Recent content by bearingsteel

Okay, thanks for the help, I will look for abrasive discs as you guys mentioned.

Hi. I need some tips for an abrasive disc that is good for cutting steel that has been heat treated(60-65 HRC). In the workshop we use the same disc as we use for softer steel (25-30 HRC), but when we have a hardened one, the disc breaks after the cutting is made. Any useful tip would be...

I uploaded some pictures from the inner ring. This is all that we got for analyse. http://files.engineering.com/getfile.aspx?folder=8389d8ee-f245-4dca-96ec-3b97bebfef51&file=DSCN5282.JPG http://files.engineering.com/getfile.aspx?folder=8d827c7d-54a9-4161-a2c5-1e724aa96b6a&file=DSCN5283.JPG...

It's ok. So i guess the second heat treatment was not done. But what did happen to the ring that it has a half annealed structure and a half normalized? It is possible that the ring was annealed and by working it reached high temperatures and normalized?

The material from whitch the bearing is made is 52100. The heat treatment is supposed to be good for this bearing. It doesn't matter the temperatures. If it was quenched+tempered, it should had have a martensite structure. Magnification of microscope pictures is x500 . My guess is that it didn't...

Austenitization is the first part of the heat treatment called quenching(followed by tempering), when steel is heated in furnace at around 945 degrees Celsius for 1, 1,5 hours. After this, it is quenched in oil, and then it's tempered at around 170-200 degrees Celsius. When quenched, the...

Here is the etched sample http://img585.imageshack.us/img585/8555/dscn5273u.jpg Annealed structure http://img109.imageshack.us/img109/4097/dscn5277h.jpg Normalized structure http://img803.imageshack.us/img803/6963/dscn5280co.jpg

I'm very sorry. I did put 3 pictures in the reply but for some reason, it didn't appear. I will put them tomorrow, I have them on the computer at work.

So it's an interior ring with a half annealed and a half normalized structure(not quenched as i said earlier). The half with annealed structure has 25-30 HRC, the other half has 40-45 HRC. Here is the etched sample. Annealed structure Normalized structure

I don't think I can do this. I would like to see how it works and then fails thou. I work in the metallographic laboratory so I must know also how they fail and how to resolve problems that arise. Thanks anyway for your response.

I see that it has a half speroidizing structure and a half that it is almost quenched-tempered.

I know that theoretical it's possible if the bearing is overheated at about 900-1000 grades Celsius, it can be annealed. May this be the explanation?

A bearing is sold to a customer and works good for 1-2 weeks, then it breaks. When it came back, he has a different structure than it should have. A good structure is quenched(martensite) and it came back with an annealing structure(speroidised, fine globular cementite). I want to know what...

Okay, thanks a lot.

It was annealed before second heat treatment and quenching in oil and tempering. Tempering was done at 180-190 degrees C. It's a new part. I just need to know what microstructure is this. Thx guys!