Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is drafted according to rules given in GB/T 1.1-2009.
This standard supersedes "Standard Test Method for Spark Discharge Atomic Emission Spectrometric Analysis of Carbon and Low-alloy Steel (Routine Method)" (GB/T 4336-2002); compared with the latter, the main technical changes in this standard are as follows:
- The standard name is changed to "Carbon and Low-alloy Steel - Determination of Multi-element Contents - Spark Discharge Atomic Emission Spectrometric Method (Routine Method)";
- The determination scope of each element in Table 1 is modified;
- Documents referred in "Normative References" (Chapter 2) are added;
- The principle description specified in "Principle" (Chapter 3) is modified;
- The description of excitation light source in 4.1 is modified;
- The description of spark chamber in 4.2 is modified;
- The argon purity requirements in 4.3 are modified, and the position of instrument with constant argon pressure and flow is specified;
- The description of electrode in 4.4 is modified;
- The focal length and wave length range in 4.5 are modified;
- The description of photometric system in 4.6 is modified;
- Chapter 6 is changed to "Standard Sample, Standardization Sample and Control Sample" from "Standard Sample and Recalibration Sample", and the description is also modified accordingly;
- "Calibration" (Chapter 8) and its description are added;
- The former Chapter 8 "Analysis Conditions and Analysis Procedures" is changed to Chapter 9, and the description is also modified;
- The former Chapter 10 "Precision" is changed to Chapter 11; the repeatability limit and reproducibility limit formulas of each element are worked out again according to the precision test result;
- "Acceptability of Measuring Result and Determination of Final Report Result" (Chapter 12) is added;
- "Accuracy Judgment for Measuring Result in Laboratory" (Chapter 13) is added;
- "Test Report" (Chapter 14) is added;
- Appendix A and Appendix B (both are informative) are added.
This standard is proposed by China Iron and Steel Association.
This standard is under the jurisdiction of the National Technical Committee on Iron and Steel of Standardization Administration of China (SAC/TC 183).
Drafting organizations of this standard: Central Iron & Steel Research Institute, Baosteel Group Co., Ltd., Wuhan Iron and Steel (Group) Corporation, Angang Steel Company Limited, Shanxi Taigang Stainless Steel Co., Ltd., Hengyang Valin Steel Tube Co. Ltd., Jiugang Steel (group) Co., Ltd., Institute of Metal Research, Chinese Academy of Sciences, National Center For Quality Supervision & Test of Steel Material Products, NCS Testing Technology Co., Ltd., Shimadzu Enterprise Management (China) Co., Ltd., Oxford Instruments (Shanghai) Co., Ltd., Yantai Dongfang Analytical Instruments Co., Ltd. and Focused Photonics (Hangzhou), Inc.
Chief drafting staff of this standard: Cheng Haiming, Jia Yunhai, Luo Qianhua, Shen Ke, Zhang Ye, Yu Yuanjun, Dai Xueqian, Sun Jianjun, Zhao Bin, Ma Hongbo, Guo Dongsheng and Gan Zhengbin.
The previous editions of the standard superseded by this standard are as follows:
- GB/T 4336-1984 and GB/T 4336-2002.
Carbon and Low-alloy Steel - Determination of Multi-element Contents - Spark Discharge Atomic Emission Spectrometric Method (Routine Method)
碳素钢和中低合金钢 多元素含量的测定
火花放电原子发射光谱法(常规法)
1 Scope
This standard specifies the method for determining the contents of carbon, silicon, manganese, phosphorus, sulphur, chromium, nickel, tungsten, molybdenum, vanadium, aluminum, titanium, copper, niobium, cobalt, boron, zirconium, arsenic and tin in carbon and low-alloy steel with the spark discharge atomic emission spectrometric method (routine method).
This standard is applicable to the analysis of as-cast or forged carbon and low-alloy steel samples such as electric furnace, induction furnace, electroslag furnace and converter. See Table 1 for the determination scope of each element.
