | Hot-rolled steel sheet and method of manufacturing the same | |
| KR20120132835A (en) | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet | |
| KR101546124B1 (en) | Hot-rolled steel and method of manufacturing the same | |
| KR101267624B1 (en) | Structural steel and method of manufacturing the structural steel | |
| KR102492030B1 (en) | High strength hot rolled steel sheet having low yield ratio and method of manufacturing the same | |
| KR101412286B1 (en) | Ultra high strength steel sheet and method of manufacturing the steel sheet | |
| KR101185199B1 (en) | Extemely low carbon steel with excellent aging resistance and workability and method of manufacturing the low carbon steel | |
| KR20160063168A (en) | Steel and method of manufacturing the same | |
| KR101443451B1 (en) | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet | |
| KR101344665B1 (en) | Method for manufacturing hot-rolled steel sheet | |
| KR20150112490A (en) | Steel and method of manufacturing the same | |
| KR101412388B1 (en) | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet | |
| KR101377890B1 (en) | High strength hot-rolled steel sheet and method of manufacturing the same | |
| KR101299276B1 (en) | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet | |
| KR20150025910A (en) | High strength hot-rolled steel sheet and method of manufacturing the same | |
| KR101412376B1 (en) | Method for hot rolling and steel sheet of line pipe manufactured using the same | |
| KR101344663B1 (en) | Cold-rolled steel sheet and method of manufacturing the same | |
| KR20140002273A (en) | High strength steel sheet for line pipe and method of manufacturing the same | |
| KR101149251B1 (en) | HIGH STRENGTH STRUCTURAL STEEL OF TENSILE STRENGTH OF 650MPa GRADE WITH LOW YIELD RATIO AND METHOD OF MANUFACTURING THE HIGH STRENGTH STRUCTURAL STEEL | |
| KR101412372B1 (en) | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet | |
| KR20140055464A (en) | Carbon steel and method of manufacturing the carbon steel |
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: 20170608 Year of fee payment: 4 |
|
| FPAY | Annual fee payment |
Payment date: 20180608 Year of fee payment: 5 |
|
| FPAY | Annual fee payment |
Payment date: 20190528 Year of fee payment: 6 |