免球化退火SWRCH35K冷镦钢的试验研究  

Study on non-spheroidized cold heading steel of SWRCH35K

作　　者：胡显军[1,2] 蒋建清[1] 陈少慧[2] 方峰[1] 戚正儒[1] 

机构地区：[1]东南大学材料科学与工程学院,江苏南京211189 [2]江苏沙钢集团有限公司技术中心,江苏张家港215625

出　　处：《金属热处理》2009年第2期85-88,共4页Heat Treatment of Metals

基　　金：国家“863”计划(2003AA331030);江苏省科技攻关计划(BE2003027)

摘　　要：采用热模拟试验研究了形变温度和冷速对SWRCH35K冷镦钢组织和硬度的影响。结果表明,形变温度低于750℃,部分珠光体发生了球化,硬度明显降低;当形变温度在700℃左右,珠光体明显球化,硬度达到最低;形变后冷速越慢,珠光体球化越明显,其硬度也越低。通过工艺调整,适当降低精轧温度及冷却强度,生产出SWRCH35K热轧盘条,抗拉强度约为560MPa,面缩率大于55%,表面硬度低于82HRB。经用户使用,该盘条能实现免球化退火生产8.8级标准件。Through the thermal simulation experiments, effects of deformation temperature and cooling rate on microstructure and hardness of cold heading steel SWRCH35K were studied. The results show that the pearlite spheroidization and softening of the steel will happen when the deformed temperature is below 750 ℃. When the deformation temperature approach to 700 ℃, the pearlite spheroidization is very obvious, and hardness of the SWRCH35K steel decreaseds to the bottom line. The lower of the deformation temperature, the more evidently of pearlite spheroidization, and the more softness. The lower cooling rate after deformation, the more obvious pearlite spheroidization and the lower hardness. According to this, the rolling process is optimized and the high performance SWRCH35K steel wire rod is obtained. The tensile strength is about 560 MPa and the reduction of area is more than 55%. The surface hardness is lower than 82 HRB. The SWRCH35K steel wire rod can be directly used to cold heading omitting spheroidizing annealing process.

关 键 词：免球化退火 冷镦钢 形变温度 冷速 珠光体球化 

分 类 号：TG113[金属学及工艺—物理冶金] TG335[金属学及工艺—金属学]