Ce对440C不锈轴承钢夹杂物演变的影响

为探究稀土Ce对440C不锈轴承钢中夹杂物的改性作用,利用实验室MoSi₂电阻炉对440C不锈轴承钢进行稀土Ce处理,采用OM、SEM等系统分析了Ce的添加对440C不锈轴承钢脱氧及夹杂物演变的影响。结果表明,随着Ce加入量的增加,其收得率逐渐升高。Ce的加入使钢中TO质量分数由0.002 5%降低至0.001 2%。未加入Ce的钢中夹杂物主要为Al₂O₃、MnS以及镁铝尖晶石;加入质量分数为0.011 5%的Ce后,夹杂物被改性为以Ce-Al-O为主的夹杂物;当Ce的添加量达到0.036 4%时,夹杂物被完全改性为Ce-O-S夹杂物。适量的Ce可以降低夹杂物尺寸及面积比例,但过量加入会使夹杂物尺寸变大。在本试验条件下,当Ce质量分数为0.011 5%时,钢中夹杂物细小弥散效果最明显。以上结论可为Ce在高碳铬不锈轴承钢中的应用提供参考。

Effect of Ce on inclusion evolution for 440C stainless bearing steel

In order to explore the modification effect of rare earth Ce on the inclusions in 440C stainless bearing steel, a laboratory MoSi₂ resistance furnace was used to treat 440C stainless bearing steel with rare earth Ce, and the effects of Ce addition on deoxidation and inclusion evolution of 440C stainless bearing steel were systematically analyzed by OM and SEM. The results show that with the increase of Ce addition, the yield gradually increases. The mass fraction of TO in steel is reduced from 0.002 5% to 0.001 2% by addition of Ce. The inclusions in steel without Ce element are mainly Al₂O₃, MnS and magnesium aluminum spinel, while the inclusions are modified to Ce-Al-O-based inclusions by adding 0.011 5% Ce. When the amount of Ce added reaches 0.036 4%, the inclusions are completely modified to Ce-O-S inclusions. The size and area ratio of inclusions can be reduced by a moderate amount of Ce, but the size of inclusions will be increased due to excessive addition of Ce. Under the test conditions, when the mass fraction of Ce is 0.011 5%, the fine dispersion effect of inclusions in steel is the most obvious. This study can provide a reference for the application of Ce in high-carbon chromium stainless bearing steel.