Analytical determination and validation by finite elements method of hydrogen weld of carbon steel after post-heating

Resumen

The objective of this work is to determine analytically the amount of hydrogen residual in a weld after having carried out post-heating for a certain period of time in order to reduce the risk of cold cracking due to the presence of hydrogen in the weld and its validation by the finite element method. Post-heating is a variable present in the welding procedures and therefore, it is mandatory in those welds that require it. This work can be helpful to determine both numerically by the finite element method and analytically the post-heating suitable in a welding process depending on that process, the welded material and the base material. In this work, the phase transformation and time difference of the phase transformation between the weld metal and base metal are not considered. The diffusivity values are those used by the reference method that analytically calculates the residual hydrogen in a carbon steel weld. There are two values of hydrogen diffusivity (minimum value and maximum value) in this way the diffusivity values that represent all types of carbon steel are collected. The least amount of hydrogen in the weld is with a post-heating to 200 °C, producing a decrease in hydrogen in the weld at a higher speed than with the rest of temperatures below this.