Experimental and Numerical Predictions of Cryogenic Leakages in Welded Steel Plates

This study presented experimental and numerical research to investigate the effect of cryogenic leakage on a plate structure of AH36-grade steel containing welded joints. To simulate the cryogenic leakage conditions, the welded plate was exposed to a temperature of -196 degrees C by supplying liquid nitrogen (LN2) to the center of the steel plate. The time-dependent temperature history and strain variation were measured by using thermocouples and strain gauges attached to the plate surface. Additionally, the residual stress of the middle surface section before and after the cryogenic leakage process was measured by X-ray diffraction analysis (XRD). A three-dimensional finite element model was created with the use of a commercial finite element analysis (FEA) program to simulate the flux-cored arc welding process and cryogenic leakage process. The steel surface temperature dropped sharply and reached approximately -196 degrees C at 160 s after LN2 supplement. After the first 650 s of the LN2 leakage experiment, the outside of the trough reached approximately -75 degrees C and -25 degrees C, depending on the location of the thermal couples. Although there was a relative difference in the results, the experiment and numerical simulation results for temperature and stress distribution showed good agreement. The results could be utilized in the ship design stage adopting welded structures as a basic database.

Automated summary

This study investigates the effect of cryogenic leakage on a plate structure of AH36-grade steel containing welded joints through experimental and numerical research. The welded plate is exposed to a temperature of -196 degrees C by supplying liquid nitrogen (LN2) to simulate the cryogenic leakage conditions. The results show good agreement between the experimental and numerical simulation results for temperature and stress distribution, and can be utilized as a basic database in ship design adopting welded structures.