KR100957974B1 - High Managese Steel Plate, Hot Rolled Steel Plate, Cold Rolled Steel Plate, Galvanized Steel Plate Having Excellent Hole Expansibility and Manufacturing Method Thereof - Google Patents
High Managese Steel Plate, Hot Rolled Steel Plate, Cold Rolled Steel Plate, Galvanized Steel Plate Having Excellent Hole Expansibility and Manufacturing Method Thereof Download PDFInfo
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Abstract
본 발명은 중량%로, C: 0.3~0.9%, Mn: 15~30%, Al: 0.01~4.0%, Si: 0.1% 미만, P: 0.05% 이하, S: 0.01% 이하, N: 0.04% 이하를 포함하며, 여기에 Nb: 0.02~0.1%, Ti: 0.01~0.1% 및 V: 0.025~0.5%로 이루어지는 그룹에서 선택되어진 1종 또는 2종 이상의 성분을 추가적으로 포함하는 것을 특징으로 하는 고강도 고망간강, 상기 고망간강을 열간압연한 열간압연 강판, 냉간압연한 냉간압연 강판을 제공한다. 나아가 본 발명은 상기 냉간압연 강판을 전기도금 처리 또는 합금화 용융도금 처리한 고망간 도금강판을 제공한다.In the present invention, by weight, C: 0.3-0.9%, Mn: 15-30%, Al: 0.01-4.0%, Si: less than 0.1%, P: 0.05% or less, S: 0.01% or less, N: 0.04% It includes the following, wherein the high-strength high, characterized in that it further comprises one or two or more components selected from the group consisting of Nb: 0.02 ~ 0.1%, Ti: 0.01 ~ 0.1% and V: 0.025 ~ 0.5% Provided are manganese steel, hot rolled steel sheet hot rolled high-manganese steel, cold rolled cold rolled steel sheet. Furthermore, the present invention provides a high manganese plated steel sheet in which the cold rolled steel sheet is subjected to electroplating or alloyed hot dip plating.
본 발명의 고망간강 및 이를 이용한 강판에 의하면 인장강도가 800MPa급 이상이면서도 30% 이상의 연신율을 가지며 구멍확장성이 우수한 자동차용 강판을 제조할 수 있다.According to the high manganese steel of the present invention and the steel sheet using the same, it is possible to manufacture a steel sheet for automobile having a tensile strength of 800 MPa or more and an elongation of 30% or more and excellent hole expansion property.
고망간강, 구멍확장성, 열간압연, 냉간압연, 전기도금 처리, 합금화 용융도금 High Manganese Steel, Hole Expandability, Hot Rolled, Cold Rolled, Electroplating, Alloy Hot-dip Plating
Description
본 발명은 가공성이 우수한 고강도 고망간강에 관한 것으로, 보다 상세하게는 연신율이 우수하여 가공성이 높고, 최적화된 Al 첨가 및 석출상 형성원소들을 이용하여 구멍확장성이 우수한 고강도 고망간강과 이를 이용하여 제조하는 열간압연 강판, 냉간압연 강판 및 이들의 제조방법에 관한 것이다. The present invention relates to high-strength high manganese steel with excellent workability, and more particularly, high elongation and high workability due to excellent elongation, and excellent hole expandability using optimized Al addition and precipitated phase forming elements, and manufacturing using the same. It relates to a hot rolled steel sheet, a cold rolled steel sheet and a manufacturing method thereof.
자동차 산업에 관한 환경 오염, 연비 향상, 안전성 향상 등에 대한 관심이 증폭됨에 따라, 각 자동차 제조업체들은 경량 소재, 고강도 소재의 적용을 확대하고 있다. 이러한 추세는 자동차 부품 이외에도 다양한 구조부재에 적용되는 재료가 가져야 할 특성이기도 하기 때문에 적극적인 연구가 지속되고 있다. With increasing interest in environmental pollution, fuel efficiency and safety in the automotive industry, automakers are expanding the application of lightweight and high-strength materials. This trend is active because the materials applied to various structural members in addition to automobile parts have active characteristics.
그러나 소재는 일반적으로 강도가 증가하면 연신율이 감소하는 특성을 가진다. 따라서, 안전성과 직결된 강도와 적절한 가공성에 관련된 연신율을 모두 만족하기는 어려운 것이 현실이다. 이러한 문제점을 극복하기 위해, 성형성이 우수한 이상조직강, 변태유기소성강 등의 강종이 종래에 개발되었으나, 이러한 강종들도 강도가 높고 연신율이 높지 않아 자동차 구조부재, 내판재 등의 자동차부품이 요구하는 가공성을 만족하지 못하기 때문에 복잡한 형상을 갖고 있는 부품을 제조하는 것에는 한계가 있다. However, the material generally has the property of decreasing elongation with increasing strength. Therefore, it is difficult to satisfy both the strength directly related to safety and the elongation associated with proper workability. In order to overcome these problems, steel grades such as abnormal tissue steels and metamorphic organic-plastic steels, which are excellent in formability, have been developed in the past, but these steel grades also have high strength and low elongation, so that automotive parts such as automobile structural members and inner plate materials are used. There is a limit to manufacturing a part having a complicated shape because it does not satisfy the required workability.
