Looking Back: Metallurgy Standards Overview – September 2025 (Part 1)

September 2025 marked a significant period for the metallurgy sector, characterized by the publication of several influential international and European standards. This monthly overview examines the five key standards released across September, addressing topics vital to steel, iron, and powder metallurgy industries. From advanced microscopic analysis of nonmetallic inclusions to optimized testing methodologies for titanium and oxygen content, this summary distills the critical changes, underlying trends, and actionable insights for professionals seeking to keep current with best practices and regulatory shifts.

Reviewing these standards not only helps organizations benchmark their quality and compliance activities—it also offers a window into where metallurgical science and technology are heading. This analysis is part 1 of a two-part series, ensuring thorough coverage of all impactful September 2025 standards in this domain.

Monthly Overview: September 2025

The metallurgical industry saw robust standardization activity during September 2025, with a distinct focus on analytical precision and material characterization. Notably, three standards focused on advanced compositional analysis (titanium and nonmetallic inclusions), while two others addressed the measurement of hydrogen-reducible oxygen in metallic powders. Such a cluster of publication suggests a growing emphasis on:

• Quantitative microstructural assessment
• Enhanced chemical analysis sensitivity
• Harmonization of international and regional (ISO/CEN) practices

This month’s standards align with industry trends that prioritize increased traceability, improved detection limits, and stricter control of impurities—each crucial for performance in steelmaking, iron foundry operations, and powder metallurgy. Furthermore, the near-simultaneous release of both ISO and EN ISO editions underlines ongoing global efforts to streamline regional adoption and promote uniformity.

Standards Published This Month

ISO 5490:2025 – Steel - Rating and classifying nonmetallic inclusions using the scanning electron microscope

Steel — Rating and classifying nonmetallic inclusions using the scanning electron microscope

This international standard details a comprehensive protocol for evaluating nonmetallic inclusions in steel via scanning electron microscope (SEM) equipped with energy dispersive X-ray spectrometer (EDS) and backscattered detector (BSD), using automated image analysis.

The document outlines two primary evaluation methods:

• Morphology rating method aligns with the traditional ISO 4967 approach but leverages the speed and objectivity of automated SEM analysis.
• Chemistry rating method classifies inclusions primarily by chemical composition, an option offering enhanced insight for specific applications.
• Statistical analysis method allows organizations to profile inclusions based on size distribution and chemical class across a variety of products and processing conditions.

Who Should Comply:

• Steel producers, metallurgical laboratories, product quality controllers, and researchers focusing on steel cleanliness and inclusions.

This standard is particularly relevant for facilities with advanced SEM equipment and those requiring precise, reproducible inclusion analysis—whether for product qualification, process optimization, or failure analysis.

Notable Features:

• Fully automated image analysis, reducing operator bias and enhancing reproducibility
• Calibration and inspection requirements for equipment, traceable to ISO 16700 and ISO 22309
• Options for both morphology-based and chemistry-based rating, allowing tailored analysis strategies

Key highlights:

• Dual rating system (morphology/chemistry)
• Automated, statistically robust inclusion analysis
• Explicit calibration and reporting requirements

Access the full standard:View ISO 5490:2025 on iTeh Standards

EN ISO 10280:2025 – Steel and iron - Determination of titanium content - Diantipyrylmethane spectrophotometric method (ISO 10280:2025)

Steel and iron — Determination of titanium content — Diantipyrylmethane spectrophotometric method (ISO 10280:2025)

This European standard, harmonized with ISO 10280:2025, defines the diantipyrylmethane spectrophotometric procedure for quantifying titanium in steels and irons. Covering titanium content from 0.002% to 0.80% by mass, it brings updated methodology and improved precision for quality control of alloy compositions.

Key elements include reagent preparation, blank testing, calibration curve establishment, and guidance on handling potential interferences. The method is especially suitable for analytical chemistry labs supporting steelmaking and foundry operations—where titanium control is often critical for mechanical or corrosion performance.

