Effects of High Temperature Heating and Quenching on the Hardness of Steel
T The change in the hardness of steel was measured after heating steel pieces to high temperatures and using different quenching techniques. A two-factor Design of Experiment (DOE) was used to analyze the data; 1000°C and dry ice/ ethanol mixture was used as the high temperature and high quenching technique, 800°C and air as the standard factors, and 600°C and ice water as the low factors. The initial hardness of each piece of steel (measured with a Rockwell Hardness Tester) was compared with the resulting hardness after each trial. Analysis of the data showed that our hypothesis was incorrect. The steel heated to 600°C and quenched in the dry ice/ ethanol mixture resulted in the most increase of hardness on the surface of the steel. However, unforeseen reactions from the extreme temperatures used in the experimentation were most likely the factors in causing this result. Data also indicated that the two factors had a strong interaction; heating temperature and quenching technique both play an equal part in achieving certain steel hardness. The information found from this study is applicable to industry and construction, and is used to obtain desired and precise material hardness for steel materials.
Research Done By:
Joel Clark
Warren Tower
Mina Switzer
Sterling Heights
Warren Consolidated Schools