海水抽水蓄能机组过流部件表面熔覆奥氏体不锈钢组织与性能研究

Study on the Structure and Properties of Austenitic Stainless Steel Cladding on theSurface of the Flow Passages Components of Seawater Pumped Storage Unit

本论文针对海水抽水蓄能过流部件耐蚀性问题,对常用的Q345B钢板,分别选择316L和309L作为耐蚀层和过渡层,开展了碳钢表面机器人堆焊熔覆奥氏体不锈钢耐蚀层研究,并通过渗透探伤、弯曲试验和电化学测试对熔覆层的性能进行了评价。结果表明,Q345B与309L过渡层,309L过渡层与316L熔覆层的熔合线清晰,界面呈波形,界面无裂纹缺陷,熔覆层组织致密均匀,碳钢与不锈钢耐蚀层为扩散型冶金结合。耐蚀层各项工艺评定试验结果均满足要求,耐蚀层在海水腐蚀环境中呈现出良好的耐腐蚀性能,对基体有很好地腐蚀防护作用。碳钢表面堆焊奥氏体不锈钢316L耐蚀层可用于海水抽水蓄能尾水管等高速过流面的腐蚀防护。

This paper aims at the corrosion resistance of seawater pumped storage flow passages components.For the commonly used Q345B steel plates,316L and 309L are selected as the corrosion resistance layer and the transition layer,respectively,and the research on the corrosion resistance layer of austenitic stainless steel by robot surfacing welding on the surface of carbon steel is carried out.The performance of the cladding is evaluated through penetrant testing,bending experiment,and electrochemical experiment.The results show that the fusion line of Q345B and 309L transition layer,309L transition layer,and 316L cladding layer is clear,the interface shape is wavy,and the interface has no crack defects.The cladding layer has a dense structure and no welding defects.There is a diffusion metallurgical bond between carbon steel and stainless steel corrosion-resistant layer.The corrosion-resistant layer's various process evaluation test results meet the requirements,and the corrosion-resistant layer exhibits good corrosion resistance in the seawater corrosive environment,which can well protect the substrate.The carbon steel surface welded austenitic stainless steel 316L corrosion resistant layer can be used for the corrosion protection of the flow passages components surface such as seawater pumped storage draft tube.