How to measure the hardness of large workpieces?

Test samples and requirements:

Measured work piece: Battery pole piece roll (Figure 1)

Work piece diameter:800mm

Chrome plating thickness: 8-12μm plating layer

Roughness: Ra 0.006um

Circular Runout:2um  

Measurement requirements:Measure the hardness of chrome plating on battery pole piece roll

Instrument used:Roller Ultrasonic Hardness Tester SU-320R


Figure 1. Battery pole piece roll



Current pain points:

1.The product is too large to be directly measured, so it needs to be measured after cutting, which is inefficient. Due to the high cost of the product can only spot check, after testing the product can only be scrapped.

2.The portable Leeb hardness tester is not suitable for chrome-plated surface workpieces because the workpieces is too thin. The thickness of the workpiece must be above 50mm.



Our Sinowon solution:

According to the current pain points of measurement, we decided to use a Rolle Ultrasonic Hardness Tester to measure the sample.

Sinowon Ultrasonic Hardness Tester SU-320R adopts 3N test force, which can fully inspect the hardness of the chrome plating on battery pole piece roll without damaging the workpiece, effectively guaranteeing the production quality of the product


Because the single measurement time of the ultrasonic hardness tester is about 6 second per time, the efficiency is improved by 17 times compared with the desktop Rockwell hardness tester. And the indentation diameter after the ultrasonic hardness tester is 0.026mm, and the indentation diameter after the Rockwell hardness tester is 0.484mm (see Figure two for the indentation). The ultrasonic hardness tester does not affect the subsequent assembly and use.


Figure 2. The size compaction between UCI Vickers indention and Rockwell HRC indention.


Test results:

Testing time 1 2 3 4 5 Average value(HRC) Repeatability(HRC)
Hardness value 66.6 66.5 67.0 66.7 66.5 66.7 0.5

Note: Maximum  Value: 67.0HRC, Minimum value: 66.5HRC





Test conclusion:

SU-320R is able to measure the hardness of hardness of large workpieces with precision, fast-speed and NDT solution.

SU-300R ultrasonic hardness tester has simple operation and high reliability. It only needs to prepare a standard sample to calibrate the instrument, which can achieve accurate hardness measurement.

While using the ultrasonic hardness tester to improve the quality control of the enterprise, it also reduces the loss and increases the profit of the enterprise.

If you have any need, please feel free to contact us. We look forward to the pleasure of serving you.