Table 1 Determination Scope of Each Element
Element Determination scope (mass fraction)/%
C 0.03~1.3
Si 0.17~1.2
Mn 0.07~2.2
P 0.01~0.07
S 0.008~0.05
Cr 0.1~3.0
Ni 0.009~4.2
W 0.06~1.7
Mo 0.03~1.2
V 0.1~0.6
Al 0.03~0.16
Ti 0.015~0.5
Cu 0.02~1.0
Nb 0.02~0.12
Co 0.004~0.3
B 0.000 8~0.011
Zr 0.006~0.07
As 0.004~0.014
Sn 0.006~0.02
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB/T 6379.1 Accuracy (Trueness and Precision) of Measurement Methods and Results - Part 1: General Principles and Definitions
GB/T 6379.2 Accuracy (Trueness and Precision) of Measurement Methods and Results - Part 2: Basic Method for the Determination of Repeatability and Reproducibility of a Standard Measurement Method
GB/T 20066 Steel and Iron - Sampling and Preparation of Samples for the Determination of Chemical Composition
3 Principle
Make the well-prepared block sample discharge with the counter electrode under the action of spark light source to generate plasma in inert atmosphere at high temperature. Where the measured element is excitated, the electron will transit in the atom between different energy levels; the characteristic spectral line will be generated when transiting from high energy level to low energy level; then measure the spectral intensity of characteristic spectral line of the selected analytical element and the internal standard element. Calculate the content of the measured element through calibration curve according to the relation between the spectral line intensity (or intensity ratio) and the concentration of the measured element in sample.
4 Instruments
The spark discharge atomic emission spectrometer is mainly composed of the following units.
4.1 Excitation light source
The excitation light source shall be a stable spark excitation light source.
4.2 Spark chamber
The spark chamber is specially designed for argon, and is directly installed on the spectrometer. It is equipped with an argon flushed spark stand to arrange planar sample and rod counter electrode. The argon gas circuit in spark chamber shall be able to displace the air in the light path between analytical gap and collecting lens, and shall provide argon atmosphere for the analytical gap.
4.3 Argon system
The argon system mainly includes the argon container, two-stage pressure regulator, gas flowmeter and the sequential control part which is able to automatically change the argon flow according to analysis conditions.
The purity and flow of argon have a significant impact on the analysis of measured value; it shall be ensured that the purity of argon shall not be less than 99.995%, otherwise, the argon purification device shall be used, and the pressure and flow of argon in spark chamber shall be maintained constant.
4.4 Counter electrode
Different counter electrodes shall be used for different equipment. Generally, the conical tungsten bar with diameter of 4~8mm and with top processed into 30°~120° or other electrode material is used, and the purity shall be greater than 99%. The flat tip tungsten electrode with diameter of 1mm may also be used. The time for replacing the counter electrode shall be determined by each laboratory according to specific conditions.
4.5 Spectrometer
Generally, the reciprocal of dispersion of first-order spectral line of spectrometer shall be less than 0.6nm/mm, the focal length is within 0.35~1.0m, and the wave length range is 165.0~410.0nm. The vacuum degree of spectrometer shall work blow 3Pa or be filled with high-purity inert gas (such gas does not absorb the spectral line with wave length less than 200nm, and its purity is not lower than 99.999%).
4.6 Photometric system
The photometric system shall include the photoelectric conversion detector receiving signal, the integrating capacitor capable of storing each output electric signal, the measuring unit used for directly or indirectly recording the voltage or frequency on the capacitor, and the necessary circuit switching device provided for the required time sequence.
5 Sampling and Sample Preparation
5.1 Sampling
Sampling and sample preparation shall be in accordance with the requirements of GB/T 20066. During sampling, the analysis sample shall be uniform, and free from shrinkage and crack. During the sampling of as-cast sample, the molten steel shall be injected into the specified mould, the content of deoxidizing agent shall not exceed 0.35% if aluminum deoxidation is adopted; the representative position shall be selected in steel sampling.