특히, 자동차용 강판으로 저탄소강 계열의 고강도강을 사용하는 경우에는 인장강도가 800MPa급 이상에서는 연신율이 최고 30% 이상 확보되어야 복잡한 형상의 부품에도 적용하기가 용이하지만, 종래의 저탄소강 계열의 고강도강에서는 이러한 물성을 얻기 어렵다는 한계가 존재한다.Particularly, in case of using low carbon steel high strength steel as the automotive steel plate, when the tensile strength is 800MPa or more, the elongation must be secured up to 30% or more, but it is easy to apply to the complicated shape parts, but the high strength of the conventional low carbon steel series In steel, there is a limit that it is difficult to obtain these properties.
따라서, 이러한 문제점들을 해소하고자 자동차 제조업체들은 부품의 형상을 간소화 하거나, 여러 개의 부품으로 구분하여 성형하고 다시 용접하는 복잡하고 우회적인 공정을 이용하고 있는 것이 현실이다. 하지만, 부품을 용접에 의해 제작하는 경우에는 용접부의 물성이 모재에 비해 취약할 수 밖에 없기 때문에 차체의 설계에 많은 제약을 받을 뿐만 아니라, 용접부의 열위에 의한 부품 특성 저하는 물론 부품을 나누어 성형하면서 공정비용이 크게 증가한다는 단점이 여전히 존재한다. Therefore, in order to solve these problems, automakers are using a complicated and bypassing process of simplifying the shape of parts or forming and re-welding them into several parts. However, when manufacturing parts by welding, the properties of the weld are inevitably weaker than those of the base metal, and therefore they are not only limited to the design of the vehicle body but also deteriorated in part characteristics due to the inferiority of the weld. There is still a disadvantage that the process cost increases significantly.
따라서 자동차 제조업체들은 복잡한 형상의 부품을 성형할 수 있으며 차체 설계시 설계자유도를 높이기 위하여 고강도를 나타내면서도 가공성과 구멍확장성이 우수한 재료를 지속적으로 요구하고 있다.Therefore, automakers can form parts with complex shapes and continuously demand materials having high strength and excellent workability and hole expandability in order to increase design freedom in designing a vehicle body.
본 발명은 상술한 자동차 제조업체들의 요구에 부응할 수 있도록 강판 자체의 강도가 높으면서도 동시에 그 가공성 및 구멍확장성이 우수하여 복잡한 자동차 제품이라도 안정적이고 용이하게 제조할 수 있는 고망간형 고강도 강판을 제공하고자 한다. The present invention provides a high manganese type high strength steel sheet that can be manufactured stably and easily even in complex automobile products due to the high strength of the steel sheet itself and excellent processability and hole expansion property to meet the demands of the above-described automobile manufacturers. I would like to.
본 발명은 중량%로, C: 0.3~0.9%, Mn: 15~30%, Al: 0.01~4.0%, Si:0.1% 미만, P: 0.05% 이하, S: 0.01% 이하, N: 0.04% 이하를 포함하며, 여기에 Nb: 0.02~0.1%, Ti: 0.01~0.1% 및 V: 0.025~0.5%로 이루어지는 그룹에서 선택되어진 1종 또는 2종 이상의 성분을 추가적으로 포함하는 것을 특징으로 하는 고강도 고망간강을 제공한다. In the present invention, by weight, C: 0.3-0.9%, Mn: 15-30%, Al: 0.01-4.0%, Si: less than 0.1%, P: 0.05% or less, S: 0.01% or less, N: 0.04% It includes the following, wherein the high-strength high, characterized in that it further comprises one or two or more components selected from the group consisting of Nb: 0.02 ~ 0.1%, Ti: 0.01 ~ 0.1% and V: 0.025 ~ 0.5% Provide manganese steel.
나아가, 본 발명은 상기 고망간강을 열간압연한 열간압연 강판, 냉간압연한 냉간압연 강판을 제공한다.Furthermore, the present invention provides a hot rolled steel sheet that hot rolled the high manganese steel, and a cold rolled steel sheet that is cold rolled.
나아가 본 발명은 상기 냉간압연 강판을 전기도금 처리 또는 합금화 용융도금 처리한 고망간 도금강판을 제공한다.Furthermore, the present invention provides a high manganese plated steel sheet in which the cold rolled steel sheet is subjected to electroplating or alloyed hot dip plating.
