PTA" Cavity" Problem

[attin]

Hi everyone,

We are producing hardfacing powder. Our customers ( they have pta machine for hardfacing) have complaint about "cavity problem" on the moulds. they are using nickel based powder (NiCrBSi). Hardness 30-35 rockwell. We dont solve this problem. Otherwise we dont know the problem occuring from us or Customesr PTA machine.

Have a good week for everyone

Bahattin

[senkcoat]

Dear Bahattin.

We can help you for your problem.

senkcoat@hotmail.com

[derek]

Cavity problem happens because the part was not clean enough, or the part was iron cast, inside the part has a lot of oil.

[attin]

Thanks for advance Derek,
Our customers dont accept the fault occuring from them. They are blaming to us because they are using others firm powder the same application and then they say, your powder are causing initial weld crack or cavity but others firm powder dont causing initial weld crack. The fault you can see in the attachment.
Thanks for opinions.

[derek]

If they say the problem is your powder, you can ask them give you some other vender's powder and analysis the powder to see how many B and Si inside the powder. Normally a little bit B and Si will reduce melting temperature and increase the wetting capacity.

If the welding area is not the seal surface, one or two crack will not affect the part function. Also pre-heat the part will help to reduce the crack.