Foshan Die Casting Plant: Quality Control Method of Production Process in Die Casting Workshop
Category: Industry Information
The quality control of production process in Foshan Die Casting Workshop involves every link of die casting process, from smelting to production debugging to inspection control
The quality control of production process in Foshan Die Casting Workshop involves every link of die casting process, from smelting to production debugging to inspection control, from key process control to maintenance of equipment and dies. The omission of each link may cause quality accidents.
I. Alloy Melting
1. The temperature of the furnace should be controlled between 630 and 680.
2. Observing the melted liquid aluminium, the liquid aluminium suitable for production is bright white. If the liquid aluminium appears red, it means that the furnace temperature is too high, and if the liquid aluminium is ice-cream, it means that the temperature is too low.
3. It is strictly forbidden to mix impurities in the process of aluminium smelting. Operators are forbidden to put unqualified products into the smelting furnace for refining without authorization. If products need to be refining in the furnace, they must be checked and confirmed by the group leader before they can be put into refining.
4. To keep the liquid level of aluminium stable and free of scum and bubbles, the oxide layer and impurities on the surface of molten aluminium must be scraped off when bailing out the liquid aluminium for die casting.
5. In the production process, the powder refiner and slag remover must be injected twice in the furnace, once every 4 hours on average. The whole filling process must be carried out under the guidance of the group leader. After the operation is completed, the impurities produced by the refining must be cleaned up before casting production can be carried out.
6. Aluminum slag must be cleaned at least twice per shift in the production process, at least once every 4 hours on average.
7. All tools in contact with liquid aluminium must be dried first. They must be absolutely dry and clean. Impurities must not be added to the liquid aluminium.
8. In the process of aluminium smelting, if excessive impurities are found in ingots or recycling charge, it is necessary to stop putting similar ingots or recycling charge back into the furnace and report to the monitor and workshop director in time.
1. First of all, the accuracy of the die type should be determined to ensure the perfection of the die.
2. When assembling the die, it should be completed with the assistance of the operator, the maintenance worker and the team leader.
3. When assembling the die, we should ensure the firmness of the solid parts and ensure the safety of the die in the production process.
3. Mould debugging
1. Die assembly is completed, test machine can be carried out (point movement), automatic low-pressure air-running once a week, to ensure the flexibility of the assembled die.
1) Check whether the screw is loose.
2) Check the equipment for oil leakage or other abnormal conditions.
3) Check whether the moving parts of die casting machine and die are refilled with lubricating oil.
2. Temperature of Die (Preheating of Die)
1) The surface temperature of the die rises to 180-220 C.
2) Check whether the cooling water is running normally.
3. Die Casting
1) Team leader sets die casting parameters.
2) Check the applicability of the molten aluminium to be cast.
3) Observe the operation of equipment and die during die casting.
4) check whether the spray pressure and water quantity of the release agent are normal.
5) Check whether the size and appearance of the die-cast products meet the requirements of drawings and inspection cards, and whether there are any defects in the products.
6) Die-casting products must be more than 50 pieces (20 moulds of low-speed injection must be made before high-speed injection test is opened).
7) The final confirmed qualified die castings can be retained as the first inspection item and the First Inspection Form shall be filled in.
IV. Die Casting Production
1. After confirming that the die-casting products are qualified, the set parameters shall be determined. The operator shall not change the set parameters without authorization.
2. If abnormal phenomena such as abnormal noise of equipment are found in the production process or castings are stuck in the mould, the machine shall be stopped immediately and the maintenance personnel shall be notified. Operators shall be strictly prohibited from repairing the castings privately.
3. During the production process, the operator should ensure the reliability of the die.
1) Because the parting surface is uneven or worn out, the clamping force is insufficient, which leads to more casting flash.
2) Aluminum spattering at the position of the ejector due to the wear of the punch.
3) Cavity and slider are damaged due to misoperation.
4) Due to the long-term use of dies, the fatigue of dies and materials will occur, which will affect the quality of products.
4. During the production process, the operator should do the product self-inspection, stipulating that every 20 products of die-casting forming should be self-checked once. If abnormal products are found, the production should be stopped immediately and the reasons should be found out.
1) Because of the low temperature of the die, the low temperature of liquid aluminium or the slow filling speed of liquid aluminium, the cold isolation of the castings occurs.
2) Because of insufficient holding time and too small drawing inclination, the casting cracks or even tension cracks are caused.
