Furnaces designed for annealing steel pistons after friction welding
Stress reduction is performed on steel pistons to minimize residual stress in the structure and thereby reduce the risk of dimensional changes during further processing or during use of the pistons. We have designed several continuous furnaces for stress relief annealing.
One of the manufactured furnaces is a gas continuous furnace PRP 3800/65 equipped with a belt conveyor with continuous feed and an automatic tensioner. The furnace frame is welded from steel profiles, the outer shell of the furnace is effectively ventilated. The inner part of the furnace is equipped with air distributions from gas burners made of heat-resistant steel. The entire furnace is insulated with isoblocks, which ensure a quick rise to working temperature and minimal heat loss. The entrance and exit parts of the furnace are protected by screens made of heat-resistant material. The conveyor belt is made of a 1000 mm wide honeycomb belt made of stainless steel. The movement of the conveyor is smooth, in the basic setting 1.2 mm / sec. The speed can be adjusted using a frequency converter. There is approx. 0.4 m of conveyor in front of and behind the furnace to secure the loading and removal of the batch. Loading the charge (steel pistons) onto the conveyor is manual, but can also be done by a robot. Steel pistons are installed on the belt in a row of 5 pcs.
This continuous gas furnace with belt conveyor is divided into several heating zones. The furnace has forced air circulation, a preheating chamber, a tempering chamber and a cooling chamber. The operating temperature of the furnace and the time course of annealing can be set on the touch screen of the PLC programmable automat, which can also be used to perform basic function tests. The temperature in the individual heating zones is controlled by K-type thermocouples connected to the PLC. The furnace is equipped with a limit unit to protect the furnace.
Continuous furnaces for removing internal stress on steel pistons after welding are normally adapted to a specific operation, a specific line, in order to optimize your production process.