나아가 본 발명은 중량%로, C: 0.3~0.9%, Mn: 15~30%, Al: 0.01~4.0%, Si: 0.1% 미만, P: 0.05% 이하, S: 0.01% 이하, N: 0.04% 이하를 포함하며, 여기에 Nb: 0.02~0.1%, Ti: 0.01~0.1% 및 V: 0.025~0.5%로 이루어지는 그룹에서 선택되어진 1종 또는 2종 이상의 성분을 추가적으로 포함하는 강 슬라브에 대해,Furthermore, the present invention is in weight%, C: 0.3-0.9%, Mn: 15-30%, Al: 0.01-4.0%, Si: less than 0.1%, P: 0.05% or less, S: 0.01% or less, N: 0.04 For steel slabs containing up to one or more components selected from the group consisting of up to and including Nb: 0.02 to 0.1%, Ti: 0.01 to 0.1% and V: 0.025 to 0.5%,
1050~1300℃로 가열하여 균질화시키는 재가열 단계;Reheating step to homogenize by heating to 1050 ~ 1300 ℃;
850~1000℃에서 마무리 열간압연하여 강판을 제조하는 열간압연 단계; 및Hot rolling step of producing a steel sheet by finishing hot rolling at 850 ~ 1000 ℃; And
상기 강판을 700℃ 이하의 온도에서 권취하는 권취단계;A winding step of winding the steel sheet at a temperature of 700 ° C. or less;
를 포함하는 것을 특징으로 하는 고망간 열간압연 강판의 제조 방법을 제공한다.It provides a method for producing a high manganese hot rolled steel sheet comprising a.
나아가 본 발명은 상기 고망간 열간압연 강판을 10~80%의 압하율로 냉간압연하여 제조하는 고망간 냉간압연 강판 및 상기 냉간압연 강판을 700℃ 이상에서 연속소둔 및 도금처리함으로써 고망간 도금 강판을 제조하는 방법을 제공한다.Furthermore, the present invention provides a high manganese hot rolled steel sheet by continuously annealing and plating the high manganese cold rolled steel sheet and the cold rolled steel sheet manufactured by cold rolling the high manganese hot rolled steel sheet at a reduction ratio of 10 to 80%. It provides a method of manufacturing.
본 발명의 고망간강 및 이를 이용한 강판에 의하면 인장강도가 800MPa급 이상이면서도 30% 이상의 연신율을 가지며 구멍확장성이 우수한 자동차용 강판을 제조할 수 있다.According to the high manganese steel of the present invention and the steel sheet using the same, it is possible to manufacture a steel sheet for automobile having a tensile strength of 800 MPa or more and an elongation of 30% or more and excellent hole expansion property.
본 발명자들은 높은 강도를 가지면서도 동시에 가공성 및 구멍확장성이 우수한 강판을 제공하기 위하여 연구를 거듭한 결과, 강재 내에 Mn을 다량 첨가하여 형성된 오스테나이트계 단상조직 고망간강에 Al을 최적화된 함량으로 적절히 첨가하여 쌍정(twinning)의 형성 속도를 제어하고, 나아가 석출상 형성원소들을 이용하여 가공경화율을 향상시켜 연신율과 같은 인장성질이나 구멍확장성을 개선할 수 있다는 사실을 알게 되었고, 이러한 사실들을 기초로 본 발명에 이르게 되었다.The present inventors have studied to provide a steel sheet having high strength and excellent workability and hole expansion property, and as a result, an aluminium-based single phase high manganese steel formed by adding a large amount of Mn in the steel material is suitably used in an optimized amount of Al. It has been found that the addition rate can control the formation rate of twinning and further improve the process hardening rate using the precipitated phase forming elements to improve the tensile properties such as elongation or hole expandability. This has led to the present invention.
나아가 이러한 고망간강에 C의 양을 적절히 제어하여 가공성을 향상시키며, Si양을 저감하여 우수한 표면품질의 확보도 함께 가질 수 있도록 하였다.Furthermore, by controlling the amount of C in the high manganese steel appropriately, the workability is improved, and the amount of Si is reduced to ensure excellent surface quality.
이하, 본 발명의 강재를 구성하는 성분계에 관하여 상세히 설명한다.(이하 중량%)Hereinafter, the component system constituting the steel of the present invention will be described in detail.
C: 0.3~0.9%C: 0.3 ~ 0.9%
C는 오스테나이트상의 안정화에 기여할 수 있는 원소이다. C의 첨가량이 0.3% 미만에서는 변형시 α'-마르테사이트상이 형성되기 때문에 강공시 크랙이 발생하고, 연성이 낮아지는 단점이 나타나며, 반면 C의 첨가량이 0.9%를 초과하는 경우에는 오스테나이트상의 안정도가 지나치게 증가하여 슬립변형에 의한 변형거동의 천이로 가공성이 낮아질 수 있다. 따라서 C의 첨가량은 0.3~0.9%로 제한한다.C is an element that can contribute to stabilization of the austenite phase. If the amount of C added is less than 0.3%, the α'-marthecite phase is formed during deformation, so that cracks occur during steelworking and ductility is lowered. On the other hand, if the amount of C is more than 0.9%, the austenite phase is stable. Too much increase may result in a lower workability due to the transition of the deformation behavior due to slip deformation. Therefore, the amount of C added is limited to 0.3 ~ 0.9%.
