induction hardening
Induction hardening is a process used for surface hardening of steel and other components of the alloy. Parts subjected to the heat treatment must be placed inside a water cooled copper coil, and then heated above the temperature of the application of alternating current to the coil. Alternating current in the coil induces alternating magnetic field inside the workpiece, which, if made of steel, caused by the outer surface of the part to heat to temperatures above the transition. Part of the hold at this temperature until the hardening depth has been reached, and then burned in oil or other medium, depending on the type of steel and firmness desired. Core component remains the same during processing and its physical properties are those bars, from which it was made, or the preheating process. If Hardness is HRC 37-58. carbon and alloyed steel grades with the carbon content in the range 0.40-0.45% are most suitable for this process. In some cases, parts of alloy steels such as 4320, 8620 and 9310, as steel and paper mill rolls, first naugleroživaût to the required depth and slow cooling, then induction hardened. The advantage of relatively high basic mechanical properties and surface hardness greater than 60 HRC that provides excellent protection.
While induction hardening most commonly used for steel parts, other alloys such as copper alloys that are solution treated and tempered, can be hardened by high frequency currents as well. Applications include hardening race bearings, gears, pinion shafts, faucet (and other) wheels and tracks, and threaded pipes for oil patch drilling.
Induction hardening of the Flame
Flame hardening, induction hardening is analogous to the fact that it is the process of hardening the surface. Heat is applied to the part being hardened, using oxy-acetylene (or similar gas) flames on the surface of the steel to be hardened and heat above the upper critical temperature surfaces before hardening steel splashing water. As a result of the hard surface layer in a range from 0.050 "to 0.250" deep. As in induction hardening, the steel must be of sufficient carbon (greater than 0.35%) steel composition is not changed; So the main mechanical properties do not change. Flame hardening gives results similar to conventional ways of hardening, but with less penetration application hardening hardness of fire are similar to those for induction hardening, Although the advantage is the ability to flame hardening harden flat surfaces. Flat-armor, and knives can be selectively hardened through the process.