连续退火工艺对冷轧马氏体钢板力学性能的影响

Effect of Continuous Annealing on Mechanical Properties of Cold-Rolled Martensitic Steel Sheets

冷轧马氏体钢采用水淬退火机组生产,可以节约合金元素,同时获得高强度,符合汽车用钢高强度和减重节能的要求。以冷轧低碳马氏体钢为研究对象,研究了连续退火工艺对马氏体钢板力学性能的影响,发现淬火温度、缓冷速度和回火温度均对马氏体钢的强度有很大影响。在奥氏体缓慢分解的较高温度区间开始淬火有利于马氏体钢强度的稳定。回火降低马氏体钢的抗拉强度,对屈服强度有提高的作用,在200～300℃之间回火,冷弯性能基本不变或有所提高,未发现在240℃以上过时效出现显著的冷弯性能下降的现象。

Cold-rolled martensitic steel sheets,produced with continuous annealing lines with water quenching capacity,have the combination of high strength and lean alloying contents,which is in good accordance with the trend of light-weighting and fuel saving.The cold-rolled matensitic steel was studied to investigate the effect of the annealing parameters on the mechanical properties.It is found that the quenching temperature and the slow cooling speed as well as the overageing temperature have significant influence on the strength of the experimental steel.The temperature zone at which the austenite decomposition is slow or has not started may be chosen as the quenching temperature to ensure the stability of strength.Tempering decreases tensile strength while increases yield strength.Tempering between 200-300 ℃,the bending property maintains or increases and the reported deterioration of bending has not been observed at tempering temperatures above 240 ℃.