Solid Solution Hardening by Ca rbon and Nitrogen and Low Cyclic Fatigue Softening of Austenitic Steels.

为了阐明碳和氮对碳和/或氮强化奥氏体钢低循环疲劳软化的影响，进行了以下研究。碳和硅对不锈钢软化的影响：得出的结论是，软化不仅仅是由低层错能引起的，碳（和氮）是软化所必需的，硅增强了碳（和氮）的这种作用。不锈钢和高锰非磁性钢XANES（x射线吸收近边缘结构）和EXAFS（扩展x射线吸收精细结构）的观察：利用国家高能物理实验室光子工厂的同步辐射，阐明了实验技术有可能阐明铬、锰或镍等取代原子周围存在的碳和氮原子的结构和数量。详细的分析正在进行中。塑性变形计算机模拟程序的构建结果表明，计算机模拟可以较好地再现其塑性变形行为及伴随现象。

Followings were investigated in order to clarify the effects of carbon and nitrogen on low cyclic fatigue softening of austenitic steels strengthened by carbon and/or nitrogen.1.THE EFFECTS OF CARBON AND SILICON ON THE SOFTENING OF STAINLESS STEELS: It was concluded that the softening was not induced only by low stacking fault energy, carbon (and nitrogen ) was necessary for the softening and silicon enhanced this effect of carbon (and nitrogen ).2.OBSERVATION OF XANES(X-RAY ABSORPTION NEAR EDGE STRUCTURE)AND EXAFS(EXPANDED X-RAY ABSORPTION FINE STRUCTURE) OF STAINLESS AND HIGH MANGANESE NON-MAGNETIC STEELS: Using synchrotron radiation of the Photon Factory in national laboratory for high energy physics at Tsukuba, it was clarified that the experimental techniques were potential to elucidate the structure and the amount of carbon and nitrogen atoms existing around substitutional atoms such as chromium, manganese or nickel. Detail analyses are now in progress.3.CONSTRUCTION OF PROGRAM FOR COMPUTER SIMULATION OF PLASTIC DEFORMATION; It was elucidated that the plastic deformation behavior and the accompanied phenomena could be reproduced fairly well by the computer simulation.