回火对超高强度马氏体钢力学性能的影响

Effect of tempering on the mechanical properties of an ultra high strength martensitic steel

马氏体钢是汽车用先进高强钢的重要品种,主要组织为马氏体,突出特点为合金含量低、强度高。随着强度的提高,马氏体钢组织逐步接近全马氏体,并且马氏体的含碳量也进一步增加,导致弯曲性能和韧性降低。以冷轧C-Si-Mn钢板为研究对象,研究了回火对淬火态超高强度马氏体钢板的弯曲性能和冲击韧性的影响,发现与淬火态相比,回火处理对试验用钢的弯曲性能和冲击韧性有明显改善,但回火温度过高会造成弯曲性能和冲击韧性的下降。

Martensitic steel sheet is an important kind of advanced high strength steel for automotive industry.With martensite as its main microstructure,martensitic steel has outstanding feature of low alloy content and ultra high strength.As the strength of martensitic steel increases,both martensite content and martensite carbon content increase,leading to reduced bending properties and toughness.The effect of tempering on the bending and impact toughness of quenched ultra-high strength martensitic steel sheet is studied.It is found that the bending and impact toughness of the experimental steel are significantly improved after tempering compared with that of as-quenched steel sheet.However,the bending and toughness may drop if the tempering temperature is excessively high.