Cutting temperature for maximum material removal with carbide on mild steel When machining a mild steel workpiece using a carbide tool under typical shop conditions, around which cutting temperature is maximum material removal rate commonly associated?

Introduction / Context:
Cutting temperature at the tool–chip interface affects shear strength of the work material, tool wear mechanisms, and achievable speed. Carbide tools retain hardness at higher temperatures than HSS, enabling higher speeds and material removal rates (MRR) on steels.

Given Data / Assumptions:

• Mild steel work material.
• Carbide tool, conventional flood coolant or dry with reasonable parameters.
• Seeking a representative temperature where MRR is high yet tool wear is manageable.

Concept / Approach:
As cutting temperature increases, the material softens in the shear zone, lowering cutting forces and allowing higher speeds/feeds. However, too high a temperature accelerates crater and flank wear, reducing tool life and making sustained high MRR impractical. Practical shop experience places efficient production for mild steel with carbide at a few hundred degrees Celsius.

Step-by-Step Solution:
Consider the trade-off: low temperature (50–175°C) → high strength and high forces → limited MRR.Moderate-high temperature (~275°C) → reduced shear strength, stable chip formation → high sustainable MRR for carbide.Very high temperature (>500°C) → excessive wear and thermal damage risks.

Verification / Alternative check:
Speed–tool-life charts (Taylor’s equation) for carbide on low-carbon steel support higher allowable speeds and temperatures than HSS, with practical thermal levels of a few hundred °C during efficient cutting.

Why Other Options Are Wrong:

• 50–175°C: typically too low for efficient carbide cutting on steel.
• “Above 500°C always required” overstates and risks rapid wear.

Common Pitfalls:
Confusing tool capability to withstand temperature with the optimal operating window for sustained production and tool life.

Final Answer:
275°C