An experimental investigation into the effect of treatment temperature on the grain size of low carbon and microalloyed steels

الملخص EN

The microstructure of material plays a significant role in its mechanical properties.

The influence of grain size on mechanical properties is complex since grain boundaries may either act as obstacle to dislocation motion (strengthening effect) or provide a positive contribution to deformation of the material (softening effect).

A series of heat treatment and quenching tests of extra-low carbon, low carbon steels and Nb-V microalloyed steels are conducted.

The grain growth behaviour at different high temperatures is investigated.

An empirical relation of grain growth behavior has been used to predict the austenitic grain size of the used materials which are subjected to different austenitization treatment temperatures.

Experimental results indicate that there is an increase in grain size with temperatures ranging from 900 to 1300 oC.

Grain size also increases with the reheating time when treated at the same temperature.

Comparison of the predicted and experimental grain size at different temperatures is made.

It is found that the empirical relation of grain growth behavior gives good agreement at temperature ranges from 1100 to 1300 oC for Nb-v microalloyed steels and extra-low carbon steels, and 900 to 1050 oC for low carbon steels.