| ECONOMICS OF ALLOY STEELS | 45 |
|
for carbon steel, both treated and untreated, is 8.5¢ per pound, then referring to Table 5i, we shall have the following: |
Carmol Steel
| 99.68 lbs. steel | @ 8.5¢ = $8.47 |
| 0.32 lb. molybdenum | @ $2.53 = .81 |
| 100.00 lbs. alloy | @ 9.28¢ = $9.28 |
| Excess cost in manufacture and erection, say | @ 1.00 ¢ = 1.00 |
| Total = $10.28 |
|
|
| Working tensile stress for heat-treated steel | = 38,000 lbs. |
| Ditto untreated (assumed) | = 30,000 lbs. |
| Average= 1/3(2 X 30,000 + 38,000) | = 32,700 lbs. |
Carbon Steel
| Working tensile stress for heat-treated steel | = 26,700 lbs. |
| Ditto untreated | = 16,000 lbs. |
| Average= 1/3(2 X 16,000 + 26,700) | = 19,600 lbs. |
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and r r' = 1.21 X 0.6 = 0.726 |
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As this is far lower than any values of r r' given in Figs. 5a and 5b, it is evident that the addition of molybdenum to carbon steel will always effect a large economy. Chromol Steel versus Chrome SteelReferring to Tables 5a and 5b, we have the following: Chromol Steel |
| 98.93 lbs. Steel | @ 8.5¢ = $8.41 |
| 0.76 lb. Chromium | @ 25¢ = .19 |
| 0.31 lb. Molybdenum | @ $2.53 = .78 |
| 100.00 lbs. Alloy | @ 9.38¢ = $9.38 |