Heat Treatment Process and Mechanical Parameter Comparison Table of High-Strength Bolts

Heat Treatment Process and Mechanical Parameter Comparison Table of High-Strength Bolts

Quenching and tempering heat treatment directly determines the fatigue resistance and load-bearing capacity of high-strength fasteners. Different heating temperature and cooling medium will cause obvious differences in hardness and fracture resistance. This article provides official national standard mechanical data table, compares two mainstream heating furnaces, and solves common processing defects in heat treatment workshop.

1. National Standard Mechanical Performance Data Table

2. Comparison of Two Heat Treatment Equipment

Mesh belt furnace features uniform temperature, low deformation and low hydrogen risk, suitable for mass standardized production. Box furnace is suitable for small-batch special-shaped bolts, with obvious oxidation and low processing consistency.

3. Common Defects and Improvement Measures

Crack failure comes from rapid cooling, which needs optimized oil temperature. Unqualified hardness is caused by insufficient tempering time. Surface decarburization can be solved by nitrogen protection inside the furnace.

4. Post-Processing Storage Rules

Place heat-treated bolts for 24 hours to release internal stress before surface treatment. High-strength bolts need hydrogen removal after electroplating to avoid delayed fracture risk in long-term use.