KR100217943B1 - Method for manufacturing cold rolled steel sheet - Google Patents
Method for manufacturing cold rolled steel sheet Download PDFInfo
- Publication number
- KR100217943B1 KR100217943B1 KR1019950045020A KR19950045020A KR100217943B1 KR 100217943 B1 KR100217943 B1 KR 100217943B1 KR 1019950045020 A KR1019950045020 A KR 1019950045020A KR 19950045020 A KR19950045020 A KR 19950045020A KR 100217943 B1 KR100217943 B1 KR 100217943B1
- Authority
- KR
- South Korea
- Prior art keywords
- rolling
- stand
- hot
- steel sheet
- rolled steel
- Prior art date
Links
- 239000010960 cold rolled steel Substances 0.000 title claims abstract description 24
- 238000000034 method Methods 0.000 title claims abstract description 11
- 238000004519 manufacturing process Methods 0.000 title abstract description 25
- 238000005096 rolling process Methods 0.000 claims abstract description 43
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 15
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 13
- 238000000137 annealing Methods 0.000 claims abstract description 9
- 238000005097 cold rolling Methods 0.000 claims abstract description 9
- 229910001209 Low-carbon steel Inorganic materials 0.000 claims abstract description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 8
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 5
- 238000005507 spraying Methods 0.000 claims abstract 2
- 239000000498 cooling water Substances 0.000 claims 1
- 239000010936 titanium Substances 0.000 abstract description 27
- 238000005098 hot rolling Methods 0.000 abstract description 12
- 229910052719 titanium Inorganic materials 0.000 abstract description 11
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 abstract description 8
- 238000001816 cooling Methods 0.000 abstract description 8
- 239000000463 material Substances 0.000 abstract description 6
- 238000003303 reheating Methods 0.000 abstract description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 2
- 239000002244 precipitate Substances 0.000 description 12
- 229910000831 Steel Inorganic materials 0.000 description 11
- 239000010959 steel Substances 0.000 description 11
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 5
- 238000001556 precipitation Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 4
- 239000010955 niobium Substances 0.000 description 4
- 230000009466 transformation Effects 0.000 description 4
- 238000004804 winding Methods 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 3
- 238000005554 pickling Methods 0.000 description 3
- 239000006104 solid solution Substances 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910052758 niobium Inorganic materials 0.000 description 2
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- JMANVNJQNLATNU-UHFFFAOYSA-N oxalonitrile Chemical compound N#CC#N JMANVNJQNLATNU-UHFFFAOYSA-N 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
- B21B3/02—Rolling special iron alloys, e.g. stainless steel
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/74—Temperature control, e.g. by cooling or heating the rolls or the product
-
- 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
-
- 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
- B21B31/00—Rolling stand structures; Mounting, adjusting, or interchanging rolls, roll mountings, or stand frames
- B21B31/02—Rolling stand frames or housings; Roll mountings ; Roll chocks
- B21B2031/021—Integral tandem mill housings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B2261/00—Product parameters
- B21B2261/20—Temperature
Abstract
본 발명은 자동차 및 가전제품에 주로 사용되는 심가공용 냉연강판의 제조방법에 관한 것이며, 보다 상세히는 냉연강판의 중간소재인 열연판 제조를 위한 마무리 압연시, 스트립을 냉각 제어함으로써 더욱 우수한 프레스 가공성을 갖는 냉연강판을 제조하는 방법에 관한 것이다.The present invention relates to a method for manufacturing a cold rolled steel sheet for deep processing mainly used in automobiles and home appliances, and more specifically, in the finish rolling for the production of hot rolled sheet, which is an intermediate material of the cold rolled steel sheet, by controlling the cooling of the strip to further excellent press formability It relates to a method for producing a cold rolled steel sheet having.
