INVESTIGATION OF MICROSTRUCTURE SENSITIVITY WITH RESPECT TO PROCESSING TEMPERATURES FOR A2 STEEL

The way steel is processed through heating and cooling has a significant influence on the properties it has including flexural strength, ductility, and hardness. It also affects the microstructure of steel by changing the grain size and controlling the dissolution of carbides. Process parameters for quenching and tempering of different grades of steel are well known and are documented by ASM International, a leading materials information society. For instance, a range of quench and temper parameters associated with A2 steel, a medium alloy air-quenchable tool steel, are prescribed to demonstrate processes leading to a range of strength and ductility in the final product. The focus of this research is to observe the sensitivity of material properties and microstructure with respect to processing parameters as a means to explore structure-process-properties relationships. In particular, the austenitization temperature of nine sets of A2 samples were set to three values within the prescribed band as well as six temperatures purposely set outside the prescribed band. Each sample of steel was processed by going through an austenitizing, quenching, and tempering phase. Although the austenitizing temperature was varied, methods of quench and temper as well as tempering temperatures remained constant throughout all testing. After processing, samples were tested to determine hardness, flexural strength, and flexural strain. Results suggest that samples processed with austenitizing temperatures within 50 degrees Celsius of the prescribed ASM band have similar properties to samples processed according to ASM prescription. As austenitizing temperature deviation increases, properties begin to vary significantly.

Additional Abstract Information

Student(s): Martin Mekhail

Department: Engineering

Faculty Advisor: Dr. Robert Prins, Dr. Heather Kirkvold

Type: Poster

Year: 2017