Development and application of 22MnB5 ultra high strength hot stamping steel
The influence of cold rolling reduction rate,annealing temperature and hot stamping cooling velocity on the microstructure and mechanical properties of 22MnB5 ultra high strength hot stamping steel(22MnB5 steel)was studied and analyzed by means of composition design,rolling,annealing and the control of key process parameters in hot stamping process.The results show that the stable rolling of acid continuous rolling of 22MnB5 steel can be achieved when the cold rolling reduction rate is controlled within the range of 50％-60％.The metallographic structure of annealed 22MnB5 steel is uniform and fine ferrite and pearlite,and the properties are uniform and stable when the annealing temperature is controlled within the range of 780-820 ℃.When the cooling velocity of hot stamping quenching is not less than 30 ℃·s-1,the whole martensitic structure with uniform size of slats can be obtained.This products passed the industrial trial of hot stamping production line,and the results show that after hot stamping,the yield strength of 22MnB5 steel is 1030-1113 MPa,the tensile strength is 1480-1520 MPa,the elongation is more than 8.0％,the hardness HV10 is not less than 500,the depth of the total decar-burization layer on the surface is below 35 μm,and the dimension accuracy and appearance of the parts meet the requirements of customers.
万方数据
维普
