Characteristics of vacuum heat treatment technology-Oxidation is inhibited

Characteristics of vacuum heat treatment technology

        Oxidation is suppressed. In order to achieve bright quenching without oxidation heating, a controllable atmosphere can be selected, but for die steel, it is very difficult to maintain a neutral state in a general controlled atmosphere under high temperature heating. Although the use of high-purity inert gas and a controlled atmosphere with low dew point can meet the above requirements, it is expensive and not suitable for use. The use of vacuum heating, due to the extremely low content of the oxidizing atmosphere, can prevent the steel from oxidation and decarburization. At a certain temperature, the following reactions exist between the metal (M) and its oxide (MxO):

xM+1/2O2=MxO

        If the decomposition pressure of oxygen in the furnace is lower than the decomposition pressure of oxides, the reaction proceeds to the left, which means that oxidation takes place. Practice has proved that as long as the decomposition pressure of oxygen in the furnace reaches 0.1-0.001 Pa, the tool steel can avoid oxidation and achieve bright quenching.