What harmful effects does sulfur have when present in steel________________?
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Answer: D. lowers the toughness and transverse ductility
Explanation
Sulfur combines with iron to form iron sulfides, which segregate at grain boundaries and lower transverse ductility and toughness. These low-melting-point sulfide inclusions create localized stress concentrations that weaken the steel matrix under multi-axial loads. High sulfur content leads to hot shortness, making the steel prone to cracking during hot rolling or forging operations. Sulfur is typically considered an undesirable impurity in standard carbon steel production due to its embrittling effects. Metallurgists add manganese to steel melts to bind with sulfur, forming harmless manganese sulfide inclusions instead of brittle iron sulfide. Transverse ductility is particularly sensitive to elongated sulfide inclusions oriented parallel to the primary working direction.
Deoxidizers like silicon and aluminum are used to remove dissolved oxygen from steel melts rather than sulfur additions. Grain size reduction in steel is primarily achieved through controlled aluminum additions and specialized thermal rolling processes. Sulfur inclusions decrease toughness and ductility rather than enhancing the tensile strength and overall hardness of the alloy.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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