Sorting and Verification Guides
ASTM E1476 is the standard guide for metals identification, grade verification and sorting. It sets out the methods, from spot tests and magnets to XRF and spark OES, and what each can and cannot tell you. API RP 578, Guidelines for a Material Verification Program (MVP) for New and Existing Assets, is the refinery and process-industry practice that made positive material identification routine. Much scrap-trade PMI practice borrows from it. See PMI for scrap lots.
Analytical Test Methods
| Standard | Method | What it is used for |
|---|---|---|
| ASTM E2465 | Wavelength-dispersive XRF | Laboratory analysis of nickel-base alloys, including elements handheld units read poorly. |
| ASTM E3047 | Spark atomic emission spectrometry | Nickel alloy analysis including carbon and light elements, on a prepared solid sample. |
| ASTM E354 | Wet chemical analysis | Referee chemical methods for high-temperature, electrical, magnetic and similar iron, nickel and cobalt alloys. |
| ASTM E1019 | Combustion and inert-gas fusion | Carbon, sulfur, nitrogen and oxygen in steel, iron, nickel and cobalt alloys. |
| ISO/IEC 17025 | Laboratory accreditation | Competence of testing and calibration laboratories; look for it on third-party reports. |
Choosing the Right Level of Proof
A handheld XRF reading is enough to sort most wrought nickel alloys by grade. It is not enough where carbon, aluminium, boron or trace zirconium decide the grade or the price, as with low-carbon variants, γ′ superalloys and low-Zr revert. Then spark OES or a laboratory analysis to one of the methods above is the right call. See XRF, OES or lab.
FAQ
What is API RP 578?
API Recommended Practice 578, Guidelines for a Material Verification Program (MVP) for New and Existing Assets. It sets out how operators verify that alloy materials are what they should be, usually by PMI.
Which ASTM standard covers metal sorting?
ASTM E1476, the standard guide for metals identification, grade verification and sorting.
Can XRF measure carbon in nickel alloys?
No. Carbon is too light for XRF. Use spark OES (ASTM E3047) or combustion analysis (ASTM E1019).