井式炉渗碳淬火钢件表面炭黑问题分析  

Analysis of carbon black on surface of steel workpieces carburized and quenched in pit furnace

作　　者：李朝青 张伟[1] 李瑶 Li Chaoqing;Zhang Wei;Li Yao(Nanjing High Speed&Accurate Gear(Group)Co.,Ltd.,Nanjing Jiangsu 211100,China)

机构地区：[1]南京高精齿轮集团有限公司,江苏南京211100

出　　处：《金属热处理》2024年第9期265-267,共3页Heat Treatment of Metals

摘　　要：用化学成分分析和理化检测研究了井式炉渗碳淬火的18CrNiMo7-6钢轴类工件表面炭黑产生的原因、纠正的方法以及预防措施。通过将表面炭黑工件进行抛丸、返修淬火,证明表面炭黑来源于淬火工序。试验结果表明,通过调整分阶梯提升淬火碳势0.65%C_(p)×2 h+0.83%C_(p)×5 h,提高富化气滴入温度至830℃,增加工件间隙至30 mm等措施,可以有效解决工件表面炭黑问题。经过试验验证,钢件表面炭黑在淬火保温阶段产生,通过调整碳势,工件装炉间隙,可以避免钢件表面炭黑的产生。Causes,corrective methods and preventive measures were described for carbon black appearing on the surface of 18CrNiMo7-6 steel shaft workpieces carburized and quenched in pit furnace by chemical composition analysis and physical and chemical detection.By shot blasting and re-quenching the workpieces with surface carbon black,it is confirmed that the carbon black originates from the quenching process.The results show that the problem of surface carbon black can be effectively solved by adjusting the staged increase of quenching carbon potential to 0.65% C_(p)for 2 h and then to 0.83% C_(p) for 5 h,increasing the temperature of enriched gas droplets to 830℃,and increasing the gap between workpieces to 30 mm.It is verified by tests that the carbon black on the surface of the steel is generated during the quenching and holding stage.By adjusting the carbon potential and the furnace gap of the workpiece,the generation of carbon black on the surface of the steel can be avoided.

关 键 词：18CrNiMo7-6钢件 井式炉 渗碳淬火 表面炭黑 碳势 间隙 

分 类 号：TG157[金属学及工艺—热处理]