水口聚集类夹杂物对车轮疲劳裂纹的影响及其控制  

Influence of nozzle aggregated inclusions on fatigue cracks and their control in wheel

作　　者：金友林[1] 杜松林 龚志翔[1] JIN Youlin;DU Songlin;GONG Zhixiang(Special Steel Plant,Ma’anshan Iron&Steel Company Co.,Ltd.,Ma’anshan 243000,China;Baowu Group Masteel Rail Transit Materials Technology Co.,Ltd.,Ma’anshan 243000,China)

机构地区：[1]马鞍山钢铁股份有限公司特钢公司,安徽马鞍山243000 [2]宝武集团马钢轨交材料科技有限公司,安徽马鞍山243000

出　　处：《炼钢》2022年第2期60-66,共7页Steelmaking

摘　　要：通过对辋裂失效车轮及其内部夹杂物的特征分析,表明该形式的疲劳裂纹是由钢中聚集类大尺寸夹杂物所致,该类夹杂物为钢中内生夹杂物在水口内壁聚集、脱落而滞留在钢中形成,其分布在连铸坯距表面20~40 mm位置,经过轧制后分布在车轮轮辋区域,位于踏面以下10~20 mm位置,夹杂物尺寸一般超过500μm,主要为钙铝酸盐类夹杂物。通过钙处理工艺优化、连铸全程保护浇铸以及电磁搅拌参数优化等工艺优化措施,夹杂物在水口内壁吸附聚集得到有效控制,连铸浇铸稳定性及车轮产品质量得到明显改善,大尺寸夹杂物数量减少76%以上,且超过1 mm当量尺寸的夹杂物比例由35%降低为8%。The characteristics of rim cracks and inclusions in the wheel were analyzed,it was shown that the type of fatigue cracks was caused by the aggregated large-size inclusions in the steel.These inclusions originated from the aggregated attachments on the inner wall of the nozzle.In the casting process,the endogenous inclusions in the molten steel aggregated and adhered on the inner wall of the nozzle,the inclusions would fall off randomly and remained in the billets during solidification.These large inclusions were distributed at the position of 20-40 mm from the surface of the continuous casting billet,which were distributed in the wheel rim area after wheel rolling,located at 10-20 mm below the tread.The sizes of inclusions generally exceeded 500μm,and the main composition was calcium aluminate.For the process optimization of calcium treatment and electromagnetic stirring and shielding casting in the overall process of continuous casting,the aggregation and attachment of inclusions on the inner wall of nozzle have been effectively controlled.The stability of continuous casting and the wheel quality have been significantly improved.The total number of large-sized inclusions was reduced by more than 76%and the number of inclusions larger than 1 mm was greatly reduced to 8%from 35%.

关 键 词：疲劳裂纹 聚集类夹杂物 水口结瘤物 保护浇铸 

分 类 号：TF777[冶金工程—钢铁冶金]