GB/T 223.73-2008Iron, steel and alloy - Determination of iron contents - Titanium trichloride-potassium dichromate titration method (English PDF)

1 Scope

GB/T 223 provisions of this part of the titanium trichloride - potassium dichromate titration Determination of iron content.

This section applies to high-temperature alloys and precision alloys for the determination of the mass fraction of 0.50% - 8.00% iron content.

2 Normative references

The following documents contain provisions which, through reference GB/T 223 of this text, constitute provisions of this section. For dated reference documents

Member, all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to reach under this section

Parties to research agreement to use the latest versions of these documents. For undated reference documents, the latest versions apply to this section.

GB/T 6379.1 measurement methods and results of Accuracy (trueness and precision) - Part 1. General principles and definitions

GB/T 6379.2 measurement methods and results of Accuracy (trueness and precision) - Part 2. Determine the weight of a standard measurement method

The basic method of refolding and reproducibility

GB/T 20066 Steel and iron - Sampling and determination of the chemical composition of the sample with a sample preparation method

Principle 3

Samples with hydrochloric acid - nitric acid dissolution mixed with smoke perchlorate, chromium and niobium acid sufficiently dehydrated, heat soluble salts dissolved in hydrochloric acid

Class, and then ammonia precipitation of iron to nickel, chromium and other element separation. With dilute hydrochloric acid to dissolve the ferric hydroxide, sodium tungstate as indicator, titanium trichloride

The ferric iron is reduced to divalent. Low potassium dichromate with an excess of titanium oxide is expensive. Then to diphenylamine sulfonate as indicator, potassium dichromate

Divalent iron standard solution titration.

4 Reagents and materials

Unless otherwise stated, the analysis using only the confirmation of analytical grade reagents and distilled water or its equivalent purity.