摘要：利用熱力學(xué)計算了S31254超級奧氏體不銹鋼在500~1 200 ℃溫度范圍內(nèi)的平衡態(tài)析出相，并結(jié)合熱模擬試驗、掃描電鏡、透射電鏡等方法，對不同析出物的析出行為進(jìn)行了表征和分析。結(jié)果表明，S31254不銹鋼奧氏體基體中可存在的第二相包括σ、χ、Laves等金屬間相，Cr2N、π型氮化物相以及M23C6型碳化物相，高M(jìn)o、高N、高Cr含量是該鋼析出相種類復(fù)雜的主要原因；試驗鋼具有高的第二相析出傾向，σ相開始析出溫度約為1 150 ℃，而在900~800 ℃區(qū)間可發(fā)現(xiàn)χ相和σ相的轉(zhuǎn)變，χ相更易作為一種穩(wěn)定相存在；析出相的析出位置和形貌呈現(xiàn)不同特點，晶界析出主要為σ相、χ相和Laves相，而晶內(nèi)主要有呈針狀和塊狀分布的χ相和呈棒狀析出的Cr2N相。

關(guān)鍵詞：S31254；超級奧氏體不銹鋼；析出相；等溫處理；顯微組織；相轉(zhuǎn)變

Evolution and microstructure characterization of precipitate phases in S31254 super austenitic stainless steel

ZHANG Ya-bin1，REN Jian-bin2，WANG Jin-yong1，ZUO Jing-jing1，WU Rui-bin1，F(xiàn)ENG Han2

(1. Xinxing Ductile Iron Pipes Co., Ltd., Handan 056000, Hebei, China;2. Institute for Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China)

Abstract： The equilibrium precipitates of S31254 super austenitic stainless steel in the temperature range of 500-1 200 ℃ were calculated by thermodynamics. The precipitating behavior of different precipitates were characterized and analyzed by thermal simulation test, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and other methods. The results show that the second phases in the austenitic matrix of S31254 stainless steel include intermetallic phases such as σ, χ and Laves, Cr2N, π-type nitride phases and M23C6 type carbide phases. The high Mo, high N and high Cr contents are the main reasons for the complexity of precipitates. The experimental steel has a high tendency to precipitate the second phase. The initial precipitation temperature of σ phase is about 1 150 ℃, and the conversion of χ phase and σ phase can be found in the range of 900-800 ℃. The χ phase is more likely to exist as a stable phase. The location and morphology of precipitates are different. The grain boundary precipitates are mainly σ phase, χ phase and Laves phase, while the intergrain precipitates are mainly acicular and massive χ phase and rod-shaped Cr2N phase.

Key words：S31254；super austenitic stainless steel；precipitated phase；isothermal treatment；microstructure；phase transition

收稿日期: 2021-04-21     

作者簡介: 張亞彬(1975—), 男, 碩士, 高級工程師; E-mail: zhangyabin007794@163.com

引用本文:   

張亞彬, 任建斌, 王錦永, 左晶晶, 武瑞斌, 豐涵. S31254超級奧氏體不銹鋼析出相演變及微觀表征[J]. 中國冶金, 2021, 31(12): 61-66. ZHANG Ya-bin, REN Jian-bin, WANG Jin-yong, ZUO Jing-jing, WU Rui-bin, FENG Han. Evolution and microstructure characterization of precipitate phases in S31254 super austenitic stainless steel[J]. China Metallurgy, 2021, 31(12): 61-66.

鏈接本文:  

http://www.zgyj.ac.cn/CN/10.13228/j.boyuan.issn1006-9356.20210215     或     http://www.zgyj.ac.cn/CN/Y2021/V31/I12/61