Do heat treatment ovens need calibration?

[Sam.F]

Hello everyone.
We have just purchased a small oven that we use to heat treat steel tools. And we verify rockwell in a calibrated rockwell tester. My question is do we need to calibrate the oven? We are verifying the tool steels in a calibrated rockwell tester. Thank you.

We are not using the oven to heat treat customers parts at all.

 

[Sidney Vianna]

Anyone who comes here expecting meaningful answers should understand they need to provide some context to the scenario. There are many unknowns here.

Is the organization a manufacturer of tools or just a heat treater?
Where will these heat treated tools be used?
Does the organization comply with standards (ISO 9001/AS9100, etc.) that have requirements related to special processes?
Surface hardness many times do not assure metallurgical internal properties. Are there any here at play?
Etc.

 

[Bev D]

On top of Sydney’s questions I would ask an even more insightful one: Why wouldn’t you calibrate the oven?

 

[Sam.F]

We are as/iso certified company we heat treat our own in house tools to make customer parts. We manufacture parts per customer blue print requirements. Im new in that company and they have never calibrated their oven. So i want to calibrate it but if i don't have to i will not do it. (This is the 2nd oven) 1st one is not calibrated.

Thank you..

 

[Funboi]

Ovens don’t measure, so the answer is “no”. But how do you determine the oven reaches temperature and in all zones? That equipment should be verified/calibrated.

 

[Sam.F]

Thank you @Funboi do you think if im verifying the tools rockwell, in a calibrated rockwell tester, i will be ok. Or no. I do calibrate the rockwell tester because i am verifying parts that i sent out to be heat treated.

Thank you.

 

[Jen Kirley]

Thank you @Funboi do you think if im verifying the tools rockwell, in a calibrated rockwell tester, i will be ok. Or no. I do calibrate the rockwell tester because i am verifying parts that i sent out to be heat treated.

Thank you.

Is it more efficient (more profitable) to test parts after their production, or to control the process through calibrating/verifying the temperature in the process?

What instrument does your overn use to tell you the temperature it reaches?

 

[Funboi]

Heat

Thank you @Funboi do you think if im verifying the tools rockwell, in a calibrated rockwell tester, i will be ok. Or no. I do calibrate the rockwell tester because i am verifying parts that i sent out to be heat treated.

Thank you.

Heat treatment is considered one of those processes where it’s not really possible to check the product afterwards. Sure, a sacrificial product can be used on the indenter, but that doesn’t tell you if the rest are the same. Temp gradients play a big part.
Heat treaters I’m familiar with use a M.O.L.E thermocouple array or have someone come in and do it

 

[Enghabashy]

Controlling the process is not limited to check only the output of the process " i.e : verify Rockwell " ; the oven manufacture instruction , information & maintenance points are considered for control also ,
*the efficiency of thermal isolation & heating for ovens maybe go down by the time in closed cycle heat process , the referring to validate the temperature uniformity issues & the parodic checks with the manufacture are considered

 

[Sebastian]

If your organization is IATF 16949 certified and your auditors know their job, answer is "yes".
All control systems identified in control plan shall be reliable.
Calibration is a method to ensure it.
Otherwise is up to you and your customers.