温压烧结316L不锈钢组织和耐3.5%NaCl腐蚀行为  

Microstructure and Anti-Corrosion Behavior in 3.5% NaCl of Warm Compacted and Sintered 316L

作　　者：李文生[1,2] 邢健 张杰 宋强[2] 孙永江[3] 成波 何东青[1] Li Wensheng;Xing Jian;Zhang Jie;Song Qiang;Sun Yongjiang;Cheng Bo;He Dongqing(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metal,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China;Gansu Luqiao Highway Investment Co.,Ltd,Lanzhou 730050,China)

机构地区：[1]兰州理工大学有色金属先进加工与再利用国家重点实验室,甘肃兰州730050 [2]山东科技大学材料科学与工程学院,山东青岛266590 [3]甘肃路桥公路投资有限公司,甘肃兰州730050

出　　处：《稀有金属材料与工程》2022年第12期4714-4725,共12页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52075234,51901093);丝绸之路经济带金属表面工程技术国际科技合作基地(2017D01003);甘肃省高等学校产业支撑计划项目(2020C-11);甘肃省科技重大专项(21ZD4WA017);兰州理工大学红柳优秀青年人才支持计划。

摘　　要：采用温压成形和真空烧结制备316L奥氏体不锈钢,研究烧结温度对材料相组织和硬度、抗拉强度等力学性能的影响,结合腐蚀失重曲线、阳极极化曲线、Nyquist图、Mott-Schottky曲线分析研究温压烧结316L不锈钢在3.5%NaCl(质量分数)溶液中的浸泡腐蚀行为。利用扫描和激光共聚焦电子显微镜分析表征拉伸断口形貌及浸泡腐蚀形貌,X射线光电子能谱分析仪分析浸泡腐蚀600h后的元素价态及钝化膜成分。结果表明:115℃温压成形、1290℃真空烧结的316L不锈钢密度达到最高7.203g/cm^(3),伸长率65.46%、抗拉强度420.37MPa和洛氏硬度63.1HRB;拉伸试样断口呈现明显的韧性断裂,韧窝深、数量多,韧性较好;在600h浸泡腐蚀后,呈现最小的腐蚀电流密度5.068×10^(-5)A·cm^(-2)和载流子密度0.723×10^(20)cm^(-3),最高的电荷转移电阻8111Ω·cm^(2)和钝化膜电阻14780Ω·cm^(2),耐腐蚀性能最优。316L austenitic stainless steel samples were prepared by warm compacting and vacuum sintering powder metallurgy method.Effects of sintering temperature on microstructure, phase and mechanical performances such as hardness and tensile strength were investigated. The immersion corrosion behaviors of the sintered 316L austenitic stainless steel in 3.5wt% NaCl solution were investigated by corrosion mass loss curve, anodic polarization curve, Nyquist diagram and Mott-Schottky curve. Tensile fracture, immersion corrosion morphology and passivation film composition and elemental valence were analyzed by SEM, laser scanning confocal microscopy and XPS,respectively. The results show that the highest sintering density(7.203 g·cm^(-3)), elongation(65.46%), mechanical tensile strength(420.37 MPa)and hardness(63.1 HRB) are achieved after warm compacting at 115 ℃ and vacuum sintering at 1290 ℃, and high toughness with the tensile fracture morphologies of ductile rupture, deep and numerous dimples is presented. In addition, the lowest corrosion current density(5.068×10^(-5)A·cm^(-2)), the carrier density(0.723×10^(20)cm^(-3)), the highest charge transfer resistance(8111 Ω·cm^(2)) and passivation film resistance(14 780 Ω·cm^(2)) of the sintered samples after 600 h immersion in 3.5wt% NaCl exhibit its very good corrosion resistance.

关 键 词：316L奥氏体不锈钢 温压成形 烧结温度 机械性能 耐腐蚀性 

分 类 号：TG142.71[一般工业技术—材料科学与工程]