Heat treatment refers to a kind of metal hot working process that changes the chemical composition and structure of the material surface or inside by means of heating, heat preservation and cooling in the solid state to obtain the required performance.
Heat treatment process generally includes three processes: heating, heat preservation and cooling, sometimes only heating and cooling. These processes are interlinked and uninterrupted.
Let's learn about the selection of tempering temperature in heat treatment:
(1) Strong cooling quenched workpiece, tempering upper limit. The lower limit of group quenching and isothermal quenching.
(2) The lower limit shall be taken for the self tempering phenomenon or possible self tempering.
(3) The temperature of packing (closing) is a little higher than that of no packing (closing).
(4) The lower limit shall be taken for well furnace with fan and uniform temperature, and the lower limit shall be taken for tempering of salt furnace.
(5) The temperature of low temperature tempering oil tank is moderate, and the lower limit should be taken for well furnace.
(6) After quenching, if the hardness of the workpiece is low, the lower limit shall be taken. (refer to carbon steel and low alloy steel, and high alloy steel shall be discussed separately)
On 2018-08-08 11:45:46
