Degradace protahovacích trnů z oceli 19552 po nitridaci a bez nitridace

Abstract

This thesis is aimed to analysis of degraded broaches made from steel 19552 both after surface nitriding and without that one. Degradation initiations are longitudinal lines, going deeper during exploitation and leading to cracks formation. Material being only quenched and tempered shows susceptibility to deeper and longer cracks, resp. to more fatal degradation unlike the broach material that was surface-nitrided. In this case cracks are shorter, are often interconnected and in final the nitrided layer is crumbled without an important broach deep degradation.