Molten metal composition analyzer

01

Set the elements and ranges for the alloys you melt

ASTM E415-21 covers simultaneous determination of 21 alloying and residual elements in carbon and low-alloy steels by spark atomic emission vacuum spectrometry, for routine control in iron and steelmaking and for processed material, on chill-cast, rolled and forged specimens. Its quantitative ranges include carbon 0.02–1.1%, manganese 0.03–2.0%, silicon 0.02–1.54%, chromium 0.007–8.14%, nickel 0.006–5.0%, molybdenum 0.007–1.3%, phosphorus 0.006–0.085%, sulfur 0.001–0.055%, boron 0.0004–0.007% and nitrogen 0.01–0.055%, established by cooperative testing of reference materials. [1]

ASTM E1251-17a covers aluminium and its alloys by spark emission, primarily on chill-cast discs; its tested ranges include silicon 0.07–16%, copper 0.001–5.5%, magnesium 0.03–5.4%, zinc 0.002–5.7%, iron 0.2–0.5% and sodium 0.003–0.02%. It notes that magnesium oxidises and sodium, lithium, calcium and strontium are volatile when samples are remelted, and that mercury should not be reported by spark emission because of an iron interference; it recommends a method with a reporting limit of 0.0001% or lower for mercury compliance. [2]

Hitachi's range guide shows the choice is made by matrix and limits: its entry model is aimed at foundries that do not need low detection limits, a second adds nitrogen, and higher models add lower limits, more matrices (Fe, Al, Cu, Ni, Co, Ti, Zn and others), ultra-low carbon with a 5 ppm limit of detection and trace elements such as Se, La and Te. [5]

Give the supplier the metal bases (iron, steel, stainless, aluminium, copper, nickel and others), grades and the elements with their lowest and highest limits, nitrogen and low-carbon needs, trace and tramp elements, the reference materials you hold, and the number of samples per hour.

02

Plan the sample from the melt and the spark stand

ASTM E1806-18 covers sampling of all grades of steel and cast iron and blast-furnace iron for chemical and spectrochemical analysis, with separate sections for spoon sampling and probe sampling of liquid iron for steelmaking, liquid iron for cast iron production and liquid steel, preparation of the sample for analysis, and annexes on sampling probes; it is similar to ISO 14284. [3]

E415 applies to specimens with a diameter large enough to overlap and seal the bore of the spark stand opening; specimen thickness depends on the stand design, but the standard reports 10–38 mm as the practical thickness, and better performance is expected when reference materials and specimens are of similar metallurgical condition and composition. E1251 accepts castings and wrought forms only if they are massive enough to avoid undue heating, can be machined to a clean flat surface that seals the stand, and have matching reference materials. [1] [2]

Hitachi describes the routine as placing the sample on the spark stand, starting the measurement and reading the result, with a stand accessible from three sides for irregular samples; its optional charge-correction software calculates how much material to add to bring a melt into specification, considering available materials and furnace capacity. [4] [5]

State the sampler type (spoon and mould, immersion probe), sample shape and size, preparation (grinding or milling), time from sampling to result you need, sample identification and data transfer, and whether charge-correction or SPC software is required.

03

Check the optics, source, utilities and footprint

Hitachi's FOUNDRY-MASTER Pro2 data sheet lists a Paschen-Runge optical system on a Rowland circle with 350 mm focus, a 130–780 nm wavelength range and high-resolution multi-CMOS detectors; a solid-state source of 250–500 V at 80–500 Hz with a high-energy pre-spark; a 90–250 V AC 50/60 Hz supply drawing up to 1,000 W, 700 W operating and 50 W standby (100 W with the source on); 180 kg; and 1,140 × 730 × 850 mm. It states the instrument is designed to minimise argon consumption and includes a grade database of more than 12 million records for over 339,000 materials. [4]

Editorial note: the published sheet does not state argon flow or purity, analysis time or precision; obtain these per method from the supplier, and confirm precision against the reference materials and grades you run [4] [1].

Ask for argon purity and consumption in standby and analysis, analysis time per burn, repeatability on your reference materials, power supply and UPS needs, room temperature and dust limits, bench or floor footprint, and service and recalibration arrangements.

04

Know the analyser parts

05

Analysis time, element count, precision, ranges and power values for a spark OES quotation

Published values in this table come from ASTM E415, E1251 and E1806 and from Hitachi's FOUNDRY-MASTER Pro2 data sheet; where none states a value, the row says what to obtain from the supplier.

06

Send the alloys, elements and sampling data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Alloys: [metal bases; grades]
Elements: [list; lowest and highest limits; N, low C, trace]
Sampling: [spoon or probe; sample size; preparation]
Throughput: [samples per hour; time to result]
Site: [argon; power; room; bench or floor]
Software: [grade database; SPC; charge correction; data links]

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