UNS S41425 - NACE - FORONI SPA

[JHWC]

Hi All,

I would like to check what is the heating treatment of the following material - UNS S41425 under NACE compliant?

I can find non-nace heating treatment for UNS S41425, but not the NACE version in MRS0175.

I was told it was implemented by Foroni SPA, but I can't seen to find the document.

Please advise.

Thanks,
Jeffrey

 

[CoryPad]

According to NACE MR0175/ISO 15156-3:

Wrought low-carbon UNS S41425 martensitic stainless steel in the austenitized, quenched, and tempered condition shall have a maximum hardness of 28 HRC.

 

[JHWC]

Hi Corypad,

You are right. But I am looking for the heat treatment procedures.

For S41427, the heating procedure is written in NACE but not for S41425. Thanks.

 

[CoryPad]

The NACE/ISO standard does not restrict the heat treating parameters for S41425 like it does for S41427.

 

[JHWC]

Thanks. correct me if i am wrong.

Nace has set the hardness to be at 28 hrc. But astm stated 32hrc instead. Therefore, i believe there must be guidelines to the heat treatment method.

 

[metengr]

Follow the ASTM A 473 heat treatment requirements for austenitizing and air cool. Instead of 1100 deg F temper minimum, increase the temper to 1250 deg F for 1 hour per inch.

 

[JHWC]

Thanks metengr.

You are right. I initially used the heating guideline from ASTSM A 473. However, as I need to compliant to the NACE hardness (29 HRC), I am searching for the heating procedure.

As you mentioned, instead of 1100 deg F, I should increase the temperature to 1250 deg F.

May I ask where can I achieve or obtain the document from?

Thanks for your help and many apologies for the late reply.

Jeffrey

 

[metengr]

JeffreyHo;
The 1250 deg F was based on a quick review of a technical paper on heat treatment and secondary hardening characteristics for similar grades of supermartensitic stainless steel. I would use the 1250 deg F as a guide and adjust or fine tune the actual tempering temperature.

 

[JHWC]

Thanks metengr =)