高强度汽车紧固件用SCM415H钢的组织转变  

Microstructure transformation of SCM415H steel for high strength automotive fasteners

作　　者：褚峰 李战卫 于学森 张继明 Chu Feng;Li Zhanwei;Yu Xuesen;Zhang Jiming(Institute of Research of Iron&Steel,Shagang,Jiangsu Province,Zhangjiagang Jiangsu 215625,China)

机构地区：[1]江苏省(沙钢)钢铁研究院,江苏张家港215625

出　　处：《金属热处理》2025年第1期63-67,共5页Heat Treatment of Metals

摘　　要：通过热模拟试验研究了汽车紧固件用SCM415H钢的组织转变行为。结果表明:冷速为0.25℃/s时,显微组织为铁素体和珠光体;冷速达到0.5℃/s时,开始出现贝氏体和马氏体;冷速达到5℃/s时,显微组织以马氏体和贝氏体为主;冷速达到15℃/s及以上时,显微组织以马氏体为主。等温转变时,珠光体转变的温度区间为700~575℃,鼻尖温度约为660℃,约428 s完成相变。依据试验结果,工业试制24 mm规格SCM415H钢盘条经过一球两拉后,成功试制10.9级汽车紧固件。The phase transformation characteristics of the SCM415H steel for automotive fasteners were studied by thermal simulation.The cooling rate of 0.25 ℃/s produces a microstructure of ferrite and pearlite,while the bainite and martensite occurs with the cooling rate reaches 0.5 ℃/s.The cooling rate of 5 ℃/s results in a microstructure of mainly martensite and bainite,and that of 15 ℃/s or above results in a microstructure of mainly martensite.The pearlitic transformation temperature is 700-575 ℃ during isothermal conditions.The nose tip temperature is about 660 ℃,and completion time of the phase transformation is about 428 s.Based on the tested results,the steel wires with a diameter of 24 mm were successfully produced,and then grade 10.9 automobile fasteners were successfully produced after one spheroidizing annealing and two drawing processes.

关 键 词：汽车紧固件用钢 SCM415H 连续冷却 等温转变 球化体等级 

分 类 号：TG142.1[一般工业技术—材料科学与工程]