Difficulty: Easy
Correct Answer: all of the above
Explanation:
Introduction / Context:
High-carbon steels are prone to grinding burn, tempering, and residual tensile stresses if excessive heat is generated. Correct wheel specification and operating parameters mitigate thermal damage and wheel loading. This question checks practical shop wisdom backed by grinding theory.
Given Data / Assumptions:
Concept / Approach:
Higher wheel peripheral speed (within safe limits) reduces undeformed chip thickness per active grit, lowering force per grit and cutting temperature. Aluminium oxide (Al₂O₃) abrasives are the standard choice for steels due to their toughness. Open-structure wheels (lower grade density) provide more chip space, reduce loading, and improve coolant access.
Step-by-Step Solution:
Verification / Alternative check:
Manufacturer catalogs and process guidelines recommend Al₂O₃ for steels and emphasize structure openness and speed selection to avoid burn and cracking.
Why Other Options Are Wrong (if taken alone):
Each individual statement is correct for the stated material; the combined best practice is captured by selecting “all of the above.”
Common Pitfalls:
Using dense wheels on gummy or heat-prone jobs, or choosing silicon carbide (better for nonferrous/carbides) instead of aluminium oxide on steels.
Final Answer:
all of the above
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