摘要：The welded joint always contains the microstrain when welding is complete. The microstrain generates distortion and changes of the physical shape of the weld joint. The purpose of the study was to observe the pattern and direction of residual stress before and after welding Q900&T125and Q900&T175Steel. The materials used for this study is Hot Rolled Plate Steel made by Indonesia steel industry. Method of this study is 1. Q900&T125and Q900&T125Steel machined in V-butt joint. This joints weld by using manual gas metal arc welding, Q900&T125and Q900&T125Steel weld joint can be found. 2. Measuring the distance from the lattice planes before and after welding by using Neutron-Ray Diffraction. Then the microstrain can be found. By involving Poisson numbers and modulus of elasticity of material in microstrain obtained residual stress. All the pattern of microstrain is compressive stress and leads to the weld center.