5.2 Sample preparation
As for the sample taken out from mould, the sample is generally cut out at the lower 1/3 point in height direction. For the uncut samples, the surface thickness shall be reduced by 1mm. The cutting machine equipped with resin cutting disc and metal-cutting machine tool etc. shall be adopted as the cutting equipment.
The analysis sample shall be sufficient to cover the excitated hole diameter of spark stand, generally, the diameter is required to be greater than 16mm and the thickness be greater than 2mm; the sample surface shall be flat and clean. Grinder, abrasive paper grinding disc or abrasive band grinding machine may be adopted, the miller may also be adopted for processing. Aluminum oxide, zirconium oxide and silicon carbide etc. are adopted as the grinding material. Generally, the particle size of grinding material is 0.25~0.124mm.
The standard sample and analysis sample shall be grinded under the same condition and shall not be overheated.
Note: the selection of different grinding materials may affect the detection of relevant trace elements.
6 Standard Sample, Standardization Sample and Control Sample
6.1 Standard sample
Standard sample is used for plotting calibration curve, of which chemical property and texture structure are similar with those of analysis sample, the content range of analytical element shall be covered and proper gradient shall be maintained, the content of analytical element is valued with accurate and reliable method.
The deviation for analysis result will be generated if improper standard sample series are selected, therefore, adequate attention shall be paid for the selection of standard sample. During the plotting of calibration curve, several standard samples with different analytical element contents are generally adopted as one series, of which composition and smelting processes are better to be similar with those of analysis sample.
6.2 Standardization sample