본 발명의 심가공성이 우수한 냉연강판의 제조방법은 중량%로 0.01% 이하의 C, 0.01% 이하의 S, 0.007% 이하의 N을 포함하고, Ti* = Total Ti-3.43(%N) - 1.5(%S)의 조건을 만족하는 유호티타늄(Ti*)량과 탄소량과의 원자당량비(Ti*/4C%)가 1 이상이 되도록 조성된 통상의 Ti 첨가 극저탄소강 슬라브를 열연 재가열후, 열간압연기에 투입하여 조압연 직후의 온도가 1050℃ 이상이 되도록 압연한 다음, 계속하여 통상 6-7 스탠드를 지닌 텐덤(Tandem) 형식의 압연기를 이용하여 마무리 압연을 실시할 때 마무리 압연기 전단부 3번째 스탠드에서의 압연온도가 940-980℃가 되도록 하고, 또한 압연기 1번째 스탠드 입측과 3번째 스탠드 출측에서의 열연스트립(strip)의 온도차이가 70℃ 이상이 되도록 물을 분사하여 냉각하면서 제어압연을 실시함으로써 열연판을 제조하고, 이 열연판을 소재로 통상의 냉연 및 연속소둔을 실시한다.The method for manufacturing a cold rolled steel sheet having excellent deep workability according to the present invention includes 0.01% or less of C, 0.01% or less of S, and 0.007% or less of N, and Ti * = Total Ti-3.43 (% N) −1.5 After hot-rolling and reheating a conventional Ti-added ultra-low carbon steel slab which is formed so that the atomic equivalent ratio (Ti * / 4C%) between the amount of eu titanium (Ti *) and the amount of carbon satisfying the condition of (% S) is 1 or more, After rolling into a hot rolling mill to make the temperature immediately after the rough rolling to be 1050 ° C or higher, and then performing finish rolling using a tandem type rolling mill having a normal 6-7 stand. Control rolling is performed while cooling by spraying water so that the rolling temperature at the first stand is 940-980 ° C, and the temperature difference between the hot rolled strips at the entrance of the first stand and the third stand is 70 ° C or more. The hot rolled sheet is manufactured by carrying out Normal cold rolling and continuous annealing are performed.
Description
[발명의 명칭][Name of invention]
심가공성이 우수한 냉연강판의 제조방법Manufacturing method of cold rolled steel sheet with excellent deep workability
[발명의 상세한 설명]Detailed description of the invention
[본 발명의 이용 분야]FIELD OF APPLICATION OF THE INVENTION
본 발명은 자동차 및 가전제품에 주로 사용되는 심가공용 냉연강판의 제조방법에 관한 것이며, 보다 상세히는 냉연강판의 중간소재인 열연판 제조를 위한 마무리 압연시, 스트립을 냉각 제어함으로써 더욱 우수한 프레스 가공성을 갖는 냉연강판을 제조하는 방법에 관한 것이다.The present invention relates to a method for manufacturing a cold rolled steel sheet for deep processing mainly used in automobiles and home appliances, and more specifically, in the finish rolling for the production of hot rolled sheet, which is an intermediate material of the cold rolled steel sheet, by controlling the cooling of the strip to further excellent press formability It relates to a method for producing a cold rolled steel sheet having.
[종래의 공지기술][Prior known technology]
일반적으로 심가공용 냉연강판을 제조하기 위해서는 극저탄소강에 탄질화물 형성원소인 티타늄(Ti) 또는 니오비움(Nb) 등을 첨가한 소위 IF강(Interstitial Free Steel)을 이용하여 열간압연-산세-냉간압연-연속소둔의 제조공정을 거쳐 제조하며, 각 제조공정에서의 조업조건은 최종 냉연제품에서의 우수한 가공성을 확보할 수 있도록 설정되어 있다. 즉, 제강공정에서는 강증 탄소량을 극도로 낮추고, 또한 탈탄한계량으로 남아 있는 수십 ppmwjd도의 소량의 탄소마저 탄질화물로 고정하기 위하여 티타늄(Ti) 및 니오비움(Nb) 등을 첨가하며, 열연단계에서는 Ar3 변태점 직상에서 마무리 압연을 완료함으로써 열연판의 미세조직 측면에서 미세하고도 균일한 페라이트 정립 조직을 얻는 한편, 냉각 압연시는 가능한한 압하율을 크게하여 압연 집합 조직을 발달시키고, 소둔시 고온소둔을 실시함으로써 우수한 가공성을 얻는다고 하는 것이 상기 IF강종의 기본적인 제조사상이다.In general, in order to manufacture cold-rolled steel sheet for deep processing, hot rolled-pickling-cold using so-called IF steel (Interstitial Free Steel) containing titanium (Ti) or niobium (Nb), which is a carbon nitride forming element, in ultra low carbon steel It is manufactured through the manufacturing process of rolling-continuous annealing, and the operating conditions in each manufacturing process are set to ensure the excellent workability in the final cold rolled product. That is, in the steelmaking process, titanium (Ti) and niobium (Nb) are added in order to extremely reduce the amount of increased carbon and to fix even a small amount of carbon, even a small amount of carbon, which remains in the decarburization limit. By completing the finish rolling directly above the Ar3 transformation point, a fine and uniform ferrite grain structure is obtained in terms of the microstructure of the hot rolled sheet, while the rolling reduction is increased as much as possible during cold rolling to develop the rolled texture, and at high annealing It is a basic manufacturer image of the IF steel grades that excellent workability is obtained by carrying out the following steps.
