GB/T 223.11-2008 in English

《GB/T 223.11-2008钢铁及合金 铬含量的测定 可视滴定或电位滴定法》由TC183（全国钢标准化技术委员会）归口，TC183SC5（全国钢标准化技术委员会钢铁及合金化学成份测定分会）执行，主管部门为中国钢铁工业协会。
GB/T 223的本部分代替GB/T 223.11-1991《钢铁及合金化学分析方法 过硫酸铵氧化容量法测定铬量》。
本部分此次修订，名称改为《钢铁及合金 铬含量的测定 可视滴定或电位滴定法》。
本部分规定了用可视滴定或电位滴定法测定铬含量。
本部分方法一与GB/T 223.11-1991相比较，主要做了以下修改：
――修改了测定含量范围；
――增加了用理论计算法校正钒干扰的内容；
――增加了分析中对试剂和水的说明内容并修改溶液浓度的表示方法；
――修改了试料量及其表示；
――修改了结果计算式中量的表示并增加了用理论计算法校正钒干扰的计算公式；
――重新组织精密度试验。
本部分方法二修改采用ISO 4937:1986《钢铁 铬含量的测定 电位或可视滴定法》，与ISO 4937:1986相比较，主要做了以下修改：
――仅采用了其中的电位滴定法，技术内容与其一致；
――在“仪器”和对“含钒试样的滴定”中各增加一个注。

1 Scope
This Part of GB/T 223 specifies the determination of chromium content with visual titration or potentiometric titration method.
Method I of this Part is applicable to the determination of chromium content with mass fraction 0.10%~35.00% in pig iron, carbon steel, alloy steel, high-temperature alloy and precision alloy; method II of this Part is applicable to the determination of chromium content with mass fraction 0.25%~35.00% in iron and steel.
2 Normative References
The following standards contain provisions which, through reference in this Part of GB/T 223, constitute provisions of this Part. For dated reference, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, the parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards. For undated references, the latest edition of the normative document referred to applies.

Contents
Foreword i
1 Scope
2 Normative References
3 Method I Visual Titration Method
4 Method II Potentiometric Titration Method
5 Test Report
Annex A (Informative) Method I Source Data of Common Precision Test
Annex B (Informative) Method II Additional Information of International Cooperation Test
Annex C (Informative) Method II Diagram of Precision Data