How do inclsuions like oxides and sulphide contribute to mechanical failure of AISI 4140 grade steel which is used for bearing housing . The oxides sulfides and dulpex oxide -sulfide inclusions are present in microstructure
1. Poor homogenization can give rise to inclusions commonly sulfides, oxides. this can initiate cracks
Example: AISI 4140 steel as quenched and tempered; tempered martensite (unetched) microstructure with cracking at inclusions or promoted by inclusions.
2. Sulfides can enhance accumulation of hydrogen and increase the susceptibility of steels to hydrogen embrittlement.