LEEB Rebound Hardness Testing

[Guest102023]

I'm having a very hard time overcoming my extreme initial skepticism about the rebound approach. The whole concept seems totally mickey mouse. (My weapon of choice for field testing has always been Microdur.)

Any experiences (preferably hands on) with this instrument? Limitations in terms of position or sample are required? What situations is it best suited for?

Thanks in advance





"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[weldstan]

What we found in hardness testing of low alloy steels and welds thereof, was that it gave very poor reults when compared with microdur, tellebrinneler and King Portable Brinnel.

 

[bobjustbob]

Ours works fine on the provided test blocks. Preforming the same test on our standard HRc test blocks does not give repeatable results. I have never seen repeatable results on production parts.

Bob

 

[r6155]

I think the secret is good surface preparation.

Regards

 

r6155,

That is where all methods fall down.
The mag & dye techs who do most of this work are not instructed in techniques of progressive grinding (and a lot else besides).


"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[arunmrao]

I am comfortable using portable brinell or the Poldi test. The reference test bars must be from a standard company, else can get erroneous results.

Rebound hardness testers are accurate on test blocks and not on the casting surfaces .

 

[SJones]

https://www.twi-global.com/technica...ting-are-available-and-which-is-most-reliable

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[Jacob Henry]

The Leeb Rebound Hardness Test (LRHT) invented by Swiss company Proceq SA is one of the four most used methods for testing metal hardness. This portable method is mainly used for testing sufficiently large workpieces (mainly above 1 kg). It measures the coefficient of restitution.

 

[geesamand]

Our Leeb has worked relatively well for incoming inspection, where we are screening for bad material and we don't required highly accurate results.

That said, it works poorly on light parts and unmachined surfaces. Castings also have innate hardness variation. It is inappropriate for hardness testing of surface-hardened material. These limitations are usually not a problem for us.