热处理与加工成型工艺对双相不锈钢流动腐蚀的影响

Influences of Heat Treatment and Shaping Process on the Flow-Induced Corrosion of Duplex Stainless Steel

研究了热处理与加工成型工艺对双相不锈钢在流动 3 .5 %NaCl溶液中流动腐蚀的影响。结果表明 ,随着固溶处理温度Ts 的升高 ,锻压双相不锈钢的耐蚀性降低 ;随着时效强化时间的延长 ,锻压双相不锈钢的硬度增大 ,耐蚀性有所提高 ,但是锻压双相不锈钢的耐流动腐蚀性能与它的硬度并不存在一致对应的关系。铸造双相不锈钢在流动 3 .5 %NaCl溶液中的腐蚀速度随着介质流速的增大而缓慢上升 ,高流速条件下 ,其表面发生了严重的坑、点等局部腐蚀。固体颗粒的加入 ,促使其流动腐蚀加剧 ,且存在一个使腐蚀速度急剧上升的临界流速值 。

The influences of heat treatment and shaping process on the flow induced corrosion of the duplex stainless steel in flowing 3.5% NaCl solution were studied. The result shows that the corrosion resistance of the forged duplex stainless steel was lowered with the increase of solution treatment temperature; the hardness of the forged duplex stainless steel was strengthened and the corrosion resistance was increased with the prolongation of age hardness time. The flow induced corrosion resistance of the forged duplex stainless steel did not correspond to its hardness. The flow induced corrosion rate of the cast duplex stainless steel in flowing 3.5% NaCl solution became slowly quick with the increase of medium flow velocity. Local serious pitting corrosion occurred on the surface of the cast duplex stainless steel under high speed flow velocity. The solid particles made the flow induced corrosion more serious, and a critical flow velocity value could make the corrosion increase quickly, the flow induced corrosion process was mainly controlled with anode process.