Preliminary creep testing of the alumina-forming austenitic stainless steel Fe-20Cr-30Ni-2Nb-5Al
Preliminary creep testing of the alumina-forming austenitic stainless steel Fe-20Cr-30Ni-2Nb-5Al
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DOI：
10.1016/j.msea.2018.01.090
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发表时间：
2018-03-07
期刊：
影响因子：
6.4
通讯作者：
Wu, Margaret
中科院分区：
文献类型：
--
作者：
Baker, Ian;Afonina, Natalie;Wu, Margaret
对Fe-20Cr-30Ni-2 Nb-5Al奥氏体不锈钢进行1250℃固溶退火，然后在800℃退火0、2.4、24、240 h，得到不同尺寸、不同晶界覆盖程度的B2相和Laves相相。对热处理后的材料和铸态合金在760℃下进行了拉伸试验和恒应力（43 MPa）蠕变试验。此外，L1(2)（有序f.c.c）析出相在500 h后的蠕变试验中形核长大，与之前的800℃热处理无关。给予最短热处理2.4 h的试样具有最小的初始粒径，在500 h后显示出最高的屈服强度和最小的蠕变应变。蠕变试验后，热处理试样未发现晶界开裂和析出物开裂，但铸态材料在600 h左右失效。
The alumina-forming austenitic stainless steel Fe-20Cr-30Ni-2 Nb-5Al was given a solutionizing anneal at 1250 degrees C followed by anneals at 800 degrees C for 0, 2.4, 24, 240 h to produce B2 (ordered b.c.c.) and Laves phase precipitates of different sizes with different extents of grain boundary coverage. Both tensile tests and constant stress (43 MPa) creep tests were performed on the heat-treated materials and on the as-cast alloy at 760 degrees C. The precipitates grew during the creep testing. In addition, L1(2) (ordered f.c.c.) precipitates nucleated and grew during the creep testing to similar particle sizes after 500 h independent of the prior heat treatment at 800 degrees C. The specimens given the shortest heat treatment of 2.4 h, which had the smallest initial particle sizes, showed both the highest yield strength and the smallest creep strain after 500 h. The extent of grain boundary coverage by precipitates did not appear to affect the creep rates. No grain boundary cracking or precipitate cracking was found in the heat-treated specimens after creep testing, but the as-cast material failed around 600 h.