摘要
基于模拟雷电流试验方法研究了回击后长持续时间雷电流分量作用下Q235合金钢的损伤特征。用光学显微镜、场发射扫描电镜(XR-SEM)、X射线能谱仪(EDS)和自动硬度计分析了试样的损伤形貌、不同区域的元素含量和材料损伤后的硬度分布。结果表明:在回击后长持续时间雷电流分量作用下,Q235钢试样剖面的微观组织形貌出现了明显的分层,分别为氧化层,马氏体(损伤区),马氏体与铁素体(过渡区),铁素体与珠光体(基体)。试样的显微硬度值随马氏体含量下降而下降,由损伤区的450 HV0.5降至基体的180 HV0.5。在电热应力作用下,裂纹的萌发发生在试样表面凹坑边缘、损伤区的气孔周围和元素分布不均匀区域。
The damage characteristics of Q235 steel under long duration lightning continuing current component was investigated based on the lightning current simulation experimental method. The damage morphology, element distribution in different regions and microhardness distribution of the sample were analyzed by means of optical microscope, extreme-resolution field emission scanning electron microscopy, X-ray energy dispersive spectrometer analysis and automatic hardness test. The results show that under long duration lightning continuing currents component, the cross section microstructure of the steel shows obvious stratification, including the oxide layer, martensite（damage zone）, martensite and ferrite（transition zone） and the ferrite and pearlite （matrix）. The microhardness of the sample decreases with the decreasing of the martensite content, which is 450 HV0.5 for the damage zone and 180 HV0. 5 for the matrix. Under the electro-thermal stress, cracks appear at the edge of the ablation crater, around the pores in the damage zone and the area with uneven elements distribution.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2017年第11期85-91,共7页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(5157717)
关键词
雷电流
Q235钢
烧蚀
微观组织
损伤特征
lightning current
Q235 steel
metal ablation
microstructure
damage characteristic
