Shaft-type furnaces for carburizing and carbonitriding

CGC 8.20/9,5	MPPA	CGC 6.12/9,5

• Processes of carburizing, carbonitriding and oxidation-free quenching are carried out in the electric furnace within a leakproof heat-resistant retort suspended inside the furnace.
• Advanced design of the fiber lining in the furnace significantly cuts energy resources consumption as compared to peers of other producers. Sidewalls and cover lining is made of ceramic fiber by Unifrax (France). The hearth of the furnace is made of light fireproof bricks.
• A lined cover is foreseen in the top part of the retort. Tightness of the contact zone between the retort and its cover is ensured by ring-shaped sealing cords and a sand lock. There are nipples to feed gas to the gas bleeder and supply the process gases. For liquid carburizing, a dripcock and a watch window are provided in the furnace cover. 
• A hydraulic drive for lifting the cover is used in the carburizing furnaces produced by JSC Nakal – Industrial Furnaces. The design is space-saving; it provides smooth and shockless opening and covering the furnace and, in addition to operational comfort, ensures high reliability of the cover / muffle contacting pair and the sealing operation.
• Lifting and lowering movement is controlled using a special push-button assembly on the cover handle.
• Loading and unloading the charge is carried out by means of the bay lifting equipment.
• Temperature control is carried out by an advanced programmed microprocessor-based controller Thermodat 14 equipped with a thermocouple. The controller enables easy setting multistage chemical heat treatment profiles and their automatic keeping.
• Highly effective stirring of the furnace atmosphere: a fan, deflectors and a diffuser. It is not needed to cool the fan by water.
• The retort pressure is controlled by a gas bleeder valve. A nipple for gas sampling and connection to a pressure gauge as well as a safety valve are provided in the nipple feeding gas to the bleeder.
• Compact generator of the furnace atmosphere based on “Oxycan-Gamma” catalyst is used in I6, I7 implements in order to create the saturating medium in retort. It allows to carry out Catalytic Gas Carburizing technology 
• Propane / butane mixture or natural gas is used as the carburizer 
• Heating elements made of Superfechral alloy comply with working safety regulations.
  

Implements

• High-quality heat-insulating fiber materials ensure lining thickness decrease as well as overall dimensions of the furnace
• Low-density lining materials ensures high efficiency and provides fast heating of the furnace due to a lower heat accumulation in the lining
• The formation rate of an effective carburized case increases up to 0.3 mm/h in I6,I7 implements. The decreased carburizing time results in a substantial cut of carburizing costs and many-fold increase in the furnace output
• In MPPA modules automatic control of the carbon potential is used which excludes a human-factor aspect in the carburizing process and rejection of materials caused by improper microstructure as well as cuts cost of heat treatment by excluding all corrective heat treatment operations
• It provides broaden options in carburized case regulation
• Construction solutions tested at hundred furnaces which have already been produced.