Variation of instrument conditions will result in deviation of the determination result. In order to directly use the original calibration curve and obtain accurate results, 1~2 samples are used for standardizing the instrument, and such sample is referred to as standardization sample. The standardization sample shall be quite uniform and provided with proper content as required, it may be selected from standard samples and may also be specially smelted. Where two-point standardization is adopted, the contents near the upper limit and lower limit of the calibration curve of each element are respectively taken as its content.
Standardization sample is intended to correct the deviation of calibration curve caused by the measured value of instrument due to various causes, the standardization sample shall be uniform and stable spectral line intensity shall be obtained.
Foreword I
1 Scope
2 Normative References
3 Principle
4 Instruments
5 Sampling and Sample Preparation
6 Standard Sample, Standardization Sample and Control Sample
7 Instrument Preparation
8 Calibration
9 Analysis Conditions and Analysis Procedures
10 Calculation of Analysis Result
11 Precision
12 Acceptability of Measuring Result and Determination of Final Report Result
13 Accuracy Judgment for Measuring Result in Laboratory
14 Test Report
Appendix A (Informative) Additional Information on Precision Experiment
Appendix B (Informative) Precision Data
碳素钢和中低合金钢 多元素含量的测定
火花放电原子发射光谱法(常规法)
1 范围
本标准规定了用火花放电原子发射光谱法(常规法)测定碳素钢和中低合金钢中碳、硅、锰、磷、硫、铬、镍、钨、钼、钒、铝、钛、铜、铌、钴、硼、锆、砷和锡含量的方法。
本标准适用于电炉、感应炉、电渣炉、转炉等铸态或锻轧的碳素钢和中低合金钢样品分析，各元素测定范围见表1。
表1 各元素测定范围
元 素 测定范围(质量分数)/％
C 0.03～1.3
Si 0.17～1.2
Mn 0.07～2.2
P 0.01～0.07
S 0.008～0.05
Cr 0.1～3.0
Ni 0.009～4.2
W 0.06～1.7
Mo 0.03～1.2
V 0.1～0.6
Al 0.03～0.16
Ti 0.015～0.5
Cu 0.02～1.0
Nb 0.02～0.12
Co 0.004～0.3
B 0.000 8～0.011
Zr 0.006～0.07
As 0.004～0.014
Sn 0.006～0.02
2规范性引用文件
下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。
GB/T 6379.1测量方法与结果的准确度(正确度与精密度) 第1部分：总则与定义
GB/T 6379.2测量方法与结果的准确度(正确度与精密度) 第2部分：确定标准测量方法重复性与再现性的基本方法
GB/T 20066钢和铁 化学成分测定用试样的取样和制样方法
3原理
将制备好的块状样品在火花光源的作用下与对电极之间发生放电，在高温和惰性气氛中产生等离子体。被测元素的原子被激发时，电子在原子内不同能级间跃迁，当由高能级向低能级跃迁时产生特征谱线，测量选定的分析元素和内标元素特征谱线的光谱强度。根据样品中被测元素谱线强度(或强度比)与浓度的关系，通过校准曲线计算被测元素的含量。
4仪器
火花放电原子发射光谱仪主要由以下单元组成。
4.1激发光源
激发光源应是一个稳定的火花激发光源。
4.2火花室
