The Effects of Martensite Content on the Mechanical Properties of Quenched and Tempered 0.2%C-Ni-Cr-Mo Steels

The martensite content in quenched and tempered steels plays a significant role in their mechanical properties, making the as-quenched microstructure critical to the material strength and hardness. 

Extensively used in structural applications, quenched and tempered steels show various microstructures in the as-quenched condition, depending on the alloy content of the steel and the quenched section size. Higher alloy content and decreasing section sizes promote the formation of martensite versus bainite, pearlite, and ferrite, which form during cooling from hot forming or during heat treatment. 

After quenching, hardened alloy steels are usually tempered to increase ductility and impact toughness at the expense of a slight reduction in strength. The choice of tempering temperature is governed by the as-quenched martensite content since this microstructural parameter has the greatest influence on the as-quenched strength and hardness of a particular steel.  

Element’s Engaged Expert John Tartaglia, Ph.D. has studied the effects of martensite content on the mechanical properties of steels after tempering. In particular, in the following research, the author evaluates the monotonic strength, impact toughness, fatigue resistance, and strain hardness response of quenched and tempered 0.2%C-Ni-Cr-Mo steels. 

The heat treatment process and the tests performed, including hardness tests, tensile tests, Charpy V-Notch impact tests, and fatigue tests are also described. To know more about the experimental procedure and the results of the research, download the article below or contact us to speak with our expert.