Heat treatment furnace is refers to the charge heat treatment heating furnace or fuel furnace. The commonly used heat treatment furnace has box type resistance furnace, well type resistance furnace, gas carburizing furnace and salt bath furnace. Usually a continuous furnace is used, the workpiece is continuously loaded from the charging door, through the furnace chamber, continuously discharged from the discharge door. Generally used in the furnace transfer mode is, the workpiece is carried on the heat resistant steel guide rail, to move the beam or push rod. In recent years, heat resistant steel conveyor belt has been used to transport materials. In this way, the heat treatment operation is more reasonable, greatly increasing the possibility of automation and unmanned management of the heat treatment process.
Due to the variety of heat treatment processes and the shape and size of heat treatment workpiece, the furnace type and structure of heat treatment furnace are also various. There are many classification methods for heat treatment furnace, and different classification methods represent its different characteristics:
(1) according to the mechanized way: roller bottom furnace, step furnace, trolley furnace, external mechanized chamber furnace, chain furnace, rotary bottom furnace, vibrating bottom furnace, hood furnace, etc.;
(2) according to the highest temperature: furnace temperature greater than 1000℃ for high temperature heat treatment furnace; 650 ~ 1000℃ is the medium temperature treatment furnace. Low temperature heat treatment furnace below 650℃;
(3) according to the main heat treatment process types: solid solution, quenching, normalizing, tempering, annealing and carburizing chemical heat treatment furnace;
XA series controllable atmosphere box type multi-purpose furnace
(4) according to the production operation mode: periodic and continuous heat treatment furnace;
(5) according to the heating mode: divided into direct heating mode, such as bright furnace; Indirect heating, such as radiation tube furnace, muffle furnace, etc.
The commonly used heat treatment furnace has box type resistance furnace, well type resistance furnace, gas carburizing furnace and salt bath furnace.
(1) box-type resistance furnace. The working principle is that the electric current is used to generate heat through the heating element arranged in the furnace, and the parts are heated by the current and radiation. It is widely used in heat treatment workshop. It is suitable for heating annealing, normalizing, quenching, tempering and solid carburizing of steel materials and non-steel materials (nonferrous metals). It has the advantages of simple operation, accurate temperature control, good working conditions and so on.
(2) well resistance furnace. The working principle of the well resistance furnace is the same as that of the box resistance furnace. There are three kinds of commonly used multipurpose heat treatment furnace: medium temperature well wou furnace, low temperature well furnace and gas carburizing furnace. Well - type resistance furnace adopts crane lifting parts, which can reduce labor intensity, so it is widely used. The medium temperature well furnace is mainly used for quenching, annealing, normalizing and other heat treatment of long dry parts, and its maximum operating temperature is 950℃. Compared with the box furnace, the well furnace has better heat transfer, and a fan can be installed on the top of the furnace to evenly distribute the temperature.
Heat treatment furnace has the following characteristics:
(1) the temperature range of heat treatment furnace is large. The main purpose is to obtain a plastic austenitic steel, its temperature range of 900 ~ 1200℃; Due to the different requirements of the heat treatment process, the temperature of high up to 1300℃, low only about 100℃. The difference in temperature is so great that the furnace structure is also very different. The heat treatment furnace whose temperature is higher than 650℃ is called high temperature heat treatment furnace. The low temperature heat treatment furnace whose furnace temperature is lower than 650℃ is called low temperature heat treatment furnace. Heat treatment requires the furnace chamber temperature uniformity, to avoid local temperature is too high, so the heat treatment furnace furnace and combustion chamber are sometimes separated.
(2) the furnace temperature of heat treatment furnace is strictly controlled. Before the pressure processing of the heating, metal temperature fluctuations of 10 or 20 degrees, generally does not have much impact on the quality. However, whether the heat treatment furnace can guarantee the temperature required by the heat treatment process has a great impact on the quality of the product, which generally does not exceed 3~10℃. The temperature distribution on the section of the heated object should be as uniform as possible, and the temperature difference should not exceed 5 ~ 15℃. In terms of temperature control, electric furnace is superior. In order to achieve the purpose of accurate control of the temperature, it is best to use uniform arrangement of small power non-flame burner, flat flame burner method, so as to facilitate the control of sections, the burner is too little, too concentrated, prone to local overheating. At the same time, the arrangement of the burner or heating element and the structure of the furnace should be conducive to the circulation of the furnace gas, so that the temperature in the furnace tends to be uniform.
On 2018-08-08 11:45:46
