Internal heating and united stirring type isothermal quenching salt-bath device

Abstract

The invention provides an internal heating and united stirring type isothermal quenching salt-bath device which at least comprises a salt bath tank, wherein a work piece rack is arranged in the salt bath tank; an internal heating system, a cooling system, a united stirring system and a temperature control system are also arranged in the salt bath tank, wherein the internal heating system consists of heating rods which are uniformly distributed in the salt bath tank; the cooling system consists of two cooling water coil pipes which are respectively arranged on two opposite inner walls of the salt bath tank; the united stirring system consists of a swinging unit and an air stirring unit, wherein the swinging unit comprises a swinging mechanism, and rails which are arranged on two sides of the top of the salt bath tank; the air stirring unit is an air pipe which is arranged at the bottom of the salt bath tank; air vents distributed uniformly are formed in the air pipe; the temperature control system comprises a temperature meter, a pipeline pump and a controller. The internal heating and united stirring type isothermal quenching salt-bath device is uniform in temperature, also small in temperature fluctuation range and capable of realizing automatic control.

Description

technical field [0001] The invention provides an internal heat combined stirring isothermal quenching salt bath device for heat treatment of austempering ductile iron (ADI), which belongs to the technical field of austempering ductile iron heat treatment. Background technique [0002] Austempered Ductile Iron (ADI) is a casting engineering material emerging in the past 30 years with high strength, high wear resistance and a certain degree of toughness. It is being continuously promoted and applied at home and abroad. [0003] ADI is obtained after the austempering process of cast ductile iron rough castings. The main process includes two processes of austenitization and austempering. The matrix structure of ADI is composed of acicular ferrite and high-carbon stable austenite. Academically, this mixed matrix is ​​called austenite. [0004] The manufacturing process is: cast ductile iron rough casting (spheroidal graphite + pearlite and ferrite matrix) → complete austenitizat...

AI Technical Summary

Problems solved by technology

When the quenching temperature is lower than 230°C, it is easy to form martensitic structure, which has high hardness, high brittleness and extremely low toughness; while it is easy to transform into ferrite and pearlite structure if it is higher than 450°C, which cannot achieve the purpose of isothermal quenching to improve performance

In the temperature range of 230-450°C, a temperature difference of 10-15°C will cause a great difference in the final performance of the workpiece

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