模铸轴承钢线材中心黑心问题分析  

Analysis of Central Black Spot Defect of Molded Bearing Steel Wire

作　　者：郭立波 周伟基 高惠菊 Guo Libo;Zhou Weiji;Gao Huiju(Dongbei Special Steel Group Co.,Ltd.,Dalian 116105)

机构地区：[1]东北特殊钢集团,大连116105

出　　处：《汽车工艺与材料》2023年第9期37-41,共5页Automobile Technology & Material

摘　　要：针对模铸轴承钢中心黑心缺陷,分别对退火态和热轧态盘条样品采用低倍酸浸、金相分析、扫描电镜微观形貌观察、能谱成分分析检测手段分析缺陷性质。通过对冶炼过程和轧制工艺流程进行调查,确认黑心缺陷是由于发热剂保温不良,导致冒口附近出现C、Cr元素偏聚造成的碳化物偏析。根据该缺陷形成原因,提出相应的现场工艺改进措施,为加强冒口的保温及时更换了发热剂,降低了浇注的过热度,最终解决了黑心问题,提高了产品合格率。For central black spot defect of molded bearing steel wire,the annealing state and hot-rolled state wire rod samples were tested by means of low acid leaching,metallographic analysis,Scanning Electron Microscopy(SEM)microstructure observation and energy spectrum analysis.By investigation of smelting and rolling process,it is confirmed that the central black spot problem is caused by poor heat preservation of heating agent,causing carbide segregation by element C and Cr concentration at the casting head.According to the causes of the defect,this paper proposed corresponding field process improvement measures,including changing the heating agent to strengthen the heat preservation of the casting head,reduce the pouring superheat,the central black spot defect was finally solved and the qualified rate of the product was increased.

关 键 词：模铸 轴承钢 微观形貌 偏析 

分 类 号：TG260[金属学及工艺—铸造]