(一)预防脱炭: 有時淬成多锋刀具,装上机器试用,不便拆下重淬,仍不硬,再重淬,更不硬,若磨去表皮试其内部,则又颇硬,蓋其表面已脱炭,普通淬火爐子之爐瞠中空氣,舆工作物之表面接觸,发生氧化作用,使钢之表面所含炭份减少,因之不能淬硬,我们名之日‘脱炭’。若淬火间中有融鹽爐者,監可 (A) to prevent decarbonization: sometimes quenching into a multi-front tool, fitted with a machine trial, difficult to remove the heavy quenching, still hard, and then hardened, not hard, if worn to the epidermis try its internal, then hard , Cover the surface of the furnace has been decarbonized, ordinary furnace quenching stove air, the surface of the work contact with the surface of the oxidation occurs, so that the surface of the steel to reduce the carbon content, which can not be hardened, our name of the day off carbon’. If quenching between melting salt furnace, supervisor can