Effect of Cr Content on Microstructure and Mechanical Properties of Low Carbon Steel Welds

The effect of Cr content on the formation of acicular ferrite was investigated in low carbon steel welds where submerged arc welding was performed. Three specimens with different Cr content were fabricated and their properties were evaluated. Upon analyzing the microstructure of the welds using optical microscopy, it was observed that a specimen with higher Cr content showed a lower Widmanstatten ferrite content, whereas the proportion of acicular ferrite was increased. Acicular ferrite improves the toughness of welds, and when present in the microstructure, it acts as an obstacle to cleavage fracture. A higher impact absorption energy was measured in a specimen with finer acicular ferrite structures from the impact test. In addition, since Cr is a ferrite-stabilizing element, a higher hardness value was measured for a specimen with higher Cr content. The electrochemical test result showed that as the Cr content increased, the corrosion potential increased and the corrosion current density decreased.