Residual stresses are invisible but extremely dangerous in welded joints. They form due to uneven heating and cooling during welding, leading to expansion, shrinkage, and locked-in stresses even without external load. These stresses can cause distortion, cracking, reduced fatigue life, and failure of critical components like pipelines, pressure vessels, and structures. In this video, we clearly explain how residual stresses develop, their types, harmful effects, and proven methods like PWHT, pre