Cold-rolling technologies of advanced high strength steels in Ansteel

Low - carbon becomes a high - frequency and fashionable word which gets the greatest concern in the world.Low - carbon refers to a minimal output of greenhouse gas emissions into the biosphere, specifically refers to the greenhouse gas carbon dioxide.To reduce energy consumption of automobile,more and more high strength steels are used by vehicle companies.To meet the request of vehicle companies, various high strength steels are developed in steel companies all over the world.Ansteel can provide,ultra-low carbon bake hardening(BH) steels,dual phase(DP) steels and transformation - induced plasticity (TRIP) steels with the grades of under 780 MPa,up to now.AHSS steels have much different composition, microstructure and strenght than conventional vehicle steels,so there are some trouble in producing in cold rolling mills,for example,difficult to join,poor thickness and flatness,accurate temperature and velocity control and so on.To reduce the opportunity of strip breakage,we have done many welding experiments and special research.Now,DP and TRIP steels can be continuously produced in Ansteel.To assure thickness and flatness of strips,we optimized the hot rolling parameter to get low deformation resistance,optimized rolling oil to get fit frictional coefficient and fix on the targat rolling curve.To get more accurate and repetitive results over the production shifts,the Mathematical Model(MM) is used in Ansteel.The MM analyses information transmitted by various sensors and transmitters,compares the collected data with the chosen parameters and adjusts the settings of the various pieces of equipment to hone on the parameter setpoints.At present,the key production technologies of AHSS were grasped by cold rolling mill Ansteel,and Ansteel is the first company to apply the TRIP with the grade of 780 MPa.