따라서 심가공용 냉연강판의 제조를 위해서는 소강성분, 열간 마무리 압연온도, 열연권취 온도, 냉간압하율, 소둔온도 등의 조업조건을 제어함으로써 가공성을 확보한다는 것이 종래의 통념이었다. 그러나, 상기 IF강증에 존재하는 탄소 및 질소 석출물의 석출거 등은 열연판의 미세조직 이상으로 냉연강판의 가공성에 큰 영향을 미치며, 또한 이러한 석출물들은 주로 열연공정에서 형성되므로 단순히 마무리 압연온도를 Ar3 변태점 이상으로 규제하여 페라이트 결정립만을 제어하는 것은 상기 강종의 안정적 재질확보에 문제가 발생할 수 있는 것이다. 예컨대, 석출물의 제어개념이 없는 경우는 열연판의 페라이트 조직이 양호한 정립 조직이 형성되고도 드로잉성이 열화되어 가공 불량을 일으키는 문제가 있는 것이다.Therefore, conventionally, in order to manufacture a cold rolled steel sheet for deep processing, it has been conventionally known that workability is secured by controlling operating conditions such as a cast steel component, a hot finish rolling temperature, a hot rolled winding temperature, a cold rolling reduction rate, and an annealing temperature. However, precipitation of carbon and nitrogen precipitates present in the IF hardening has a great influence on the workability of the cold rolled steel sheet beyond the microstructure of the hot rolled sheet, and these precipitates are mainly formed in the hot rolling process, so that the finish rolling temperature is simply changed to Ar3. Controlling only ferrite grains by regulating above the transformation point may cause problems in securing a stable material of the steel grade. For example, if there is no control concept of the precipitate, there is a problem in that the ferrite structure of the hot-rolled sheet has a good grain structure and the drawing property is deteriorated, resulting in poor machining.
[발명의 목적][Purpose of invention]
따라서, 본 발명은 극저탄소 IF강을 소재로 심가공용 냉연강판을 제조하는 경우, 열간 마무리 압연시 냉각제어를 실시하여 냉연강판의 가공성에 큰 영향을 미치는 탄.질화물의 석출 거동을 제어함으로써, 동일한 강으로도 프레스 가공성이 한층 우수한 심가공용 냉연강판을 안정적으로 제조하는 방법을 제공하고자 하는데 그 목적이 있다.Therefore, in the present invention, when manufacturing cold-rolled steel sheet for deep processing based on ultra-low carbon IF steel, by performing cooling control during hot finish rolling, by controlling the precipitation behavior of carbon and nitride having a great influence on the workability of the cold-rolled steel sheet, It is an object of the present invention to provide a method for stably manufacturing a cold rolled steel sheet for deep processing, which is excellent in press workability even with steel.
[발명의 구성과 작용][Configuration and Action of the Invention]
본 발명은 심가공용 냉연강판의 제조방법에 있어서, 중량%로 0.01% 이하의 C, 0.01% 이하의 S, 0.007% 이하의 N을 포함하고, Ti* = Total Ti-3.43(%N) - 1.5(%S)의 조건을 만족하는 유호티타늄(Ti*)량과 탄소량과의 원자당량비(Ti*/4C%)가 1 이상이 되도록 조성된 통상의 Ti 첨가 극저탄소강 슬라브를 열연 재가열후, 열간압연기에 투입하여 Ar3 변태점(900℃) 이상에서 마무리 압연을 실시하여 열연판을 제조하고, 이 열연판을 이용하여 통상의 산세, 냉연 및 연속소둔처리를 함으로써 심가공용 냉연강판을 제조하는 기본적인 제조방법은 종래의 방법과 유사하다.The present invention is a method for manufacturing a cold rolled steel sheet for deep processing, the weight percent of less than 0.01% C, 0.01% or less S, 0.007% or less N, Ti * = Total Ti-3.43 (% N)-1.5 After hot-rolling and reheating a conventional Ti-added ultra-low carbon steel slab which is formed so that the atomic equivalent ratio (Ti * / 4C%) between the amount of eu titanium (Ti *) and the amount of carbon satisfying the condition of (% S) is 1 or more, It is put into a hot rolling mill and finish-rolled at an Ar3 transformation point (900 ° C) or higher to manufacture a hot rolled sheet, and a basic manufacturing process for manufacturing a cold rolled steel sheet for deep processing by performing normal pickling, cold rolling and continuous annealing using the hot rolled sheet. The method is similar to the conventional method.
