高级别汽车桥壳钢Q460QK的生产  

PRODUCTION OF HIGH-GRADE AUTOMOTIVE AXLE SHELL STEEL Q460QK

作　　者：邢天庆 耿云飞 杨玉厚 金玉 Xing Tianqing;Geng Yunfei;Yang Yuhou;Jin Yu(HBIS Group Tangsteel Company,Tangshan 063000,Hebei)

机构地区：[1]河钢集团唐钢公司,河北唐山063000

出　　处：《河北冶金》2024年第4期59-63,82,共6页Hebei Metallurgy

摘　　要：驱动桥桥壳是中重型商用汽车的重要零件之一,既是承载零件,也是传力部件,同时又是主减速器、差速器及驱动车轮传动装置的外壳,因而要求汽车桥壳钢除具备综合力学性能外,还应具备一定的耐低温疲劳服役性能。由于汽车桥壳零件采用冲压工艺,且零件形状较为复杂,要求桥壳钢具备一定的成型性能。本文根据汽车桥壳钢加工方式及服役工况,采用低碳锯钛微合金成分体系细化晶粒尺寸,通过高纯净度双联冶炼工艺降低钢水中非金属夹杂物,采用TMCP控轧控冷工艺控制带钢组织类型,生产出了高韧性耐低温Q460QK桥壳钢。采用室温拉伸试验、折弯试验、夏比摆锤冲击试验、光镜检验、扫描电镜检验等检验手段,经检测,该桥壳钢在-60℃温度下冲击功>300J且无明显的韧脆转变点,断后延伸率>24%,冷弯d=a折弯合格,微观组织为铁素体+贝氏体,其中的针状铁素体在改善强度的同时,还能显著提高带钢低温韧性,晶粒度评级达11.5级,带状组织评级1级,具备较优异的综合性能。The drive axle housing is one of the important components of medium and heavy-duty commercial vehicles.It is not only a load-bearing component,but also a transmission component.At the same time,it is the outer shell of the main reducer,differential,and drive wheel transmission device.Therefore,it is required that the automotive axle housing steel not only has comprehensive mechanical properties,but also has certain low-temperature fatigue service performance;Due to the stamping process used for automotive axle housing parts and the complex shape of the parts,it is required that the axle housing steel has certain formability.Based on the processing method and service conditions of automotive bridge shell steel,using a low-carbon niobium titanium microalloy composition system to refine grain size,reduces non-metallic inclusions in the molten steel through high-purity dual smelting process,and controls the microstructure type of the strip steel using TMCP controlled rolling and cooling process.High toughness and low temperature resistant Q460QK bridge shell steel is produced.By using room temperature tensile test,bending test,Charpy pendulum impact test,optical microscope inspection,scanning electron microscope inspection and other inspection methods,it was found that the bridge shell steel has an impact energy of>300 J and no obvious ductile brittle transition point at a temperature of-60℃.The elongation after fracture is>24%,and the cold bending d=a is qualified.The microstructure is ferrite+bainite,and the needle shaped ferrite can significantly improve the low-temperature toughness of the strip steel while improving strength.The grain size rating is 1l.5 level,and the strip structure rating is 1 level,with excellent comprehensive properties.

关 键 词：桥壳钢 Q460QK 低碳锯钛微合金 高韧性 低温冲击功 

分 类 号：TG335.1[金属学及工艺—金属压力加工]