摘要
采用膨胀测量法并结合金相-硬度法测定了42CrMo钢的动态连续冷却转变曲线(CCT曲线)及组织演变。结果表明,在较低冷却速度下显微组织由铁素体、珠光体和贝氏体组成,冷却速度范围为0.2~1℃/s时,随着冷速的增加,铁素体和珠光体组织逐渐减少直至消失,当冷速增加到1℃/s时,转变组织主要由贝氏体构成。冷却速度≥3℃/s时,显微组织中开始生成马氏体,并在冷却速度≥10℃/s完全转变为马氏体组织。研究还认为马氏体组织的生成是由于大的冷速和大的变形量共同作用的结果。
Dynamic CCT curves and microstructure evolution of 42CrMo steel were detected by dilatometry and metallography and hardness test. The results show that at low cooling rate, the microstructure of 42CrMo steel mainly consists of ferrite, pearlite and bainite. With increasing of cooling rate (in the range of 0.2-1 ℃/s), the ferrite and pearlite reduce gradually until the microstructure mainly composed of bainite at the cooling rate of 1 ℃/s. As the cooling rate≥3 ℃/s, martensite starts to form and until the martensite completely formed at the cooling rate ≥ 10 ℃/s. The high cooling rate and deformation is proposed to be responsible for the formation of martensite.
出处
《金属热处理》
CAS
CSCD
北大核心
2012年第12期37-40,共4页
Heat Treatment of Metals