Analýza povrchových defektů na cementovaných ozubených kolech z oceli 20MnCr5

Abstract

This thesis deals with analysis of gear wheels made of 20MnCr5 (14221) steel, where cracks in a carburizing layer were detected after a final process of grinding. The theoretical part is focused on a chemical and heat treatment, especially in carburizing. The other processes which belong to a chemical heat treatment are summarised briefly as well. There are also mentioned various carburizing environments in which carburizing can take place and ways of heat treatment after carburizing. The experimental part deals with the quality assessment of the carburizing layer of gear wheels. For the analysis two sample series labelled Q4 and Q5 were selected which were analyzed in detail in order to find the cause of the subsurface cracks in the carburized layer.