Decarburization Control of H13 Steel Under Varying Process Pressures During Austenitization

Area of Science:

• Materials Science
• Metallurgy
• Surface Engineering

Background:

• Decarburization during austenitization compromises tool steel performance.
• The quantitative effect of process pressure on decarburization is not well understood.

Purpose of the Study:

• To investigate the influence of process pressure on the decarburization behavior of H13 tool steel.
• To quantify the relationship between pressure, carbon diffusion, and surface reactions.

Main Methods:

• Austenitization of H13 tool steel at 920-1020 °C under varying pressures (0.01-760 Torr).
• Measurement of carbon concentration profiles using electron probe microanalysis.
• Evaluation of hardness degradation and mass loss.
• Application of a one-dimensional diffusion model with a Robin boundary condition.

Main Results:

• High vacuum suppressed decarburization, preserving surface integrity.
• Increased process pressure accelerated carbon loss, resulting in deeper decarburized layers.
• Significant hardness reduction was observed with increasing pressure.
• The diffusion model accurately reproduced experimental findings.

Conclusions:

• Process pressure is a critical factor controlling decarburization in H13 tool steel.
• A pressure-dependent transition in the dominant decarburization mechanism was identified.
• Optimizing process pressure is crucial for maintaining tool steel quality.