(1) Fire protection requirements for buildings of heat treatment plant:
The heat treatment workshop or working section shall be set at the periphery of the workshop and separated from other workshops by firewalls. There shall be a special warehouse for storing flammable or combustible liquids and meeting the fire protection requirements. Generally, the storage tank of combustible oil for quenching shall be set outside the workshop in underground or semi underground type.
(2) Main equipment and operation fire protection requirements:
① The oil used for refining should have a higher flash point. Generally, the oil with a flash point above 180 ℃ ~ 200 ℃ should be used. The quenching oil tank should not be full, and at least a quarter of its height should be left. In order to prevent the temperature of the quenching oil from rising and spontaneous combustion, circulating cooling measures should be taken to control the oil temperature of the oil tank below 80 ℃.
② The structure of the saltpetre tank furnace must be in accordance with the safety requirements of the design, strictly prevent leakage, prevent moisture and sundries from blowing into the saltpetre to cause explosion, strictly control the temperature of the saltpetre tank not to exceed 550 ℃, the parts and tools to be processed into the tank must be dry, clean and free of oil, strictly prevent combustible substances from falling into the tank; no more than 300 mm saltpetre block is allowed to be added into the saltpetre tank, and the added saltpetre is not allowed to be added It must be preheated to 100-200 ℃, and the liquid level of nitrate shall be 100mm lower than the groove edge.
Operating procedures
- Clean the operation site, check whether the power supply, measuring instruments and various switches are normal, and whether the water source is unobstructed.
- Operators shall wear labor protection articles, otherwise there will be danger.
- Turn on the universal change-over switch of the control power supply, raise and lower the temperature in stages according to the technical requirements of the equipment, extend the service life of the equipment and keep the equipment in good condition.
- Pay attention to the furnace temperature and mesh belt speed regulation of heat treatment furnace, master the temperature standards required for different materials, ensure the hardness of workpiece, surface straightness and oxide layer, and do a good job in safety.
- Pay attention to the furnace temperature and mesh belt speed regulation of tempering furnace, open the exhaust air, so that the workpiece can meet the quality requirements after tempering.
- We should stick to our posts in our work.
- Necessary fire-fighting equipment shall be equipped and familiar with the use and maintenance methods.
The above analysis of gear heat treatment process shows that different manufacturers have different heat treatment processes for gears. In recent years, China’s heat treatment production technology has made remarkable changes and achieved considerable development through digestion and absorption of imported advanced technology. Because of the low starting point and thin foundation in the past, there is still a big gap between the level of heat treatment production technology and advanced industrial countries as a whole. In the current trend of world economic integration, it is imperative to improve the quality of mechanical products and the competitiveness of domestic and foreign markets. Heat treatment production technology must catch up with each other to seize the opportunity and meet the new challenges, so as to reduce and shorten the gap with the international advanced water level as soon as possible, and make China’s heat treatment technology and mechanical product quality enter the world’s advanced ranks as soon as possible 。 In the manufacturing and production of gears, there will be some gears with special performance requirements. It is required that the designer should make all-round analysis and comprehensive consideration according to the basic principle of material selection to select the most suitable material and heat treatment process.