Effects of Specimen Surface Condition and Atmosphere on Small Punch Creep Property of Low Alloy Steel
Effects of Specimen Surface Condition and Atmosphere on Small Punch Creep Property of Low Alloy Steel
复制标题
试件表面状况和气氛对低合金钢小冲头蠕变性能的影响
DOI：
10.2472/jsms.60.146
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Yoshiatu Sawaragi
中科院分区：
文献类型：
--
作者：
Tomoya Nishioka;Hiromi Uemura;T. Ohsawa;Yoshiatu Sawaragi
通过小冲孔试验，研究了试样表面光洁度、润滑剂、氩气流量等因素对2.25Cr-1Mo锅炉用低合金钢蠕变变形行为和断裂时间的影响。由于1200 #抛光试样的表面粗糙度与镜面抛光试样的表面粗糙度差异，其小冲孔蠕变行为和破裂时间差异不大。由于摩擦系数的降低，BN润滑剂在试样表面的应用导致试样破裂时间的缩短。随着氩气流量的增加，破裂时间也随之增加。通过μ-ESCA对氩气气氛下表面氧化膜的深度分析表明，在低氩气流速条件下，低摩擦系数富铁氧化膜的形成使其破裂时间缩短。在高氩气流量条件下，高摩擦系数富cr氧化膜的形成使断裂时间延长。这表明，通过小冲孔蠕变试验评估材料的寿命，氩气流量的可靠控制是非常重要的。
The effects of various factors such as the surface finish condition of specimens, lubricant and argon gas flow rate on both the creep deformation behavior and time to rupture for 2.25Cr-1Mo low alloy steel used for boilers by small punch testing were studied. There was little difference in both the small punch creep deformation behavior and time to rupture due to the difference in surface roughness between #1200 polished specimens and those in mirror polished condition. The application of BN lubricant to the specimen surface resulted in the decrease in time to rupture, due to the lowering of friction coefficient. Furthermore, the time to rupture increased according to the increase of argon gas flow rate. The depth analysis by μ-ESCA for surface oxide film formed in an argon gas atmosphere demonstrated that the formation of Fe-rich oxide film with a low friction coefficient produced a decrease in time to rupture under a low argon gas flow rate condition. The formation of Cr-rich oxide film with high friction coefficient produced the increase in time to rupture under high argon gas flow rate condition. This suggests that the reliable control of argon gas flow rate is very important in order to evaluate the life of material by small punch creep testing.