A welding heat conduction simulator to analyze melting, solidifying and cooling processes in arc welding has been developed using an interactive personal computer (CPU: Z80).
The system is characterized in procedures as follows:
1) Basic routine for the determination of welding conditions by interaction between an engineer and a computer: In the first step, desirable or expecting welding parameters are input by an engincer.
Next, the computer checks whether these conditions are reasonable or not, and displays the results.
Finally, if the results are not satisfied, the flow is returned to the first step and the conditions are corrected by the engineer.
With repetition of the above trial, practicable and reasonable conditions can be found out.
2) A method for presetting three dimensional weighted distribution as a simulation of arc heat source in each welding process: Geometrical heat elements, such as line, disk, half-elliptical plane or -ellipsoid composed of point heat sources are prepared. Then, each dimension and distribution of each element are set, and each direction and combination of the elements are input according to display on the CRT.
3) A method for deciding position of heat source and its extent in a given groove: The first approximation of deposited and molten regions in the groove is carried out using the estimating value of melting efficiency, wire melting rate and mean bead width. The heat source can be set on the CRT on the basis of the result.
4) A procedure for determining optimum welding conditions: Three routines, that is, approximation of deposited and molten regions, computation of a weld thermal cycle and shapes of penetration and HAZ boundary, and estimation of hardness and microstructural constituents with memorized SH-CCT diagrams, are utilized to determine optimum welding conditions.