그러나, 본 발명은 상기의 성분으로 조성된 강을 조압연 직후부터 마무리 압연의 단계까지 제어압연을 실시함으로써 냉연 가공성을 한층 더 상승시키는 제조방법을 제공한다는 점에서 종래의 방법과는 근본적으로 다르다.However, the present invention is fundamentally different from the conventional method in that it provides a manufacturing method for further increasing cold-rolling workability by performing control rolling of the steel composed of the above components from the rough rolling to the stage of finish rolling.
즉, 본 발명은 재가열된 슬라브를 열연 조압연 직후의 온도가 1050℃ 이상이 되도록 압연한 다음, 계속하여 통상 6-7 스탠드를 지닌 텐덤(Tandem) 형식의 압연기를 이용하여 마무리 압연을 실시할 때 마무리 압연기 전단부 3번째 스탠드에서의 압연온도가 940-980℃가 되도록 하고, 또한 압연기 1번째 스탠드 입측과 3번째 스탠드 출측에서의 열연스트립(strip)의 온도차이가 70℃ 이상이 되도록 물을 분사하여 냉각하면서 제어압연을 실시함으로써 열연판을 제조하고, 이 열연판을 소재로 통상의 냉연 및 연속소둔을 실시하여 동일한 성분계로도 한층 더 가공성이 우수한 심가공용 냉연강판을 제조하는 방법을 제공하는 것을 특징으로 한다.That is, in the present invention, when the reheated slab is rolled so that the temperature immediately after hot-rolling rough rolling is 1050 ° C. or higher, and then finish rolling is performed using a tandem rolling mill having a normal 6-7 stand. Water is sprayed so that the rolling temperature at the third stand of the finishing mill front end is 940-980 ℃ and the temperature difference between the hot rolled strip at the entrance of the first stand of the rolling mill and the exit of the third stand is 70 ℃ or more. A method of producing a hot rolled steel sheet for deep processing, which is excellent in workability even with the same component system, by producing a hot rolled sheet by performing control rolling while cooling, and performing normal cold rolling and continuous annealing on the hot rolled sheet as a material. It is done.
이하 본 발명에서 제조 조건을 한정한 이유를 자세히 설명하면 다음과 같다.Hereinafter, the reason for limiting the manufacturing conditions in the present invention will be described in detail.
강증 탄소, 황, 질소 등과 탄질화물 형성원소로써 첨가하는 티타늄(Ti)의 함유량은 현행의 연주-열연-산세-냉연-연속소둔의 제조공정으로 제조하는 심가공용 냉연강판의 일반적인 성분계와 동일하며, 그 한정 이유는 주로 프레스 가공성의 확보를 위한 것이지만, 제조 조건에 따라서는 동일 성분계에서도 가공성의 중요한 척도인 드로잉성(r값)은 매우 다르게 나타날 수 있다.The content of titanium (Ti) added as a carbonitride forming element such as carbon, sulfur, nitrogen, etc. is the same as that of the general component system of the cold rolled steel sheet for deep processing manufactured by the current production process of hot rolling, hot rolling, pickling, cold rolling, and continuous annealing. The reason for the limitation is mainly for securing press formability, but depending on manufacturing conditions, drawing property (r value), which is an important measure of workability, may appear very differently in the same component system.