Who Should Comply:

• Steelworks laboratories, iron foundries, independent test laboratories, and procurement organizations needing documentation of titanium levels.

The 2025 edition supersedes earlier versions, aligning with updated ISO terminology and precision data.

Notable Features:

• Wide applicable titanium concentration range (0.002%–0.80% by mass)
• Stepwise sample preparation, solution treatment, and calibration
• Integrated controls for analytical accuracy and repeatability

Key highlights:

• Harmonized with the latest ISO 10280:2025
• Re-evaluated precision data
• Targeted to both steel and iron matrices

Access the full standard:View EN ISO 10280:2025 on iTeh Standards

EN ISO 4491-3:2025 – Metallic powders - Determination of oxygen content by reduction methods - Part 3: Hydrogen-reducible oxygen (ISO 4491-3:2025)

Metallic powders — Determination of oxygen content by reduction methods — Part 3: Hydrogen-reducible oxygen (ISO 4491-3:2025)

EN ISO 4491-3:2025 provides a standardized method for determining the hydrogen-reducible oxygen content in metallic powders, essential for the quality assurance of feedstock used in powder metallurgy. Applicable to unalloyed, alloyed, and carbide-binder mixtures (but not powders with lubricants/organic binders), the method covers powders with oxygen levels from 0.05% to 3%.

Sample preconditioning, hydrogen reduction in a controlled furnace environment, and Karl Fischer titration are central features of the protocol. The standard also includes guidance on mitigation of carbon interference via catalytic conversion for improved result accuracy—a must for advanced powder production and research.

Who Should Comply:

• Powder metallurgy manufacturers, quality control labs, research institutes specializing in metal powders and hardmetal components.

The EN ISO and ISO editions are technically harmonized, ensuring alignment across Europe and globally.

Notable Features:

• Detailed apparatus and reagent requirements
• Protocol extensions for powders containing carbon (with catalytic conversion)
• Incorporation of contemporary ISO references (ISO 760, ISO 4491-1)

Key highlights:

• Applicable to a range of powder types
• Karl Fischer titration ensures sensitivity
• Updated to align with the most recent ISO drafting directives

Access the full standard:View EN ISO 4491-3:2025 on iTeh Standards

ISO 4491-3:2025 – Metallic powders - Determination of oxygen content by reduction methods - Part 3: Hydrogen-reducible oxygen

Metallic powders — Determination of oxygen content by reduction methods — Part 3: Hydrogen-reducible oxygen

This ISO standard mirrors EN ISO 4491-3:2025 in technical content, reflecting the Vienna Agreement for ISO/CEN standard harmonization. It formalizes international procedures for quantifying hydrogen-reducible oxygen in metallic powders, ensuring globally consistent material quality.

Designed for laboratories with powder processing and quality control functions, the standard incorporates pre-drying, controlled hydrogen furnace reduction, and Karl Fischer titration. Explicit steps are provided for managing samples containing carbon through use of a nickel catalyst to neutralize gas-phase interferences.

Who Should Comply:

• Powder producers, labs serving international supply chains, and metallurgical research organizations focused on material integrity and standards compliance.

Notable Features:

• Supports a range of alloyed/unalloyed powders
• Detailed apparatus layout and safety guidance
• Updated editorial and normative reference alignment (September 2025)

Key highlights:

• Flexible method extension for carbon-containing samples
• Reference to other essential standards (ISO 760, ISO 4491-1)
• Internationally harmonized wording and steps

Access the full standard:View ISO 4491-3:2025 on iTeh Standards

ISO 10280:2025 – Steel and iron - Determination of titanium content - Diantipyrylmethane spectrophotometric method

Steel and iron — Determination of titanium content — Diantipyrylmethane spectrophotometric method

ISO 10280:2025 delivers the revised methodology for titanium determination in steel and iron using spectrophotometric analysis with diantipyrylmethane. Its scope spans analytical contexts where titanium content verification (0.002%–0.80%) is essential for process qualification, alloy design, and regulatory conformance.

