An approach for assessing the weldability of new and advanced materials

Most structural materials that are in use today were designed to meet specific requirements,including strength,toughness,stress-rupture life,corrosion resistance,and combinations of these properties.Often,the weldability of these materials is not considered until late in the alloy development phase,if at all.Over the past 10 years,researchers at OSU have developed procedures that would allow weldability to be evaluated as part of the alloy development process by using test techniques that require only small amounts (less than 5 kg) of material.These techniques include the following,1) button melting in conjunction with Single Sensor Differential Thermal Analysis (SS DTA TM) for determining the non-equilibrium solidification temperature range and phase transformation behavior during cooling,2) hot ductility testing for evaluation of ductility-dip cracking and liquation cracking susceptibility,3) cast pin tear testing for assessment of weld solidification cracking,and 4) a modified implant test for evaluation of hydrogen induced cracking susceptibility.This paper describes these techniques and gives examples of how they can be used during alloy design and development.