상기 강종으로 제조한 냉연강판의 프레스 가공성은 강중에 존재하는 티타늄계 석출물의 석출거등과 매우 밀접한 관계를 가지고 있으며, 석출물의 조성은 주로 TIN, Ti4C2S2, TiC 등이다. 또한, 상기 석출물은 그 종류에 따라 석출되는 온도영역이 서로 다르며, TiN의 경우는 1200℃ 이상의 고온에서 석출되며, TiC는 700-900℃ 사이의 비교적 저온에서 활발하게 석출이 일어나고, 또한 Ti4C2S2는 TiN과 TiC 석출온도의 중간영역에서 주로 석출이 일어난다.Press workability of the cold rolled steel sheet produced by the steel species has a very close relationship with the precipitation of titanium-based precipitates present in the steel, the composition of the precipitate is mainly TIN, Ti 4 C 2 S 2 , TiC and the like. In addition, the precipitates are different in the temperature range that is precipitated according to the type, in the case of TiN is precipitated at a high temperature of more than 1200 ℃, TiC is actively precipitated at a relatively low temperature between 700-900 ℃, and also Ti 4 C 2 S 2 mainly precipitates in the middle region of TiN and TiC precipitation temperatures.
상기 석출물중 TiN이 냉연강판의 가공성에 미치는 영향이 미미하나, Ti4C2S2및 TiC의 석출, 고용거동은 열연권취 후의 잔류 고용탄소량과 함께 매우 큰 영향을 미친다. 즉, 고용탄소 및 수십Å 이하의 미세한 TiC는 가공성에 악영향을 미치므로 양호한 프레스 가공성을 확보하기 위해서는 강중 고용탄소량을 제로(zero)로 만들고, 또한 석출물도 주로 에너지적으로 안정한 Ti4C2S2및 조대한 TiC를 수백Å의 크기로 형성시키는 것이 필요하며, 본 발명은 열간압연시 냉각제어를 실시함으로써 상기 개념을 실현시키는 수단을 제공하는 것이다.Although the influence of TiN on the workability of the cold rolled steel sheet in the precipitate is minimal, precipitation and solid solution behavior of Ti 4 C 2 S 2 and TiC have a great influence with the amount of residual dissolved carbon after hot rolling. That is, the employment of carbon and several fine TiC of Å or less is so adversely affect workability preferred in order to ensure press formability is created and the steel employed carbon amount to be zero (zero), also precipitates mostly energetically stable Ti 4 C 2 S It is necessary to form 2 and coarse TiC in the size of several hundred microns, and the present invention provides a means for realizing the above concept by performing cooling control during hot rolling.
슬라브를 통상의 재가열 온도인 1200℃ 정도에서 균열하면 강증 석출물은 TiN만이 존재하게 되며, 다른 석출물은 거의 용해된다. 계속하여 조압연을 실시하는 경우 조압연 후에도 고용원소의 고용도가 높은 상태로 유지되도록 하여, 뒤이은 마무리 압연시 Ti4C2S2를 효과적으로 석출시키기 위하여 조압연 직후의 온도를 1050℃ 이상이 되도록 제한한다.When the slab is cracked at about 1200 ° C., which is a normal reheating temperature, only the TiN is present in the hardened precipitate, and other precipitates are almost dissolved. In the case of continuous rough rolling, the solid solution of the solid solution element is maintained even after rough rolling, and the temperature immediately after the rough rolling is increased to 1050 ° C. or more in order to effectively precipitate Ti 4 C 2 S 2 during subsequent finish rolling. Limit as much as possible.
마무리 압연시의 텐덤압연기중 1-3번째 스탠드 사이의 온도차가 70℃ 이상이 되도록 제한한 이유는 가공성에 유리한 Ti4C2S2및 비교적 조대한 수백Å의 TiC를 효과적으로 석출시키기 위한 수단이며, 또한 마무리 압연시 3번째 스텐드에서의 압연온도 제한범위 중, 상한치 온도를 980℃로 제한한 이유는 조압연 후부터 마무리 압연까지의 열손실을 고려했을 때 마무리 압연 전단부에서의 냉각온도를 최소한 70℃ 이상으로 유지하기 위한 온도이며, 하한치 온도를 940℃로 제한한 이유는 마무리 압연 완료 온도를 Ar3 변태점 이상으로 안정적으로 유지하기 위해서다.The reason why the temperature difference between the first and third stands in the tandem rolling mill during the finish rolling is limited to 70 ° C. or more is a means for effectively depositing Ti 4 C 2 S 2, which is advantageous for workability, and relatively coarse hundreds of TiC. In addition, the reason why the upper limit temperature was limited to 980 ℃ among the rolling temperature limitation ranges in the third stand during finish rolling was that the cooling temperature at the front end of the finish rolling was at least 70 ℃ considering the heat loss from rough rolling to finish rolling. It is temperature for maintaining above, and the reason which limited the lower limit temperature to 940 degreeC is in order to hold | maintain finish rolling completion temperature stably above Ar3 transformation point.
