超高强度弹簧钢SAE9254拉拔过程断裂原因分析  

Analysis of the causes of fracture of ultra⁃high strength spring steel SAE9254 in the drawing process

作　　者：王帅 王灿祥 邱军华 韩玉梅 WANG Shuai;WANG Canxiang;QIU Junhua;HAN Yumei(Special Steel Division of Nanjing Iron and Steel Co.Ltd.,Nanjing 211500,China)

机构地区：[1]南京钢铁股份有限公司特钢事业部,江苏南京211500

出　　处：《现代交通与冶金材料》2023年第2期81-84,共4页Modern Transportation and Metallurgical Materials

基　　金：南京钢铁股份有限公司超高强度弹簧钢重点研究计划项目(A174906010)。

摘　　要：在拉拔过程中发现部分超高强度弹簧钢SAE9254发生异常断裂,通过对试样断口宏微观形貌、化学成分、金相组织和力学性能等分析,发现断裂属于杯状脆性断裂,裂纹起源点于试样表面擦伤处,微观组织为少量铁素体+珠光体+马氏体组织,无全脱碳,总脱碳层深度为46μm;试样的化学成分符合行业标准,抗拉强度为1988 MPa,硬度平均值为54.5 HRC。优化盘条轧制工艺和拉拔工艺,可以有效减少表面缺陷;降低打捆压力,提高打捆道次,可以明显减少打捆造成的挤压伤,降低拉拔过程的断裂情况。In the process of drawing,it is found that some ultra-high-strength spring steel SAE9254 has abnormal fractures.Through the analysis of macro and microscopic morphology,chemical compo⁃sition,metallographic structure and mechanical properties of the specimen fractures,it is found that the fractures belong to cup-like brittle fractures.The origin of the cracks is at the abrasion on the sur⁃face of the specimen.The microscopic tissue is a small amount of ferrite+pearlite+martensitic tis⁃sue without full decarburization,and the total decarburization layer depth is 46μm.The chemical com⁃position of the specimen meets the industry standard,with a tensile strength of 1988 MPa and average hardness of 54.5 HRC.Optimizing the wire rod rolling process and drawing process can effectively re⁃duce surface defects.Reducing the baling pressure and increasing the baling pass can significantly re⁃duce the crush damage caused by baling and reduce the fracture of the drawing process.

关 键 词：拉拔 超高强度弹簧钢 杯状脆性断裂 表面擦伤 

分 类 号：TG356.21[金属学及工艺—金属压力加工]