Could you provide specific hardness data for H13 material after tempering?

After tempering, the specific hardness data for H13 material is usually steady between 48 and 52 HRC. The measured hardness may be carefully regulated within 49~51 HRC with a single-piece range of ≤2 HRC using a standardized two-tempering procedure (e.g., 580℃×2h×2 times), exhibiting great batch consistency.

 

1. Hardness Data Measured Using Standard Procedures

Controlling the Temperature

Keeping Time

Tempering Periods

Hardness Measured (HRC)

Situations for Applications

550°C

Two hours

twice

50.5–52.0

High standards for wear resistance and the necessity to detect brittleness

580°C

Two hours

twice

49.0 to 51.0

Mainstream procedure, optimal overall performance

600°C

Two hours

twice

48.0 to 50.0

High toughness circumstances that allow for a small amount of softening

Case Study from a Wuhan Mold Factory: The hardness at five measuring locations was 49.8, 50.1, 50.3, 49.9, and 50.0 HRC after tempering a hot runner nozzle at 580°C for two hours and twice, with an average of 49.9 HRC and a range of just 0.5 HRC. There are more than 500,000 cycles throughout the service life.

 

2. Important Elements Impacting the Consistency of Hardness Data

Temperature Control Accuracy: Hardness variations of 1~2 HRC may result from temperature differences greater than ±5°C;

Inadequate Tempering Cycles: With just one tempering cycle, hardness frequently surpasses 52 HRC, creating an unstable microstructure;

Workpiece Thickness and Holding Time: To guaranty adequate core tempering, an extra 30 minutes are needed for every 25 mm of thickness;

Raw Material Composition: The contents of Cr, Mo, and V must adhere to specifications (Cr: 5.0%~5.5%, Mo: 1.1%~1.75%, V: 0.8%~1.2%).

Abnormal Case: After just three days on the production line, a batch with a tempering temperature below 530°C had brittle fracture and a measured hardness of 53.5 HRC.

 

3. Data Validation and Quality Control

Multi-point testing: to guaranty a range ≤ 2 HRC, three to five points are examined per item (center, edge, thickness boundary);

Metallographic evidence: Dispersed carbides and homogeneous tempered martensite make up the microstructure;

Process documentation: Test records and furnace temperature curves are kept for traceability.

Safety standards: "Data speaks for itself, process is controllable, and microstructure is reliable." The legitimacy and dependability of hardness data are guarantyd by the combination of these three concepts.