3) Due to the deviation of liquid aluminium material, rough surface of die cavity, insufficient demoulding dose or failure, the casting sticks to the mould.
5. In the process of production, if it is found that the die is slightly fractured, and the casting only needs to be repaired in appearance, without affecting the performance, it is necessary to report to the team leader and workshop director in time. The treatment methods are as follows:
1) According to the actual situation, production can not be terminated, but all castings must be repaired. After the die casting of the batch of products is completed, the mould must be repaired. This situation is applicable to products with small batches.
2) Stop production immediately, disassemble the defective mould for maintenance, and continue to put into production only after maintenance and test die casting confirm its integrity.
V. Demoulding Agent
1. Before die casting in the production process, release agent must be sprayed on the die.
2. Check whether the injection pressure of release agent is suitable for die casting production.
3. Check whether the flow rate of release agent is suitable for production.
4. Check whether the release agent is invalid.
5. In case of the above problems, the team leader and workshop director shall be notified immediately, and the injection pressure, flow rate and release agent ratio shall be adjusted in time for production.
VI. Production Inspection
Confirmation and assembly of dies
1. The team leader must confirm the conformity of the die models to be assembled, and the product models should be uniform in production.
2. The group leader must confirm the perfection of the die and avoid the failure and damage of the die assembly production.
3. For the assembled die, the tightness should be checked and lubricating oil should be added to ensure the flexibility of the die operation.
4. The conformity of die-casting products must be confirmed.
II. First Inspection of Products
1. The team leader must confirm whether the first die-casting piece produced meets the requirements of the drawing.
2. During the first product inspection, the team leader must confirm whether the size and appearance of the die-casting parts meet the requirements of the drawings and inspection cards.
3. The group leader must confirm the good operation of the die-casting equipment and die during the first product inspection.
III. Patrol Inspection
1. The team leader should inspect at least once every hour every running equipment to correct the operator's bad operation.
2. Inspect each machine and sample the products it is producing in order to confirm the instant conformity of the products.
3. The team leader should deal with the abnormal production situation in time, and report the major quality problems to the workshop director in time.
1. The team leader shall verify and record the succession procedures at each succession.
2. Team leaders should fill in working diaries to record the quality problems and production conditions on duty and give tips to the next shift.
I. Full Inspection of Products
1. Full inspectors carry out full inspection of die-casting products.
2. The main items of inspection are appearance and defect of products.
3. During the whole inspection process, if many quality problems are found in the product, the situation should be reported to the team leader and workshop director in time.
4. The inspectors should record the quality problems of the products they inspected.
SEPARATION OF PRODUCTS
1. The inspectors should sort the products they have inspected and resolutely eliminate the unqualified ones.
2. Unqualified products rejected in the whole inspection process are classified, isolated and marked according to different quality problems.
3. Products of different types and models should be placed differently to prevent the mixing of different products.
III. Identification of Products
1. The products that have been inspected must be identified. Different types and models of products must be distinguished.
2. In the marking of the product, it is necessary to indicate the model, type, quantity of the product, the number of the die casting machine, the name of the operator and the name of the inspector.
3. Non-conforming products must be identified and segregated so as to prevent the selected non-conforming products from being mixed into the qualified products again.
3. Sample Inspection of Products
First Inspection of Products
1. The quality inspector must participate in the first inspection of the first product.
2. The quality inspector must confirm that the first inspection product fully meets the requirements of the drawings before continuing production.
3. For products that fail to pass the first inspection, the quality inspector is responsible for requiring the operator and group leader to adjust or repair the equipment and dies until the qualified products are produced.
II. Patrol Inspection of Products
1. The quality inspector conducts at least one inspection tour of each product under production every hour to confirm whether the product under production meets the requirements of the drawings.
2. The quality inspector conducts an hourly inspection of the products being sorted by the full inspector to confirm whether the products under full inspection meet the requirements of the drawings.
3. In the process of inspection, the unqualified products found should be identified and isolated immediately. The quality inspector has the responsibility to urge the operators and team leaders to correct them.
4. In the process of inspection, if major quality problems or serious hidden dangers are found, they should report to the workshop director and quality department immediately so as to facilitate timely treatment.
5. In the process of patrol inspection, if minor repairable quality problems are caused by equipment and mould problems, the quality inspector should inform the workshop director and quality supervisor in time. This kind of situation, if can be solved by repairing after the event, can continue to produce. After the batch production is completed, the relevant personnel shall be notified to repair the equipment and dies in time.
