大型液化石油气储罐组装环焊缝的残余应力分析

Analysis of Residual Stress at Assembled Circular Weld of Large Liquid Petroleum-Gas Storage Tanks

采用钻小盲孔残余应力释放法，测量250m^3液化石油气储罐组装环焊缝在退火前后的残余应力，分析局部退火工艺的退火效果，结果表明：高残余应力区出现在外壁面环向上，其退火后残余应力降幅在37％～60％之间，平均降幅达50％，最大减幅达299MPa；环焊缝局部退火工艺可消除30％～60％环向残余应力，达到了消除焊接残余应力的要求．

Residual stresses between before and after annealing at the assembled circuit weld for a 250 m^3 liquid petroleum - gas storage tank were determined through the measurement of relaxed surface strains by the incremental hole drilling method, and the affect of location annealing process was analysis. The experimental result shows that high stress area appeared at the circuit direction of outside wall;after being annealed,those residual stresses decreased 37 % - 60% , average 50%, max decreasing stress 299 MPa ; circuit direction residual stresses could be decreased 30% -60% by location annealing process for circuit weld, which satisfies the requirement of eliminate residual stress.