CAJ | 학술논문

为了研究镍基合金焊材FM-52M的高温失延裂纹(DDC),采用改进的应变?裂纹(STF)实验方法,提出新的裂纹敏感性判据——晶界滑移量.并将之与裂纹数量相结合定量评估不同温度、不同变形量条件下材料的DDC敏感性.结果表明:本研究中所得到的材料临界变形量6%大于传统 STF方法得到的4%的临界变形量.预热处理、峰值温度、变形速率等条件都能显著影响 DDC 的敏感性.此外,利用显微硬度标记了许多微区,并对实验前后的微区进行了SEM观察,探讨晶界滑移与析出物在DDC的萌生与扩展过程中的作用.
위료연구얼기합금한재FM-52M적고온실연렬문(DDC),채용개진적응변?렬문(STF)실험방법,제출신적렬문민감성판거——정계활이량.병장지여렬문수량상결합정량평고불동온도、불동변형량조건하재료적DDC민감성.결과표명:본연구중소득도적재료림계변형량6%대우전통 STF방법득도적4%적림계변형량.예열처리、봉치온도、변형속솔등조건도능현저영향 DDC 적민감성.차외,이용현미경도표기료허다미구,병대실험전후적미구진행료SEM관찰,탐토정계활이여석출물재DDC적맹생여확전과정중적작용.
According to the improved strain-to-fracture test (STF) method, the value of grain boundary sliding was used as a new criterion to evaluate the susceptibility of ductility-dip cracking (DDC) in Ni-based alloy filler metal 52M(FM-52M) under various temperature and deformation conditions. The results show that the threshold strain of the test is 6%, which is larger than 4%obtained by previous STF method. Heat pretreatment, peak temperature, strain rate all have a great influence on the DDC susceptibility. Microhardness was used to mark interested micro-regions, from which SEM images were made before and after the test in order to explain the roles of grain boundary sliding and precipitates in DDC.