ISO 4941:1994 PDF

Name: ISO 4941:1994 — Steel and iron — Determination of molybdenum content — Thiocyanate spectrophotometric method
SKU: ISO 4941:1994
Price: 25 EUR
Availability: InStock

Steel and iron — Determination of molybdenum content — Thiocyanate spectrophotometric method

Название (английский):

ISO 4941:1994

Steel and iron — Determination of molybdenum content — Thiocyanate spectrophotometric method

Статус документа:: Отменён
Формат:: Электронный (PDF)
Количество страниц:: 8
Дата публикации:: 22 декабря 1994 г.
Издание:: ISO IS 4941 edition 2 version 1
ICS:: 77.080.01

Тип поставки:

Full version120 €Read online 24h10 €Read online 72h15 €

Язык документа:

ruen

Срок поставки:2 раб. дн. (перевод)

Цена:120 €

Описание (английский):

Cancels and replaces the first edition (1978). Specifies a thiocyanate spectrophotometric method for the determination of the molybdenum content in steel and iron. Applicable to molybdenum contents between 0,005 % (m/m) and 0,125 % (m/m). Vanadium and tungsten interfere with the measurement if, because of their contents, the V/Mo ratio is greater than 16 or the W/Mo ratio is greater than 8.

Abstract

Похожие стандарты

Стандарты, упомянутые в описании

Overview

ISO 4941:1994 specifies a validated analytical procedure - the thiocyanate spectrophotometric method - for the determination of molybdenum (Mo) content in steel and iron. This second edition (1994) replaces the 1978 version and is applicable to Mo contents from 0.005 % (m/m) to 0.125 % (m/m). The method produces a coloured molybdenum–thiocyanate complex that is extracted and measured spectrophotometrically at about 470 nm.

Key topics and technical requirements

Scope and limits

Applicable Mo range: 0.005–0.125 % (m/m). The upper limit was reduced from the earlier edition because precision criteria were not met at higher concentrations.

Analytical principle

Dissolution of the test portion (acid digestion and carbide oxidation), formation of a molybdenum–thiocyanate coloured complex in the presence of iron(II) and/or copper(II) and extraction into butyl acetate.
Spectrophotometric measurement at ~470 nm using 1 cm or 2 cm optical path cells (use 2 cm for Mo <0.025 % and 1 cm for Mo >0.025 %).

Reagents and apparatus

Specified reagent grades (concentrated acids, ammonium thiocyanate, L-ascorbic acid, copper(II) solution, tin(II) copper chloride) and class A volumetric glassware.
Required apparatus includes a separating funnel, spectrophotometer, and matched optical cells.

Calibration and calculation

Use calibration graph of absorbance versus Mo concentration (μg/mL). The standard gives equations and a formula to convert measured absorbance into % Mo.

Interferences and timing

Vanadium (V) and tungsten (W) interfere if V/Mo > 16 or W/Mo > 8. Higher ratios may be tolerated only if the measurement is performed quickly after extraction (within ~30 minutes).

Precision

Precision data (repeatability and reproducibility) are provided following ISO 5725 methodology; example values: at 0.01 % Mo r ≈ 0.0008, R ≈ 0.0023.

Applications and users

Practical uses:

Quality control and chemical analysis in steelworks and iron foundries.
Materials testing laboratories, certification bodies and third‑party analytical services verifying Mo alloying levels.
Research and development in metallurgy and process optimization where trace Mo quantification is required.

Primary users:

Metallurgical analysts, analytical chemists, laboratory managers in the steel industry, and conformity assessment laboratories.

Related standards

ISO 5725 - precision of test methods (repeatability/reproducibility)

ISO 3696 - water for analytical laboratory use

ISO 377-2 - sampling of wrought steels

ISO 4800, ISO 1042, ISO 648 - laboratory glassware specifications

Keywords: ISO 4941, molybdenum determination, thiocyanate spectrophotometric method, steel analysis, Mo content, spectrophotometry, analytical standard, vanadium interference, tungsten interference.

ISO 4941:1994 PDF

Abstract

Похожие стандарты

Overview

Key topics and technical requirements

Applications and users

Related standards

Технические детали

ISO 5725-6:1994/Cor 1:2001

Accuracy (trueness and precision) of measurement methods and results — Part 6: Use in practice of accuracy va…

SIST EN ISO 3696:1998

Water for analytical laboratory use - Specification and test methods (ISO 3696:1987)

SIST EN ISO 377:2017/A1:2025

Steel and steel products - Location and preparation of samples and test pieces for mechanical testing - Amend…

SIST ISO 4800:2002

Laboratory glassware -- Separating funnels and dropping funnels

BS EN ISO 10427-1:2024

Oil and gas industries including lower carbon energy. Equipment for well cementing. Casing bow-spring central…

ISO 6487:2015/Amd 1:2017

Road vehicles — Measurement techniques in impact tests — Instrumentation — Amendment 1

ISO 4941:1978

Steels and cast irons — Determination of molybdenum content — Photometric method