摘要
盲孔法是工程中测量残余应力最普遍的方法,其中材料的应变释放系数是该方法中的关键参数,目前国内外对球墨铸铁的应变释放系数研究相对较少。本文采用盲孔法对四种常用球墨铸铁QT450-10、QT550-6、QT600-3和QT700-4的应变释放系数进行了标定,得到应变释放系数与应力的关系曲线,发现低牌号的球墨铸铁由于铁素体含量多,对应力集中更为敏感,在标定试验中易产生局部的塑性变形。使用基于形状改变比能S的修正方法对四种球墨铸铁的应变释放系数进行修正,发现和其他均质金属材料不同,球墨铸铁应变释放系数与■之间存在良好的线性关系,因此提出了球墨铸铁应变释放系数关于■的修正公式,可直接应用于盲孔法测量球墨铸铁的残余应力。
The blind hole method is the most common method for measuring residual stresses in engineering,in which the strain release coefficient of the material is the key parameter in the method,and there are relatively few studies on the strain release coefficient of ductile iron at home and abroad.In this paper,the strain release coefficients of four commonly used ductile iron QT450-10,QT550-6,QT600-3 and QT700-4 were calibrated by the blind hole method,and the relationship curves between strain release coefficients and stresses were obtained.It was found that the lower grades of ductile iron are more sensitive to stress concentration due to the high ferrite content,and are prone to local plastic deformation in the calibration test.The strain release coefficients of the four ductile irons were corrected using a correction method based on the shape change ratio S.It was found that,unlike other homogeneous metallic materials,there was a good linear relationship between the strain release coefficients and S for ductile irons,so the correction formula for the strain release coefficients of ductile irons with respect to S was proposed,which can be directly applied to the measurement of residual stresses in ductile irons by the blind hole method.
作者
汪友路
钱冬冬
刘爱军
解明国
张学斌
WANG You-u;QIAN Dong-dong;LIU Ai-jun;XIE Ming-guo;ZHANG Xue-bin(School of Material Science and Engineering,Hefei University of Technology,Hefei 230009,Anhui,China;Hefei Casting and Forging Factory,Anhui Heli Co.,Ltd.,Hefei 230601,China)
出处
《铸造》
CAS
2024年第7期1017-1023,共7页
Foundry
基金
国家重点研发计划“网络协同制造和智能工厂”重点专项(2020YFB1710100)。
关键词
球墨铸铁
应变释放系数
盲孔法
残余应力
塑性修正
ductile iron
strain release coefficient
blind hole method
residual stress
plasticity correction
