REMARKABLE STEEL ALLOY

Dominion, Volume 9, Issue 2686, 4 February 1916, Page 6

REMARKABLE STEEL ALLOY

A remarkable steel alloy was described in a paper read by Mr. John Younger beforo the American Society of Engineers. Some trouble had been experienced with heavy motor truck axles, though the metal, when tested, had given an elastic limit of 90,0001b., and a tensile strength of 105,0001b. per square inch. The steel oontained .2 per cent, of carbon, 4 per cent, of nickel, 1.5 per cent; of chromium, and .3 per cent of manganese. A new alloy was prepared with a carbon content of .3 per cent., and with the mangoneso increased to .5 per cent. No change was made in the chromium percentage, but the nickel was reduced to 3.5 per cent. After they wore machined the axles were subjected: to heat treatment front 1450deg. to 1500deg. Fate., aud they were then quenched in oil. ><ext, they i were lieated to 700 deg. Mr and allowed to cool slowly m air. \Vhon tested it was found that the clastic limit had been increased to 170,0001b. per square inch, and tho tensile strength to 185,0001b. per square inch it was estimated that the cost of the lieat treatment was only a Wtlo nver ld a pound. This is a remarkable advance, when it is considered that quite recently steel having a tensile strength of 100,0001b. to the square inch represented the limit of strength that had been obtained.