Mn: 15~30%Mn: 15 ~ 30%
Mn은 역시 오스테나이트상을 안정화시키는데 필수적인 원소이지만, 15% 미만에서는 성형성을 해치는 α'-마르테사이트상이 형성될 수 있어 강도는 증가하지만 연성이 급격히 감소할 수 있다. 반면, Mn의 첨가량이 30%를 초과하는 경우에는 쌍정의 발생이 억제되어 강도는 증가하지만 연성이 감소할 수 있다. 나아가 Mn의 첨가량이 증가할수록 열간압연 크랙발생이 잘 일어나고, 제품 생산 단가가 상승하기 때문에 Mn 첨가량의 상한은 30%로 한정한다. Mn is also an essential element for stabilizing the austenite phase, but at less than 15%, an α'-marthecite phase can be formed which impairs the formability, thereby increasing the strength but decreasing the ductility rapidly. On the other hand, when the amount of Mn added exceeds 30%, the occurrence of twins is suppressed to increase strength but decrease ductility. Furthermore, as the amount of Mn added increases, hot rolling cracking occurs well, and the production cost of products increases, so the upper limit of the amount of Mn added is limited to 30%.
Al: 0.01~4.0%Al: 0.01 ~ 4.0%
Al은 통상 강의 탈산을 위하여 첨가되지만 본 발명에서는 가공경화지수를 증가시켜 가공경화율을 향상시키기 위해 첨가되는 원소로서 본 발명에서는 매우 중요한 원소로 기능한다. 본 발명과 같은 고망간형강에서 Al은 페라이트상의 안정화 역할 뿐만 아니라 강의 슬립면에서 적층결함 에너지(stacking fault energy)를 증가시켜 ε-마르테사이트상의 생성을 억제함으로써 연성을 향상시킨다. 나아가 Al은 낮은 Mn 첨가량의 경우에도 ε-마르테사이트상의 생성을 억제할 수 있기 때문에 Mn의 첨가량을 최소화하고 가공성을 향상시키는데 큰 기여을 한다. Al is usually added for deoxidation of steel, but in the present invention, Al is added to increase the work hardening index and thus the work hardening rate. In high manganese steels such as the present invention, Al improves ductility by suppressing formation of ε-marte cite phase by increasing the stacking fault energy in the slip surface of the steel as well as the stabilizing role of the ferrite phase. Furthermore, Al can suppress the formation of the epsilon-marte cite phase even in the case of low Mn addition amount, thus making a great contribution to minimizing Mn addition amount and improving workability.
또한 Al 첨가시 성분 편석이 감소하여 재질이 균일화되고 성형성이 증가한다. 따라서 이러한 특성 때문에 0.01%이상을 첨가하는 것이 필요하며, 그 미만의 첨가량에서는 ε-마르텐사이트가 생성되어 강도는 증가하지만 구멍확장성이 감소할 수 있다. 하지만, 그 첨가량이 4.0%를 초과하는 경우에는 쌍정의 발생을 억제하여 연성의 감소, 연속주조시 주조성의 저하, 열간압연시 표면산화의 발생으로 인한 제품의 표면품질 저하 등의 문제점이 존재할 수 있으므로 그 상한은 4.0%로 한정한다.In addition, the segregation of components is reduced when Al is added, so that the material becomes uniform and formability is increased. Therefore, it is necessary to add more than 0.01% because of this property, the ε-martensite is produced at the addition amount of less than that may increase the strength but decrease the hole expandability. However, if the added amount exceeds 4.0%, there may be problems such as reducing the ductility by reducing the occurrence of twinning, deterioration of castability during continuous casting, and deterioration of the surface quality of the product due to surface oxidation during hot rolling. Therefore, the upper limit is limited to 4.0%.
Nb: 0.02~0.1%Nb: 0.02-0.1%
Nb은 Ti과 같은 형태로 C와 결합하여 탄화물을 형성하는 강탄화물 형성 원소로서 본 발명에서는 중요한 원소로 기능한다. Nb로 형성된 탄화물은 결정립의 성장을 억제하여 결정입도 미세화에 효과적인 원소이며 통상적으로 Ti보다 낮은 온도에서 석출상을 형성하므로 결정입도 미세화와 석출상 형성에 의한 석출강화효과가 큰 원소이기 때문에 0.02~0.1%를 첨가한다. 그러나 0.02% 미만의 첨가량에서는 그 효과가 미미하고, 반면 0.1%를 초과하여 과다하게 첨가하면 과량의 Nb이 결정입계에 편석하여 입계취화를 일으키거나, 석출상이 과도하게 조대화되어 결정립의 성장 효과를 떨어뜨리므로 Nb의 첨가량은 0.02 ~ 0.1%로 한정한다.Nb is a strong carbide forming element that forms carbide such as Ti in combination with C in the same form as Ti, and functions as an important element in the present invention. Carbide formed of Nb is an effective element for miniaturization of grain size by suppressing the growth of crystal grains. Since it forms a precipitated phase at a temperature lower than Ti, since it is an element having a large precipitation strengthening effect due to refinement of grain size and formation of a precipitated phase, 0.02 to 0.1 Add% However, at less than 0.02%, the effect is insignificant. On the other hand, if it is added more than 0.1%, excessive Nb segregates at grain boundaries, causing grain embrittlement or excessively coarsening of precipitated phases. Since it falls, the amount of Nb added is limited to 0.02 to 0.1%.
