INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
(OP)
Hello
I have some thinwall parts made of inco718. Part diameter is about 6 mm and wall thickness is about 1 mm. The problem is hardness value after heat treatment process. Heat treatment process that i did is conventional inco 718 heat treatment (solution heat treatment between 930-1010 C - min 1 hour - air cooling, 2 step aging 720 C/620 C - 8 hours/8 hours - air cooling). I changed solution temperature, cooling rates, cooling media everything that spec allows me. But i have never found a part has hardness lower than 44.5 HRc. This makes me crazy. Please help me.
Thank you.
I have some thinwall parts made of inco718. Part diameter is about 6 mm and wall thickness is about 1 mm. The problem is hardness value after heat treatment process. Heat treatment process that i did is conventional inco 718 heat treatment (solution heat treatment between 930-1010 C - min 1 hour - air cooling, 2 step aging 720 C/620 C - 8 hours/8 hours - air cooling). I changed solution temperature, cooling rates, cooling media everything that spec allows me. But i have never found a part has hardness lower than 44.5 HRc. This makes me crazy. Please help me.
Thank you.





RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
I would go to 30N or 45N.
The next question is are you testing ID or OD? what are you using for curvature correction factor?
If you are testing on the ID using HRC your readings will be high by 3-4 points due to the curvature.
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P.E. Metallurgy, Plymouth Tube
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
Yes ı have access to metallurgical lab. I checked the microstructere and grain size. It wasnt homogenous and grains were really small.(something between ASTM 8-9)
EdStainless;
Actually i always find the hardness between 45-46 HRc. I didnt understand your questıon because i dont know what is ID or OD. But i have never tested heat treated parts in rockwell machine because of the wall thickness. It is about the same size with indenter. Generally, i test it in Microvickers machine then i convert it to HRc ( 0.3 Hv, 40x ).
(Note : Sorry about my english, it not my native language. My grammer could be hard to understand)
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
You said that the part had a diameter, so I presumed that you were testing on a curved surface.
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P.E. Metallurgy, Plymouth Tube
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
The smaller the indenter and lighter the load the more impact the size and distribution will have.
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P.E. Metallurgy, Plymouth Tube
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc
RE: INCO718 thinwall parts heat treatment - maximum hardness 44.5 hrc