Do you need to perform sulfur determination according to ISO 4935 ?
Securing metallic materials for the ASD sector with ISO 4935
In the Aerospace, Space, and Defense (ASD) sectors, the purity of ferrous alloys is a safety imperative. Sulfur content is a parameter monitored very closely: excessive concentration can lead to hot shortness and severely impair the integrity of your essential parts.
ISO 4935 specifies a method for the determination of sulfur in steels and cast irons by infrared absorption spectrometry after combustion in an induction furnace. This method is the benchmark for guaranteeing reliable and repeatable measurements, essential for validating your metallic grades.
At FILAB, we support manufacturers in the ASD supply chain with the characterization and control of their materials according to ISO 4935. Our goal is clear: to ensure the reliability of your technical and industrial decisions.
ISO 4935: a key challenge for steel and cast iron integrity
Sulfur analysis by combustion according to ISO 4935
The ISO 4935 standard relies on the total oxidation of the sample. The sulfur present in the metal matrix is converted into sulfur dioxide (SO2), which is then quantified with very high sensitivity by infrared detectors.
It is specifically used to:
- Precisely measure sulfur content, even at trace levels.
- Check compliance of stainless steels, alloy steels, and cast irons.
- Verify the absence of sulfur segregations that could weaken structures during forging or welding.
In the Aerospace and Defense industries, mastering sulfur according to ISO 4935 has a direct impact on:
- Hot ductility during forming processes.
- Resistance to pitting corrosion (limiting Manganese Sulfide inclusions).
- In-service behavior of strategic components subjected to high tensile stress.
FILAB, a laboratory tailored to Aerospace & Defense requirements
An analytical park dedicated to ISO 4935 testing
Analysis according to ISO 4935 requires perfect mastery of high-temperature combustion. To meet these demands, FILAB provides its clients with state-of-the-art equipment :
Dedicated material expertise services
At FILAB, ISO 4935 analysis is part of a comprehensive material characterization approach. We do not just produce results: we help you understand the influence of sulfur on your alloy properties. Our teams work on :
Carbon, stainless, and refractory steels
High-quality cast irons
Why Choose FILAB ?
- 45 years of recognized expertise in analysis and materials science
- Dual competence: Chemistry / Materials
- Specializing in metallic alloys and critical applications
- Customer qualification : Safran, Dassault Aviation, and Framatome
- ISO 17025 Accreditation regarding metallic alloys
Analysis of Iron, Aluminium, Molybdenum, Copper, Tin, Chromium, Titanium, Lead, Nickel, Zinc
Learn moreOur analytical services based on ISO and ASTM standards for the ASD sector
Our analytical services in accordance with MIL requirements for the ASD sector
FAQ
Optical Emission Spectrometry (OES) is fast for routine control, but ISO 4935 by combustion is the reference method for sulfur. It allows for the analysis of the sample's total volume, offering significantly higher precision, especially for ultra-low sulfur steels.
ISO 4935 is effective for sulfur contents ranging from 0.002% to approximately 0.10%, thus covering almost all industrial needs in the ASD sector.
The sample is taken in the form of chips or small solid pieces. It undergoes rigorous degreasing to remove any trace of cutting oil, ensuring that the measured sulfur comes exclusively from the metallic material.
Yes, the equipment used for ISO 4935 generally allows for Carbon determination (according to ISO 15350) during the same combustion cycle, optimizing both lead times and costs.
