RESEARCH ON IRRADIATION ASSISTED STRESS CORROSION CRACKING(IASCC) OF REACTOR INTERNALS

本研究的目的是模拟辐照辅助晶界偏析的晶界结构和热处理的化学性质，并利用SSRT表征模拟低水堆水环境中与igscc敏感性相关的晶界。在这一年中，主要的工作是确定上述目的的材料选择，最终确定了7种不同杂质含量的奥氏体不锈钢。通过epr和coriou试验对晶界进行表征。在非敏化条件下，在硫磷晶界偏析的材料上重现了Igscc。有偏析的试样具有较高的开裂敏感性。

OBJECTIVES OF THIS RESEARCH ARE TO SIMULATE THE GRAIN BOUNDARY STRUCTURE AND CHEMISTRY OF IRRADIATION ASSISTED GRAIN BOUNDARY SEGREGATION BY THERMAL TREATMENTS ANF TO CHARACTERIZE THE GRAIN BOUNDARIES IN CORRELATION WITH IGSCC SUSCEPTIBILITY BY MEANS OF SSRT IN SIMULATED LWR WATER ENVIRONMENTS.IN THIS YEAR, MAIN EFFORTS HAVE BEEN PAID FOR DETERMINATION OF MATERIALS SELECTION FOR THE PURPOSE MENTIONED ABOVE AND FINALIZED 7 AUSTENITIC STAINLESS STEELS WITH A VARIATION OF IMPURITY CONTENTS.CHARACTERIZATION OF GRAIN BOUNDARY WERE PERFORMED BY EPR AND CORIOU TESTS. IGSCC WAS REPRODUCED ON THE MATERIALS WITH GRAIN BOUNDARY SEGREGATION OF SULFUR AND PHOSPHOROUS AND WITH NON SENSITIZED CONDITIONS. HIGH CRACKING SUSCEPTIBILITY WAS OBTAINED ON THE SPECIMENS WITH SEGRAGATION.