论文部分内容阅读
对1Cr11MoNiWVNbN不锈钢在600℃气体氮化过程中出现的黑色条纹进行了深入研究。结果表明:黑色条纹不是裂纹,而是一种异常组织。分析这种异常组织出现的原因是和γ’相的存在、碳原子远程迁移、硬度落差、腐蚀剂作用下的电化学作用、冷却介质等有密切联系;提出在625℃氮化、640℃退氮、在氮气保护气氛中冷却的气体氮化方法,获得了层深0.36~0.39mm,硬度798HV,脆性1级,无黑色条纹的渗层。并从理论上解释了这种氮化方法不产生黑色条纹的原因。
The black streaks of 1Cr11MoNiWVNbN stainless steel during gas nitriding at 600 ℃ have been studied deeply. The results show that the black stripe is not a crack, but an abnormal tissue. The reasons for the occurrence of such anomalous structure are closely related to the presence of γ ’phase, the remote migration of carbon atoms, the drop in hardness, the electrochemical action under the etchant and the cooling medium. Nitrogen at 625 ℃, nitrogen at 640 ℃ , A gas nitriding method cooled in a nitrogen atmosphere to obtain an infiltrated layer having a depth of 0.36 to 0.39 mm, a hardness of 798 HV, a brittleness level of 1, and no black stripes. The reason why this nitriding method does not produce black streaks is theoretically explained.