Is Heat Treatment for Metal a Special Process?

[AndyN]

Is this the same place with the cheese on rusty racks and the sewer pipe?

 

[Big Jim]

i think it is not special process because we have a device to measure the Hardness of metal

Is hardness the only characteristic you care about, or is hardness used to confirm that the heat treat has progressed to the point you want?

Depending on what you are after, hardness could be part of your validation or it might be your ability to fully test the outcome.

You really need to be able to answer the question "does hardness tell us all we need to know?"

The heat treat shops I call on check hardness, but they also keep meticulous records about oven temperatures and times during the heat treat process. In their case, hardness is not enough.

 

[Kales Veggie]

i think it is not special process because we have a device to measure the Hardness of metal

Do you measure 100% of the parts?
What is your process capability?
Is the hardness check destructive to the part?
Is hardness the only criteria? (what about through hardening, micro/macro structure?
What is your customer requirement?

I think it is unless it can be proven otherwise?

 

[AndyN]

Do you measure 100% of the parts?
What is your process capability?
Is the hardness check destructive to the part?
Is hardness the only criteria? (what about through hardening, micro/macro structure?
What is your customer requirement?

I think it is unless it can be proven otherwise?

Plus, an indentor check isn't a check of homogeneity of the hardness throughout the part.....

No, it is a special process and requires validation.....
(unless you're checking the hardness of dairy products......)

 

[Sidney Vianna]

No, it is a special process and requires validation.....

As in the Welding - Is welding always a special process per ISO9001:2000 Clause 7.5.2 thread, my conclusion is that all encompassing generalizations bring a degree of risk.

 

[AndyN]

As in the Welding - Is welding always a special process per ISO9001:2000 Clause 7.5.2 thread, my conclusion is that all encompassing generalizations bring a degree of risk.

Well yes Sidney, however, once again, since we're only given a general question, we can only reasonably answer in general terms, lest we confuse the issue with all the caveats..........and what use is that for 90+% of the cases we're presented with.

There is an inherent risk with anything you read here. Who knows anything about the background competencies, knowledge etc. of anyone offering advice?

 

[Sidney Vianna]

Well yes Sidney, however, once again, since we're only given a general question, we can only reasonably answer in general terms, lest we confuse the issue with all the caveats..........and what use is that for 90+% of the cases we're presented with.?

In another post, you were concerned with someone potentially misleading readers here.

If someone asks

Is Heat treatment for metal a special process?

the only possible answer is: Not always/It depends.

To state that heat treating is ALWAYS a special process that requires validation would be misleading, in my opinion.

 

[w_grunfeld]

I beg to differ. Heat treatment is a classical example of a special process.

 

[AndyN]

In another post, you were concerned with someone potentially misleading readers here.

If someone asks the only possible answer is: Not always/It depends.

To state that heat treating is ALWAYS a special process that requires validation would be misleading, in my opinion.

So, I will have to disagree with you. Heat treatment in my experience - not opinion - has always been something that cannot be checked - adequately - after the product has been processed! Ask anyone who has ever cooked something......

 

[Randy]

I beg to differ. Heat treatment is a classical example of a special process.

Why?

What makes it special?

What is the definition of special as it relates to an ISO based QMS?