Thermal Analysis Experiments in Titanium and Magnesium Additions to 4130 Steel

摘要

Titanium and magnesium additions singly and together were examined in 4130. A thermal analysis system measured the cooling rate of molten steel samples. These curves were analyzed for changes in phases evolved and phase reactions. The samples were also sectioned to determine the solidification structure. All additions refined the structure; however, magnesium and titanium additions together resulted in the finest structure. The peritectic reaction temperature was found to decrease with the additions. This decline may indicate an increase in the delta-ferrite stability due to favorable nucleation of that phase. The solidus temperature also appeared to decline. Inclusion analysis found TiN particles in the magnesium/titanium-containing sample. Only titanium-containing oxides were observed in the titanium-only samples. It appeared that the addition of magnesium made the formation of TiN more favorable.