摘要
针对700 MPa级HSLA钢冲裁开裂问题,利用拉伸、冲击、弯曲试验机,扫描电镜及光学显微镜分别对其力学性能、断口形貌及显微组织进行了分析。结果表明:经Nb、Ti复合强化的HSLA带钢强度较高,夹杂物控制较好,但由于组织不均导致材料韧性较差,进而在加工过程中出现开裂。通过将Mn、Ti含量分别降低0.40%及0.030%,增加终轧后两道次压下量至17%及11%,降低终轧温度40℃,从成分调整及控轧控冷工艺方面进行优化,可得到均匀细小的F+P热轧组织,在降低材料强度的同时提高了冲击韧性,且冷弯性能良好,完全满足冲裁加工的要求。
Aiming at the blanking crack of 700 MPa HSLA steel,the mechanical properties,fracture morphology and microstructure of HSLA steel were analyzed through tensile,impact and bending test machines,scanning electron microscopy and optical microscopy.The results show that the HSLA strip strengthened by Nb and Ti has higher strength and better inclusion control,but the material toughness is poor due to the uneven structure,which leads to cracking during the processing.By reducing the content of Mn and Ti by 0.40%and 0.030%respectively,increasing the reduction of two passes to 17%and 11%after finishing rolling,reducing the finishing rolling temperature by 40℃,optimizing the composition adjustment and controlled rolling and controlled cooling process,uniform and fine F+P hot rolling structure can be obtained,which reduces the material strength and improves the impact toughness with good cold bending properties.It fully meets the requirements of blanking.
作者
宋志岗
张星
梅淑文
Song Zhigang;Zhang Xing;Mei Shuwen(HBIS Group Tangsteel Company,Tangshan,Hebei063016)
出处
《河北冶金》
2019年第8期32-34,74,共4页
Hebei Metallurgy
关键词
HSLA钢
冲裁开裂
拉伸强度
显微组织
冷弯性能
控轧控冷
冲击韧性
HSLA steel
blanking cracking
tensile strength
microstructures
cold bending properties
controlled rolling and cooling
impact toughness
