How to Determine if Hot Runner Bolts Have Good Solution Treatment?

Considering the preceding background of the solution treatment process, the compliance criteria and performance indicators of hot runner stainless steel bolts, a tiered method can be adopted to accurately assess the success of the solution treatment:

Fast On-Site Test: A standard file is used to lightly scratch the surface of the bolt. A well set bolt will be uniformly low in hardness, without hard patches. Use special stainless steel test solution; no obvious corrosion or discoloration should appear within 3 minutes.

Proper Laboratory Testing: Sample for metallographic examination. This shows a homogeneous single-phase austenite microstructure with no considerable grain boundary carbide precipitation and no excessively big grains.

Performance Compliance Verification: Hardness test verifies ≤HB187. Stress test revealed no substantial residual internal stress. The report of the factory process is checked against the national standards.

This procedure can identify the solution treatment effect with 100% accuracy and meets the acceptance standards of hot runner bolts.