奥氏体不锈钢磁记忆检测与研究

发布时间：2018-06-27 13:51

本文选题：金属磁记忆检测 + 奥氏体不锈钢　；参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：常规的无损检测技术难以实现奥氏体不锈钢的检测,而金属磁记忆检测技术不仅可以检测已经形成的宏观缺陷,还可以检测构件中的微观缺陷及尚在萌芽状态的损伤,显示了在奥氏体不锈钢设备检测中的独特优势,但因起步较晚,在机理研究、基础试验研究、定性定量评估缺陷等方面还有待完善。本论文主要从实验室基础研究和现场应用两个方面展开试验研究。实验室阶段,主要进行了对比试块、预制缺陷试块以及拉伸试块的磁记忆检测;后期现场应用阶段,结合了前期实验室阶段的理论,对奥氏体不锈钢设备的焊缝及封头处进行了金属磁记忆检测研究。研究发现:(1)比较合适的试验参数为南北放置,正面检测,提离值0.5mm;(2)对磁记忆检测各特征参量应综合考虑,对于缺陷定性判断可借助H-L的特征曲线,定量方面主要注意K值与m值,其他特征参量如Hmax-Hmin,S(K)max,K(x,z)max作为辅助判据;(3)磁记忆特征参量X能够很好的指示所选区域最大应力集中的部位,因此可以根据金属磁记忆检测技术判断裂纹尖端所在处,以及预测裂纹的发展方向;(4)金属磁记忆检测可用来判断裂纹走向、评价残余应力;(5)构件断裂前,会出现各通道间H-L曲线不同极性分布,K值剧增的现象;(6)金属磁记忆检测技术能够很好的应用于奥氏体不锈钢设备的检测。
[Abstract]:Conventional nondestructive testing technique is difficult to detect austenitic stainless steel, while metal magnetic memory testing technology can not only detect macroscopic defects that have been formed, but also detect microscopic defects in components and damage in budding state. It shows the unique advantages in the detection of austenitic stainless steel equipment, but due to the late start, the mechanism research, basic test research, qualitative and quantitative evaluation of defects still need to be improved. This paper mainly from the laboratory basic research and the field application two aspects carries out the experimental research. In the laboratory stage, the magnetic memory test of the contrast test piece, the prefabricated defect test piece and the tensile test block was carried out; in the later stage of field application, the theory of the previous laboratory stage was combined. The metal magnetic memory test of weld and head of austenitic stainless steel equipment was carried out. The results show that: (1) the suitable test parameters are placed in the north and south, the positive detection, the lifting value is 0.5 mm; (2) the characteristic parameters of magnetic memory testing should be considered comprehensively, and the characteristic curve of H-L can be used to judge the defect qualitatively. In quantitative aspect, K value and m value are paid attention to, other characteristic parameters such as Hmax-HminS (K) max-K (XZ) max as auxiliary criterion; (3) Magnetic memory characteristic parameter X can well indicate the position of maximum stress concentration in the selected region. Therefore, it is possible to judge the crack tip and predict the development direction of the crack according to the metal magnetic memory testing technology; (4) metal magnetic memory testing can be used to judge the crack strike and evaluate the residual stress; (5) before the fracture of the member, The H-L curve with different polarity distribution and K value will increase rapidly. (6) the metal magnetic memory detection technology can be used in the detection of austenitic stainless steel equipment.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG142.15

【参考文献】