采用井式电炉气体渗氮工艺对40CrNiMoA钢制曲轴进行渗氮处理时，原渗氮工艺存在氨气消耗量大，设备老化严重和产品质量不合格等问题，因此进行了渗氮工艺的改进。结果表明：通过采用降低渗氮温度、对工件进行充分预氧化、对马弗罐定期进行退氮和合理控制氨气流量等新工艺后，产品质量和设备利用率均得到提高,氨气消耗量降低，因而渗氮成本大幅下降。

Nitriding treatment was conducted on 40CrNiMoA steel crankshaft by using pit furnace gas nitriding process. Problems such as large consumption of ammonia,seriously aging of equipment and disqualification of product existed in the original nitriding process,so improvement was done. The resutls show that optimization measures such as lowering nitriding temperature,full pre-oxidation of the crankshaft,denitriding the equipment on a regular basis and control ammonia flow were adopted. After Optimization,product quality and equipment utilization rate were both raised,and ammonia consumption was lowered,so the costs were dropped largely.