热处理温度对海水循环泵叶轮用双相不锈钢冲击性能的影响

Influence of Heat Treatment on Impact Properties for Duplex Stainless Steel by Sea Water Circulating Pump Impeller

针对海水循环泵叶轮的服役条件,利用烟台台海玛努尔核电设备有限公司提供的材料,研究了热处理工艺对GX2GrNiMoN22-5-3双相不锈钢冲击性能的影响。结果表明,双相不锈钢的冲击性能在常温下随固溶温度的升高而逐渐下降,并且在1120～1160℃固溶温度范围内下降明显,在1160～1200℃温度范围内下降趋势缓慢。铁素体含量测试表明,随固溶温度的升高,铁素体的变化趋势与冲击功的变化趋势具有良好一致性,表明固溶温度升高铁素体含量降低,是冲击功减小的重要原因。对冲击断口形貌进行观察,冲击断口以韧窝型断裂为主。

The microstructure and impact properties influenced by the temperature of heat treatment for the GX2GrNiMoN22-5-3 duplex stainless steel serving as the sea water circulation pump impeller conditions were investigated. The results show that the impact strength for the duplex stainless steel at room temperature is gradually de- creasing and declines significantly when the quenching temperature is 1120-1160℃, and it declines slowly at 11601200℃. The results for relative content test of ferrite phase show that the change for content of ferrite phase with the solid solution temperature rising has good uniformity in the change of the impact strength. That is the main reason that the impact strength is on the decrease with the content decline for ferrite phase. It is shown that the impact frac- ture type is toughness nest primarily by the fracture morphology.