2205双相不锈钢中σ相的析出规律

Precipitation law of σ phase in 2205 duplex stainless steel

2205双相不锈钢经过1300℃固溶处理和不同程度的冷轧变形后,在不同温度下保温不同时间后水冷.利用金相显微镜和透射电镜观察试样的组织,用Image Tool软件分析组织中σ相的含量,研究2205双相不锈钢中σ相的析出规律.在950℃保温,当冷轧变形量从50%增大到85%时,σ相析出时间从30 min缩短为3 min.冷轧变形量为85%的试样,在950℃保温,当保温时间从3 min延长至30 min时,σ相的体积分数从1.2%增大到11.8%.在875~950℃保温5 min后,当温度从875升高至950℃时,σ相的体积分数从8.9%降低至3.6%;在975℃保温5 min后,组织中不存在σ相.

After solution treatment at 1300℃ and cold rolling deformation at different reductions, 2205 duplex stainless steel was homogenized at different temperatures for different time intervals. To study the precipitation behavior of σ phase in the steel, the mi- crostructure of specimens was observed by optical microscopy and transmission electron microscopy, and the volume fraction of σ phase in the microstructure was calculated by Image Tool software. The results show that when the steel is homogenized at 950℃, the pre- cipitation time of σ phase is shortened from 30min to 3 rain with the increase of cold rolling reduction from 50% to 85%. As to speci- mens with a cold rolling reduction of 85% , the volume fraction of σ phase increases from 1.2% to 11.8% when the homogenizing time is prolonged from 3 min to 30 min at 950 ℃ However, after homogenization for 5 min, the volume fraction of σ phase decreases from 8.9% to 3.6% with the rise of temperature from 875 to 950℃ ; moreover, when the homogenizing temperature is 975℃, No phase exists in the specimen.