Regression equation for Ar3 temperature for coarse grained as cast steels

Abstract A regression equation for the Ar3 temperature for as cast ferrite/pearlite steels has been obtained. At these coarse grain sizes, very little influence of grain size on the Ar3 is observed. Out of all the elements examined, C, Mn and Nb had the major influence in decreasing the Ar3. A change in cooling rate from 10 to 200 K min−1 results in only a small decrease of around 20°C. Of particular interest is the very marked effect of Nb in reducing the Ar3, an addition of 0·03%Nb causing a decrease in the Ar3 of 50°C.