International Journal of Korean Welding Society
- Volume 2 Issue 2
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- Pages.36-41
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- 2002
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- 1598-1177(pISSN)
The Effects of Heat Input and Gas Flow Rate on Weld Integrity for Sleeve Repair Welding of In-Service Gas Pipelines
- Kim, Y.P. (R&D Center, Korea Gas Corporation) ;
- Kim, W.S. (R&D Center, Korea Gas Corporation) ;
- Bang, I.W. (School of material science and Engineering, Seoul National University) ;
- Oh, K.H. (School of material science and Engineering, Seoul National University)
- Published : 2002.12.01
Abstract
The experimental and numerical study has been conducted on the sleeve repair welding of API 5L X65 pipeline. SMAW and GTAW were applied to weld the sleeve. The macrostructure and hardness of repair welds have been examined. The finite element analysis of the multi-pass sleeve-fillet welding has been conducted to validate the experiment and investigate the effects of in-service welding conditions. The effect of gas flow rate on the hydrogen cracking was investigated. The effect of internal pressure on residual stresses and plastic strain was investigated. The allowable heat input was predicted considering the maximum temperature of inner surface of pipe and cooling rate at CGHAZ.