Investigation and description of potential safety hazards in northeast foundry workshop

Casting jobs: woodworker, sand mixer, smelter, shaper, pouring worker, baking worker and heat treatment worker.

Safety management system of foundry workshop

First, the furnace worker

1. When entering the work site, operators must wear personal protective equipment, and non-operators are not allowed to stay in the furnace. Firemen are not allowed to pose naked except for their faces.

2. Before starting the equipment, you must first check the circuits, lines, waterways, instruments, meters and some accident-prone parts, and then work can be carried out after it is confirmed to be normal.

3. Before starting the equipment, it must be discharged (not less than 1/2 furnace volume) before starting it. During operation (blanking, slag scraping, etc. ), must stand on the insulation (dry wood or rubber), and always pay attention to the hum of the electric cabinet when working. If there is any abnormality, the machine must be stopped immediately for inspection to ensure the safe operation of the equipment.

4. In the process of smelting, the metal in the furnace must be constantly shaken with a slag rod to make it move down slowly, and solid-liquid separation is not allowed to avoid splashing; After the metal begins to melt, special attention should be paid to blanking, and direct contact between cold iron and liquid is not allowed to prevent molten steel from splashing.

5. Before being discharged from the furnace, the amount of elements must be supplemented according to the test results of samples in front of the furnace, and pouring is not allowed if it exceeds the prescribed upper limit; Oxygen must be thoroughly removed, and sparks at the furnace mouth are not allowed to pour out of the furnace. At the same time, pay attention to baking the ladle in advance, and it is not allowed to tap the black ladle.

6. When pouring molten steel, the ladle lifter must stand on a dry plate, add an appropriate amount of deoxidizer into the ladle, lift the ladle, aim at the burner, and then pour water.

7. The pouring amount of molten steel in the ladle must be guaranteed, and it shall not exceed 4/5 of the ladle volume at most, so as to prevent the molten steel from pouring out during ladle lifting.

8. Blow-in and ingredients must be well coordinated, observe the surrounding furnace lining at any time, and identify the materials to ensure early detection of problems.

9. When blanking in the hot furnace, small materials must be used at the bottom, and the volume shall not exceed 1/2 of the total furnace volume. It is not allowed to directly discharge large materials, so as not to damage the furnace wall and bottom.

10. After the smelting on duty, the molten steel in the furnace must be drained and the furnace lining carefully checked. If you need to repair the furnace the next day, you must quickly shovel off the surface of the furnace lining at the high temperature of the furnace lining to expose new meat.

1 1. When repairing the furnace, carefully check whether the lining contains metal. If it does, it must be completely removed before repairing the furnace.

12. The whole operation process must be diligent, accurate in judgment, quick in response, timely discover hidden dangers of accidents, decisively deal with unexpected accidents, and minimize losses. If there is a fault, you must cut off the power supply first, and then take troubleshooting measures to prevent live work.

13. Before building the furnace, it is necessary to ensure the dryness and humidity of the mixed burden, and carefully check whether the winding of the induction coil is connected. After confirmation, make the furnace bottom according to the thickness of 150mm, put the crucible in the center of the induction coil, fix it around with a positioning wedge, and evenly compact it according to each layer of about 60 mm.

14. chemical composition of molten steel: a: composite casting infiltration (c: 0.32-0.38; si:0.4-0.6； Mn:0.7-0.9； S & lt0.04; p〈0.04)； B: overall alloy: the deviation of basic elements content shall not exceed 0.3%; The deviation of alloy element content is less than 0.05%, and the lower limit is taken.

Second, the sand mixer

1. You must wear neat labor protection articles before going to work.

2. Before starting sand mixing, it is necessary to check whether the no-load operation of the sand mixer is normal, and it can be operated only after confirmation.

3. The one-time loading capacity of quartz sand shall not exceed 10% of the maximum nuclear load, and it shall not fly out of the machine basin during operation.

4. The dosage of binder must be controlled between (3.5-4.5%) and adjusted appropriately according to the climate. Mixing time must reach (surface sand 5-7 minutes; Back sand for 3-5 minutes).

5. When surface sand and back sand are exchanged and mixed, the machine basin must be cleaned before mixing, and the residual part of back sand (too high water content) is not allowed to be mixed into surface sand.

6. Hands and tools are not allowed to enter the machine basin during the whole process of remote rotation of the machine.

7. The mixed surface sand and back sand must be stacked separately, with a spacing of not less than 1 m, and covered with plastic sheets, and shall not contact with the atmosphere in a large area.

