Heat treatment effects on the tensile properties of annealed 2.25 Cr - 1 Mo steel

The effect of heat treatment on the tensile properties of annealed 2.25 Cr - 1 Mo steel was investigated. Detailed tensile properties were determined from 25 to 5930C and strain rates between 2.67 x 10-6 and 6.67 x 10-3/s on steel plates (from a single heat) given three different heat treatments. For all heat treatments, dynamic strain-aging peaks were observed between 200 and 4000C. The peak height for the annealed material that was cooled fastest was largest and occurred at the highest temperature. The dynamic strain aging was concluded to be the result of interaction solid solution hardening in the proeutectoid ferrite and involves interactions between molybdenum and carbon atoms or atom clusters with dislocations. The difference in the dynamic strain-aging effects for the different heat treatments was explained in terms of the precipitation reactions that occur during the heat treatment. (Auth.)