Metalografické hodnocení drátů z legovaných ocelí

Abstract

The presented bachelor thesis is devoted to the methods of evaluation of the rolled wire made of alloyed spring steel 54SiCr6. The main attention is paid to the methods of metallographic evaluation, especially to the cleanliness evaluation in accordance to DIN, ASTM and MBN standards. Furthermore, methods of decarburisation measurements are mentioned. The presented bachelor thesis also describes principal types of surface defects, including mechanisms of their formation in rolled wires. The thesis emphasises high demands on production technology of spring steels, in all their steps, mainly in order to achieve high micro-cleanliness. The micro-cleanliness represents the key parameter to achieve needed resistance to fatigue degradation.