IV. Final Inspection of Products (Sample Inspection before Warehousing)
1. Quality inspectors conduct final spot checks on products before entering warehouses.
2. Inspection of product performance, size and appearance shall be carried out according to production drawings.
3. For substandard batch products, scrap, repairs and sub-inspection can be carried out according to the actual situation.
1. Be responsible for filling in the inspection, acceptance and inspection records of die-casting dies, and timely submit the relevant Daily Quality Report.
2. Responsible for the workshop process control, responsible for the first inspection, inspection and warehousing inspection of products, and fill in the relevant inspection records.
3. Responsible for the final inspection of products into warehouse (out of warehouse) inspection, non-conforming products are not allowed into warehouse (out of factory).
4. Supervise and inspect the work of part-time inspectors and full-time inspectors, and coordinate the handling of quality problems in the workshop.
5. Be responsible for keeping the quality inspection records of the workshop and assist the workshop in handling customer returns.
6. Assist workshop to put forward product quality improvement plan and improve manufacturing technology level.
8. Other issues to be noted in process control:
First, key processes should be controlled.
2. Operators, team leaders and quality inspectors should strengthen the inspection of die castings which are prone to deformation due to long core-pulling to ensure that qualified products flow into the next process.
3. Semi-finished products completed in the process should not be stacked too high during full inspection. For products with similar shape and different specifications, effective product identification is needed between different products to prevent major confusion in handling, moving and production process due to too close distance between different products.
IV. CONTROL OF NON-QUALITY PRODUCTS
1. In the process of production, if found that the die-casting products are not up to standard or the die is damaged, the discoverer shall report immediately. Team leaders, quality inspectors or workshop directors organize the identification and isolation of non-conforming products, and place non-conforming products in designated areas.
2. In the process of testing, if the unqualified products can be solved by technical treatment, the whole inspection work and the quality inspector can request the production line to make technical treatment, and the processed products must be re-examined.
3. The quality inspector of the workshop shall fill in the Quality Report Form and report it to the Quality Supervisor. The quality supervisor calls the relevant personnel of the workshop to analyze the unqualified products and make a written decision.
5. The quality inspector can summarize the quality situation of workshop production once a week or a month. The contents include product quality, customer returns, customer quality complaints and so on, and report to the quality supervisor, who will make the final monthly quality report.
IX. Laboratory, Test, Batch Number Management of Raw Materials and Aging Treatment of Die Castings
I. Laboratory and Die Casting of Raw Materials (Aluminum Ingot)
1. All incoming aluminium ingots must undergo physical and chemical laboratory tests. Only qualified aluminium ingots can enter the die casting workshop for trial die casting.
2. Newly arrived aluminium ingots that have not been tested can be stored temporarily in warehouses. Warehouse administrators should strictly distinguish the newly arrived aluminium ingots from those currently in use, and mark the newly arrived aluminium ingots temporarily stored in warehouses. The same batch of aluminium ingots with different stacks should be identical.
3. Aluminum ingots temporarily stored in new warehouses are not allowed to be used in production workshops without permission. The batch of aluminium ingots are marked. There should be a clear code of material and alloy, quantity, date of purchase and inspection status of aluminium ingots. (Aluminum ingots that have not been tested and die-cast must be suspended pending inspection marks.)
4. The qualified aluminium ingots must be tested in the die-casting workshop. The test-casting products should not be less than 2000 small parts and 800 large parts. The test-casting products must be inspected by the workshop director and the quality management department, and must be inspected after aging treatment, such as cracking, cracking and deformation. Surface inspection.
5. Qualified aluminium ingots can be identified as qualified raw materials only when the quality inspector of the Quality Management Section fills in the "Aluminum Ingot Inspection Report". According to the above test report, the Quality Management Section signs and confirms the warehouse receipt and indicates that the batch of aluminium ingots has passed the above two tests. At this time, the material can be officially put into warehouse. The warehouse administrator formally hangs the inspected mark, indicating that the material can be formally put into production.
6. For aluminium ingots that have passed the inspection, the warehouse administrator shall prepare the material batch number for them:
II. Aging Treatment of Die Castings
1. All die castings must undergo aging treatment to eliminate the die-casting stress of the product.
2. The die castings produced in the die-casting workshop must be stacked for 15-20 days after full inspection to eliminate the die-casting stress of the products. Only the die castings after aging treatment can flow into the next process.
