Influence of non-metallic inclusions on the strength properties of screws made of 35B2+Cr steel after softening

Purpose: This paper presents the results of the research on the influence of non-metallic inclusions on strength properties of 35B2+Cr steel screws. Design/methodology/approach: The investigations were carried out on screws after softening. The investigated steels with different fraction of non-metallic inclusions were delivered by three different suppliers. Findings: It was proved, that in spite of the level of fraction of non-metallic inclusions compatible with the corresponding standards, they directly or indirectly influence the strength properties of 35B2+Cr steel screws. This influence depends on the character of the inclusions. Research limitations/implications: The investigations were carried out only on screws made of only one steel grade. Practical implications: Influence of non-metallic inclusions on properties of 35B2+Cr steel, within analysed range of their content, is not significant enough to be a critical factor in relation to operating failures of the screws made of this steel. Originality/value: Influence of non-metallic inclusions on properties of 35B2+Cr steel was analysed.