摘要
采用热膨胀法并结合金相组织分析及硬度变化来测定12Cr2Mo1R钢变形奥氏体的连续冷却转变温度,研究了钢的相变规律,结果表明,12Cr2Mo1R钢未变形奥氏体连续冷却转变,冷却速度<0.27 ℃/s时,组织为贝氏体+铁素体+珠光体;在0.27～8.4 ℃/s之间时,组织为贝氏体;>8.4 ℃/s时,组织为马氏体+贝氏体。变形奥氏体连续冷却转变,冷却速度<5 ℃/s时,组织为铁素体+珠光体+贝氏体;在5～20 ℃/s之间时,主要为贝氏体组织;>20 ℃/s时,得到的组织为马氏体+贝氏体。形变加速了奥氏体连续相变,使连续冷却相变温度提高。钢中Cr、Mo等合金元素,提高了过冷奥氏体的稳定性,使连续转变过程中出现了亚稳奥氏体区,提高了贝氏体的淬透性。
The continuous cooling transformation temperature of deformation austenite of 12Cr2MolR steel was determined and the phase transformation rule was studied by thermal dilation method and combining with metallurgical microstructure analysis and hardness change. The results showed that in continuous cooling transformation of undeformed austenite of 12Cr2MolR steel, the cooling speed is less than 0.27 ℃/s, the microstructure is bainite ＋ ferrite ＋ pearlite; the cooling speed is between 0.27 and 8.4 ℃/s, the microstructure is bainite and more than 8.4 ℃/s, the microstructure is martensite ＋ bainite. In continuous cooling transformation of the deformed austenite, the cooling speed is less than 5 ℃/s, the microstructure is ferrite ＋ pearlite ＋ bainite; the cooling speed is between 5 and 20 ℃/s, the microstructure is bainite and more than 20 ℃/s, the microstructure is martensite ＋ bainite. The deformation accelerates the continuous phase transformation of the austenite and makes the continuous transformation temperature increase. The Cr, Mo and other alloy elements in steel improve the stability of overcooling austenite; make metastable austenite area appear in the transformation process and increase the hardenability of bainitic.
出处
《山东冶金》
CAS
2013年第3期11-14,共4页
Shandong Metallurgy
