Hydrogen Determinator for Steel and Weld Metal

What is the Hydrogen Determinator for Steel and Weld Metal?

A hydrogen determinator for steel and weld metal measures diffusible and total hydrogen at 0.1–100 ppm using a low-temperature furnace and thermal conductivity detection. It is used to assess hydrogen-induced cracking risk in weld deposits and high-strength steels.

Overview

The hydrogen determinator uses a dedicated hydrogen analysis route in which a pre-quenched specimen of 0.5–5 g is heated in a nitrogen or argon stream, either at moderate temperature for diffusible hydrogen or by fusion for total hydrogen. The carrier gas sweeps released hydrogen through a thermal conductivity detector with a reference stream, and optional molecular sieve separation improves selectivity. Diffusible hydrogen is collected at 150–400 °C over controlled time, consistent with ISO 3690 and related weld metal standards. Quench and storage in liquid nitrogen preserve hydrogen, and quick transfer to the analyzer minimizes losses. Reproducibility depends on sample handling more than on electronics, so temperature and time between sampling and measurement are documented. Calibration is performed by injecting calibrated volumes of hydrogen or using certified reference materials.

How does it work?

An oxygen nitrogen hydrogen analyzer places a sample of 0.1–1 g in a high-purity graphite crucible clamped between two electrodes in a sealed furnace flushed with helium or argon. A high current heats the crucible to 2000–3000 °C, melting the sample and releasing its gases. Oxygen reacts with graphite to form CO, nitrogen leaves as N2, and hydrogen as H2. CO and, after oxidation, CO2 are detected by non-dispersive infrared cells, while N2 and H2 are measured by a thermal conductivity cell after the gas stream passes rare earth copper oxide and absorbent traps. Hydrogen may be separated by a molecular sieve column. Results are calibrated against certified reference materials such as steel, titanium, and nickel alloys. Since gases are extracted from the bulk, the analysis gives total content, not surface contamination.

What are the key features?

• Dedicated hydrogen route with thermal conductivity detection from 0.1 to 100 ppm.
• Low-temperature heating stage for diffusible hydrogen at 150–400 °C.
• Fusion mode for total hydrogen in steel and alloys.
• Optional molecular sieve column improves separation from nitrogen and other gases.
• Gas injection calibration gives traceable hydrogen quantitation.

What are the technical specifications?

A typical hydrogen determinator for steel and weld metal configuration offers hydrogen range of 0.1–100 ppm, sample mass of 0.5–5 g, diffusible hydrogen temperature of 150–400 °C, fusion temperature of Up to about 2500 °C, precision (RSD) of ≤2% at 10 ppm and detection limit of About 0.1 ppm. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Hydrogen Determinator for Steel and Weld Metal is used in weld metal hydrogen control, high-strength steel embrittlement assessment, plating bake-out verification and pipeline and pressure vessel fabrication. Across the wider Oxygen Nitrogen Hydrogen Analyzers class, laboratories also deploy it for steel cleanliness and gas content control, titanium and zirconium alloy qualification and hydrogen embrittlement investigation.

Which standards and certifications apply?

Relevant standards and methods include ASTM E1409, ASTM E1447, ASTM E1019, ISO 10720, GB/T 11261, GB/T 20124 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Hydrogen and oxygen results depend strongly on sample handling. Steel hydrogen specimens must be quenched in cold water and stored in liquid nitrogen or dry ice to prevent diffusion, and analyzed promptly. Oxygen and nitrogen samples are cleaned, dried, and handled with tongs. Use helium of at least 99.995% purity, regulated pneumatic gas, and cooling water at 15–25 °C. Crucible outgassing is performed before each run and furnace electrodes and dust filters need cleaning after a defined number of analyses, usually 30–100. Calibrate frequently with certified standards and check blanks daily. Installation requires fume extraction and adequate power, since the impulse furnace draws high current. Validate methods against ASTM E1409, ASTM E1447, and ISO 4295-type procedures.

How do I select the right Hydrogen Determinator for Steel and Weld Metal?

Select this variant where hydrogen is the critical parameter and diffusible hydrogen must be measured on quenched specimens. If oxygen and nitrogen are also needed, choose an O/N/H version. Specify hydrogen range, heating temperature options, sample size, and standard support such as ISO 3690. Confirm the calibration procedure.

How does it compare with other Oxygen Nitrogen Hydrogen Analyzers variants?

Decide which gases matter and in which matrices. Oxygen and nitrogen in steel and titanium require a standard impulse furnace, while hydrogen in steel at 0.5–10 ppm often calls for a dedicated hydrogen channel or a separate hydrogen analyzer with a thermal conductivity cell. For ceramics and refractory powders that release gas slowly, higher furnace power up to 5–8 kW and longer integration are needed. Specify expected ranges, because ppm-level oxygen needs low-range infrared cells and careful blank control. Consider sample geometry: pins and rods need a cutting station, whereas powders require tin or nickel capsules. Autosamplers with 20–50 positions and automatic crucible handling increase throughput. Check the availability of certified reference materials for your alloys and ask for detection limits, typically 0.05 ppm to 1 ppm, verified on matching materials.