College of Engineering
Materials Engineering Department
BS in Materials Engineering
Dr. Trevor Harding
This investigation details the effect of a quench-and-temper processing treatment on the mechanical properties of a microalloy steel being considered for use as a pipeline flange. Microalloy steels are normally processed via Thermo-Mechanically Controlled Processing (TMCP) due to the increased strength from ferrite grain refinement; however, the geometry of a pipeline flange requires post processing beyond TMCP which diminishes the strengthening effect provided by TMCP. The purpose of this research project is to determine the mechanical properties produced when a vanadium microalloy steel is quenched and tempered. The two major considerations are the effect of tempering time on properties and the property increase due to a vanadium microalloy inclusion. In order to quantify the property increase the vanadium inclusion is responsible for, a plain carbon steel of equivalent carbon content to the microalloy steel was processed alongside the microalloy steel. Sections of a vanadium microalloy flange were tempered for eight and sixteen hours at 600oC, then examined for their microstructure. Longer tempering time resulted in larger grain size, lower hardness, and increased toughness for both alloys. Microalloy samples were harder than their plain carbon equivalent in each processing condition and generally exhibited higher toughness.