Ti: 0.01~0.1%Ti: 0.01 ~ 0.1%
Ti은 탄소와 결합하여 탄화물을 형성하는 강탄화물 형성원소로 본 발명에서 석출상 형성원소로 작용하며, 이때 형성된 탄화물은 결정립의 성장을 막아 결정입도 미세화에 효과적이다. 그러나 0.01% 미만으로 미량 첨가하는 경우 그 효과가 미미하고, 반면 0.1%를 초과하면 과량의 Ti이 결정입계에 편석하여 입계취화를 일으 키거나, 석출상이 과도하게 조대화되어 결정립의 성장 효과를 떨어뜨리므로 Ti의 첨가량은 0.01 ~ 0.1%로 한정하였다.Ti is a strong carbide forming element that combines with carbon to form carbide, and acts as a precipitated phase forming element in the present invention, and the carbide formed is effective for miniaturizing grain size by preventing the growth of grains. However, if the addition amount is less than 0.01%, the effect is insignificant, whereas if it exceeds 0.1%, the excess Ti segregates at the grain boundaries, causing grain embrittlement, or excessively coarsening of the precipitate phase, thereby decreasing the grain growth effect. Therefore, the amount of Ti added was limited to 0.01 to 0.1%.
V: 0.025~0.5% V: 0.025-0.5%
V은 Ti, Nb과 같이 C와 결합하여 탄화물을 형성하는 강탄화물 형성원소로서 본 발명에서는 중요한 원소로 기능한다. 또한 V는 저온에서 미세한 석출상을 형성하므로 석출강화 효과가 큰 원소이기도 하다. 그러나, 0.02% 미만으로 미량 첨가하는 경우 효과가 미미하고, 반면 0.5%를 초과하면 과량의 Nb이 결정입계에 편석하여 입계취를 일으키거나, 석출상이 과도하게 조대화되어 결정입 성장 효과를 떨어뜨리므로 V의 첨가량을 0.025 ~ 0.5%로 한정하였다.V is a strong carbide forming element that forms carbide by bonding with C, such as Ti and Nb, and functions as an important element in the present invention. In addition, since V forms a fine precipitated phase at low temperature, V is also an element having a large precipitation strengthening effect. However, when added in a small amount of less than 0.02%, the effect is insignificant, whereas if it exceeds 0.5%, excess Nb segregates at the grain boundaries, causing grain boundary odors, or excessively coarsening of the precipitate phases, thereby reducing the grain growth effect. Therefore, the amount of V added was limited to 0.025 to 0.5%.
Si: 0.1% 미만Si: less than 0.1%
Si은 고용강화 원소로 고용효과에 의해 결정입도를 감소시켜 항복강도를 증가시킬 수 있다. 하지만, Si는 열간압연시 강판표면에 Si 산화물이 형성되어 산세 효과가 저감될 수 있고 이에 따라 열연강판의 표면품질이 저하될 수 있다. 또한, 과도한 Si은 연속소둔공정과 연속용융도금공정에서 고온 소둔시 강판표면에 농화되어 용융도금시 강판표면에 용융아연의 젖음성을 감소시키기 때문에 도금성에도 좋지 않은 영향을 미칠 수 있으며 용접성을 크게 저하시킬 수 있으므로 본 발명에서는 Si를 0.1% 미만으로 제한한다.Si is a solid solution strengthening element, the grain size can be reduced by the solid solution effect can increase the yield strength. However, since Si oxide is formed on the surface of the steel sheet during hot rolling, the pickling effect may be reduced, and thus the surface quality of the hot rolled steel sheet may be reduced. In addition, excessive Si is concentrated on the surface of the steel sheet during high temperature annealing in the continuous annealing process and the continuous hot dip plating process, thereby reducing the wettability of molten zinc on the surface of the steel sheet during hot dip plating. In the present invention, the Si is limited to less than 0.1%.
P: 0.05% 이하P: 0.05% or less
P은 제조 시 불가피하게 함유되는 원소이며, 연주크랙 형성 등 품질을 저하시키므로 그 첨가범위를 0.05% 미만으로 제한한다.P is an element that is inevitably contained in the manufacturing process, and the quality thereof, such as the formation of performance cracks, is reduced, so the range of addition is limited to less than 0.05%.
S: 0.01% 이하S: 0.01% or less
S는 제조 시 불가피하게 함유되는 원소이며, 조대한 망간황화물(MnS)을 형성하여 플렌지 크랙과 같은 결함을 발생시킬 수 있으며, 강판의 구멍확장성을 감소시키므로 그 첨가량을 최대한 억제하는 것이 바람직하다. 따라서, 그 첨가량은 0.01% 이하로 제한한다.S is an element that is inevitably contained during manufacture, and may form coarse manganese sulfide (MnS), which may cause defects such as flange cracks, and it is preferable to suppress the addition amount as much as possible because it reduces the hole expandability of the steel sheet. Therefore, the addition amount is limited to 0.01% or less.
