超级双相不锈钢σ相析出及对组织性能的影响  

Precipitation behavior of σ-phase and its effect on microstructure and properties of a super duplex stainless steel

作　　者：赵志毅[1] 徐林[1] 李国平[2] 薛润东[1] 郑建华[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]太钢不锈钢股份有限公司技术中心,山西太原030003

出　　处：《材料热处理学报》2010年第10期75-79,共5页Transactions of Materials and Heat Treatment

摘　　要：利用光学显微镜、扫描电子显微镜(SEM)、X射线衍射(XRD)、纳米力学探针、常温拉伸等方法,研究了S32750超级双相不锈钢中σ相的析出规律及其对组织性能的影响。结果表明,σ相优先析出于奥氏体晶粒边界处、铁素体含量稀少之处,其析出量随固溶温度的升高而呈现出先增大后减小的趋势,在900℃时,析出量达到最大。材料的硬度与变形抗力会随着σ相析出量的增多而增大;σ相析出时引起的体积膨胀会引起奥氏体边部的硬度与杨氏模量增大;σ相析出也容易造成材料中微裂纹的形成。S32750双相不锈钢应在1020℃到1080℃温度范围内进行固溶,以获得较好的冷加工性能。The σ-phase precipitation behavior of a super duplex stainless steel S32750 and its influence on microstructure and properties were investigated by means of optical microscope,scanning electron microscopy（SEM）,X-ray diffraction（XRD）,nano indenter and tensile tests.The results show that the σ-phase has priority to precipitate at austenite grain boundary where there is rare ferrite.The precipitation quantity of σ-phase increases firstly then decreases with increase of the solution temperature,which has the peak value at 900 ℃.Hardness and deformation resistance of the steel increases with increase of σ-phase precipitation.The volume expansion caused by the σ-phase precipitation induces the increase of hardness and Young modulus of the austenite edge region,meanwhile the σ-phase precipitation also leads to the formation of micro-crack in the material.The solution treatment of duplex stainless steel S32750 can be carried out in the range 1020 ℃ to 1080 ℃ in order to get good cold-workability.

关 键 词：超级双相不锈钢 Σ相 固溶 力学性能 

分 类 号：TG142.71[一般工业技术—材料科学与工程]