GCr15轴承钢酸洗腐蚀麻点成因分析  

Anaysis on the Causes of Picking Corrosion Pit of GCr15 Bearing Steel

作　　者：王娇娇 刘泳 刘宏春 陈红卫 田志强 WANG Jiaojiao;LIU Yong;LIU Hongchun;CHEN Hongwei;TIAN Zhiqiang(HBIS Materials Technology Research Institute,Shijiazhuang 050023,China)

机构地区：[1]河钢材料技术研究院,河北石家庄050023

出　　处：《工业加热》2023年第6期71-73,76,共4页Industrial Heating

摘　　要：轴承钢作为加工滚珠、滚柱以及轴承套圈的原材料,在机械装备、交通运输、航空航天等方面均发挥至关重要作用。针对某钢厂工业化生产的GCr15轴承钢,在酸洗过程中出现的腐蚀麻点问题,利用金相、扫描电子显微镜、电子探针X射线显微分析等实验方法对其组织形貌及化学元素分布进行分析。结果表明,在截取试样横截面的边部及中心位置腐蚀麻点密集数量较多,C、Cr元素在凝固过程中发生偏析,最终形成与腐蚀坑位置相对应较为平直的富Cr的碳化物带状组织,并且沿纵向贯穿整个试样,晶界周围的基体形成贫Cr区,在贫Cr区域抗腐蚀能力下降,这是腐蚀麻点产生的主要原因。通过采用高温扩散的方式,在开坯加热过程中提高加热温度20℃并延长扩散时间30 min,对酸洗过程中产生的腐蚀麻点缺陷有显著的改善作用。Bearing steel as a raw material for processing balls,rollers,and bearing rings,plays a crucial role in mechanical equipment,transportation,aerospace,and other fields.Aiming at the corrosion pitting problem of CCr15 bearing steel produced industrially in a steel plant during pickling,the microstructure and chemical element distribution of GCr15 bearing steel were analyzed by metallography,scanning electron microscope,electron probe X-ray microanalysis and other experimental methods.The results indicate that there is a dense number of corrosion pits at the edges and center of the cross-section of the sample.During the solidification process,C and Cr elements undergo segregation,ultimately forming a relatively straight Cr rich carbide band structure corresponding to the corrosion pit position.It runs through the entire sample longitudinally,and the matrix around the grain boundary forms a Cr poor area.The corrosion resistance of the Cr poor area decreases,which is the main reason for the occurrence of corrosion pits.By using high-temperature diffusion,increasing the heating temperature by 20 C and extending the diffusion time by 30 minutes during the billet heating process has a significant improvement effect on the corrosion pitting defects generated during the pickling process.

关 键 词：GCR15轴承钢 腐蚀麻点 元素偏析 碳化物带状组织 

分 类 号：TF762.4[冶金工程—钢铁冶金]