摘要
利用Thermo-Calc软件计算Nb对309S(Fe-22Cr-14Ni-2Mn-0.5Si-0.3V-0.07C-0.07N)奥氏体不锈钢相组成的影响。高温下(1100℃左右)Nb与C形成NbC,随着Nb含量的增加,NbC的量增加,析出温度升高;当Nb含量达到0.28wt.%时,NbC相开始从液相中析出。研究了四种不同Nb含量的合金,经1100℃固溶处理后,显微组织观察表明,合金中NbC的析出量随Nb含量的增加而增加,实验结果与Thermo-Calc计算结果一致。高温拉伸试验结果表明:添加0.54Nb的合金比不添加Nb的合金在600℃、700℃、800℃的抗拉强度分别提高了30M Pa、32M Pa和22M Pa,屈服强度分别提高了27M Pa、39M Pa、16M Pa。
The phase fraction diagrams varying with the niobium content in 309 S （Fe-22 Cr-14Ni-2Mn-0. 5Si-0. 3V-0. 07C-0. 07N）austenitic stainless steels have been calculated by the Thermo-Calc software. It has been shown that with the increasing of Nb content,the content and precipitation temperature of NbC phase increases. When the Nb content is higher than 0. 28wt.%（mass fraction）,NbC phase precipitates from liquid directly. According to the thermodynamic calculation results,four alloys with different Nb contents have been de-signed and smelt. After 1100℃ solution treatment,microstructure observation indicates that the content of NbC precipitation increases with the growing of Nb content in Nb bearing austenitic stainless steel. Experimental results are all well consistent with the calculation re-sults. The high temperature tensile test results illustrate that high temperature ultimate tensile strength of 0. 54% Nb alloy improve 30MPa,32MPa and 22MPa and high temperature yield strength improve 27MPa,39MPa and 16MPa at 600℃,700℃,800℃ respectively comparing with no Nb-bearing alloy.
出处
《沈阳理工大学学报》
CAS
2017年第5期57-60,共4页
Journal of Shenyang Ligong University
关键词
NBC
309S奥氏体不锈钢
相图计算
析出物
NbC
NbC
309 S austenitic stainless steel
thermodynamic calculation
precipitate
