This standard specifies the method for determining chromium and nickel-chromium-iron alloys by the perchloric acid dehydration gravimetric method. This standard is applicable to the determination of silicon content in nickel-chromium and nickel-chromium-iron alloys. Determination range: 0.50% to 2.00%. JB/T 6326.3-1992 Chemical analysis method for nickel-chromium and nickel-chromium-iron alloys Determination of silicon content by the perchloric acid dehydration gravimetric method JB/T6326.3-1992 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T6326.3-1992
Chemical analysis method for nickel-chromium and nickel-chromium-iron alloys Determination of silicon content by perchloric acid dehydration gravimetric method
Published on June 26, 1992
Implementation by the Ministry of Machinery and Electronics Industry of the People's Republic of China on January 1, 1993
Mechanical Industry Standard of the People's Republic of China
Chemical analysis method for nickel-chromium and nickel-chromium-iron alloys Determination of silicon content by perchloric acid dehydration gravimetric method
Subject content and scope of application
This standard specifies the method for determining silicon content in nickel-chromium and nickel-chromium-iron alloys by perchloric acid dehydration gravimetric method. JB/T6326.31992
This standard is applicable to the determination of silicon content in nickel-chromium and nickel-chromium-iron alloys. Determination range: 0.50% to 2.00%. 2 Reference Standards
GB1467 General Principles and General Provisions for Chemical Analysis Methods of Metallurgical Products 3 Summary of Methods
The sample is dissolved in acid and dehydrated with perchloric acid fumes, filtered, burned to generate silicon dioxide, and sulfuric acid-hydrofluoric acid is added to generate silicon tetrafluoride and volatilized and removed. The percentage of silicon is calculated from the mass difference before and after hydrofluoric acid treatment. 4 Reagents
4.1 Hydrochloric acid (density pl.19g/ml).
4.2 Nitric acid (density pl.42g/ml).
4.3 Perchloric acid (density pl.67g/ml). 4.4 Hydrofluoric acid (density pl.15g/ml).
Sulfuric acid (density pl.84g/m1).
Hydrochloric acid-nitric acid mixture: hydrochloric acid (4.1) + nitric acid (4.2) + water (1+1+1). 4.6
Sulfuric acid (1+99).
Sulfuric acid (1+1),
Analysis steps
5.1 Sample amount
Weigh 1.0000g of sample
Blank test
Perform a blank test together with the sample,
5.3 Determination
5.3.1 Place the sample in a 250ml smooth beaker, add 20~30ml of hydrochloric acid-nitric acid mixture (4.6), cover with a watch glass, heat at low temperature until the sample is completely dissolved, cool slightly, add 25ml of perchloric acid (4.3), heat and evaporate until smoke appears, cover with watch glass and continue to heat until white smoke of perfluoric acid refluxes for 25min, remove and cool slightly, add 100ml of hot water, stir, then heat to dissolve the salt, and immediately filter with quantitative medium-speed filter paper Filter, wipe the silica attached to the beaker with a glass rod with a rubber head, wash the precipitate and filter paper ten times with sulfuric acid (4.7), and then wash it three times with hot water. 5.3.2 Place the precipitate and filter paper in a platinum crucible, dry and ash, burn in a high-temperature furnace at 1000°C for 30 minutes, take it out and place it in a desiccator, cool to room temperature, weigh it, and burn it again until constant weight. Approved by the Ministry of Machinery and Electronics Industry on June 26, 1992, implemented on January 1, 1993
JB/T6326.31992
5.3.3 Add 45 drops of sulfuric acid (4.8) along the inner wall to wet the precipitate, add 3ml of hydrofluoric acid (4.4), heat at low temperature until sulfuric acid smoke is completely emitted, and then place the platinum crucible in a high-temperature furnace at 1000°C and burn it to constant weight. Calculation of analysis results
Calculate the percentage of silicon according to the following formula.
(m;-m;一m,)X0. 4674 ×100
si(%)=
Wherein,:
Mass of platinum clamp and precipitate before hydrofluoric acid treatment, 8Mass of platinum clamp and residue after hydrofluoric acid treatment, g: m
mMass of accompanying sample blank, g;
Sample volume, g:
Allowable difference
-Coefficient of silicon dioxide conversion to silicon,Www.bzxZ.net
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. Table
Silicon content
0.50~1.00
>1.00~2.00
Additional remarks:
This standard was proposed and managed by Shanghai Electric Science Research Institute of the Ministry of Machinery and Electronics Industry. This standard was drafted by Shanghai Materials Research Institute of the Ministry of Machinery and Electronics Industry. The main drafters of this standard are Zhu Fuqi and Fan Yi. 2
Allowable difference
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