Sowards Jeffrey W, Hussey Daniel S, Jacobson David L, Ream Stan, Williams Paul
NASA, Marshall Space Flight Center, Huntsville, AL 35812, USA.
National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
J Res Natl Inst Stand Technol. 2018 Jun 11;123:1-8. doi: 10.6028/jres.123.011. eCollection 2018.
Bragg edge neutron transmission imaging was used to characterize the spatial distribution of thermally induced residual strains in a steel armor plate welded with a hybrid laser arc process. This residual strain distribution was compared to the spatial development of mechanical strain during uniaxial deformation. By correlating the strain measurements of both methods, the failure mechanism was determined in armor welds joined with this process. Weld failure consistently occurred in the subcritical heat-affected zone where mechanical strain accumulation in softened martensitic parent material was superimposed upon the weld region containing the highest residual thermally induced strain.
利用布拉格边缘中子透射成像技术来表征采用混合激光电弧工艺焊接的钢装甲板中热致残余应变的空间分布。将这种残余应变分布与单轴变形过程中机械应变的空间发展情况进行了比较。通过关联这两种方法的应变测量结果，确定了采用该工艺连接的装甲焊缝的失效机制。焊缝失效始终发生在亚临界热影响区，在该区域，软化马氏体母材中的机械应变积累叠加在含有最高热致残余应变的焊缝区域上。
