Hardening, tempering, annealing and forging of steel; a treatise on the practical treatment and working of high and low grade steel .. . ome idea may be gained of the great and varied alterationsproduced in high-carbon steel through the different methods ofhardening by a description of a test experiment. If a forged orrolled bar of high-grade steel is nicked at a number of placesequidistant apart along its entire length a suitable specimen willbe obtained for experimental purposes. Place one end of the barin the fire far enough to allow of heating the first section up tothe nick to a white hea
Hardening, tempering, annealing and forging of steel; a treatise on the practical treatment and working of high and low grade steel .. . ome idea may be gained of the great and varied alterationsproduced in high-carbon steel through the different methods ofhardening by a description of a test experiment. If a forged orrolled bar of high-grade steel is nicked at a number of placesequidistant apart along its entire length a suitable specimen willbe obtained for experimental purposes. Place one end of the barin the fire far enough to allow of heating the first section up tothe nick to a white heat. Thus the rest of the bar, being out ofthe fire, will be heated to a decreasing temperature toward theother end. As soon as the first section is at a white heat, thusburning the steel, through its being of a high carbon percentage^ i6 HARDENING, TEMPERING AND ANNEALING. and the heat of the remainder of the bar becomes a dull red, takethe bar from the fire and quench it instantly into a cold water the metal in the bath until cold and then remove and dryit. By testing with a file the first section will, of course, prove. the hardest, and the intermediate sections of degrees of hardnesspassing from the softest to the hardest. Thus the conditions ofthe different sections, when broken apart at the fracture points,will show the operator the results in the steel when hardened at agiven temperature. On breaking the pieces at each neck it will be STEEL, ITS SELECTION AND IDENTIFICATION 17 noticed that very considerable changes have taken place in thegrain of the metal. The first piece, which has been burnt, throughheating to a white, has a very open and crystallized fracture,while the succeeding pieces are of a closer grain as they approach
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Keywords: ., bookcentury1900, bookdecade1900, bookidhardeningtem, bookyear1903
