Forging of iron and steel; a text book for the use of students in colleges, secondary schools and the shop

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 edition. Excerpt: ...enough to keep the blast of air from striking the work. Also the work should be covered with a layer of coal to prevent its contact with the air. Otherwise the oxygen will decarbonize the steel and thus keep it from hardening. Steel will crack from sudden contraction if the fire is so shallow or the steel so placed in the fire that a cold blast strikes it. Especially is this so if the piece has thin projections, which owing to their small size are very susceptible to changes in temperature. If a big piece of steel is to be heated it is necessary to have the fire large enough to heat the piece uniformly. Charcoal is considered an ideal fuel for heating steel as it is practically pure carbon, but if it is used the fire should be kept well supplied with new coal, or it will be necessary to use a strong blast, which is likely to reach the steel and cause it to crack. It is stated by E. R. Markham in his most excellent work "The American Steel Worker," that high carbon steel will not become so hard on the surface if heated in charcoal fire as if heated in one burning coke. The best way is to heat in such a manner that the steel will not come in contact with the fuel: as in a muffle furnace, a piece of pipe or an iron box. When, however, the work is to be turned in a lathe afterwards, the open fire is better because it heats rapidly. Furnaces.--The muffle furnace (Fig. 166) is neat and easily managed. It is made to use illuminating gas, and make a very good furnace adapted to burn any kind The Gas Torch (Fig. 163) answers for heating an occasional small piece. The flame impinges upon the fire-brick and reflects the heat onto the piece which is can be procured in almost any size. The steel is placed in the muffle and the gas burned in...