中温时效对超级双相不锈钢2507组织及性能的影响

Effect of Medium Temperature Aging on Microstructures and Properties of Super Duplex Stainless Steel 2507

双相不锈钢2507耐蚀性优异，但热处理不当时会影响其组织和性能。借助光学显微镜和透射电子显微镜研究了超级双相不锈钢2507在不同温度（360，580℃）时效处理后的组织结构和力学性能．并采用动电位极化曲线结合FeEl，浸泡方法研究其耐点蚀性能。结果表明：不同温度时效处理后，双相不锈铜2507均析出纳米级富铬仅’相，其中360℃时效产生α相与α相共格，580℃时效产生α相与仅相非共格；α＇相主要在α相内、α／α和α／У晶界处析出；当α相与仅相非共格时，试样强度和韧性变化更为明显；360℃时效试样较5801：时效试样能更好地抑制稳定点蚀的萌生和发展长大。

Abstraα： The microstruαures and mechanical properties of super duplex stainless steel 2507 after aging treatment at different temperatures （ 360℃ and 580 ℃ ） were investigated by means of optical microscope （OM） and transmission eleαron microscopy （ TEM）, and the pitting corrosion resistance was investigated by combining potentiodynamic polarization curves and FeC13 immersion method. Results showed that the nanoscale chromium- rich α＇ phase was produced after aging treatment with different temperature. Among them, the α＇ phase at 360 ℃ was coherent with the α phase, while the a＇ phase at 580 ~C was non-coherent with the α phase. The α＇ phase was mainly precipitated in the α phase, α/α and α/У grain boundaries. When α＇ phase was non-coherent with α phase, the strength and toughness changed more obviously. Moreover, pitting corrosion test showed that the sample after aging at 360 0（2 was better than the sample aged at 580 ℃ to inhibit the steady pitting initiation and steady pitting growth.