A36 against SS400

Date 04-05-2016 06:00

Hello,

We have some left overs of SS400 and A36 from our previous project, the problems is, our team forgot to wrote the material grades or identifications on the left overs/drops/off cut plates. We can assume that all grades can be SS400 but to utilize A36 plates from the current projects is a tricky task.

   We know that this is in equivalent material and both chemical and mechanical properties are kinda similar.

   Does anyone can help on what could be the alternative process on how to identify/verify A36 from SS400 without knowing the actual material grade/specs.

   Will highly appreciate any of responses.

   Thanks.

By welderbrent (*****)

Date 04-05-2016 07:59

Cut a piece off of it and send it to a lab for analysis.

Brent

By Mark Anthony Nofuente (*)

Date 04-05-2016 08:36

Thanks Brent.

But how can we ensure that the correct grade/specs can be identified as the both chemical and mechanical properties of the said grade and specs are almost similar?

If there's any specific chemical element that can be identified for A36 then it would be great since SS400 grade only indicated phosphorus and sulfur.

By welderbrent (*****)

Date 04-05-2016 09:12

Once the tests are done, preferably on a sample of both, they can tell you what they are based upon the ASTM specs for the various grades of steel.

Everything has its own specific chemical/mechanical signature.

Brent

By 803056

Date 04-05-2016 13:34

Short of performing chemical and mechanical testing, there is no way that I know of to determine what the materials are. Even then, there is sufficient latitude in the permitted ranges of chemistry to include several different material specifications. Likewise, the mechanical testing will provide information regarding the actual mechanical properties, but not their minimum values. Once again the test results will include several different base metal specifications.

The laboratory will most likely tell you the sample submitted is "similar to ASTM XYZ or AISI ABC".

If this is for an ASME code job, I doubt the AI will buy into this approach. Under ASME you would have to consider the material to be unknown.

Best regards - Al

By TimGary (****)

Date 04-05-2016 17:38

Would this be a job for ax XRF elemental analyzer?

such as one like this -
http://www.spectro.com/products/xrf-spectrometer/xsort-xrf-gun-handheld-analyzer?gclid=CPWni7SE-MsCFcQkhgod0ZYGsg

Tim

By Mark Anthony Nofuente (*)

Date 04-06-2016 03:11

Thanks Al and this is what I've thought as well, the laboratory result might and perhaps will only give their interpretation as similar to ASTM Axxx or AISC xxx as what you've said.

These materials are basically from our stock and for sure will not be utilized for ASME coded job.

Anyhow, I guess those materials should be considered as SS400 only.

By 803056

Date 04-06-2016 03:12

The XRF type of analyzer does not provide information regarding the state of heat treatment, what manufacturing process or rolling practice was used, or the mechanical properties, i.e., yield or tensile strength or ductility. Most of the X-ray diffraction analyzers will not identify the lighter elements such as carbon, sulfur, etc. What X-ray diffraction will do nicely is differentiate between different alloys of 300 series of stainless steel, i.e. 304 from 316 or 317, etc. However, most will not differentiate between 304L and 304 or 304H.

Best regards - Al

By TimGary (****)

Date 04-06-2016 12:03

Thanks Al!

Tim