GB/T 223.67-2008 English PDF (GB/T223.67-2008)

GB/T 223.67-2008: Iron, steel and alloy -- Determination of sulfur content -- Methylene blue spectrophotometric method
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GB/T 223.67-2008
Iron, steel and alloy. Determination of sulfur content. Methylene blue spectrophotometric method
ICS 77.080.01
H11
National Standards of People's Republic of China
GB/T 223.67-2008/ISO 10701..1994
Replacing GB/T 223.67-1989
Steel and alloy - Determination of sulfur content
Methylene blue spectrophotometry
(ISO 10701..1994, IDT)
2008-05-13 released
2008-11-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China
China National Standardization Administration released
Foreword
This part of GB/T 223 is equivalent to ISO 10701..1994 "Determination of sulfur content of steel and alloy Methylene blue spectrophotometric
law".
This section is equivalent translation ISO 10701..1994.
For ease of use, this section made the following editorial changes.
a) Replace the word "international standard" with "this part";
b) Use the decimal point "." instead of the decimal point ",";
c) Delete the preface to the International Standard.
This Part Replaces GB/T 223.67-1989 "Methods for chemical analysis of iron, steel and alloy - The reductive distillation - Methylene blue spectrophotometric method for the determination of sulfur
Quantity ", compared with the main changes made to the following.
--- Determination range from 0.001% to 0.030% adjusted to 0.0003% ~ 0.01%;
--- "Use bromine to make sulfur oxidation, and evaporate to drive nitric acid" to "use perchloric acid to smoke and drive away nitric acid";
--- The amount of sample is adjusted from 1.0000g to 0.50g and 1.0g respectively according to the content difference;
--- Distillation and purification devices have been changed.
This part of Appendix A, Appendix B are informative appendix.
This part is proposed by China Iron and Steel Association.
This part of the National Standardization Technical Committee Iron and Steel centralized.
This section mainly drafted by. China Steel Research Technology Corporation.
The main drafters of this section. Yang Guixiang, Teng Xuan.
This part of the standard replaces the previous editions are.
GB 223.2 (three) -1981, GB 223.67-1989.
GB/T 223.67-2008/ISO 10701..1994
Steel and alloy - Determination of sulfur content
Methylene blue spectrophotometry
Warning. Personnel using this section should have practical experience in formal laboratory work. This section does not indicate all possible security issues. Make
It is the user's responsibility to take appropriate safety and health measures and to ensure compliance with the requirements of the relevant state laws and regulations.
1 range
GB/T 223 provisions of this part of the Methylene blue spectrophotometric determination of sulfur content in steel and alloy.
This section applies to steel and alloy mass fraction of 0.0003% ~ 0.01% sulfur content determination. Niobium, Silicon, Tantalum and Titanium to Sulfur
Determination of interference. According to the content of interfering elements, the applicable range and the amount of sample are given in Table 1.
Table 1
Interference elements of the maximum allowable content (mass fraction) /%
Nb Si Ta Ti
The amount of sample
Application (mass fraction) /%
0.5 1.0 0.3 1.0 1.0 0.0003 ~ 0.0010
1.0 2.0 0.6 2.0 0.50 0.0010 ~ 0.010
2 Normative references
The following documents contain provisions which, through reference in this Part of GB/T 223, become the provisions of this section. Any reference to the date of the citation
All subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouraged to be reached under this section
The parties to the agreement study whether the latest versions of these documents are available. For undated references, the latest version applies to this book
section.
ISO 377-2. 1989 Selection and preparation of test specimens for sample and forged steels - Part 2. Samples for determination of chemical composition
ISO 385-1. 1984 Laboratory glassware burets - Part 1. Basic requirements
Laboratory glassware Monoscript pipettes
ISO 1042. 1983 Laboratory glassware single standard line volumetric flask
ISO 3696. 1987 Analysis of laboratory water specifications and test methods
ISO 5725. 1986 Precision of measurement methods - Repeatability and reproducibility of standard measurement methods are determined by interlaboratory tests
3 principle
The sample is dissolved in a mixed acid of hydrochloric acid and nitric acid, evaporated to white smoke with perchloric acid to drive off hydrochloric acid and nitric acid. Dissolved salt with hydrochloric acid to hydrogen
A mixture of iodic acid and hypophosphorous acid was used as a reducing agent, and hydrogen sulfide generated under a stream of nitrogen was distilled and taken up in a zinc acetate solution. Through with N,
N-dimethyl-p-phenylenediamine solution and the ferric solution to produce methine blue. Absorbance was measured at a wavelength of 665 nm.
4 reagent
Unless otherwise stated, use only analytical reagents of very low sulfur content, approved analytical reagents and newly prepared ISO 3696
Level 2 water.
4.1 Hydrochloric acid, p approximately 1.19 g/mL.
4.2 hydrochloric acid, ρ about 1.19g/mL, diluted to 1 +15.
4.3 perchloric acid, ρ about 1.54g/mL.
