17-4PH钢激光固溶-时效强化及抗空蚀性能  

Microstructure and properties of 17-4PH steel by laser solid solution and aging treatment and its cavitation erosion resistance

作　　者：王维夫[1,3] 郑玉贵[2] 

机构地区：[1]特种装备制造与先进加工技术教育部/浙江省重点实验室(浙江工业大学),浙江杭州310014 [2]中国科学院金属研究所,金属腐蚀与防护国家重点实验室,辽宁沈阳110016 [3]浙江工业大学机械工程学院,浙江杭州310014

出　　处：《材料热处理学报》2013年第9期155-159,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金资助项目(51131008,51105340);浙江省教育厅科研项目(Y201121488);特种装备制造与先进加工技术教育部/浙江省重点实验室开放基金资助项目(2010 EM001)

摘　　要：为了研究沉淀硬化不锈钢激光局部强化的可行性，采用激光固溶＋时效工艺对17-4PH不锈钢表面进行了强化处理，并分析了强化机制，测试了其抗空泡腐蚀性能。结果表明，在优化工艺参数（功率2．1kW，扫描速度50mm／min，460℃时效3h）下，可获得最大厚度约4mm的强化层。强化层性能呈梯度分布特征，最高硬度可达约510HV，比传统的整体高温固溶一时效处理高50～60HV以上。蒸馏水中的空泡腐蚀性能表明，4．5h累积质量损失仅约为基体的40％。分析认为，硬度的提高和抗空泡腐蚀性能的改善主要与s-cu相等析出相的弥散强化有关，激光处理的高冷却速度有利于获得更多的位错等微观缺陷，因此相对于传统热处理更有利于s—cu相等的析出强化。In order to study the feasibility of laser strengthening precipitation hardening stainless steel, surface laser solid solution experiment and aging treatment were used on 17--4PH steel. The strengthening mechanism was discussed and cavitation erosion resistance of the treated steel was evaluated. The results show that, the hardened layer of 4 mm thickness can be obtained by the laser solution and aging treatment with the optimized parameters of power 2. 1 kW, scanning velocity 50 mm/min and aging at 460 ℃ for 3 h. The microhardness display gradient distribution characteristics. The maximum hardness is 510 HV, which is about 50 - 60 HV higher than that of the steel by traditional solution and aging treatment. Cavitation erosion test results in distilled water show that the cumulative mass loss of the laser hardened sample is only 4-0% of the 17-4PH steel substrate after testing for 4.5 h. The improvements on microhardness and cavitation erosion resistance are mainly attributed to the dispersion strengthening of a-Cu and other precipitate phases. The laser treatment increases the density of dislocation and micro defects, which accelerates the diffusion of Cu atom and is favorable for precipitation of strengthening phases, leading to better strengthening effects in hardened layer.

关 键 词：沉淀硬化不锈钢 激光 固溶 时效处理 空泡腐蚀 

分 类 号：TG142.7[一般工业技术—材料科学与工程]