The assessment of carbon equivalent formulas in predicting the properties of steel weld metals

The susceptibility to cold cracking in steel welds can be assessed by using carbon equivalent formulae based on the composition of steel being welded. In this study, carbon equivalent formulae available in literature have been tested for their sufficiency on what they can measure in weld metal properties by performing calculations using compositions of structural shielded metal arc welding (SMAW) steel weld metals. A set of correlation data was produced to demonstrate the level of relationship between the microstructural and mechanical properties of weld metals and carbon equivalent values. It is shown that carbon equivalent formulae are designed to measure certain mechanical performance of the steel weld metals as well as their hardness rather than microstructural content. A new formula is also proposed to predict weldability by including Ti content of the steel weld metal.