Engineering and Technology Journal

Abstract

This work deals with improvement of the mechanical properties of low alloy steel (DIN 40
Cr) using surface thermochemical heat treatments ,Carbonizing, Nitriding, and
Carbonitriding. Carborizing processes were performed at 900 – 950 Cº for 3hrs. Nitriding
processes were performed at 570Cº for 1.5 hrs. Carbonitriding processes were performed at
840 Cº for 3hrs. Some specimens were oil quenched at 860 Cº followed by tempering at 500
Cº. The microstructure, tensile, hardness, and impact tests were measured. The results
showed that Carbonizing, Nitriding, and Carbonitriding processes caused improvement of
mechanical properties of low alloy steel. However specimens that were subject to quenching
and tempering had better mechanical properties than specimen that were subject to
carbonizing, Nitriding, and carbonitriding.