汽车稳定杆用高品质弹簧钢55Cr3生产工艺实践

Production practice of high quality spring steel 55Cr3 for automobile stabilizer bar

采用120t转炉BOF→精炼LF炉→真空RH炉→220mm×260mm矩形坯连铸CCM→铸坯防脱碳涂料喷涂→热轧工艺生产高品质汽车稳定杆用弹簧钢55Cr3圆钢。通过转炉自动副枪、滑板挡渣和下渣红外检测系统实现高拉碳低磷成分控制,精炼LF炉炉渣高碱度控制和窄成分控制,真空RH炉高真空度循环脱气和充足软吹时间,连铸全程保护浇铸、结晶器和末端电磁搅拌以及轻压下技术,铸坯表面进行防脱碳涂料喷涂,热轧低温控轧控冷等技术,使其成分、组织和表面质量等控制均达到较高水平。钢中磷质量分数小于0.010%,硫质量分数小于0.006%,氧质量分数小于10×10^-6,钢中夹杂物为A类和D类夹杂,均小于1级,表面脱碳基本为零,偶尔存在零星的过渡脱碳层,各项性能均满足客户要求。

The following process is carried out to produce 55Cr3 round steel using as high quality automobile stabilizer bar:120 ton converter(BOF)→LF furnace,vacuum RH furnace→220 mm×260 mm rectangular billet continuous casting(CCM)→casting billet anti decarburization coating →hot rolling process. The composition of high carbon and low phosphorus are controlled by the automatic secondary gun of converter and slag detection system. Combining with the high alkalinity control and narrow composition control of the refining LF furnace slag,the high vacuum cycle degassing and sufficient soft blowing time of the vacuum RH furnace,the casting whole protection casting,the mould and the end electromagnetic stirring and the light pressing technology,the technology of decarburization coating spraying,hot rolling,low temperature control rolling and controlled cooling technology on the surface of the billet,the product can achieve high level of composition,organization and surface quality. The content of phosphorus in steel is less than 0.010%,sulfur content is less than 0.006%,oxygen content is less than 10×10-6,inclusions in steel are class A and D inclusions that both are less than Grade 1,surface decarburization is basically zero,occasionally there is sporadic transition decarburization layer,and all the properties meet the requirements of customers.