How to optimize the process for H13 material with a hardness of 48-52 HRC?

For H13 material with a hardness of 48–52 HRC, the process must be optimized by carefully regulating the tempering temperature, carrying out two tempering cycles, and stepping up process monitoring to guaranty stable microstructure and reliable performance.

 

1. Fundamental Process Optimization Techniques

Item for Optimization

Particular Practice

Impact

Adjusting the Temperature

precisely regulated using a PID temperature control system at 580°C.

A hardness shift of 1~2 HRC can occur every ±10°C. Stability is built on precise temperature management.

Carry out two cycles of tempering

After the first tempering, let the air drop to room temperature before doing a second tempering, which should take at least two hours.

Release residual stress completely, stop microstructure rebound, and increase toughness.

Verification of Multi-Point Temperature Measurements

Set up at least three temperature monitoring locations in the furnace's upper, middle, lower, and corner sections.

To prevent localized overheating or cold zones, make sure the actual temperature differential is ≤±5°C.

Standardized Method for Furnace Loading

Workpiece spacing should be at least 5 cm, stacking should be avoided, and high-temperature resistant tools should be used.

Boost the consistency of heat circulation and lessen hardness variations brought on by uneven cooling.

Practical Case: By switching to a PID furnace with multi-point temperature measurement, Jingmo Technology increased the batch pass rate to 99.2% while reducing the hardness range of H13 manifold plates from 2.8 HRC to 1.2 HRC.

 

2. Data Closed Loop and Process Control

item-by-Piece Multi-Point Inspection: Determine the range, measure three to five spots per item (center, edge, thickness boundary), and make sure the HRC is less than two;

Verification of Metallographic Sampling: ≥5% of each batch is sampled to ensure that the microstructure consists of scattered carbides and homogenous tempered martensite;

Furnace Temperature Curve Retention: To ensure process traceability, keep thorough heating and cooling records for every furnace;

Establishing a Quality Archive: Keep track of operator details, equipment numbers, and hardness data for simple problem analysis.

Advice: To quickly spot trend deviations (like a steady decline in average hardness), control charts can be created using data from several successive batches.

 

3. Suggested Service Providers (Local Assurance)

Jingmo Technology: Offers comprehensive reports, CQI-9 certification, and accelerated delivery;

Wuhan Heat Treatment Plant: A reputable local service provider with high consistency and stringent temperature control requirements.

"Precise temperature control, accurate number of tests, and data archiving" are safety standards that guaranty the procedure is repeatable and under control.