齿轮钢带状组织的差异性与优化实践  

Differences and optimization practice of banded structure in gear steels

作　　者：张志兴 郭子强 王海龙 秦萱 Zhang Zhixing;Guo Ziqiang;Wang Hailong;Qin Xuan(Nanjing Iron&Steel Co.,Ltd.,Nanjing Jiangsu 210044,China)

机构地区：[1]南京钢铁股份有限公司,江苏南京210044

出　　处：《金属热处理》2025年第2期81-86,共6页Heat Treatment of Metals

摘　　要：研究了合金元素含量不尽相同、冶炼轧制生产工艺基本相近的常用汽车齿轮钢(SCr420H、16MnCr5、20CrMnTiH、SAE8620H、22CrMoH)所形成带状组织的差异与机理,并进行了工艺优化。结果表明,SCr420H钢、16MnCr5钢和20CrMnTiH钢带状偏析相对较轻,22CrMoH钢与SAE8620H钢带状组织明显。22CrMoH钢与SAE8620H钢中的Mo、Ni合金元素影响轧制冷却过程中的组织转变,使得在轧制后成品钢材易产生异常组织(贝氏体)。通过调整连铸过热度在15~30℃,恒拉速,增加结晶器及二冷冷却强度,轧制加热均热温度在1200~1240℃,扩散时间≥90 min,终轧温度为910~960℃,实现了对SAE8620H圆钢带状组织的改善,达到≤2.0级。A comprehensive study on the formation mechanisms and differences in the banded structure of commonly used automotive gear steels,namely SCr420H,16MnCr5,20CrMnTiH,SAE8620H and 22CrMoH,which possessed varying alloy element compositions but underwent similar smelting and rolling processes,was conducted.In addition,the process was optimized.The findings reveal that SCr420H,16MnCr5 and 20CrMnTiH steels exhibit relatively less pronounced banded segregation,whereas 22CrMoH and SAE8620H steels display distinct banded structures.The alloying elements Mo and Ni in 22CrMoH and SAE8620H steels affect the microstructure transformation during rolling and cooling,resulting in the development of an abnormal microstructure,bainite,in the final rolled steel.By adjusting the continuous casting superheat to a range of 15-30℃,maintaining a consistent pulling speed,intensifying the crystallizer and secondary cooling,achieving a homogeneous rolling heating temperature of 1200-1240℃,ensuring a diffusion duration of at least 90 min,and maintaining a final rolling temperature of 910-960℃,the banded structure in SAE8620H round steel is effectively improved to a grade of≤2.0.

关 键 词：齿轮钢 带状组织 合金元素含量 工艺优化 

分 类 号：TG142.1[一般工业技术—材料科学与工程]