火花室是为使用氩气而专门设计的，火花室直接装在分光计上，有一个氩气冲洗火花架，以放置平面样品和棒状对电极。火花室的氩气气路应能置换分析间隙和聚光镜之间光路中的空气，并为分析间隙提供氩气气氛。
4.3氩气系统
氩气系统主要包括氩气容器、两级压力调节器、气体流量计和能够按照分析条件自动改变氩气流量的时序控制部分。
氩气的纯度及流量对分析测量值有很大的影响，应保证氩气的纯度不小于99.995％，否则应使用氩气净化装置，且火花室内氩气的压力和流量应保持恒定。
4.4对电极
不同型号的设备使用不同的对电极。一般使用直径为4 mm～8 mm，顶端加工成30°～120°的圆锥型钨棒或其他电极材料，其纯度应大于99％。也可使用直径为1 mm的平头钨电极。每个实验室根据具体情况确定更换对电极的时间。
4.5分光计
一般分光计的一级光谱线色散的倒数应小于0.6 nm/mm，焦距为0.35 m～1.0 m，波长范围为165.0 nm～410.0 nm，分光计的真空度应在3 Pa以下工作，或充高纯惰性气体(该气体不吸收波长小于200 nm谱线，且纯度不低于99.999％)。
4.6 测光系统
测光系统应包括接收信号的光电转换检测器、能存储每一个输出电信号的积分电容器、直接或间接记录积分器上电压或频率的测量单元和为所需要的时序而提供的必要的开关电路装置。
5取样和样品制备
5.1 取样
按照GB/T 20066的规定取样和制样。取样时应保证取出的分析样品均匀、无缩孔和裂纹。铸态样品取样时，应将钢水注入规定的模具中，用铝脱氧时，脱氧剂含量不应超过0.35％；钢材取样时，应选取具有代表性部位。
5.2样品的制备
从模具中取出的样品，一般在高度方向的下端1/3处截取样品。未经切割的样品，其表面应去掉1 mm的厚度。切割设备采用装有树脂切割片的切割机、金属切削机床等。
分析样品应足够覆盖火花架激发孔径，通常要求直径大于16 mm，厚度大于2 mm，并保证样品表面平整、洁净。研磨设备可采用砂轮机、砂纸磨盘或砂带研磨机，亦可采用铣床等加工。研磨材料有氧化铝、氧化锆和碳化硅等。研磨材质的粒度通常为0.25 mm～0.124 mm。
标准样品和分析样品应在同一条件下研磨，不得过热。
注：选择不同的研磨材料可能对相关的痕量元素检测带来影响。
6标准样品、标准化样品和控制样品
6.1标准样品
标准样品是为绘制校准曲线使用的，其化学性质和组织结构应与分析样品相近似，应涵盖分析元素的含量范围，并保持适当的梯度，分析元素的含量系用准确可靠的方法定值。
选择不适当的标准样品系列会使分析结果产生偏差，因此，对标准样品的选择应充分注意。在绘制校准曲线时，通常使用几个分析元素含量不同的标准样品作为一个系列，其组成和冶炼过程最好与分析样品近似。
6.2标准化样品
由于仪器状态的变化，导致测定结果的偏离，为直接利用原始校准曲线，求出准确结果，用1个～2个样品对仪器进行标准化，这种样品称为标准化样品。该样品应非常均匀并要求有适当的含量，可以从标准样品中选出，也可专门冶炼。当使用两点标准化时，其含量分别取每个元素校准曲线上限和下限附近的含量。
标准化样品是用来修正由于各种原因引起的仪器测量值对校准曲线的偏离，标准化样品应均匀并能得到稳定的谱线强度。
6.3控制样品
控制样品是与分析样品有相似的冶金加工过程、相近的组织结构和化学成分，用于对分析样品测定结果进行校正的均匀样品，可以用于类型标准化修正。
控制样品可通过取自熔融状金属铸模成型或金属成品进行自制；在冶炼控制样品时，应适当规定各元素含量，使各样品的基体成分大致相等；对控制样品赋值时，应注意标准值定值误差以及数据、方法的可溯源性。
7仪器的准备
7.1仪器的存放
光谱仪应按仪器厂家推荐的要求，放置在防震、洁净的实验室中，通常室内温度保持在15℃～30℃，相对湿度应小于80％。在同一个标准化周期内，室内温度变化不超过5℃。
7.2 电源
为保证仪器的稳定性，电源电压变化应小于±10％，频率变化小于±2％，保证交流电源为正弦波。根据仪器使用要求，配备专用地线。
7.3激发光源
为使激发光源电器部分工作稳定，开始工作前应使其有适当的通电时间。
用电压调节器或稳压器设备将供电电压调整到仪器所要求的数值。
7.4对电极
对电极需定期清理、更换并用极距规调整分析间隙的距离，使其保持正常工作状态。
7.5光学系统
聚光镜应定期清理，定期描迹来校正入射狭缝位置。
7.6 测光系统
停机后，重新开机，一般应保证足够的通电时间，使测光系统工作稳定。
通过制作预燃曲线选择分析元素的适当预燃时间。积分时间是以分析精度为基础进行实验确定的。
8 校准
8.1校准曲线法
在所选定的工作条件下，激发一系列标准样品，原则上使用5个水平以上的标准样品，每个样品至少激发3次，绘制分析元素的发光强度(或强度比)与含量(或含量比)的关系曲线作为校准曲线。使用该校准曲线，测量样品中的元素含量。
8.2原始校准曲线法
原始校准曲线法是先使用校准曲线法绘制校准曲线。当光谱仪器因温度、湿度、震动等因素导致谱线产生位移，或因发光强度变化导致校准曲线发生漂移时，通过标准化样品对校准曲线的漂移进行整体标准化修正，使修正后的元素强度恢复到最初建立校准曲线时强度的方法。