N: 0.04% 이하N: 0.04% or less
N는 오스테나이트 결정립 내에서 응고 과정 중 알루미늄과 작용하여 미세한 질화물을 석출시켜 쌍정발생을 촉진하는 원소이다. 따라서 강판의 성형시 강도와 연성을 향상시키지만, 그 첨가량이 과도하여 0.04%를 초과하면 질화물이 과다하게 석출되어 열간가공성 및 연신율이 저하될 수 있으므로 질소의 첨가량은 0.04% 이하로 제한한다.N is an element that acts with aluminum during the solidification process in the austenite grains to precipitate fine nitrides to promote twin formation. Therefore, the strength and ductility of the steel sheet is improved. However, when the addition amount is excessively more than 0.04%, the nitride may be excessively precipitated and the hot workability and elongation may be lowered, so the amount of nitrogen is limited to 0.04% or less.
이하 본 발명의 고망간강을 제조하는 방법에 관하여 상세히 설명한다.Hereinafter, a method of manufacturing the high manganese steel of the present invention will be described in detail.
일반적으로 고망간강의 열연강판 제조는 일반강의 제조공정과 마찬가지로 연 속주조법을 이용한다. 상술한 성분계로 조성된 강 슬라브를 먼저 1050~1300℃ 범위에서 균질화 처리를 실시한다. In general, the production of hot rolled steel sheet of high manganese steel uses the continuous casting method as in the manufacturing process of ordinary steel. The steel slab composed of the above-described component system is first subjected to a homogenization treatment in the range of 1050 to 1300 ° C.
본 발명에서 열간압연시 강 슬라브 가열온도를 1050~1300℃로 제한하는데, 가열온도가 1300℃를 초과하면 결정입도가 증가하고, 표면산화가 발생하여 강도가 감소하거나, 표면이 열위될 수 있기 때문이다. 또한, 1300℃를 초과하는 온도로 가열하면 강 슬라브의 주상정입계에 액상막이 생길 수 있어 열간압연시 균열이 발생할 수도 있다. 하지만, 가열온도가 너무 낮으면 마무리 압연시 온도 확보가 어려워 온도감소에 의해 압연하중이 증가하여 소정의 두께까지 충분히 압연을 할 수 없으므로 그 하한은 1050℃로 제한한다. In the present invention, the steel slab heating temperature during hot rolling is limited to 1050 to 1300 ° C., when the heating temperature exceeds 1300 ° C., since the grain size increases, surface oxidation may occur, the strength may decrease, or the surface may be inferior. to be. In addition, when heated to a temperature exceeding 1300 ℃ can form a liquid film in the columnar grain boundary of the steel slab may cause cracks during hot rolling. However, if the heating temperature is too low, it is difficult to secure the temperature during the finish rolling, so the rolling load increases due to the temperature decrease, so that the rolling cannot be sufficiently rolled to a predetermined thickness, and the lower limit thereof is limited to 1050 ° C.
가열에 의하여 균질화 처리가 이루어진 상기 강 슬라브에 대해 850~1000℃ 범위에서 마무리 열간압연을 실시한다. 마무리 압연온도가 850℃ 미만으로 낮아지면 압연하중이 높아져 압연기에 무리가 갈 뿐만 아니라 강판 내부의 품질이 저하될 수 있다. 반면 압연 마무리 온도가 과도하게 높은 경우에는 압연시 표면 산화가 발생할 수 있으므로 압연마무리 온도는 850~1000℃로 제한한다.Finishing hot rolling is performed in the range of 850 to 1000 ° C. for the steel slab in which the homogenization treatment is performed by heating. When the finish rolling temperature is lowered below 850 ° C., the rolling load may be increased, which may not only impair the rolling mill but may also deteriorate the quality of the steel sheet. On the other hand, if the rolling finish temperature is excessively high, surface oxidation may occur during rolling, so the rolling finish temperature is limited to 850 to 1000 ° C.
마무리 열간압연 이후에 강판은 700℃ 이하의 온도에서 열연권취가 이루어진다. 상기 열연권취의 온도가 700℃를 초과하면 열연강판의 표면에 두꺼운 산화막과 내부산화가 발생할 수 있기 때문에 산세 과정에서 산화층의 제거가 용이하지 않게 된다. 따라서 열연강판의 권취온도는 700℃ 이하로 다소 낮게 하는 것이 바람직하다.After finishing hot rolling, the steel sheet is hot rolled at a temperature of 700 ° C or lower. When the temperature of the hot rolled coil exceeds 700 ℃, since the thick oxide film and internal oxidation may occur on the surface of the hot rolled steel sheet it is not easy to remove the oxide layer during the pickling process. Therefore, the coiling temperature of the hot rolled steel sheet is preferably lowered to 700 ℃ or less.
열간압연이 끝나면 강판 형상과 두께를 맞추기 위해서 냉간압연을 실시하게 되는데, 냉간압연의 압하율은 10~80%의 압하율로 실시한다. 냉간압연된 강판에 대하여 연속소둔 처리를 실시한다. 소둔 온도는 700℃ 이상에서 수행되는 것이 필요한데, 이는 소둔온도가 너무 낮으면 충분한 가공성을 확보하기 어렵고 저온에서 오스테나이트상을 유지할수 있을 만큼 오스테나이트로의 변태가 충분히 일어나지 않기 때문이다. 본 발명의 고망간강은 상변태가 일어나지 않는 오스테나이트강이기 때문에 재결정온도 이상으로 가열하면 충분히 가공성을 확보할 수 있기 때문에 700℃ 이상의 통상적인 소둔조건으로 소둔을 실시하여 제조한다. After hot rolling, cold rolling is performed to match the shape and thickness of the steel sheet. Cold rolling is performed at a rolling rate of 10 to 80%. The cold rolled steel sheet is subjected to a continuous annealing treatment. The annealing temperature needs to be performed at 700 ° C. or higher, because when the annealing temperature is too low, it is difficult to secure sufficient processability and transformation into austenite does not occur sufficiently to maintain an austenite phase at low temperatures. Since the high manganese steel of the present invention is an austenite steel which does not cause phase transformation, it is produced by annealing under ordinary annealing conditions of 700 ° C. or higher because heating can be ensured sufficiently when it is heated above the recrystallization temperature.
