Comparison of inclusions in A286 precipitation hardening stainless steel with different smelting processes
WEI Liangliang1, SUN Yongqing*2, GUAN Yulong3, WANG Changjun2, LIU Zhenbao2
1. Aerospace Precision Products Inc., China Aerospace Science & Industry Corp., Tianjin 300308, China; 2. Special Steel Institute, Central Iron & Steel Research Institute Co., Ltd., Beijing 100081, China; 3. Technical Center, Fushun Special Steel Co., Ltd., Fushun 113000, China
Abstract：A286 austenitic precipitation hardening stainless steel (also known as GH2132 superalloy in China) is a widely used high-temperature fastener material with service temperature below 650 ℃. In the actual production and use of this material, two smelting production processes, including electric arc furnace + ladle furnace + electro slag remelting (EAF+LF+ESR) and vacuum induction melting + vacuum arc remelting (VIM+VAR), have been used. So far, no systematic comparative studies on A286 stainless steel produced by these two processes have been carried out in China. The A286 test steel samples produced by the above two smelting processes were taken as the research object. The differences and characteristics of the two test steels in terms of structure, type, composition, particle size, distribution and morphology of non-metallic inclusions were compared and studied using Aspex inclusion analyzer, scanning electron microscope (SEM) and other test tools. The results showed that the amount and area of inclusions in EAF + LF + ESR steel were more than 3 times of those in VIM + VAR steel. The inclusions in both test steels were composed of TiC, TiN, Ti (C, N), etc. The inclusions in the former sample were mainly in the form of TiN inclusions, and most of them were large-size chain like with large aspect ratio and complex shape, which were unfavorable to the mechanical properties and corrosion resistance of the material at room temperature. The inclusions in the latter sample were mainly in the form of TiC with small size and simple shape. By controlling the N mass fraction in A286 test steel below 0.001%, the amount and size of Ti containing inclusions could be controlled at a low level. Due to the characteristics of EAF + LF + ESR process, the content of P in the test steel was high, which was about 10 times of that in VIM+VAR test steel. According to the data, it may be beneficial to the high temperature creep property of A286 stainless steel. The results of the study could provide technical reference for the use of A286 stainless steel in different environments and service requirements.
[1] 北京钢铁学院高温合金教研室.GH132合金[M].北京:国防工业出版社,1980. [2] 郭诚,都祥元,李红军,等.不同冶炼工艺对1Cr18-Ni10Ti钢夹杂物的影响[J].航空制造技术,2016(Z2):129-132. GUO Cheng,DU Xiangyuan,LI Hongjun,et al.Effect of different smelting process on the non-metallic inclusions of 1Cr18Ni10Ti[J].Aeronautical Manufacturing Technology,2016(Z2):129-132. [3] 洪巨锋,刘俊亮,庞厚君,等.夹杂物及组织对FB780高扩孔钢扩孔性能的影响[J].冶金分析,2016,36(1):29-35. HONG Jufeng,LIU Junliang,PANG Houjun,et al.Influence of inclusion and microstructure on the hole-expansion property of FB780 high hole-expansion steel[J].Metallurgical Analysis,2016,36(1):29-35. [4] 王宝明,赵志毅,陈凌峰.夹杂物尺寸及数量对无取向硅钢磁性能影响的主成分回归分析[J].冶金分析,2014,34(10):1-6. WANG Baoming,ZHAO Zhiyi,CHEN Lingfeng.Principal component regression analysis on the size and quantity of inclusions affecting magnetic properties of non-oriented silicon steel[J].Metallurgical Analysis,2014,34(10):1-6. [5] 彭涯,李冬玲,周晴晴.大尺寸动车组车轮剖面夹杂物原位统计分布表征方法研究与应用[J].冶金分析,2021,41(4):1-8. PENG Ya,LI Dongling,ZHOU Qingqing.Research and application of original position statistic distribution characterization method for inclusions in profile of large-size high speed train wheels[J].Metallurgical Analysis,2021,41(4):1-8. [6] 张淑兰,王辉,王昌.扫描电镜测量非金属夹杂物分类方法探讨[J].冶金分析,2020,40(1):7-16. ZHANG Shulan,WANG Hui,WANG Chang.Discussion on the classification rule for the nonmetallic inclusions measured by scanning electron microscope[J].Metallur-gical Analysis,2020,40(1):7-16. [7] 祝凯,杨健,王睿之.钢中微细夹杂物的评价方法[J].冶金分析,2011,31(2):1-7. ZHU Kai,YANG Jian,WANG Ruizhi.A method for evaluating fine inclusions in steels[J].Metallurgical Analysis,2011,31(2):1-7. [8] Wang M,Du J,Deng Q,et al.The effect of phosphorus on the microstructure and mechanical properties of ATI 718Plus alloy[J].Materials Science & Engineering A,2015,25(2):382-389. [9] 章莎,信昕,孙文儒,等.磷偏聚对IN706合金铸态组织及均匀化处理的影响[J].中国有色金属学报(英文版),2015,25(9):2939-2947. ZHANG Sha,XIN Xin,SUN Wenru, et al.Effect of phosphorus segregation on as-cast microstructure and homogenization treatment of IN706 alloy[J].Trans. Nonferrous Met. Soc. China,2015(25):2939-2947. [10] 孙文儒,郭守仁,郭建亭,等.磷含量对GH761合金凝固,偏析及η相析出的影响[J].金属学报,1995,31(8):A346-A350. SUN Wenru,GUO Shouren,GUO Jianting,et al.Effect of phosphorus on solidification element segregation and η-phase precipitation in GH761 alloy[J].Acta Metallurgica Sinica,1995,31(8):A346-A350. [11] 杨树林,孙文儒,郭守仁. 磷对GH761合金力学性能的影响[J].金属学报,2005,41(12):1249-1255. YANG Shulin,SUN Wenru,GUO Shouren.Effect of phosphorus on mechanical properties of GH761 alloy[J].Acta Metallurgica Sinica,2005,41(12):1249-1255. [12] Zhang S,Xin X,SUN W R,et al.Effect of phosphorus segregation on as-cast microstructure and homogenization treatment of IN706 alloy[J].Transactions of Nonferrous Metals Society of China,2015,25(9):2939-2947. [13] Duan H,Zhang Y,Ren Y,et al.Distribution of TiN inclusions in Ti-stabilized ultra-pure ferrite stainless steel slab[J].Journal of Iron and Steel Research International,2019,26(9):962-972. [14] Tirumalasetty G K,van Huis M A,Fang C M,et al.Characterization of NbC and (Nb,Ti)N nanoprecipitates in TRIP assisted multiphase steels[J].Acta Materialia,2011,59(19):7406-7415. [15] Michelic S K,Loder D,Reip T,et al.Characterization of TiN,TiC and Ti(C,N) in titanium-alloyed ferritic chromium steels focusing on the significance of different particle morphologies[J].Materials Characterization,2015,100:61-67.