GB/T 223.67-2008/ISO 10701..1994
4.4 hydrobromic acid, p about 1.48 g/mL.
4.5 hydrochloric acid - nitric acid mixed acid. Mix 1 volume of hydrochloric acid (4.1) with 1 volume of nitric acid (ρ of about 1.40/mL) and prepare beforehand.
4.6 Reducing agent solution..200 mL of hydriodic acid [about 57% (mass fraction)] and 50 mL of hypophosphorous acid [about 50% (mass fraction)] were transferred
Into the purification device (see Figure 1). Flush with nitrogen at a flow rate of 100 mL/min for 10 min to mix the acid and expel the air from the system.
Open the heating mantle, heat to boiling, and then keep slightly boiled for about 120 min at a temperature of about 115 ° C in a stream of nitrogen. After purification (see
10.3), turn off the heating cover. The solution is then cooled and stored in a brown bottle.
Figure 1 reduction solution purification device diagram
4.7 Absorption solution. 5g of zinc acetate dihydrate [(CH3COO) 2Zn · 2H2O] was dissolved in 400mL of water,.200mL of hydrogen peroxide
Sodium solution (30g/L) and 70g of ammonium chloride, then diluted with water to 1000mL, and mix.
4.8 iron solution, 10g/L. Weigh 1.00g sulfur-free pure iron, transferred to a 300mL beaker, add 20mL hydrochloric acid (ρ about
1.19g/mL, diluted to 1 + 1), covered with a watch glass, heated to dissolve, and slightly boiled for about 10min. Then, 2mL of nitric acid was added dropwise (ρ approx
1.40 g/mL) so that the iron is oxidized. Boil to drive nitrogen oxides, cooled to room temperature. Transfer to 100mL single-labeled volumetric flask, diluted with water
To the mark, mix well.
4.9 Ferric chloride solution. 1g of ferric chloride hexahydrate (FeCl3 · 6H2O) was dissolved in about 40mL of water, 10mL of hydrochloric acid was added
(4.1), diluted with water to 100mL, mix well.
GB/T 223.67-2008/ISO 10701..1994
4.10 N, N-dimethyl-p-phenylenediamine solution, hydrochloric acid medium. 0.5 g of N, N-dimethyl-p-phenylenediamine hydrochloride [NH2C6H4N
(CH3) 2 · 2HCl] dissolved in about 100mL water, add 230mL hydrochloric acid (4.1), diluted with water to 500mL, and mix.
4.11 sulfur standard solution
4.11.1 sulfur stock solution, equivalent to 1g sulfur per liter. Weigh pre-dried at 110 ℃ 2h, and cooled to room temperature in a desiccator of potassium sulfate
5.4352g [purity ≥ 99.5% (mass fraction)], dissolved in water, quantitative transferred to 1000mL single-labeled line volumetric flask, diluted to the mark, mixed
uniform. This stock solution 1mL contains 1mg sulfur.
4.11.2 sulfur standard solution A, equivalent to 10mg sulfur per liter. Pipette 10.00mL sulfur stock solution (4.11.1) placed in 1000mL single standard
Line capacity bottle, diluted with water to the mark, mix well. 1 mL of this solution contains 10 μg sulfur.
4.11.3 sulfur standard solution B, equivalent to 1mg sulfur per liter. Pipette 10mL standard solution (4.11.2) placed 100mL single standard line capacity
Bottle, diluted with water to the mark, mix well. Prepared before use. 1 mL of this solution contains 1 μg sulfur.
4.12 nitrogen.
5 device
All glass feelers shall comply with Class A of ISO 385-1, ISO 648 or ISO 1042.
Normal laboratory equipment and the following instruments are used.
5.1 reductive distillation unit in millimeters
Figure 2 reduction distillation unit diagram
Assemble the reductive distillation unit as shown in Fig. 2, all using a close-to-ground glass interface. If this unit is used for the first time, or for a long time no
Use, blank test should be repeated until a stable low blank value.
GB/T 223.67-2008/ISO 10701..1994
5.1.1 decomposition flask, the volume of about 300mL.
5.1.2 reflux condenser, about 150mm.
5.1.3 gas cylinder, the volume of about 150mL.
5.1.4 Absorption bottle, 20mL or 100mL single-labeled volumetric flask.
5.2 spectrophotometer, absorbance can be measured at a wavelength of 665nm.
6 take samples
Take sample according to ISO 377-2 or the appropriate national standard of steel.
7 operating procedures
Warning. Perchloric acid vapor can cause explosions when ammonia, nitrous acid smoke or organic matter are present.
7.1 Sample
According to the estimated sulfur content, weighed sample, accurate to 1mg.
a) Sulfur content (mass fraction) is 0.0003% to 0.0010%, and the amount of sample is about 1.00 g.
b) sulfur content (mass fraction) is 0.0010% ~ 0.010%, the amount of sample is about 0.50g.
