Determination of Mn, P, Si, Cr, Ni, Cu, Mo, Ti, V in alloy steel

Determination of Mn, P, Si, Cr, Ni, Cu, Mo, Ti, V in alloy steel

Determination of Mn: Ammonium persulfate oxidation photometric method

Reagents:

1. Silver nitrate solution (0.2%): 1g AgNO3 dissolved in 500 ml 1 + 4 HNO3, shake well.

2. Ammonium persulfate: 10%

Analysis operation:

Weigh the sample (0.3-0.8%, 60mg,) (0.9-2.1%, 40mg) in a 100ml steel measuring flask, add 10ml AgNO3, after heating and dissolve, add 10ml ammonium persulfate, boil for 30S, take the water and cool to room temperature After constant volume, shake it, use water as reference, at 530nm, 2cm cuvette.

Determination of Si: silicon molybdenum blue photometric method

Reagents:

1. Nitric acid 1 + 4

2. Potassium permanganate: 2%

3. Oxalic acid: 2.5%

4. Ammonium ferrous sulfate: 1.5%

5. Alkaline ammonium molybdate: 9% ammonium molybdate solution and 18% potassium carbonate solution are mixed in equal volume and shake well

Analysis operation:

Weigh the sample (0.05—0.5% 50mg, 0.5—1.0% 30 mg), add 10mlHNO3 in a 100ml steel measuring flask, dissolve it after heating, add 2 drops of KMNO4, shake well, boil, add 10ml basic molybdenum while hot Ammonium acid, shake 10S, add 40ml of oxalic acid, 40ml of ammonium ferrous sulfate, dilute to volume with water, shake well, the reference solution is the same as above. However, after dissolving the sample, oxalic acid is added first, followed by ammonium molybdate, and the rest is operated with the color developing solution. At 680 nm, the reference solution is “full”.

Determination of phosphorus: phosphorus bismuth molybdenum blue photometric method

Reagents:

1. Bismuth nitrate solution (1%): formulated with 1 + 3 nitric acid.

2. Potassium permanganate: 4%

3. Ascorbic acid (2%): formulated with 1 + 1 ethanol.