8. Sand mixing and molding are cross operations, so as to avoid collision as much as possible.

Third, the modeler

1. You must wear neat labor protection articles before going to work.

2. Before modeling, be sure to carefully check whether the wooden mold, riser, gate, locating pin and other accessories are complete, and then confirm them before modeling.

3. The wooden model should be placed on the tray smoothly. After pouring and riser are in place according to the process requirements, boxes can be placed in turn, and surface sand and back sand can be added. When adding face sand, it must be ensured that the wooden mold will not move on the tray.

4. The surface of the wooden pattern must be covered with surface sand, the thickness is greater than 30mm, all surfaces of the wooden pattern must be covered with surface sand, and then back sand is added, and the whole sand box should be filled with back sand.

5. When tamping sand, you must first use a pointed rammer to eat the position with less sand, and then use a flat rammer to shape it. Large ones should be compacted by layers, and the thickness of each layer is generally less than150 mm.

6. When punching holes, the model should be removed, as deep as possible, and distributed reasonably to ensure the minimum gas consumption and the best curing effect. In the meantime, it is difficult to pull out the mould, but the quantity of the mould must not be greater than+1mm.

7. The quality of air outlet will directly affect the quality of workpiece. Punching principle: try to be close to the surface of the mold under the condition of ensuring no flash. In addition, there should be enough quantity to ensure that the gas generated in the pouring process can be discharged smoothly.

8. After the sand mold hardens, blowing must be small first and then large. There is no visible white fog around the blowhole to the maximum extent to avoid waste.

9. When demoulding, the demoulding needle should be stuck in the middle of the wooden mold as far as possible. When pulling out, tap the model with a rubber hammer and pull it out slowly. It is not allowed to hit the wooden mold with hard objects to avoid damage.

10. The sand mold should be flat. If there are defects larger than 20 mm, they must be repaired. The repair position must be lower than the parting surface to avoid batch seams and cracks.

1 1. Sandboxes must be placed neatly according to the process requirements to ensure smooth roads.

12. The sand box must be placed neatly, and the alloy should be placed flat on the ground, and the other half of the box should stand at one end of the box.

Fourth, container workers

1. You must wear neat labor protection articles before going to work.

2. Before closing the box, the floating sand in the mold must be wiped off and blown clean, then the sample box is closed, then it is opened, blown clean and closed again, and the box can be closed after confirming that there are no batch seams.

3. The upper clamp must be used symmetrically. It is required that the clips of each pair of boxes must be tightened, and less clips are not allowed.

4. Don't use too much force when erecting the box, so as to avoid violent vibration and loose alloy.

5. Before pouring, check the casting mold where the alloy can be seen, and check the large boxes (more than three boxes) to prevent the alloy from causing waste products.

Verb (abbreviation for verb) seasoning bottle

1. You must wear neat labor protection articles before going to work.

2. Whistle should know the poured workpiece, master the temperature and quantity of molten steel, and stop the ignition of slag in time to avoid forming defects. Accurate judgment, loud password and proper command.

3. When lifting the bag, you must first add an appropriate amount of deoxidizer to the bag, stand on the heat preservation, and lift the bag to the vicinity of the furnace mouth. Do not put down the bag when the forehearth topples, and do not wear gloves when lifting the bag.

4. Ladle bearers should cooperate with each other to keep the ladle stable and avoid molten steel splashing.

5. Before pouring, the temperature must be adjusted according to the size and shape of the poured workpiece.

6. When pouring, be sure to aim at the gate and pour according to the principle of slow first and then fast. The pouring speed is not easy to be too fast, so as not to hurt people by molten steel.

7. When pouring wine, you must obey the command of the whistle and never pour wine blindly. If there is not enough molten steel, it must not be forced to pour. According to the process requirements, clean up the sticky sand and smash the door.

8. Special workpieces shall be operated according to special process requirements.

Six, sand cleaner

1. You must wear neat labor protection articles before going to work.

2. General workpieces should be unpacked for more than 40 minutes after pouring, and large workpieces (more than three boxes) should be unpacked for more than 90 minutes. Extra-large and special workpieces should be unpacked in time according to process requirements.

3. When the sand falls, three boxes or less shall not be placed on the car. Drop the hammer accurately, and don't hit the box and workpiece.

4. The sand on the road should be cleaned up, and the sandbox should be placed in a proper position and placed neatly, so as not to block the road.

5. Be sure to clean up the iron in the sand during loading.

6. Stack them one by one according to what the stylist said. Hot workpieces are not allowed to leak in rainy and snowy weather.