Recent content by priyam07

If the issue is bothering so much, how about using a spectrometer in house and send the results to your client. As said XRF is for alloy ID you should not be questioned based on the levels the client sees. IMO the client's concern is not valid after you send MTR results unless they used a third...

Thanks Maui, I think you made it clear what I intended in my reply.

To reply to fapper: "You say the carbides are like hard cobbles and the steel matrix is like the mortat.I wonder,why even bother with carbides/cobbles,why not just use super hard mortar/steel matrix?" Because the carbides can go up to really high hardness such as 2200HV for WC used in a metal...

40J at -40C is really high spec, this part must have been tempered wrong. Not sure if it met the hardness spec, cant see in the image? Possibly temper embrittled going by the low CVN values, SEM would identify any intergranular fracture on the surface to confirm. Any microstructure results you...

Looks like overload failure, casting seems to have lot of defects.

Late reply I guess, anyways 24-25 HRC and low impact indicates Bainite. Was it supposed to be heat treated though? Again do you have the chemistry confirmed?

I would agree, looks like uncontrolled cooling (faster cooling in this case) and forming bainitic instead of pearlitic microstructure. Do you have hardness measurement done, high hardness might confirm this?

Make sure to stay around the 900F tempering temperature and fast cool after it, slow cooling might induce low toughness by temper embrittlement!

HI, the fracture surface indicates this is of typical "rock candy" brittle, intergranular failure because of Aluminum nitride precipitation associated with Quenched and tempered cast steels. This is clearly visible in the visual examination and associated with low toughness values. Of course...

Thanks redpicker and all, I think so too.

Thanks Lyrl! This is a cast part and the section cut for analysis is about an inch thick. The hardness was done on the cross section and the micro as well.

Thanks metengr and mrfailure, What I meant by average hardness is through hardness across the specimen thickness and it is very consistent. I did try with 25g load micro-Vickers hardness on the white phase and the martensite. The hardness on the martensite is about 700 HV and on the white phase...

Yes, did double check the chemistry and hardness. Hardness done using macro Rockwell machine, i.e. bulk hardness.

Not induction hardened! Only the hardness make me doubt about ferrite as it is 46 HRC. With that amount of ferrite it is amazing the average is that high.

Hi, I have here a very interesting microstructure of a low alloy steel with 0.3 carbon in quenched and tempered condition. I dont have much information on the heat treatment temperatures. Usually I would expect to see a tempered martensitic microstructure but this one is kind of mixed with light...