1Cr11MoNiWVNbN不锈钢氮化组织异常原因分析及解决措施  

Reason Analysis and Solution Method of Abnormal Nitrided Structure of 1Cr11MoNiWVNbN Alloy

作　　者：李万军 李肖霞[2] 

机构地区：[1]华电电力科学研究院山东分院,山东济南250014 [2]哈尔滨汽轮机厂有限责任公司,黑龙江哈尔滨150046

出　　处：《热加工工艺》2017年第18期250-252,255,共4页Hot Working Technology

摘　　要：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。Black stripes appearing in the process of 1Cr11MoNiWVNbN alloy gas nitriding at the temperature of 600 ℃ were studied. The results show that the black stripe is not crack but abnormal structure.The reason for the appearance of this abnormal structure is that it is closely related to the existence of γ＇ phase, the remote migration of carbon atoms, the hardness drop, the electron chemical effect under the action of corrosive agent and the cooling medium, etc. So a kind of new gas nitriding method of nitriding at the temperature of 625 ℃, denitriding at the temperature of 640 ℃ and cooling in the nitrogen atmosphere is proposed. Using this method, a nitridingzone was obtained, which has a depth of 0.36-0.39 mm, surface hardness 798 HV, one class brittle and no black stripe. Meanwhile, the reason that this method does not produce black stripes is explained in theory.

关 键 词：1Cr11MoNiWVNbN 气体氮化 黑色条纹 原因分析 解决措施 

分 类 号：TG156.82[金属学及工艺—热处理]