The Analysis of Initial Welding Defect and Structure Improvement of Converter Loop

摘要

Aimed at the welding initial defect fatigue extension of 300t converter loop in a factory, the whole assembly finite-element (FE) model of converter loop with the welding initial defect is established. The converter loop FE model with different depth initial defect is computed by using 3D nonlinear finite element method at different tilting angles. And the stress intensity factor is extracted and analyzed under different working circumstances. The analysis results show that when the initial defect depth is greater than 11.715mm, the defect will result in fatigue crack extension at the complex alternating stress. To solve the cracking leakage problem of converter loop, the original welding manholes is replaced by the movable manhole. In the past over one year, the fatigue cracking and leaking phenomena did not occur in the converter loop, so the effect is obvious.