What is everyone's opinion on verifying mechanical properties on heat treated material per the ASTM spec for heat treated material. The mechanical properties are listed on the material cert for annealed state but we currently do not check them after heat treat. This material is used for medical devices and are we to assume that if the mechanical properties are correct in the annealed state they will be to spec in the heat treated state if done correctly to the ASTM?
Heat Treat - Verifying mechanical properties on heat treated material per the ASTM
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Re: Heat Treat - Verifying mechanical properties on heat treated material per the AST
Assuming is counter intuitive to managing risks. If the mechanical properties are critical for product safety/integrity, you most definitely need to verify mechanical properties, post heat treatment, especially because heat treatment is a "special" process which not always deliver the intended results.
Re: Heat Treat - Verifying mechanical properties on heat treated material per the AST
I agree but this has never been required by the customer just the original material cert and the RC value. It would not be possible to send out hundreds of jobs a week to be tested as they are heat treated individually. Bar stock is possible.
I agree but this has never been required by the customer just the original material cert and the RC value. It would not be possible to send out hundreds of jobs a week to be tested as they are heat treated individually. Bar stock is possible.
Re: Heat Treat - Verifying mechanical properties on heat treated material per the AST
Maybe you can sample test either a finished product, post heat treat, which, would likely mean a destructive test, or you can run a representative "coupon" (from the bar stock) with the products being heat treated and have the coupon tested for the mechanical properties.
Maybe you can sample test either a finished product, post heat treat, which, would likely mean a destructive test, or you can run a representative "coupon" (from the bar stock) with the products being heat treated and have the coupon tested for the mechanical properties.
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Re: Heat Treat - Verifying mechanical properties on heat treated material per the AST
I have never heard such a thing. I would be leery. The properties would possibly likely change as you worked the material anyway. I know we deal with work hardening a lot. It would seem to me, once the part is made, then the mechanical properties of the part take over and the astm spec is not all that relevant. Find yourself a metallurgist and see what they think.
I have never heard such a thing. I would be leery. The properties would possibly likely change as you worked the material anyway. I know we deal with work hardening a lot. It would seem to me, once the part is made, then the mechanical properties of the part take over and the astm spec is not all that relevant. Find yourself a metallurgist and see what they think.
V
vivkrish
Re: Heat Treat - Verifying mechanical properties on heat treated material per the AST
For heat treated materials Hardness verification is enough. We can conclude mechanical properties by hardness(Vickers hardness is preferable).
But the agreement between you and your customer states what are the properties you need to verify.
Hardness is non destructive testing only. You may have the hardness tester in your plant also. Which reduces the time spend to verify the material.
possessing hardness tester is mandatory for surface treatment company.
Hello,
For heat treated materials Hardness verification is enough. We can conclude mechanical properties by hardness(Vickers hardness is preferable).
But the agreement between you and your customer states what are the properties you need to verify.
Hardness is non destructive testing only. You may have the hardness tester in your plant also. Which reduces the time spend to verify the material.
possessing hardness tester is mandatory for surface treatment company.
S
suffelde
Re: Heat Treat - Verifying mechanical properties on heat treated material per the AST
Which ASTM spec? For instance, ASTM A105 allows you to use the mechanical properties found from one heat treat lot (providing it is the same mill heat lot) and use those values on subsequent heat treat lots if the same cycle is used and the furnace has a recorder - not a direct quote but the substance is the same.
Are you certifying to that ASTM spec? Has the customer given you a variance from the ASTM spec?
Where is the data / proof there are no product integrity issues in your overall or a specific heat cycle ?
What does your risk assessment address?
There is a correlation between hardness values and tensile properties - if you have enough statistical data, then one might be able to use just hte hardness test as verification of a proper process.
Overall, a process - special or not - requires a feedback function in order to ensure the process was effective.
Depending on the end product's form, fit, or function, I would be very concerned about not having an effectively implemented feed-back process and it would definitely raise product integrity issues.
Which ASTM spec? For instance, ASTM A105 allows you to use the mechanical properties found from one heat treat lot (providing it is the same mill heat lot) and use those values on subsequent heat treat lots if the same cycle is used and the furnace has a recorder - not a direct quote but the substance is the same.
Are you certifying to that ASTM spec? Has the customer given you a variance from the ASTM spec?
Where is the data / proof there are no product integrity issues in your overall or a specific heat cycle ?
What does your risk assessment address?
There is a correlation between hardness values and tensile properties - if you have enough statistical data, then one might be able to use just hte hardness test as verification of a proper process.
Overall, a process - special or not - requires a feedback function in order to ensure the process was effective.
Depending on the end product's form, fit, or function, I would be very concerned about not having an effectively implemented feed-back process and it would definitely raise product integrity issues.
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