马氏体不锈钢上梯度纳米结构表层的形成及其对电化学腐蚀行为的影响  

FORMATION OF A GRADIENT NANOSTRUCTURED SURFACE LAYER ON A MARTENSITIC STAINLESS STEEL AND ITS EFFECTS ON THE ELECTROCHEMICAL CORROSION BEHAVIOR

作　　者：黄海威[1] 王镇波[1] 刘莉[2] 雍兴平[3] 卢柯[1,4] 

机构地区：[1]中国科学院金属研究所沈阳材料科学国家(联合)实验室,沈阳110016 [2]中国科学院金属研究所,沈阳110016 [3]沈阳鼓风机集团股份有限公司,沈阳110869 [4]南京理工大学格莱特纳米科技研究所,南京210094

出　　处：《金属学报》2015年第5期513-518,共6页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展计划资助项目2012CB932201~~

摘　　要：采用表面机械滚压处理(SMRT)在Z5CND16-4马氏体不锈钢上制备出梯度纳米结构(GNS)表层.利用SEM和TEM研究了GNS表层的组织特点.结果表明:晶粒尺寸随深度的增大由最表层的25 nm逐渐增加到基体的原始尺寸,整个组织细化层的厚度约为150 mm.对比研究了SMRT样品与原始样品在3.5%Na Cl(质量分数)水溶液中的电化学腐蚀行为,发现点蚀击破电位由原始样品的0.179 V提高到0.313 V,自腐蚀电位也有所提高.分析表明,GNS表层中晶粒尺寸纳米化、组织均匀性提高、残余压应力的产生以及表面光洁度的提高有利于其耐点蚀能力的提高.A gradient nanostructured（GNS） surface layer was fabricated on a Z5CND16-4 martensitic stainless steel by means of surface mechanical rolling treatment（SMRT）. The microstructure in the GNS surface layer was characterized by using SEM and TEM. The results showed that the mean grain size increases with depth, from about 25 nm at the topmost surface layer to the initial value in the matrix. The total thickness of the grain-refined layer is about 150 mm. The electrochemical corrosion property of the SMRT sample was compared with that of the as-received sample in a 3.5%Na Cl aqueous solution. It is shown that the pitting corrosion potential increases from about 0.179 V in the as-received sample to about 0.313 V in the SMRT sample, and the self-corrosion potential also increases evidently. The formation of nanostructures, the increased structural homogeneity, and the introduction of compressive residual stresses in the GNS surface layer, as well as the decreased surface roughness, were discussed to promote the pitting corrosion resistance of the SMRT sample.

关 键 词：纳米材料 梯度纳米结构 表面机械滚压处理 马氏体不锈钢 点蚀 

分 类 号：TG172.5[金属学及工艺—金属表面处理]