2205双相不锈钢晶间腐蚀试验的裂纹判定和影响因素分析  

Determination of Crack and Influencing Factors Analysis of 2205 Duplex Stainless Steel by Intergranular Corrosion Test

作　　者：罗先甫[1] 郭仲阳 张恒坤 张文利[1] 刘晓勇[1] 查小琴[1,2] LUO Xianfu;GUO Zhongyang;ZHANG Hengkun;ZHANG Wenli;LIU Xiaoyong;ZHA Xiaoqin(Luoyang Ship Material Research Institute,Luoyang 471023,China;Henan Key Laboratory of Technology and Application of Structural Materials for Ships and Marine Equipments,Luoyang 471023,China)

机构地区：[1]中国船舶重工集团公司第七二五研究所,河南洛阳471023 [2]河南省船舶及海工装备结构材料技术与应用重点实验室,河南洛阳471023

出　　处：《材料开发与应用》2020年第6期36-42,共7页Development and Application of Materials

基　　金：国家重点研发计划项目(2016YFC0401205)。

摘　　要：通过金相观察(OM)、透射电镜观察(TEM)对2205双相不锈钢经铜-16%硫酸-硫酸铜晶间腐蚀试验后压弯产生的裂纹进行判定,采用拉伸性能测试、残余应力测试和粗糙度检测等对产生裂纹的影响因素进行分析.结果表明:经675℃×1h敏化处理后,在铁素体晶界、铁素体-奥氏体相界均析出少量富(Mo,Si)化合物,在铁素体晶粒内部析出弥散碳化物,奥氏体晶内存在少量未转变铁素体,压弯产生的裂纹均为穿晶裂纹,材料无晶间腐蚀敏感性.试验双相钢力学性能符合2205双相不锈钢标准要求,较小的残余拉应力、弯头直径等对裂纹的产生影响不大.压弯后表面粗糙度为1.6 μm的试样产生裂纹,表面粗糙度≤0.9 μm的试样均未产生裂纹.因此,进行铜-16%硫酸-硫酸铜晶间腐蚀试验前需控制试样的表面粗糙度.The cracks of 2205 duplex stainless steel after the intergranular corrosion test with copper-16% sulfuric acid-copper sulfate were determined by optical microscope and transmission electron microscope. The influencing factors of cracking were analyzed by tensile property test, residual stress test and roughness test. The results show that after sensitization at 675 ℃ for 1 hour, a small amount of(Mo, Si) riched compounds are precipitated at the ferrite boundary and the ferrite-austenite phase boundary, and dispersed carbides are precipitated in the ferrite grains. There is a little non transformed ferrite in the austenite grains. The cracks produced by bending are transgranular cracks, and the materials have no intergranular corrosion sensitivity. The mechanical properties of the experimental DP steel can meet the standard of 2205 DSS. The small residual tensile stress and elbow diameter have little influence on the crack generation. The specimen with a surface roughness of 1.6 μm after bending has cracks, and the specimens with a surface roughness of equal to or less than 0.9 μm have no cracks. Therefore, it is necessary to control the surface roughness of the sample before the intergranular corrosion test with copper-16% sulfuric acid-copper sulfate.

关 键 词：2205双相不锈钢 铜-16%硫酸-硫酸铜 晶间腐蚀 裂纹 

分 类 号：TG142[一般工业技术—材料科学与工程]