精密成形齿轮用20MnCr5H钢的球化退火处理  

Spheroidizing annealing of 20MnCr5H steel for precision formed gears

作　　者：袁静 左彪 孙万利 戴柯明 许宝玉 张朝磊[3,4] Yuan Jing;Zuo Biao;Sun Wanlia;Dai Keming;Xu Baoyu;Zhang Chaolei(Technology Center,Zenith Steel Group Co.,Ltd.,Changzhou Jiangsu 213011,China;Jiangsu Airship Co.,Ltd.,Taizhou Jiangsu 225300,China;Institute for Carbon Neutrality,University of Science and Technology Beijing,Beijing 100083,China;Liaoning Academy of Materials,Shenyang Liaoning 110179,China)

机构地区：[1]中天钢铁集团有限公司技术中心,江苏常州213011 [2]江苏飞船股份有限公司,江苏泰州225300 [3]北京科技大学碳中和研究院,北京100083 [4]辽宁材料实验室,辽宁沈阳110179

出　　处：《金属热处理》2024年第12期67-71,共5页Heat Treatment of Metals

摘　　要：对精密成形齿轮用20MnCr5H钢进行亚温球化退火(710℃×8.5 h)和双相区球化退火(750℃×1.5 h+680℃×7 h、750℃×4 h+710℃×4 h、770℃×4 h+720℃×4 h)处理,探究了不同工艺下的球化处理效果。结果表明,双相区球化退火工艺下,较高的奥氏体区温度会导致片状珠光体难以短时间发生球化转变,而较短的奥氏体区保温时间有助于球化效率提升,750℃×1.5 h+680℃×7 h取得了较好的球化效果。相较于双相区球化退火,710℃×8.5 h亚温球化退火工艺下,20MnCr5H钢球化效果最好,球化率达到98%,这是由于经该工艺处理后,组织中较多的位错和小角度晶界可以促使片状渗碳体更迅速地实现溶断和球化,该工艺是精密成形齿轮的合理球化退火工艺制度。The 20MnCr5H steel for precision formed gears was subjected to subcritical spheroidizing annealing(710 ℃×8.5 h) and spheroidizing annealing in dual-phase region(750 ℃×1.5 h+680 ℃×7 h, 750 ℃×4 h+710 ℃×4 h, 770 ℃×4 h+720 ℃×4 h), and the spheroidizing effects under different processes were investigated. The results show that under the spheroidizing annealing in dual-phase region, higher austenite zone temperature will make it difficult for lamellar pearlite to spheroidize in a short time, while shorter austenite zone holding time will help to improve the spheroidization efficiency. Good spheroidization effect is achieved under 750 ℃×1.5 h + 680 ℃×7 h process. Compared with the spheroidizing annealing in dual-phase region, the spheroidization effect of the 20MnCr5H steel is the best under 710 ℃×8.5 h subcritical spheroidizing annealing, and the spheroidization rate reaches 98%. This is due to the fact that after the process treatment, more dislocations and small-angle grain boundaries in the microstructure can promote the dissolution and spheroidization of flaky cementite more quickly. It is a reasonable spheroidizing annealing process for precision forming gears.

关 键 词：20MnCr5H钢 亚温球化退火 双相区球化退火 球化率 

分 类 号：TG142.1[一般工业技术—材料科学与工程]