소둔이 이루어진 강판은 도금강판으로 제조될 수 있는데, 본 발명에서는 전기도금에 의한 전기도금 강판 또는 합금화 용융도금 처리에 의한 합금화 용융도금 강판으로 각각 처리하는 것이 가능하다. 상기 전기도금 강판으로 제조하기 위해서는 종래에 사용되는 통상의 방법 및 조건에서 전기도금을 실시하는 것으로 가능하다. 또한, 합금화 용융도금 처리는 연속소둔이 이루어진 냉연강판에 통상적인 합금화 용융도금 처리를 수행함으로써 이루어지며, 이러한 처리에 의하여 합금화 용융도금 강판을 제조할 수 있다. The annealing steel sheet may be made of a plated steel sheet, in the present invention, it is possible to treat the electroplated steel sheet by electroplating or the alloyed hot-dip steel sheet by alloyed hot-dip plating. In order to manufacture the electroplated steel sheet, it is possible to perform electroplating under conventional methods and conditions conventionally used. In addition, the alloying hot-dip plating treatment is performed by performing a conventional alloying hot-dip plating treatment on the cold rolled steel sheet is continuous annealing, it is possible to produce an alloyed hot-dip steel sheet by this treatment.
통상적인 변태조직강에 대해서 전기도금 공정이나 합금화 용융도금 처리를 수행하는 경우에는 적절한 열처리 조건이 요구되는 경우가 대부분이지만, 본 발명의 고망간강은 오스테나이트 단상 조직으로 구성되며 변태가 일어나지 않기 때문에 특별한 열처리 조건이 없어도 기계적 특성에 큰 차이가 나타나지 않으므로 통상의 조건에서 도금을 실시하여 강판을 제조할 수 있다.When performing the electroplating process or alloying hot-dip galvanizing treatment for a conventional metamorphic steel, in most cases, appropriate heat treatment conditions are required, but the high manganese steel of the present invention is composed of austenite single-phase structure and does not occur because transformation does not occur Since there is no significant difference in mechanical properties even without heat treatment conditions, the steel sheet may be manufactured by plating under normal conditions.
이하 실시예를 통해 본 발명을 보다 상세히 설명한다.The present invention will be described in more detail with reference to the following examples.
하기 표1은 발명강과 비교강들의 성분 조성을 나타낸 표이다. Table 1 is a table showing the composition of the inventive steel and comparative steels.
상기 표 1은 발명강과 비교강의 조성을 나타낸 것으로 각 조성의 강괴를 1200℃의 가열로에서 한시간 동안 유지한 후 열간압연을 실시하였다. 이어 이러한 열간압연 강판들에 대해 산세를 실시하고 냉간압하율을 50%로 하여 냉간압연을 하였다. Table 1 shows the compositions of the inventive steel and the comparative steel, and the steel ingots of each composition were maintained in a heating furnace at 1200 ° C. for one hour, and then hot rolled. Subsequently, pickling was performed on the hot rolled steel sheets and cold rolled at a cold rolling rate of 50%.
냉간압연된 각 시편들을 800℃에서 소둔처리 하고 과시효 온도를 400℃로 연속소둔, 용융도금 모사 열처리를 실시해서 도금강판을 제조하였다. 제조된 도금강판들에 대하여 석출상을 미세 관찰하였으며, 발명강 1 및 발명강 2에서는 미세한 석출상들이 미세하게 분포되어 있음을 확인할 수 있었다. 이러한 발명강 1 및 발명강 2의 석출상의 존재를 도 1 및 도 2에 나타내었다.Each cold-rolled specimen was annealed at 800 ° C., and the overaging temperature was continuously annealed at 400 ° C., followed by hot dip galvanizing to prepare a plated steel sheet. Precipitated phases were observed for the manufactured plated steel sheets, and it was confirmed that fine precipitated phases were minutely distributed in the inventive steels 1 and 2. Presence of the precipitated phases of the inventive steels 1 and 2 is shown in FIGS. 1 and 2.
발명강 1 및 발명강 2의 석출상에 의하여, 특히, Al 첨가량이 없거나 매우 적은 비교강들은 심각한 편석조직을 보였으며, 이러한 강재로 컵을 성형한 실험(도 2 참고)에서는 컵의 성형 과정에서 주름이나 파괴 현상이 발생하였다.Due to the precipitation phases of Inventive Steel 1 and Inventive Steel 2, in particular, comparative steels with little or no Al added showed severe segregation, and in an experiment in which cups were formed from these steels (see FIG. 2), Wrinkles or fractures occurred.
