The factors influencing the heating of the chips to the flash point or combustion during the processing of magnesium alloy are: (1) processing speed; (2) high relative humidity (3) feed rate or the amount of knife is too small; (4) processing The pause time in the middle is too long (5) the back angle of the tool and the chip space are too small; (6) the cutting speed is used without using the cutting fluid; (7) the metal collides to generate sparks; (8) Magnesium chips accumulate around or under the machine, and so on.
The central task of the safe production of magnesium alloys is: burning and explosion of light and thin materials of dust-proof magnesium dust, magnesium powder, magnesium chips and magnesium.
First, safety management requirements
(1) The production site requires high space, natural ventilation, and the site is bright and spacious.
(2) The building facilities should be divided into several areas that are independent of each other and maintain a relatively safe distance.
(3) Inflammable and explosive materials are not allowed to be stored at the production site and around.
(4) The working area and management area should be equipped with corresponding fire-fighting facilities and equipment. The fire protection signs are obvious and easy to use, and should be maintained by special personnel.
(5) The operating area must implement strict fire and water control, and prevent the generation of sparks and sparks.
(6) The installation of power lines and electrical equipment must comply with the national safety regulations and be equipped with suitable overcurrent power-off devices.
(7) The wire arrangement and joints must meet the requirements of the code, and must not be connected indiscriminately, and may be protected against lightning and static electricity. Vacuuming equipment, exhaust fans, and lighting fixtures must be riot-proof.
(1) Operators must conduct corresponding safety training before they are employed, and they can pass the exam if they pass the exam.
(2) The operator must properly wear the labor protection articles as required before performing the work.
(3) Operators are not allowed to take sick and post-employment, and smoking is prohibited in the work area. Fire, water and prohibited items must not be brought into the work.
(4) The production site must be kept clean and hygienic, and no oil and sewage stains should be left. The magnesium chips, magnesium slag, flashing edge, light and thin materials must be cleaned once in 2 hours, and loaded into a special transfer container for disposal and harmless treatment.
(1) Magnesium products and magnesium material warehouses are suitable for miniaturization, division and decentralization, and the height of magnesium ingot stacking should not exceed 5.5 m to prevent major damage caused by magnesium alloy fire caused by excessive storage.
(2) Magnesium scrap should be stored in special stock, stacking generally does not exceed 1.4m3, and is suitable for storage in flame-retardant containers.
(3) The oxidant, reducing agent and flammable substances cannot be mixed with magnesium products or magnesium materials.
(4) It is strictly forbidden to bring fire source, fire and water into the warehouse to prevent magnesium products and magnesium materials from being exposed to rain, who are dipped, damp, and keep ventilation and heat.
(1) The content of fire safety measures. Safety first, anti-cancellation. Three know four sessions: know how to alarm; know the fire protection knowledge of magnesium and magnesium alloys and the harmfulness of magnesium alloy combustion and explosion; know how to find safety hazards; set up and maintain fire-fighting equipment; will alarm; will use fire-fighting equipment correctly; Fight the initial fire.
(2) "Three-use", "three-proof" and "four-hazard" for magnesium fire protection. "Three-use", that will use "D-kill" (D-class fire extinguisher), dry sand, covering agent; "three-proof", that is, fire, waterproof, high temperature; "four hazards", that is, strong light, high heat, rapid burning In case of water explosion.
(3) Eight measures for magnesium fire protection: 1) Use D-class fire extinguishing, dry sand and covering agent as soon as possible to extinguish the initial fire; 2) alarm; 3) power off; 4) cool down; 5) water stop; 6) air isolation ; 7) escape in distress; 8) prevent the expansion of fire sources.
Second, the actual processing process considerations
(1) Keep the tool sharp, and the front and rear corners are the right size;
(2) Use strong chips from large-entry tools to form thick chips and avoid small feeds;
(3) When the amount of feed is small, use mineral oil to reduce heat generation;
(4) When the chip ends, the knife should be retracted immediately, otherwise the workpiece will continue to rotate to form fine chips and it is easy to catch fire;
(5) Try not to use the chip liquid, especially the water-soluble chip liquid;
(6) In the case of high-speed chips that produce fine chips, compressed air or carbon dioxide gas can be blown;
(7) The machine tool near the processing machine should be kept dry;
(8) Regularly clean the chips and store them in a steel drum with a lid;
(9) Before the machining, the sand or other hard objects adhered to the castings should be clear;
(10) Avoid sparks caused by the impact of the tool on the steel insert;
(11) Smoke and fire are not allowed to be close to the processing area;
(12) It is not allowed to accumulate chips on machine tools or overalls. Dust and chips should be kept clear and stored in a covered flame-retardant container with a label;
(13) Ensure adequate fire-fighting facilities where the operator can reach.
Grinding, grinding, polishing precautions
(1) The operation is carried out in a dry state. When the polishing liquid must be used, the acid should be removed immediately using an acid-free oil.
(2) The chromate treated surface should not be ground; the chemically treated surface film should be removed.
(3) On the grinding machine for grinding magnesium, do not grind materials that are prone to sparks such as iron products, and use non-ferrous metal products. A special grinder should be used.
(4) The work site should be kept clean, dry and ventilated.
(5) The processing machine should be stable.
(6) Fireworks are strictly prohibited at the operation site.
(7) Use a special wet dust collector.
(8) Leather shoes with iron studs shall not be worn at the production site, and iron tools and hits shall not be used.