Y. LAKHTIN, “Engineering physical metallurgy”. 1975, pp 241.
 Jaykant Gupta, “Mechanical and wear properties of carburized mild steel samples”, A thesis submitted in partial fulfillment of the requirement for the degree of Master of Technology, Department of Mechanical Engineering, National Institute of Technology, Rourkel A, May 2009, pp 1-58.
[3[ David K., Matlock, khaled A., Alogab, Mark D., Richard; John G. Speer,“Surface processing to improve the fatigue resistance of advanced bar steels for automotive applications”, Advanced steel processing and products Research center, Department of Metallurgical and Materials Engineering, Colorado – USA, Materials Research, Vol. 8, No. 4, 2005, pp 453-459.
 Fuad M. Khoshnaw, Abdulrazzaq I.Kheder, and Fidaa S.M. Ali, “Corrosion behavior of nitride low alloy steel in chloride solution”, Anti – Corrosion Methods and Materials, Volume 54. Number 3, 2007, pp 173-179.
 Ryan M. Wagar, John G., Spoeer, David K. Matlock, and Patricio F. Mendez.“Examination of pitting Fatigue inCarburized steel with ControlledRetrained Austenite Fractions”, Colorado School of Mines paper Number: 2006-01-0896, DOI: 10.4271/2006-01-0896, 2006-04-03.
Tikrit Journal of Engineering Sciences (2013) 20(4) 1-10
Effect of Austenizing and Tempering Heat Treatment Temperatures on the Fatigue Resistance of Carburized 16MnCr5 (ASTM 5117) Steel
|Jamal Nayief Sultan|
|Mosul Technical College, Iraq|
The present investigation deals with the study of the effect of austenizing and tempering heat treatment temperatures on the fatigue resistance of carburized 16MnCr5 steel. Rotating bending fatigue specimens were machined from 16MnCr (ASTM 5117(steel rod, and pack carburized at 900°C for 2 hours soaking time. Carburized specimens were then austenized at 900°C for one hour, water quenched, reaustenized at temperatures 750°C, 800°C and 900°C for one hour, then tempered at 200°C temperature. Other carburized specimens were tempered by heating to 760°C temperature, water quenched to room temperature, then tempered at temperatures 200°C, 300°C, and 400°C for one hour. Austenized and tempered steel specimens after carburization as well as uncarburized steel specimens were then tested by rotating bending fatigue machine up to fracture under different stress levels (200, 250, 300, 350, 400) Mpa. Experimental results showed that fatigue resistance of austenized steel specimens after carburization process has been increased, and the crack length developed on the specimen surfaces was decreased with an increase in austenizing temperature up to 800°C, due to lath martensitic microstructure formation, beyond this temperature fatigue resistance was decreased and crack lengths were increased due to the grain coarsening of the lath martensite. It was also concluded that fatigue resistance of steel specimens that have been tempered after carburization process was increased, while crack lengths due to fatigue have been decreased with an increase in tempering temperatures due to the formation of tempered martensite and troostitic microstructure. The results also revealed that uncarburized steel specimens showed a lower fatigue resistance and a higher crack lengths than those austenized and tempered specimens after carburization.
Keywords: Pack Carburization, Austenizing Temperature, Tempering Temperature, Fatigue Resistance, Crack Length, Lath Martensite, Troostite.