상기와 같은 방식으로 마무리 압연을 실시하면 종래 극저탄소강에서 중요시하던 조업인자였던 고온권취를 실시할 필요도 없을 뿐만 아니라, 또한 후속 공정인 산세, 냉간압연 및 연속소둔후, 동일한 성분계에서도 한층 더 가공성이 우수한 심가공용 냉연강판을 안정적으로 제조할 수가 있는 것이다.When the finish rolling is carried out in the above manner, it is not only necessary to carry out the high temperature winding, which is an operation factor that has been important in the conventional ultra low carbon steel, but also further workability in the same component system after pickling, cold rolling and continuous annealing. This excellent deep-rolled cold rolled steel sheet can be manufactured stably.
이하 본 발명의 실시예에 대하여 설명한다.Hereinafter, embodiments of the present invention will be described.
[실시예]EXAMPLE
0.004%C, 0.008%S, 0.005%N 및 0.043%Ti의 화학성분을 갖는 통상의 티타늄(Ti) 첨가 극저탄소강을 용해하여, 하기 표1의 열간압연 조건으로 3.2mm 두께의 열연판을 제조하였다.Melting the conventional titanium (Ti) addition ultra low carbon steel having the chemical composition of 0.004% C, 0.008% S, 0.005% N and 0.043% Ti, to prepare a 3.2mm thick hot rolled sheet under the hot rolling conditions of Table 1 It was.
상기의 열연판을 염산용액으로 산세하여, 75%의 압하올로 냉간압연한 후, 810℃의 온도로 연속소둔을 실시하였으며, 상기의 열간압연 조건에 의해 제조된 시료의 기계적 성질을 표 2에 나타내었다.The hot rolled plate was pickled with a hydrochloric acid solution, cold rolled with 75% rolled olol, and then continuously annealed at a temperature of 810 ° C. The mechanical properties of the samples prepared by the hot rolling conditions described in Table 2 below. Indicated.
상기 표 2에 나타낸 바와 같이, 동일한 성분의 티타늄(Ti) 첨가 극저탄소강을 이용하였는데도 불구하고, 본 발명의 방법에 의하면 종래의 방법으로 제조한 냉연강판(비교재)과 비교해 볼 때 한층 더 우수한 기계적 성질을 안정적으로 나타내는 것이다.As shown in Table 2, despite the use of titanium (Ti) -added ultra-low carbon steel of the same component, according to the method of the present invention further compared to the cold-rolled steel sheet (comparative material) prepared by the conventional method It stably exhibits excellent mechanical properties.
결국, 본 발명의 방법에 의하면 열연 마무리 압연시 냉각제어를 실시함으로써 프레스 가공성이 한층 더 우수한 심가공용 냉연강판의 제조가 가능할 뿐만 아니라, 심가공용 Ti첨가 극저탄소강의 안정적인 재질확보를 꾀할 수 있기 때문에 재질불량 발생에 의한 생산실수율 하락등의 문제를 피할 수 있는 것이다. 또한, 본 발명은 열연권취 온도(표1 참조)의 적용범위가 넓어 조업이 용이하며, 저온권취도 가능하기 때문에 표면스케일 측면에서도 유리한 부수적인 잇점이 있는 것이다.As a result, according to the method of the present invention, by performing cooling control during hot-rolled finish rolling, it is possible not only to manufacture cold-rolled steel sheet for deep work, which is more excellent in press formability, but also to obtain a stable material of ultra-low carbon steel with Ti for deep work. Problems such as falling production yield due to defects can be avoided. In addition, the present invention has a wide range of application of the hot rolled winding temperature (see Table 1) is easy to operate, and low-temperature winding can also be advantageous in terms of surface scale is an additional advantage.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019950045020A KR100217943B1 (en) | 1995-11-29 | 1995-11-29 | Method for manufacturing cold rolled steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019950045020A KR100217943B1 (en) | 1995-11-29 | 1995-11-29 | Method for manufacturing cold rolled steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR970027325A KR970027325A (en) | 1997-06-24 |
| KR100217943B1 true KR100217943B1 (en) | 1999-09-01 |
Family
ID=19436646
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1019950045020A KR100217943B1 (en) | 1995-11-29 | 1995-11-29 | Method for manufacturing cold rolled steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR100217943B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9962760B2 (en) | 2009-02-09 | 2018-05-08 | Toho Titanium Co., Ltd. | Titanium slab for hot rolling produced by electron-beam melting furnace, process for production thereof, and process for rolling titanium slab for hot rolling |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100282192B1 (en) * | 1996-11-27 | 2001-02-15 | 이구택 | Manufacturing method of cold rolled steel sheet for deep processing with excellent fatigue characteristics and secondary workability |
