(1) Fully automatic controlled heat treatment production line
In order to enable the workpiece to freely complete the entire required heat treatment process on the production line, a specially designed continuous furnace is connected and communicated with each other. The furnace can be penetrated in many directions, and the workpiece material basket can be turned into the next heating zone or transitional insulation box at a 90°C angle, and then transferred to the next process or enters the cooling chamber for cooling. This kind of furnace structure and conveying device have a fairly high level. Taking the controllable atmosphere box furnace as an example, in order to meet the implementation of heat treatment processes such as carburizing, carbonitriding, nitrocarburizing, quenching or bright quenching, and austempering, the workpieces on the tray and the rack are driven by the cold chain The method is automatically fed into, passed and sent out of the furnace, and the required process is completed in the respective furnace. The box furnace is used in conjunction with the corresponding computer-aided measurement, control and adjustment system to form each independent modular unit, which is easy to connect to each other, forming a complete, flexible, and combined automatic heat treatment system.
(2) High-pressure gas quenching sealed box furnace and multi-chamber through sealed box furnace
The high pressure gas quenching sealed box back chamber is a sealed box furnace structure, and the front chamber is subjected to high pressure gas quenching. The workpiece is heated without oxidation in the protective atmosphere of the back chamber or carburized in the carburizing atmosphere, and bright quenching without oxidation in the front chamber. The back chamber is lined with alumina and thermal insulation ceramic fiber, the heating element is a horizontal parallel electric heating radiant tube, the hot air circulation fan in the top furnace, the protective atmosphere can be methanol or nitrogen; the middle part of the front chamber is the workpiece gas quenching chamber, and the lower part is the air inlet pipe , The upper part is the cooling return air heat exchanger. A high-power fan with variable frequency speed regulation is installed outside the front room, and the workpiece is cooled and quenched through the rapid circulation of nitrogen or helium. The quenching cooling rate can be controlled by adjusting the fan speed. The workpiece after high-pressure gas quenching is non-oxidized, the surface is silver-gray, and the deformation is small, which avoids the cleaning process after oil quenching.
The multi-chamber through-type sealed box furnace was manufactured by the German company Ipsen (see Figure 1). After the front chamber is preheated and carburized, the workpiece is sent to the back chamber for quenching, and then directly out of the furnace from the back, reducing the idle time of the heating chamber, improving work efficiency and reducing energy consumption.
At the outlet end of the push rod furnace, a high-pressure gas quenching chamber is sealed and connected. When the workpiece runs into the gas quenching chamber, it can be quenched with high-pressure helium or nitrogen. In order to reduce costs, high-pressure air quenching can also be used. Because the quenching time is extremely short, the workpiece will not appear oxide scale, only the surface is light black. Figure 2 shows the high-pressure gas quenching push rod furnace production line manufactured by the Austrian AICHELIN company. The production line includes parts cleaning, preheating, carburizing, high pressure gas quenching, tempering, inspection, etc. The preheating temperature is 400℃, 925℃/860℃ carburizing, and high pressure gas quenching uses 2×106Pa helium or nitrogen Quenching, tempering at 170～190℃, carburized layer depth is 1.4mm, production efficiency is 400kg/h.
Furnace well-shaped bell jar structure, WDS furnace lining insulation, stainless steel vacuum tank cover type single layer, three-zone three-layer closed heating elements are installed on the outer wall, so that the furnace temperature is uniform from top to bottom. The furnace body is equipped with three side fans at the top, middle and bottom, and the three zones are independent of hot air circulation. When working, the return air duct is closed. The hot air can only circulate in the heating layer in the furnace to achieve the goal of uniform furnace temperature. When the process is completed and the furnace is shut down, the return air duct is opened, and the cold air is sent into the heating chamber interlayer at the same time in the upper, middle and lower areas, so that the furnace body is quickly cooled and the furnace can be discharged in a short time. The base of the furnace is a conjoined double-seat. The hydraulic lifting column can be rotated left and right between the two bases, and the furnace body is lifted and rotated to another base that has been loaded with materials. This two-seat furnace can improve production efficiency. Figure 3 shows the MICROPULS ion nitriding equipment of RUBIG, Austria.