Table I
Operating schedule.
Photographing plate containing nine samples and iron calibration | |
Prespark | 15 sec. | |
Spark exposure | 40 sec. | |
Pre-arc | 5 sec. | |
Arc | 20 sec. | |
|
| |
Total | 80 sec.×9 samples | 12 minutes |
Iron calibration | |
min. |
Loading electrodes and making out necessary legend | |
min. |
Processing and loading plate | | 10 min. |
Reading, calculating and recording plate | | 45 min. |
| |
|
Total man minutes required to analyze 9 samples for 9 elements each | 76 minutes |
Table II
Line pairs used in analysis.
Element | Percentage range | Arc Reference line | Unknown line | Element | Percentage range | Spark Reference line | Unknown line |
---|
Cd | 0.001–0.1 | 2698 Mg or B.G. | 2288 | Al | 0.001–0.1 | 4167 Mg | 3962 Al |
Fe | 0.001–0.05 | 2698 Mg or B.G. | 2483 | | 0.05–2.0 | 3074 Mg | 3082 Al |
Fe | 0.001–0.05 | 2698 Mg or B.G. | 2488 | | 0.4–12.0 | 2736 Mg | 2568 Al |
Ni | 0.001–0.05 | 2698 Mg or B.G. | 3415 | Ca | 0.01–0.50 | 3074 Mg | 3179 Ca |
Pb | 0.001–0.15 | 2698 Mg or B.G. | 2614 | Cd | 0.1–6.0 | 3074 Mg | 3261 Cd |
Pb | 0.01–0.5 | 2698 Mg or B.G. | 2663 | Cu | 0.001–0.3 | 3074 Mg | 3274 Cu |
Sn | 0.001–0.3 | 2698 Mg or B.G. | 3175 | Mn | 0.001–0.01 | 2736 Mg | 2606 Mn |
| | | | Mn | 0.01–0.5 | 3074 Mg | 2950 Mn |
| | | | Mn | 0.3–3.0 | 2736 Mg | 2610 Mn |
| | | | Pb | 0.1–6.0 | 2736 Mg | 2614 Pb |
| | | | Si | 0.01–1.5 | 2736 Mg | 2516 Si |
| | | | Sn | 0.1–6.0 | 3074 Mg | 3034 Sn |
| | | | Zn | 0.01–1.0 | 3074 Mg | 3303 Zn |
| | | | | 0.3–4.0 | 3074 Mg | 3282 Zn |
B.G. = background.
Table III
Chemical and spectrographic determination of the zinc content of porous and non-porous areas of magnesium casting.
Spec. | % Zn (Spect.) | % Zn (Chem.) |
---|
H8259S | 3.2 | 3.02 |
P | 2.6 | 2.80 |
30696–9S | 2.8 | 2.91 |
P | 2.45 | 2.50 |
30696–13S | 2.9 | 2.80 |
P | 2.65 | 2.64 |
Table IV
Composition of porous and non-porous areas.
Spec. | % Al | % Mn | % Zn |
---|
H8550S | 6.2 | 0.13 | 3.0 |
H8550P | 5.8 | .12 | 2.6 |
H8558S | 6.1 | .25 | 3.1 |
H8558P | 5.8 | .25 | 2.6 |
Table V
Spectrographic and chemical analysis of various samples of the same metal cast in different ways.
| | % Al | % Mn | % Zn |
---|
Spec. | Description | Spect. | Chem. | Spect. | Chem. | Spect. | Chem. |
---|
9715 | Chill cast test spec. | 5.9 | 6.1 | 0.29 | 0.30 | 3.0 | 2.96 |
9715-1-A | Ingot section | 6.5 | 6.23 | .20 | .32 | 3.15 | 3.13 |
-1-B | Ingot section | 5.7 | 5.86 | .24 | .31 | 2.9 | 2.41 |
-1-C | Ingot section | 6.3 | 6.17 | .23 | .33 | 3.17 | 3.15 |
-1-D | Ingot section | 5.3 | 5.17 | .29 | .33 | 2.5 | 2.35 |
-T-1 | Chill cast test spec. | 6.2 | 6.13 | .30 | .31 | 3.0 | 3.04 |
-T-2 | Chill cast test spec. | 6.0 | 6.03 | .31 | .31 | 3.0 | 3.13 |
Table VI
Typical precision data.
| % Al | % Cu | % Mn | % Zn |
---|
Composition | 6.3 | 0.023 | 0.22 | 3.36 |
Standard deviation | ±.15 | ±.0013 | ±.01 | ±.12 |
Table VII
Comparison of chemical and spectrographic determinations for aluminum manganese and zinc.
Alloy | Chemical % Al | Spect. % Al | Chemical % Mn | Spect. % Mn | Chemical % Zn | Spect. % Zn |
---|
H785 | 5.6 | 5.6 | 0.229 | 0.22 | 3.0 | 2.9 |
786 | 5.7 | 5.8 | .219 | .22 | 3.0 | 2.9 |
787 | 5.6 | 5.6 | .226 | .21 | 3.0 | 2.8 |
788 | 5.7 | 5.6 | .413 | .40 | 2.9 | 3.1 |
789 | 5.9 | 6.2 | .224 | .21 | 3.1 | 3.2 |
790 | 6.2 | 6.2 | .248 | .25 | 3.1 | 3.2 |
791 | 6.2 | 6.0 | .26 | .25 | 3.0 | 2.9 |
792 | 6.5 | 6.5 | .25 | .26 | 3.2 | 3.1 |
793 | 6.0 | 5.8 | .224 | .21 | 3.0 | 3.2 |
794 | 6.0 | 5.8 | .224 | .21 | 3.2 | 3.3 |
795 | 6.1 | 5.8 | .15 | .17 | 3.1 | 3.1 |
796 | 5.7 | 5.8 | .18 | .17 | 2.6 | 2.6 |
797 | 5.9 | 5.8 | .17 | .17 | 2.6 | 2.4 |
798 | 5.8 | 6.0 | .16 | .16 | 3.4 | 3.4 |
799 | 6.1 | 6.1 | .15 | .15 | 3.5 | 3.5 |
800 | 6.2 | 6.1 | .13 | .14 | 3.4 | 3.5 |
Table VIII
Comparison of chemical and spectrographic determinations for iron.
| % Fe |
---|
| Spectrographic | Chemical |
---|
Sample | A | B | C | D |
---|
5581 | <0.0004 | 0.0009 | 0.0002 | |
5586 | <.0004 | .0009 | .0004 | |
6468 | .002 | .0014 | .0017 | |
6730 | <.0004 | .0007 | .0002 | |
6776 | .0015 | .0012 | .0016 | 0.0021 |
6888 | .0010 | .0010 | .0010 | .0014 |
6896 | .0008 | .0003 | .0006 | |
6897 | .0005 | .0004 | .0006 | |
1199 | .013 | .011 | .013 | |
1204 | .003 | .0035 | .0038 | |
1234 | .005 | .0062 | .0067 | |
720 | .004 | .003 | .0038 | |
721 | .003 | .004 | .0038 | |
A—Original spectrographic value used to certify batch.
B—Check analysis run immediately before sending the electrodes to the chemistry laboratories for analysis.
C—Determined by the
a,
a′ dipyridyl colorimetric method, with the aid of a photoelectric colorimeter.
D—Determined by HBr method, similar to that in A.S.T.M. methods, but with the use of a photoelectric colorimeter and correction for effect of copper.