This standard is applicable to the determination of aluminum content in nickel-based alloy powder. Determination range: 0.05% to 1.00%. This standard complies with GB 1467-78 "General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products". GB/T 8638.2-1988 Chemical analysis method for nickel-based alloy powder - Determination of aluminum content by chrome azurol S spectrophotometry GB/T8638.2-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method for nickel-based alloy powder
Determination of aluminium content-Chromeazurol Sspectrophotometriemethod
Nickel base alloy powder-- Determination of aluminium content-Chromeazurol Sspectrophotometriemethod This standard is applicable to the determination of aluminium content in nickel-based alloy powder. Determination range: 0.05% to 1.00%. UDC 669.245-492.2
GB 8638.288
This standard complies with GB1467-78 "General Principles and General Provisions for Chemical Analysis Methods of Metallurgical Products" 1 Method Summary
The sample is dissolved in acid. In a weakly acidic medium of pH 5.3 to 5.9, aluminium and chromeazurol S form a purple-red complex, and its absorbance is measured at a wavelength of 545nm on a spectrophotometer.
100ug vanadium and 2mg chromium in the colorimetric solution do not interfere with the determination. The interference of iron and nickel can be masked by Zn-EDTA, and 300ug titanium can be masked by 0.15g mannitol. bZxz.net
2 Reagents
2.1 Hydrochloric acid (pl.19g/mL).
2.2 Nitric acid (μ1.42g/mL).
2.3 Perchloric acid (pl1.67g/mL).
2.4 Hydrofluoric acid (p1.15g/mL).
2.5 Ammonium hydroxide (p0.90g/mL).
2.6 Hydrochloric acid (1+1).
2.7 Hydrochloric acid (5+95).
2.8 Mannitol solution (5%).
2.9 Hexamethylenetetramine solution (40%). 2.10 Ammonium fluoride solution (0.5%): Store in a plastic bottle. 2.11
Chrome azure S solution (0.05%).
2.12 Disodium zinc ethylenediaminetetraacetate (Zn-EDTA) solution: Weigh 8.1g zinc oxide into a beaker. Add 40mL hydrochloric acid (2.6) and heat to dissolve. Weigh 37.2g disodium ethylenediaminetetraacetate (EDTA) and dissolve it in 800mL water, add 15ml ammonium hydroxide (2.5), combine the net solutions, mix well, adjust the solution to pH 4-6 with ammonium hydroxide (2.5) and hydrochloric acid (2.6), dilute to 1L with water, and stir. 2.13 Iron solution: Weigh 1.00g pure iron into a 300mL beaker, dissolve it with 30mL hydrochloric acid (2.6), transfer it to a 100mL volumetric flask, dilute to the mark with water, and mix well.
2.14 Nickel solution: weigh 1.00g pure nickel and place it in a 300mL beaker, dissolve it with 20mL nitric acid (1+3), transfer it to a 100mL volumetric flask, dilute it with water to the mark, and mix it. 2.15 Aluminum standard storage solution: weigh 0.1000g pure aluminum and place it in a 200mL plastic cup, add 10mL sodium hydroxide solution (20%), heat it in a water bath to dissolve, add 100mL water, add hydrochloric acid (2.6) dropwise until the solution is acidic, then add 10mL, cool it, transfer it to a 1000ml volumetric flask, dilute it with water to the mark, and mix it. 1mL of this solution contains 100ug aluminum. China Nonferrous Metals Industry Corporation approved on January 11, 1988 370
implemented on January 1, 1989
GB8638.2--88
2.16 Aluminum standard solution: Pipette 50.00mL of aluminum standard storage solution (2.15) into a 1000mL volumetric flask, dilute to scale with water, and mix with a spoon. 1mL of this solution contains 5μg aluminum. 3 Instruments
Spectrophotometer.
4 Analysis steps
Number of determinations
Measure twice in parallel and take the average value.
4.2 Sample quantity
Weigh 0.1000g of sample.
4.3 Determination
4.3.1 Place the sample (4.2) in a polytetrafluoroethylene beaker, add 15mL hydrochloric acid (2.1) and 2mL nitric acid (2.2), and heat to dissolve [for poorly soluble samples, hydrofluoric acid (2.4) can be added to assist dissolution]. Add 5mL perchloric acid (2.3) and heat to evaporate until smoke appears. After removing all the hydrofluoric acid, transfer it to a 200mL teflon beaker, heat to produce perchloric acid smoke to oxidize chromium, and add hydrochloric acid (2.1) to drive out the chromium. 4.3.2 Control the volume of the remaining solution to 1-1.5mL, cool it slightly, add 30mL water, heat to dissolve the salts, cool it to room temperature, transfer it to a 100mL volumetric flask, dilute it to the mark with water, and mix it well. 4.3.3 Take two portions of 2.50~10.00mL of the test solution (4.3.2) and place them in 50mL volumetric flasks respectively (samples containing tungsten, etc. must wait until the solution is clear or dry-filtered with filter paper before taking them out). The following shall be carried out according to 4.3.4 and 4.3.5 respectively. 4.3.4 Color developing solution: add 5mL of mannitol solution (2.8) to the solution (mannitol solution may not be added to samples not containing titanium). 5.0ml of hydrochloric acid (2.7), 5mL of Zn-EDTA solution (2.12), and 5mL of hexamethylenetetramine solution (2.9). (Mix each reagent after adding it). Immediately add 4.0mL of chrome azuro blue S solution (2.11) and mix well. Dilute to the mark with water and mix well. 4.3.5 Reference solution: add 1mL of ammonium fluoride solution (2.10) to the solution and mix well. The following shall be carried out according to 4.3.4. 4.3.6
After standing for 20 minutes, transfer the above two solutions into 2cm colorimetric III respectively, and measure the absorbance at 545nm wavelength on a spectrophotometer with reference solution (4.3.5) as reference, and find out the amount of aluminum from the working curve. 4.4 Drawing of working curve
4.4.1 According to the content of the main components (iron and nickel) of the sample, transfer appropriate amounts of iron solution (2.13) and nickel solution (2.11) into a 200mL beaker, add 5mL perchloric acid (2.3), heat and evaporate until smoking, and proceed as in 4.3.2. Take seven portions of the same amount of solution as the test solution (4.3.3) and place them in a group of 50mL volumetric flasks. Add 0, 1.00, 2.00, 3.00, 4.00, and 5.00mL of aluminum standard solution (2.16) to six portions respectively, and proceed as per 4.3.4; proceed as per 4.3.5 to the other portion. After 20 minutes of placement, transfer the colorimetric solution and the reference solution into a 2cm colorimetric IIIl, and measure the absorbance at a wavelength of 545nm using the reference solution as the reference. Draw a working curve with the aluminum content as the horizontal axis and the absorbance as the vertical axis.
5 Calculation of analysis results
Calculate the percentage of aluminum according to formula (1):
Wherein: m.-
Al(%) - m:V.X10--
mo·V,
The amount of aluminum found from the working curve, ug; the volume of the sample solution transferred, mL;
V. …The total volume of the sample solution, mL;
mThe sample weight, g.
6 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 1. -X100
（1）
Additional Notes:
Aluminum Content
0.0500.100
>0.10 ~~ 0.50
>0.50~1.00
This standard was drafted by the Iron and Steel Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by the Iron and Steel Research Institute of the Ministry of Metallurgical Industry. The main drafters of this standard are Yang Qiuping and Zhou Rong. 372
Allowable Difference
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