GB/T 223.43-2008Iron, steel and alloy - Determination of tungsten content - Gravimetryc method and spectrophotometric method (English PDF)

GB/T 223.43-2008 is the English-translated version of 钢铁及合金 钨含量的测定 重量法和分光光度法.

GB/T 223.43-2008 is the part of GB/T 223 that determines the tungsten content of iron, steel and alloys.

Clause 1 states that this part specifies the cinchonine gravimetric method and the tetrakis phenylarsonic - thiocyanate - chloroform extraction photometric method for measuring tungsten content, that the cinchonine gravimetric method suits steel, high temperature alloys and precision alloys with a tungsten mass fraction of 1.00 percent to 22.00 percent, and that the extraction spectrophotometric method suits carbon steel, alloy steel and high temperature alloys with a tungsten mass fraction of 0.050 percent to 1.50 percent.

A warning placed before clause 1 states that the user of this part should be a person with regular laboratory experience, that the part does not indicate all possible safety issues and that the user is responsible for appropriate safety and health practices in line with national regulations.

The draft shows clause 1 Scope, clause 2 Normative references and a clause 3 whose heading it renders as method cinchonine gravimetric method, with 3.1 Principle and 3.2 Reagents, and it breaks off at 3.2.2, so the spectrophotometric method has no clause text on the page.

Clause 2 cites GB/T 223.12, GB/T 223.14, GB/T 223.26, GB/T 6379.1, GB/T 6379.2 and GB/T 20066.

Under 3.1 the principle precipitates the tungsten of a niobium free sample as tungstate in hydrochloric acid solution, completes the precipitation with cinchonine, then filters and ignites the precipitate, volatilizes silicon with hydrofluoric acid and ignites to constant mass to give an impure tungsten trioxide; for a niobium bearing sample the niobium pentoxide and tungsten trioxide are taken into a sodium carbonate melt, the niobium is separated by precipitation and the tungsten is then precipitated and ignited to constant mass in the same way.

The same subclause corrects that impure tungsten trioxide by fusing it with sodium carbonate and filtering, determining molybdenum, chromium and vanadium in the filtrate by spectrophotometry, and igniting and weighing as oxides the iron, titanium and other impurities held on the filter paper, the masses of which are subtracted from the mass of the impure tungsten trioxide to give the mass of pure tungsten trioxide.

The foreword records that the part was proposed by the China Iron and Steel Association, that it falls to the national steel standardization technical committee, that it was drafted by the Institute of Metal Research and the Daye steel mills as the draft names them, that Appendix A is an informative appendix, and that against the 1994 edition the title was changed, provisions on water and reagents for analysis were added, and the way the content and concentration, the weighed sample amount, the amounts in the result formula and the precision are expressed was modified.

It replaces GB/T 223.43-1994, which the foreword lists together with GB 223.43-1985 and GB 223.44-1985 among the standards it supersedes, was issued on 13 May 2008 and has applied since 1 November 2008.

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This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 15 pages — is available in the English PDF.

GB/T 17616-2025|GB/T 223.8-2025|GB/T 223.92-2023|GB/T 223.89-2019|GB/T 223.82-2018|GB/T 223.87-2018

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