PROPERTIES OF ALLOY STEELS
The following table shows the percentages of carbon, manganese, nickel, chromium and vanadium in typical steel alloys for engineering purposes. It also gives the elastic limit, tensile strength, elongation and reduction of area of the various alloys, all being given the same heat treatment with a drawing temperature of 1,100°F. (600°C.). The specimens were one inch rounds machined after heat treatment.
Tungsten is not shown in the table because it is seldom used in engineering construction steels and then usually in combination with chromium. Tungsten is used principally for the magnets of magnetos, to some extent in the manufacture of hacksaws, and for special tool steels.
| Carbon, per cent | Manganese, per cent | Nickel, per cent | Chromium, per cent | Vanadium, per cent | Elastic limit, lb. per sq. in. | Tensile Strength, lb. per sq. in. | Elongation in 2 in., per cent | Reduction of area, per cent |
|---|---|---|---|---|---|---|---|---|
| 0.27 | 0.55 | 49,000 | 80,000 | 30 | 65 | |||
| 0.27 | 0.47 | 0.26 | 66,000 | 98,000 | 25 | 52 | ||
| 0.36 | 0.42 | 58,000 | 90,000 | 27 | 60 | |||
| 0.34 | 0.87 | 0.13 | 82,500 | 103,000 | 22 | 57 | ||
| 0.45 | 0.50 | 65,000 | 96,000 | 22 | 52 | |||
| 0.43 | 0.60 | 0.32 | 96,000 | 122,000 | 21 | 52 | ||
| 0.47 | 0.90 | 0.15 | 102,000 | 127,500 | 23 | 58 | ||
| 0.30 | 0.60 | 3.40 | 75,000 | 105,000 | 25 | 67 | ||
| 0.33 | 0.63 | 3.60 | 0.25 | 118,000 | 142,000 | 17 | 57 | |
| 0.30 | 0.49 | 3.60 | 1.70 | 119,000 | 149,500 | 21 | 60 | |
| 0.25 | 0.47 | 3.47 | 1.60 | 0.15 | 139,000 | 170,000 | 18 | 53 |
| 0.25 | 0.50 | 2.00 | 1.00 | 102,000 | 124,000 | 25 | 70 | |
| 0.38 | 0.30 | 2.08 | 1.16 | 120,000 | 134,000 | 20 | 57 | |
| 0.42 | 0.22 | 2.14 | 1.27 | 0.26 | 145,000 | 161,500 | 16 | 53 |
| 0.36 | 0.61 | 1.46 | 0.64 | 117,600 | 132,500 | 16 | 58 | |
| 0.36 | 0.50 | 1.30 | 0.75 | 0.16 | 140,000 | 157,500 | 17 | 54 |
| 0.30 | 0.50 | 0.80 | 90,000 | 105,000 | 20 | 50 | ||
| 0.23 | 0.58 | 0.82 | 0.17 | 106,000 | 124,000 | 21 | 66 | |
| 0.26 | 0.48 | 0.92 | 0.20 | 112,000 | 137,000 | 20 | 61 | |
| 0.35 | 0.64 | 1.03 | 0.22 | 132,500 | 149,500 | 16 | 54 | |
| 0.50 | 0.92 | 1.02 | 0.20 | 170,000 | 186,000 | 15 | 45 |
NON-SHRINKING, OIL-HARDENING STEELS
Certain steels have a very low rate of expansion and contraction in hardening and are very desirable for test plugs, gages, punches and dies, for milling cutters, taps, reamers, hard steel bushings and similar work.
It is recommended that for forging these steels it be heated slowly and uniformly to a bright red, but not in a direct flame or blast. Harden at a dull red heat, about 1,300°F. A clean coal or coke fire, or a good muffle-gas furnace will give best results. Fish oil is good for quenching although in some cases warm water will give excellent results. The steel should be kept moving in the bath until perfectly cold. Heated and cooled in this way the steel is very tough, takes a good cutting edge and has very little expansion or contraction which makes it desirable for long taps where the accuracy of lead is important.
The composition of these steels is as follows:
| Per cent | |
| Manganese | 1.40 to 1.60 |
| Carbon | 0.80 to 0.90 |
| Vanadium | 0.20 to 0.25 |
FIG. 13.—Effect of copper in steel.