热处理工艺对高强韧耐磨铸钢组织和性能的影响

研究了淬火温度及回火温度对高强韧耐磨铸钢组织和性能的影响.结果表明:淬火温度低于930 ℃时,材料的硬度随淬火温度的升高而增大;高于930 ℃时,硬度降低,在930 ℃出现硬度峰值;冲击韧度随淬火加热温度的升高先降低后增大.随着回火温度的升高,材料的硬度缓慢降低,而冲击韧度值升高.高强韧耐磨铸钢经930 ℃×2 h淬火(油淬)+240 ℃×2 h回火+240 ℃×2 h回火后,具有较高的强韧性,硬度≥54 HRC,冲击韧度≥43 J/cm~2,组织为回火马氏体+少量的残留奥氏体,试样冲击断口为准解理断裂.

Effects of heat treatment on microstructure and properties of high strength-toughness and wear-resistant cast steel

The effects of quenching and tempering temperature on microstructure and mechanical properties of high strength-toughness and wear-resistant cast steel were studied.The results show that the hardness of the cast steel increases with increase of quenching temperature,while quenching temperature is lower than 930 ℃,and vice versa,while quenching temperature is higher than 930 ℃.The impact toughness of the cast steel firstly increases with increase of quenching temperature,and then decreases.The impact toughness increases and the hardness decreases slowly along with increase of tempering temperature.High strength-toughness and wear-resistant cast steel can have high strength,hardness and high toughness after oil quenching at 930 ℃ for 2 h and tempering at 240 ℃ for 2 h.The hardness is ≥54 HRC,the impact toughness is ≥43 J/cm~2,the microstructure is martensite and residual austenite,and impact fracture of the steel is quasi-cleavage failure.