ISO/TR 4644:2021

Overview

ISO/TR 4644:2021 - Nickels, ferronickels and nickel alloys - Standards for the determination of chemical composition - is a Technical Report that compiles and describes the International Standards currently available for chemical composition determination in nickel-based materials. Rather than prescribing a single test, the document lists applicable ISO methods, summarizes their range of application and explains the principle of each analytical method. Annex A provides graphical content-range maps for nickels, ferronickels and nickel alloys; Annex B gives a bilingual key of abbreviations used in those figures.

Key technical topics and requirements

• Catalog of methods: ISO/TR 4644:2021 references established ISO methods for many elements (Ag, As, B, Bi, Cd, Co, Cr, Cu, Fe, Mn, Ni, P, Pb, S, Se, Sn, Te, Tl, Zn, and others). Examples include:
  • Flame atomic absorption spectrometry (e.g., ISO 6351:1985)
  • Electrothermal atomic absorption spectrometry (e.g., ISO 7523:1985)
  • Curcumin molecular absorption spectrometry for boron (ISO 11436:1993)
  • Phosphovanadomolybdate molecular absorption for phosphorus (ISO 11400:1992)
  • Iodimetric titration after induction furnace combustion for sulfur (ISO 7527:1985)
  • Infrared absorption after induction furnace combustion for carbon (ISO 7524:2020)
  • ICP-OES (inductively coupled plasma optical emission spectrometry) for elements in ferronickels (ISO 23156:2021)
• Method classification: Defines and distinguishes referee methods (stoichiometric or calibrated against pure materials, used for certification/arbitration) and routine methods (calibrated against certified reference materials or standard solutions for day-to-day control).
• Scope and applicability: For each listed standard, the report summarizes the element(s) covered, the applicable matrices (nickels, ferronickels, nickel alloys), and the principle of the analytical technique.
• Graphical aids: Annex A visualizes content ranges and fields of application, helping users choose appropriate methods for specific concentration ranges and matrices.

Practical applications and intended users

ISO/TR 4644:2021 is a practical reference for:

• Analytical laboratories performing elemental analysis of nickel, ferronickel and nickel-alloy samples
• Quality control and metallurgy teams in nickel producers, smelters and alloy manufacturers
• Procurement and specification writers who need to reference appropriate ISO test methods
• Accreditation bodies and auditors evaluating method selection and conformity
• R&D groups selecting validated methods for product development or failure analysis

By consolidating relevant ISO methods and their principles, ISO/TR 4644:2021 streamlines method selection for reliable chemical composition analysis and supports consistent testing practice across the nickel industry.

Related standards (examples cited)

• ISO 6351:1985, ISO 7523:1985, ISO 11436:1993, ISO 11400:1992, ISO 7527:1985, ISO 7524:2020, ISO 23156:2021.