Mikročistota oceli 54SiCr6 v závislosti na pořadí tavby v sekvenci

Abstract

Presented diploma thesis is devoted to the analysis of influence of the heat order in sequence casting on the micro-cleanliness of the spring steel grade 54SiCr6. The first part of the diploma thesis is oriented on the problems of non-metallic inclusions in steels and on the methods of non-metallic inclusion characterisation. A special attention is paid to the characterisation of non-metallic inclusions in spring steels. In the experimental part the production technology is described at first in relation to high demands on steel micro-cleanliness. Micro-cleanliness of 128 heats of 54SiCr6 spring steel was evaluated in accordance to MBN standard. Possible reasons of different micro-cleanliness are discussed in relation to different heat order in the sequence.