喷丸起落架外筒焊接热影响区的残余应力测定

Measurements of Residual Stresses on the Weld HAZ of Shot-Peened Landing Gear Tubes

本文用X射线法测定了喷丸起落架外筒焊缝影响区的残余应力,并从残余应力角度考察了起落架外筒现行工艺路线的优劣。测定结果表明,在相同构件上虽然所测方向和部位不同,但残余应力的分布、大小及符号基本相同。与前起外筒相比,喷丸处理在主起外筒上形成的残余压应力值较低。分析认为消除焊接残余拉应力的合理工序,是两种外筒均应采用焊后热处理,但应防止表面脱碳。

The residual stresses were detevmined with X-ray diffraction method on the shot peened weld HAZ of landing gear tubes,and the working processes of the tubes were examined from the experimental results. It is shown that the distributions and magnitudes of compressive residual stresses are nearly the same in ten different directions and positions measured for the definite tube. The compressive residual strsses induced by shot peening on the nose landing gear exhibit higher values than those on the main landing gear. The analyses showed that the heat treatment should be directly preceded by welding process for both tubes so as to remove the tensile residual stresses near the welded seam, but the surface decarburizing should be avoided.