摘要
试验测定了GH3230合金超温至1200℃循环氧化动力学,采用SEM、XRD和EPMA观察分析氧化行为及其对近表面层成分、组织的影响。结果表明,1200℃循环热暴露使合金持续产生氧化失重,失重速率由高变低再逐渐增加,但100次超温产生的减薄量小于板材厚度波动的控制限度;热暴露后表面残留氧化物主要是Cr_(2)O_(3)和MnCr_(2)O_(4);碳氧化产生的气体形成的法向压力、氧化物生长应力的增大以及大温差冷却产生的热应力的叠加作用导致外层氧化膜的不断开裂、剥离。同时,沿晶界发生明显内氧化,但氧化脱碳形成的Ni基固溶体层远大于内氧化的深度,可抑制内氧化物的致脆效应。
The oxidation kinetics of GH3230 alloy was measured as a function of the cumulative time during cyclic thermal exposure at 1200℃.The oxidation behavior,the resulting composition,and microstructure of the nearby surface layer were observed and analyzed by SEM,XRD and EPMA.The results show that GH3230 alloy exhibits continuous oxidation mass loss during cyclic thermal exposure,and the mass loss rate is decreased from the highest value to the lowest level and then gradually increased with proceeding the thermal exposure.Nevertheless,the alloy thickness loss after 100 exposure cycles is obviously less than the thickness-fluctuation limit of standardized plate products.The remaining oxides on the surface after thermal exposure are mainly composed of Cr_(2)O_(3) and MnCr_(2)O_(4).The normal gas pressure produced by carbon oxidation,the increment in oxide growth stress and the thermal stress caused by overtemperature exposure lead to the cracking and spallation of the outer oxides.At the same time,internal oxidation occurs along grain boundaries significantly.Additionally,it is worth noting that the Ni-based solid solution layer transformed through selective oxidation and oxidative decarbonization is ductile and its thickness is always much larger than the internal oxidation depth.Therefore,the embrittlement effect of internal oxides can be inhibited.
作者
张亚玮
沈宇
鞠泉
胥国华
张继
Zhang Yawei;Shen Yu;Ju Quan;Xu Guohuang;Zhang Ji(Gaona Aero Material Co.,Ltd,Beijing 100081,China;Central Iron and Steel Research Institute,Beijing 100081,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2023年第9期3221-3229,共9页
Rare Metal Materials and Engineering
