Forging - Cracks requirements

[Jeroki]

Hello everybody

I am writing due to a doubt I have related to forging products. One of the reqeuriments we have for this purchased product is, of course, no presence of cracks.
However, I don't know whether there is any standard for forged products in which the test method to be applied is indicated, so I can confirm that my supplier is using the correct test method according to assure this.

May anyone help me?

Thanks a lot, regards

 

[Miner]

If you are USA based, try the ASTM standards. There is also the Forging Handbook. ISO also has a series of forging standards.

 

[Jeroki]

Hi

Thanks a ot

Just for information for potential people interested in tis topic in the future, the ISO9327:1999 and ASTM-A708 talk about the minimum reuirements, and in none of them a specific test method/requrement is specified

However, at the very least in ASTM, there is a possibility of requesting ultrasound tests, magnetic plrticles tests... and so on, but the needed of compiling to such standard needs to be requested in the order, as it is supplement to the miminmum requierement.

Thanks, regards

 

[Randy]

Would you be willing to fly in a plane with cracks in forged pieces like a wing spar, turbine blade or landing gear strut?

 

[Jeroki]

Hello
I am sorry but I dont catch it Randy

I arise this issue because my designer just request a 100% inspection of absence of cracks in first samples, not indicating any requirement after it.

Of course, any forging part received in series condition would also lead to a non conformity, but I wanted to now what are the tests and minimum requirements which they have to do mandatory in series condition. Supplier will make a lower than 10% of the batch inspection with magnetic particle Inspection but I would want to force them to increase such inspection rate, that is why I wanted to know the minimum requirements

Regards

 

[Randy]

Supplier will make a lower than 10% of the batch inspection with magnetic particle Inspection but I would want to force them to increase such inspection rate, that is why I wanted to know the minimum requirements

Who's paying for the product, you or the supplier?

 

[Jeroki]

Who's paying for the product, you or the supplier?

I get It and I can push them to improve the rate but... Up to how much...? (Neither are they just going to increase their production as much as I request without requesting a price increase) What is considered an average standard in this commodity..?

Of course it is supplier's responsibility to deliver product acc. to specs, but as it is a new supplier we haven't worked with up to now I want to feel we are in a safe position.

Regards

 

[Randy]

OK, not knowing the industry involved just ask the simple question........Would you trust the life of you or your family with a material that is less than 100%......Yes or No? I've been in one really good aircraft accident because of a single cracked item, nobody killed, but the aircraft was totally destroyed and the 2 of us needed clean knickers after.

How about this claim in your advertising? "Our products are manufactured with items that are only assured to be only 90% crack free"

Of course that's crazy but what's the potential end use? Besides, did the design stipulate acceptable cracks? Probably not so therefore by accepting cracked material you are in fact knowingly accepting non-conforming product.

I'm doing a 3rd party recertification audit today (at lunch now relaxing a bit), how do you thing the above would impact my report if I found it?

 

[Jeroki]

Thanks a lot for your comments Randy. Commented this way it changes a lot.
I will make a deeper check of the function of this part with our Design Dept. and I will also check with supplier what is the root cause of defining such rate and why they feel so confident with it

Thanks, regards

 

[Miner]

Just some additional information on the causes of different types of cracks in forging.