-
1995
- 1995-11-29 KR KR1019950045020A patent/KR100217943B1/en not_active IP Right Cessation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9962760B2 (en) | 2009-02-09 | 2018-05-08 | Toho Titanium Co., Ltd. | Titanium slab for hot rolling produced by electron-beam melting furnace, process for production thereof, and process for rolling titanium slab for hot rolling |
Also Published As
| Publication number | Publication date |
|---|---|
| KR970027325A (en) | 1997-06-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU652694B2 (en) | High-strength cold-rolled steel sheet excelling in deep drawability and method of producing the same | |
| KR100500791B1 (en) | FERRITIC Cr-CONTAINING STEEL SHEET HAVING EXCELLENT DUCTILITY, FORMABILITY, AND ANTI-RIDGING PROPERTIES, AND METHOD OF PRODUCING THE SAME | |
| JP2000144258A (en) | Production of titanium-containing ferritic stainless steel sheet excellent in ridging resistance | |
| JPH08253818A (en) | Production of ferritic stainless steel strip reduced in inplane anisotropy and excellent in balance between strength and elongation | |
| KR100217943B1 (en) | Method for manufacturing cold rolled steel sheet | |
| JP3302118B2 (en) | Manufacturing method of cold rolled steel sheet with excellent deep drawability | |
| EP0130221B1 (en) | Process for producing corrosion-resistant alloy steel | |
| GB2107226A (en) | Process for producing deep-drawing cold rolled steel sheet | |
| JPS62192539A (en) | Manufacture of high gamma value hot rolled steel plate | |
| KR960005225B1 (en) | Making method of excellent deep drawing cold steel sheet | |
| JPS6052551A (en) | Steel having high ductility and high workability and its production | |
| JP2948416B2 (en) | High strength cold rolled steel sheet and hot dip galvanized steel sheet with excellent deep drawability | |
| JPH05239554A (en) | Production of cold rolled steel sheet for extra deep drawing having baking hardenability | |
| JP3043901B2 (en) | Method for producing high-strength cold-rolled steel sheet and galvanized steel sheet with excellent deep drawability | |
| JP3735142B2 (en) | Manufacturing method of hot-rolled steel sheet with excellent formability | |
| JP3446001B2 (en) | Method for producing cold-rolled steel sheet and hot-dip galvanized steel sheet with excellent workability | |
| JP2526122B2 (en) | Manufacturing method of cold-rolled steel sheet for deep drawing by strip casting | |
| KR20010074992A (en) | Method for producing cold-rolled bands or sheets | |
| KR100415721B1 (en) | continuous annealing cold rolled steel and method of manufacturing the same | |
| JPS593528B2 (en) | Manufacturing method of galvanized steel sheet for deep drawing with excellent formability | |
| JP3366661B2 (en) | Manufacturing method of high tensile cold rolled steel sheet with excellent deep drawability | |
| JPH0225518A (en) | Production of hot-rolled steel sheet having excellent deep drawability | |
| KR100282192B1 (en) | Manufacturing method of cold rolled steel sheet for deep processing with excellent fatigue characteristics and secondary workability | |
| JPS59123721A (en) | Production of cold rolled steel sheet having excellent processability | |
| JPS59575B2 (en) | Manufacturing method for high-strength cold-rolled steel sheets with excellent formability |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant | ||
| FPAY | Annual fee payment |
Payment date: 20030529 Year of fee payment: 5 |
|
| LAPS | Lapse due to unpaid annual fee |