A computerized tool for prediction of properties of welds in duplex material

Important results from the project

The aim of this project has been to develop a computerized guide for welding of duplex stainless steels. A method has been developed and refined where data from experimental welding are used in conjunction with thermodynamic and kinetic simulations to build FE models of welds. The tool predicts the final microstructure and gives general advice on welding of duplex. It also contains many useful pWPS´s. By using the tool, a welding engineer can test different approaches beforehand in order to minimize time and cost for qualification of new welding procedures.

Expected long term effects

A webbased guideline provides an easy way to predict the weld result for end-users. An advanced version of the guideline, in form of a detailed report, is available to project partners. This will contribute to: -Faster development of new duplex grades and filler materials. -Better understanding of how compositional variations affect microstructure and expected properties of welded components. -Decreased material consumption and less rejection or repair welding. -Possibility to introduce duplex in new applications. -Increased sales of duplex stainless steel.

Approach and implementation

Experimental welding were used in conjunction with thermodynamic and kinetic simulations to build FE models of welds that were later used to fill the database of the webbased tool. Dilution of the base material in the weld metal was measured using geometrical and chemical analysis techniques and thermal cycles were recorded with thermocouples. The ferrite content was measured using image analysis. The investigations showed that single-pass welds and the final pass in multi-pass welds may be critical areas.