7.2 blank test
Follow the same procedure using the same amount of all reagents and perform a blank test parallel to the sample. Recommended. For the sulfur content (mass points
) Is less than 0.001%, the blank value should not exceed 0.7μg of sulfur. For the sulfur content (mass fraction) of 0.001% to 0.010%, the blank
The value should not exceed 1.5 μg of sulfur.
7.3 Determination
7.3.1 Preparation of test solution
7.3.1.1 Place the sample (7.1) in a disintegration flask (5.1.1) and add 15 mL hydrochloric acid-nitric acid mixed acid (4.5). Place at room temperature
After 30 min, heat gently until the dissolution reaction has stopped.
7.3.1.2 Pipette 5.0mL perchloric acid (4.3) and 1.0mL iron solution (4.8), heated to evaporate until white smoke appears. After cooling,
Add 5 mL hydrochloric acid (4.1). (For a possible modification of this step, see 9.) Heat again to smoke on a hot plate at about 300 ° C. Of course
After continued evaporation of perchlorate white smoke to make do.
7.3.1.3 Remove the cooling, add 10mL hydrochloric acid (4.1), heated to dissolve salts, cooled to room temperature.
7.3.2 Reduced distillation
Add 20 mL reducing agent solution (4.6) to the disintegration flask (5.1.1) and allow to stand for 10 min. Add 30mL of water to the scrubbing flask, root
Depending on the sulfur content to be tested, place an appropriate volume of absorbent solution (4.7) in the absorbent container (5.1.4) as follows.
a) The content of sulfur (mass fraction) is less than 0.0010%. Add 10mL absorption solution (4.7) into 20mL absorption bottle.
b) The content of sulfur (mass fraction) is 0.0010% ~ 0.010%, add 50mL absorption solution (4.7) in 100mL absorption
Bottle
Water was introduced into the condenser and connected to a decomposition flask (5.1.1) equipped with a test solution. Nitrogen was passed into the apparatus at a flow rate of 100 mL/min, as shown in the figure
2 shows. The test solution was heated to 114 ℃ ~ 118 ℃ for 30min. This can usually be done by setting the hotplate temperature to 250 ° C (see 10.2)
To be done. The generated gas is carried by the nitrogen carrier gas into the absorption bottle through the scrubber.
7.3.3 color
7.3.3.1 Sulfur content (mass fraction) less than or equal to 0.0010%
Remove 20 mL of the absorbent bottle (5.1.4) and the gas inlet tube from the device. The tube of liquid droplets into the absorption solution, with a trace amount of migration
Dispenser Add 1.0 mL of hydrochloric acid (4.2) from the upper end of the tube to the inner surface of the tube and rinse with 1 mL of water.
Remove the gas inlet tube, gently swirl the 20 mL absorption bottle and place in a thermostat at 25 ° C for 20 min. Then in the absorption bottle
(5.1.4) Add 2.0 mL N, N-dimethyl-p-phenylenediamine solution (4.10) and shake gently. Immediately add 0.4mL ferric chloride solution
(4.9), intense shaking 1min. Dilute to the mark with water and mix well. Place 15min.
GB/T 223.67-2008/ISO 10701..1994
7.3.3.2 sulfur content (mass fraction) of 0.0010% ~ 0.010%
Remove 100 mL of the absorbent bottle (5.1.4) and the gas inlet tube from the device. The tube of liquid droplets into the absorption solution, with a trace amount of migration
Add 1.0 mL of hydrochloric acid (4.2) from the upper end of the tube to the inner surface of the tube and rinse with 1 mL or 2 mL of water.
Remove the gas inlet tube and gently swirl the 100 mL absorption bottle and place in a thermostat at 25 ° C for 20 min. Then in the absorption bottle
(5.1.4) 10.0 mL N, N-dimethyl-p-phenylenediamine solution (4.10) was added and shaken gently. Immediately added 2.0mL ferric chloride solution
(4.9), intense shaking 1min. Dilute to the mark with water and mix well. Place 15min.
7.3.4 Spectrophotometric measurement
After zeroing the spectrophotometer (5.2) with water as reference, a 1 cm dish was used and spectrophotometry was performed at a wavelength of 665 nm.
7.4 Calibration curve establishment
7.4.1 Preparation of calibration solution
1.0mL iron solution (4.8) were placed in six decomposition flask (5.1.1), according to Table 2 were added to the corresponding volume of sulfur standard solution
liquid. Then add 15mL hydrochloric acid - nitric acid mixed acid (4.5), 5.0mL perchloric acid (4.3), heated to smoke. The following press 7.3.1.2
To 7.3.3.
Table 2
Sulfur content (mass fraction) /% Volume of sulfur standard solution A (4.11.2)/mL Volume of sulfur standard solution B (4.11.3)/mL Mass of corresponding sulfur/μg
Less than or equal to 0.0010
0a
1.0
3.0
5.0
7.5
10.0
1.0
3.0
5.0
7.5
10.0