The procedure is rooted in test material dissolution, reagent-driven complex formation, and the photometric measurement of the resultant colored species. Enhanced guidance on blank correction, calibration, and sample preparation supports improved test accuracy and repeatability.

Who Should Comply:

• Steelmakers, foundries, contract testing laboratories, and organizations certifying compliance of raw materials and finished products.

Notable Features:

• Comprehensive documentation of reagents, apparatus, and experimental steps
• Updates to terminology and precision data (reflecting international interlaboratory testing)
• Integration with relevant laboratory glassware and water standards

Key highlights:

• Applicable to a broad titanium concentration range
• Reinforced validation of test precision
• Harmonized with EN ISO 10280:2025 for global interoperability

Access the full standard:View ISO 10280:2025 on iTeh Standards

Common Themes and Industry Trends

This month’s standards signal a clear focus on improved analytical methodologies and alignment between global and regional regulatory frameworks. Key patterns observed:

• Advancement in Chemometric Methods: The growth in SEM-based inclusion analysis (ISO 5490:2025) and the reinforcement of spectrophotometry’s place in titania analysis show a maturation of laboratory best practices.
• Convergence of ISO and EN ISO Texts: The simultaneous release of ISO and EN ISO editions in both titanium and oxygen testing reflects deepening harmonization, simplifying compliance for organizations operating internationally.
• Broader Applicability for Powder Metallurgy: The updates to the ISO 4491-3 series, echoes rising demand for precision in feedstock quality in additive manufacturing and hardmetal industries.
• Emphasis on Calibration and Repeatability: Explicit clauses prescribing calibration, control samples, and blank tests signal increased priority on analytical reliability—mirroring quality expectations in advanced industrial sectors.

These trends meet growing market demands for consistent, reproducible results and support the evolving regulatory climate where traceability and material performance are paramount.

Compliance and Implementation Considerations

For organizations impacted by these standards, timely assessment and adoption are recommended:

1. Gap Analysis: Compare existing laboratory practices and equipment against new requirements, especially automation, calibration frequency, and reagent specifications.
2. Staff Training: Ensure laboratory chemists, metallographers, and QA staff are informed about procedural updates—especially automated SEM analysis and enhanced titration protocols.
3. Documentation: Update internal test methods, reports, and calibration logs in line with latest clauses; include explicit references to ISO/EN ISO standards in quality manuals.
4. Supplier and Client Communication: Use the harmonization of ISO and EN ISO standards to demonstrate compliance in international trade and supply agreements.

Timeline Considerations:

• Most national and regional bodies require transition to new editions within 6–12 months of publication; review stakeholder requirements for specific deadlines.

Resources for Implementation:

• Access the full text via iTeh Standards for detailed methodology, calibration routines, and reporting templates.
• Participation in relevant technical committees and user groups can ease knowledge transfer and troubleshooting.

Conclusion: Key Takeaways from September 2025

Looking back, September 2025 was pivotal for metallurgy professionals focused on compositional analysis and feedstock certification. Key standards—ranging from ISO 5490’s advanced SEM-based inclusion rating, through the harmonized ISO/EN ISO 10280 procedures for titanium, to the oxygen quantification in powder metallurgy (ISO 4491-3 and equivalents)—jointly signal:

• Intensified emphasis on analytical precision, automation, and harmonized global practices
• The need for upskilling laboratory teams and modernizing equipment
• Opportunities for streamlined cross-border compliance through unified standards

Industry professionals are strongly advised to review these standards in depth, assess their compliance posture, and leverage new analytical capabilities to maintain quality competitiveness.

Explore these and other essential documents on iTeh Standards to remain at the forefront of the metallurgy sector’s evolving regulatory and quality environment.