Ways and methods of heat treatment energy saving and emission reduction in auto parts industry

With the continuous development of my country's national economy, the number of heat treatment in my country's auto parts manufacturing industry is also increasing with the development of the manufacturing industry. At present, heat treatment parts account for more than 50% of the total steel. There are many types and names of auto parts, and there are many types that require heat treatment, such as engine valves, springs, tappets, camshafts, crankshafts, connecting rods, pistons, etc., half shafts, half shaft sleeves, steering knuckles, etc. , Steering ball, steering arm, steering rod, steering interface, etc., transmission differential gears, transmission shaft gears, pin shafts, etc., automobile leaf springs, bolts, screws and other fasteners used for shock absorption, and production of various Molds for various parts.

Energy saving in heat treatment of auto parts is embodied in saving energy and improving the overall efficiency of energy utilization. Energy saving in heat treatment runs through all links of the entire production process and requires all links (including production organization, process technology, materials, equipment, and management. ) To control and continuously rectify. Energy saving in heat treatment is a systematic project, which mainly includes three major sections: energy saving in process technology, energy saving in equipment, and energy saving in management. From the perspective of process design, it is the duty of the heat treatment worker to achieve the purpose of energy saving and environmental protection under the premise of meeting the heat treatment requirements of the parts.

It should be noted that the degree of heat treatment technology is a key factor to ensure the quality of parts and components. Energy saving and clean production in the heat treatment industry have been implemented, and the "four wastes" emissions have been carried out in the fields of heat treatment equipment, heat treatment process and quenching cooling medium. However, the problems of high energy consumption and environmental pollution have not improved greatly. Therefore, strengthening energy-saving production and environmental protection of heat treatment has become a top priority in the auto parts manufacturing industry.

The heat treatment methods of auto parts include conventional heat treatment, chemical heat treatment, induction heat treatment, etc. The heat treatment methods and processes that need to be selected to meet the working conditions and technical requirements of the parts are inseparable from the key heat treatment equipment to complete the heat treatment. It should be pointed out that under the premise of meeting the performance requirements, heat treatment equipment and process equipment with low consumption, less pollution and high degree of automation should be selected as much as possible. At the same time, the heat treatment equipment should be regularly calibrated with temperature control instruments and thermocouples. Checking the uniformity of furnace temperature and correcting errors in time are very important basic work of heat treatment.

The environmental pollution caused by heat treatment is mainly manifested in four aspects, namely, waste water, waste gas, waste residue and noise, etc., which are usually referred to as the "four urban hazards" and require special attention. In addition, check the equipment and tooling to ensure that the equipment is operating normally. Several types of heat treatment equipment and auxiliary equipment are introduced below for reference.

1. Adopt energy-saving heat treatment production line

The basic furnace types of controllable atmosphere heat treatment equipment include periodic sealed box multi-purpose furnace production line, continuous controllable atmosphere heat treatment furnace production line, mesh belt furnace heat treatment production line, etc. Most manufacturers use periodic sealed box multi-purpose furnace production line, because of this production line It has the characteristics of design and manufacture, high degree of automation, strong flexibility, flexible and reliable operation, and diversified structure types. It not only adapts to the requirements of multi-variety, medium and small batch production, but also meets the requirements of single-variety mass production. It has several heat treatment equipment appearances. And work situation.

Equipment should be selected reasonably when preparing the heat treatment process of auto parts, so as to achieve energy saving and environmental protection. Large furnaces are more energy-efficient than small furnaces, continuous furnaces are more energy-efficient than periodic furnaces, and cylindrical furnaces are more energy-saving than rectangular furnaces; reduce the weight of trays, baskets and fixtures , Can save 10%-20% of electric energy; optimize the design of the furnace body structure, adopt a sealed furnace body structure to prevent air leakage and inhalation of air, and select light refractory materials with good insulation performance as the furnace lining to reduce heat loss and increase heat Utilization rate; make full use of waste heat to achieve multiple uses in one furnace.

2. High frequency induction equipment

Induction heat treatment is a heat treatment technology with high productivity, no environmental pollution, easy automation and energy saving. This technology has been developing rapidly since its inception. According to data, the installed capacity of induction heating equipment in the United States was 100 sets in 1965 and 400 sets in 1985, a threefold increase. The largest user of induction heat treatment technology is in the field of auto parts.

Because induction heat treatment technology has many advantages such as, energy saving, environmental protection, etc., which meets the needs of modern automobile production, it has been widely used and the technical level has been rapidly improved. High-frequency induction heating equipment is widely used in the field of auto parts, such as valves, tappets, connecting rods, crankshafts, camshafts, gears, etc.

3. Vacuum heat treatment furnace

Multifunctional atmosphere furnaces, mesh belt furnaces, etc. can be heated in an oxygen-less atmosphere. Vacuum heat treatment is an energy-saving and clean heat treatment process method. While ensuring the quality of heat treatment of auto parts, it has good energy-saving and environmental protection effects and can realize clean production.

The vacuum heat treatment furnace is known as energy-saving, clean and environmentally friendly heat treatment equipment. It is a typical equipment that can realize heat treatment technologies such as vacuum oil quenching, high pressure vacuum air quenching, and vacuum tempering. At present, the total number of vacuum furnaces and multi-function furnaces accounts for about 10% of the heat treatment equipment, which can basically realize automation, intelligence and flexibility. The developed heating technology has so far achieved degreasing, degassing, and non-oxidizing heating. Problems such as adhesion.

The heating of parts can be divided into heating and ineffective heating. The energy consumed by directly heating the parts is called heat, and the heat dissipation of the furnace wall, the heating of the basket and the fixture are invalid heat. From the perspective of energy saving, the loss of ineffective heat should be reduced as much as possible. The use of flexible double-row furnaces and multi-row furnaces will greatly reduce the heat loss of the furnace wall and reduce the unit energy consumption. The use of heat-resistant structural parts in the furnace with high thermal strength and reducing the mass ratio of the tray to the parts as much as possible are also important measures for energy saving and consumption reduction. Comprehensive utilization of waste heat. Comprehensive utilization of quenching waste heat, such as using waste heat to heat the cleaning solution, or as an auxiliary heat source for the pre-oxidation furnace.