도 1은 본 발명의 발명강 1의 미세조직을 나타내는 사진1 is a photograph showing a microstructure of the inventive steel 1 of the present invention
도 2는 본 발명의 발명강 2의 미세조직을 나타내는 사진Figure 2 is a photograph showing the microstructure of the inventive steel 2 of the present invention
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101360581B1 (en) | 2012-04-06 | 2014-02-11 | 주식회사 포스코 | Nonmagnetic steel with excellent machinability and method of manufacturing the same |
| CN107574377A (en) * | 2017-09-07 | 2018-01-12 | 北京科技大学 | High manganese TWIP steel of a kind of high energy absorbing type based on nanostructured and preparation method thereof |
| WO2018117522A1 (en) * | 2016-12-21 | 2018-06-28 | 주식회사 포스코 | Hot rolled steel sheet having excellent formability and fatigue properties and manufacturing method therefor |
| KR101988762B1 (en) * | 2017-12-20 | 2019-06-12 | 주식회사 포스코 | High-manganese steel sheet having excellent formability, and method for manufacturing thereof |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013095005A1 (en) * | 2011-12-23 | 2013-06-27 | 주식회사 포스코 | Non-magnetic high manganese steel sheet with high strength and manufacturing method thereof |
| KR101360519B1 (en) * | 2011-12-26 | 2014-02-10 | 주식회사 포스코 | High strength steel sheet havung excellent yield ratio and method for manufacturing the same |
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| KR102209406B1 (en) | 2019-11-21 | 2021-01-29 | 주식회사 포스코 | High manganese steel having fine cast structure and method of manufacturing the same and high manganese steel sheet using the same |
| KR102256376B1 (en) * | 2019-12-11 | 2021-05-27 | 주식회사 포스코 | High-manganese steel sheet having excellent quality of surface, and method for manufacturing thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04272130A (en) * | 1991-02-28 | 1992-09-28 | Kobe Steel Ltd | Production of high mn nonmagnetic steel having superior drillability |
| KR950026569A (en) * | 1994-03-25 | 1995-10-16 | 김만제 | High manganese steel with good hot workability and its hot rolling method |
| KR20070067950A (en) * | 2005-12-26 | 2007-06-29 | 주식회사 포스코 | High manganese steel strips with excellent coatability and superior surface property, coated steel strips using steel strips and method for manufacturing the steel strips |
| KR100742833B1 (en) * | 2005-12-24 | 2007-07-25 | 주식회사 포스코 | High Mn Steel Sheet for High Corrosion Resistance and Method of Manufacturing Galvanizing the Steel Sheet |
-
2007
- 2007-12-27 KR KR1020070138539A patent/KR100957974B1/en active IP Right Grant
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04272130A (en) * | 1991-02-28 | 1992-09-28 | Kobe Steel Ltd | Production of high mn nonmagnetic steel having superior drillability |
| KR950026569A (en) * | 1994-03-25 | 1995-10-16 | 김만제 | High manganese steel with good hot workability and its hot rolling method |
| KR100742833B1 (en) * | 2005-12-24 | 2007-07-25 | 주식회사 포스코 | High Mn Steel Sheet for High Corrosion Resistance and Method of Manufacturing Galvanizing the Steel Sheet |
| KR20070067950A (en) * | 2005-12-26 | 2007-06-29 | 주식회사 포스코 | High manganese steel strips with excellent coatability and superior surface property, coated steel strips using steel strips and method for manufacturing the steel strips |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101360581B1 (en) | 2012-04-06 | 2014-02-11 | 주식회사 포스코 | Nonmagnetic steel with excellent machinability and method of manufacturing the same |
| WO2018117522A1 (en) * | 2016-12-21 | 2018-06-28 | 주식회사 포스코 | Hot rolled steel sheet having excellent formability and fatigue properties and manufacturing method therefor |
| KR20180072498A (en) * | 2016-12-21 | 2018-06-29 | 주식회사 포스코 | Hot-rolled steel sheet having superior formability and fatigue property, and method for manufacturing the same |
| KR101889185B1 (en) * | 2016-12-21 | 2018-08-16 | 주식회사 포스코 | Hot-rolled steel sheet having superior formability and fatigue property, and method for manufacturing the same |
| US11591664B2 (en) | 2016-12-21 | 2023-02-28 | Posco Co., Ltd | Hot rolled steel sheet having excellent formability and fatigue properties and manufacturing method therefor |
| US11970749B2 (en) | 2016-12-21 | 2024-04-30 | Posco Co., Ltd | Hot rolled steel sheet having excellent formability and fatigue properties and manufacturing method therefor |
| CN107574377A (en) * | 2017-09-07 | 2018-01-12 | 北京科技大学 | High manganese TWIP steel of a kind of high energy absorbing type based on nanostructured and preparation method thereof |
| KR101988762B1 (en) * | 2017-12-20 | 2019-06-12 | 주식회사 포스코 | High-manganese steel sheet having excellent formability, and method for manufacturing thereof |
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