8.3控制样品法
由于分析样品与绘制校准曲线的标准样品存在冶炼工艺过程和组织结构的差异，常使校准曲线发生变化。为避免这种差异造成的影响，通常使用与分析样品的冶金工艺过程和组织结构相近的控制样品，用于控制分析样品的分析结果。
首先利用标准样品制作原始校准曲线，在日常分析时，在同样的工作条件下，将控制样品与分析样品同时分析，利用控制样品的分析结果与其标准值之间的偏差对分析样品的分析结果进行修正。
9分析条件和分析步骤
9.1 分析条件
本标准推荐的分析条件见表2，分析线与内标线列入表3中。
表2分析条件
项目 内容
分析间隙 3 mm～6 mm
氩气流量 冲洗：3 L/min～15 L/min
测量：2.5 L/min～10 L/min
静止：0 L/min～1 L/min
预燃时间 3 s～20 s
积分时间 2 s～20 s
放电形式 预燃期间高能放电，积分期间低能放电
表3推荐的内标线和分析线
元素 波长/nm 可能干扰的元素
Fe 187.7(内标线)
271.4(内标线)
273.0(内标线)
287.2(内标线)
C 165.81
193.09
Al、Mo、Co、Cr、W、Mn、Ni
Si 181.69
212.41
251.61
288.16 Ti、V、Mo
C、Nb
Ti、V、Mo、Mn
Mo、Cr、W、Al
Mn 192.12
263.80
293.30
Cr、Si、Mo
P 177.49
178.28 Cu、Mn、Ni
Ni、Cr、Al
S 180.73 Si、Ni、Mn、Cr
表3(续)
元素 波长/nm 可能干扰的元素
Cr 206.54
267.71
286.25
298.91
Mo、V
Si、Ni
V、Mo、Ni
Ni 218.49
227.70
231.60 Cr、Mn
Cr、Mn、Si、Mo
W 202.99
209.86
220.44
400.87
Ti
Al、Ni、V、Cr
Ti、Mn
Mo 202.03
203.84
277.53
281.61
386.41
Mn
Mn、Ni
Mn、V、Si
Mn、V
V 214.09
290.88
310.22
311.07
311.67
Al、Mn、Cr、Ti
Cr、Mn、Nb
Al 186.27
199.05
308.21
394.40
396.15
Si、Cr、V、Mo、Ni
Ni、V、Mo、Cr、Mn
Si、Cr、V、Mo、Ni
Ti 190.86
324.19
334.90
337.28
W
Cu 211.20
212.30
224.26
327.39
337.20
Si、Mn
Cr、Ni、W
Nb、Si、W
Ni、Mo
Nb 210.94
224.20
313.10
319.50
Cu、Ni、V
Ti、Cr、V、Ni、Si
Ti、V、Ni、Cr
表3(续)
元素 波长/nm 可能干扰的元素
Co 228.61
258.03
345.35 Mo、Ni
Mo、Ni、V、W、Ti、Si
B 182.59
182.64 S
Mo、Mn、Ni
Zr 179.00
339.19
343.82
349.62
Cr、Cu、Mo、Ti、Ni
Ni
As 197.26
189.04
228.81
234.98
Cr、W
Sn 189.99
317.51
326.23 Cr、Al、Mn
9.2分析步骤
9.2.1按7.2～7.6的要求准备好仪器。
9.2.2分析工作前，先激发一块样品2次～5次，确认仪器处于最佳工作状态。
9.2.3校准曲线的标准化：在所选定的工作条件下，激发标准化样品，每个样品至少激发3次，对校准曲线进行校正。仪器出现重大改变或原始校准曲线因漂移超出校正范围时，需重新绘制校准曲线。
9.2.4校准曲线的确认：分析被测样品前，先用至少一个标准样品对校准曲线进行确认。在满足第12章规定的测量精密度的基础上，测量结果与认定值之差应满足第13章的要求，否则，应重新进行标准化。
9.2.5必要时，可选择控制样品，用于校正分析样品与绘制工作曲线样品存在的较大差异。
9.2.6按9.2.2选定的工作条件激发分析样品，每个样品至少激发2次(样品激发1次，获得1个独立测量结果；在样品激发点的对面位置再激发1次，获得第2个独立测量结果)。按第12章的要求，判断测量结果的可接受性，并确定最终报告结果。
10分析结果的计算
根据分析线的相对强度(或绝对强度)，从校准曲线上求出分析元素的含量。
待测元素的分析结果，应在校准曲线所用的一系列标准样品的含量范围内。
11精密度
本标准的精密度试验分别在2013年由15个实验室对低合金钢中14元素的11个～22个水平进行测定，以及在2014年由12个实验室对中低合金钢中的5个元素的18个～36个水平进行测定。按照GB/T 6379.1规定的重复性条件下，每个实验室对每个水平的元素含量测定2次。
所用试样列于附录A中表A.1～表A.19。
按照GB/T 6379.2，对得到的结果进行统计处理。各元素的含量与试验结果的重复性限r和再现性限R的函数关系式汇总于表4。
