热处理对C12A耐热钢的组织与性能影响

Effect of Heat Treatment on Microstructure and Mechanical Properties of C12A heat resisting casting steel

通过对铸造C12A耐热钢进行热处理，观察其微观组织，测定其力学性能。试验结果表明：正（淬）火组织为板条马氏体＋部分针状马氏体＋少量残余奥氏体，其硬度比较高，塑性和韧性不是很好；正（淬）火＋回火组织为回火马氏体，其硬度不是很高，塑性和韧性比较好，具有良好的综合性能；退火组织为铁素体，其硬度低，塑性和韧性高；通过正火＋回火，研究回火温度对其微观组织和力学性能的影响。试验结果表明：回火温度对C12A钢的组织和性能有较大影响，其硬度随回火温度的升高呈先降后升趋势。

In this paper, heat treatment on C12A cast heat-resistant steel was carried out. The microstructure was observed and the mechanical properties were tested after heat treatment. The result showed that： after normalizing（quenching）,the structure were lath martensite q- partial acicular martensite -＋- little residual austenite, its hardness was high, but plastici- ty and toughness were not very well; after normalizing（quenching） and tempering , the structure was tempered martensite; its hardness wasn＇t very high, but plasticity and toughness were good, it possesses excellent comprehensive properties; after an- nealing, the structure was ferrite, its hardness was low, plasticity and toughness were good. The effect of tempering tempera- ture on microstructure and mechanical property were studied. The result indicated as follows： tempering temperature had great effect on microstructure and property of C12A, the hardness descend first and then increased with the increase of tempering temperature.