What are the characteristics of multi-purpose heat treatment furnace?

What are the characteristics of multi-purpose heat treatment furnace?

(1) Box-type resistance furnace. It works by using an electric current to heat through an electric heating element placed in the furnace, and by heating the parts through an electric current and radiation. It is a heating equipment widely used in heat treatment workshops. Suitable for annealing, normalizing, quenching, tempering, solid carburizing and other heating of steel and non-steel (non-ferrous metals). It has simple operation, accurate temperature control, protective gas can be entered to prevent oxidation when parts are heated, and good working conditions.

(2) Well resistance furnace. The working principle of the well-type resistance furnace is the same as that of the box-type resistance furnace, with the furnace opening facing upward and the shape being like a well. There are three kinds of multi-purpose furnace commonly used in heat treatment: medium temperature well furnace, low temperature well furnace and gas carburizing furnace. Shaft type resistance furnace adopts crane lifting parts, which can reduce labor intensity and is widely used. The medium temperature well furnace mainly uses dry long parts quenching, annealing, normalizing and other heat treatment, and its high working temperature is 950℃. Compared with the box type furnace, the well type furnace has good heat transfer, the top of the furnace can be installed with fans, the temperature distribution is uniform, and the thin parts placed vertically can overcome the bending deformation caused by the weight of the parts placed horizontally.

Heat treatment multi-purpose furnace has the following characteristics:

(1) The temperature range of heat treatment furnace is large. The main purpose is to obtain a good plastic austenitic steel, the temperature range of 900~1200℃; Due to different process requirements, the high temperature can reach 1300℃, and the low temperature is only about 100℃. With such a big temperature difference, the furnace structure is very different. The furnace temperature is higher than 650℃ called high temperature heat treatment furnace, heat transfer mainly by radiation, convection as a supplement; The furnace temperature is below 650℃, which is called low temperature heat treatment furnace, and the heat transfer mainly depends on the convection mode. Heat treatment is uniform to avoid excessive local temperature, so the furnace of the heat treatment furnace is sometimes separated from the combustion chamber.

(2) The temperature control of the heat treatment furnace is relatively strict. Heating before pressurization, metal temperature fluctuations of 120 degrees, generally have little impact on quality. However, whether the heat treatment furnace can ensure the temperature required by the heat treatment process has a great impact on the quality of the product, generally not more than 3~10 ° C. The temperature distribution on the section of the heated material should be as uniform as possible, and the temperature difference should not exceed 5~15℃. As far as controlling furnace temperature is concerned, electric furnace is superior. In order to achieve the purpose of accurate temperature control, the use of small power of the non-flame burner and the method of flame burner, then segmented control, the burner is too small, too concentrated, easy to local overheating. At the same time, the arrangement of the burner or the electric heater and the furnace structure should be conducive to the circulation of the furnace gas, so that the temperature in the furnace tends to be uniform. Therefore, the fan can be used in the furnace.