254SMo和2507超级不锈钢中的σ析出相  

Precipitation of σ-phase in 254SMo and 2507 super stainless steels

作　　者：王冬[1] 邹德宁[1] 韩英[2] 程宝[1] 

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]长春工业大学材料科学与工程学院,吉林长春130012

出　　处：《材料热处理学报》2016年第5期103-109,共7页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金-钢铁联合基金面上培育项目(U1460104);陕西省自然科学基础研究计划面上项目(2015JM5197);国家重点实验室开放基金(20151202)

摘　　要：通过JMat Pro软件,计算预测254SMo超级奥氏体不锈钢(SASS)和2507超级双相不锈钢(SDSS)中σ相的热力学析出条件,并制定了不同的热处理制度;同时借助光学显微镜、扫描电镜等手段分析研究了经不同温度时效不同时间后σ析出相的形态及析出机理。结果表明:254SMo SASS在1020℃不同时效时间下,在晶界上析出富含Cr、Mo和低Ni的σ相。随着时效时间增加,σ相数量增多、尺寸增大,且呈短棒状、长条状和胞状等形态,并按照γ→σ方式析出;2507 SDSS在950℃不同时效时间下,在α/γ界面和α/α晶界处析出富含Cr、Mo和更低水平Ni的σ相。随着时效时间增加,σ相数量增多,向铁素体内部长大并最终呈网状分布在奥氏体基体上,且伴有二次奥氏体(γ_2)生成,其是按照α→σ+γ_2方式析出。The thermodynamic precipitation conditions of σ-phase in 254 SMo super austenitic stainless steel（ SASS） and 2507 super duplex stainless steel（ SDSS） were investigated by calculation using JMat Pro software and experiments. Morphology and precipitation mechanism of the σ-phase in the steels after aging at different temperatures for different time were analyzed by optical microscope,scanning electron microscopy and EDS analysis. The results show that the σ-phase rich in Cr,Mo and low Ni is precipitated on the grain boundaries for the 254 SMo SASS aged at 1020 ℃ for different time. With the aging time increases,the amount and size of the σ-phase increase,and it is presented short rod,strip,cellular morphology,and precipitated in accordance with the γ→σ way. The 2507 SDSS under different aging time at 950 ℃,the σ-phase rich in Cr,Mo and low Ni is precipitated on α / γ interface and the α / α grain boundaries. As the aging time increases,the amount of the σ-phase increases,and it grows into ferrite with reticular distribution in the austenitic matrix eventually,and the secondary austenite（ γ_2） is generated,the precipitation occurs by the α→σ ＋ γ_2way.

关 键 词：254SMo超级奥氏体不锈钢 2507超级双相不锈钢 Σ相 热力学计算 

分 类 号：TG142.7[一般工业技术—材料科学与工程]