3. For die castings with aging treatment, a clear time mark must be made.
4. The quality inspector shall sample the die castings after aging treatment. To ensure that the product fully meets the production requirements, the warehouse can be formally entered into the next process of production.
5. If the product with unfinished ageing treatment is to be started due to urgent production needs, the quality inspector of the die casting workshop shall fill in the "Concession Letter" and it must be approved by the company inspection department and the director of the die casting production workshop.
6. When using products that have not completed the timeliness treatment, the products that are first processed should be shipped first.
III. Batch Number Management of Raw Materials (Aluminum Ingot)
1. Because each batch of raw materials (aluminium ingots) has different components, the batch management of raw materials must be carried out in the die casting workshop.
2. The batch number of aluminium ingots put into production must be aluminium ingots that have passed the above-mentioned inspection.
3. The products produced by the same batch of aluminium ingots must be strictly distinguished from those produced by other batches of aluminium ingots and marked. The labeling contents include: product type, material batch number, production time (time labeling of timeliness treatment), etc.
4. Later processing also needs to be done according to the batch number of materials.
9. Control of Return Material
1. In the process of die-casting production, operators are strictly prohibited from privately putting back the furnace charge (such as defective products, slag-collecting bags, etc.) into the furnace. It is a serious violation of the production and operation rules to put back the burden to the holding furnace without permission, and it will be subject to economic penalty of 50-100 yuan.
2. Operators in the production process, will be unqualified products and slag discharge materials separately placed in a special basket, strictly prohibit the return charge directly placed on the ground. All return charge should be stacked separately and marked.
3. Slag discharging materials of die castings and waste materials after sand blasting are strictly forbidden to be put into use in insulation furnaces. They must be used after smelting, degassing, slag removal and refining.
4. Return charge should be put into refining. Whether it is suitable for re-refining or not should be decided after testing. Return burden should be sorted before refining to remove impurities and other irrelevant materials. After sorting, the return charge must be cleaned to remove the impurities and dirt attached to it.
5. The workshop director decides when to put the recycled burden into refining, which equipment to process the recycled product, and which products to produce (mainly non-hermetic products and products with low strength requirements) after the qualified recycled material has been tested. Production squad leader and quality inspector monitor the input of return charge to the furnace, and strengthen the inspection of return charge die castings, including strengthening inspection and product sampling.
6. All return charge die castings must also be aged to eliminate the die-casting stress of the products.
7. All die castings with return charge must be clearly marked.
8. Disposal of non-Refining waste:
1) The scrap is melted into aluminium ingot by workshop.
2) After sorting, scrap aluminium will be sold off.
10. Maintenance and Maintenance of Die Casting Equipment and Moulds
Maintenance and maintenance of die casting equipment:
1. All die-casting equipment should be used in strict accordance with the operating rules of the equipment.
2. Daily maintenance and maintenance of all die casting equipment, secondary maintenance, intermediate repair and overhaul, please refer to Equipment Management Procedure for:
1) Daily maintenance and maintenance of die casting equipment, such as daily inspection of equipment before going to work, adding lubricant, etc., to ensure the normal operation of die casting equipment.
2) The die casting equipment runs 1000H for one maintenance.
3) Die casting equipment running 6200H for medium repair.
4) The die casting equipment runs 18000H for overhaul.
3. Establish operation instruction for daily maintenance and maintenance of equipment. Die-casting workers carry out daily maintenance and maintenance of equipment in accordance with the requirements of the operation instruction before each shift goes to work.
4. Establish a equipment file for each die-casting machine. The monitor of each shift records the daily maintenance and maintenance of the equipment. For example, the type and quantity of products produced by this equipment in this class.
5. Records of all levels of maintenance, repair and overhaul of die casting equipment constitute a relevant file of equipment.
2. Maintenance and maintenance of die casting dies;
1. For each set of die-casting dies currently in use and newly manufactured, a die file should be established.
2. The old mold files should clearly indicate the time when the mold was put into use and the number of molds that had been suppressed. The above data can be estimated.
3. Establish daily maintenance and maintenance instructions for diecasters, squad leaders, diecasters, repairmen, etc. to carry out daily maintenance and maintenance of dies and moulds according to the requirements of the operation instructions.
4. The daily maintenance and maintenance instructions for dies and moulds should specify the following aspects:
1) Who is responsible for installing the mould on the machine?
2) Who is responsible for cleaning, inspecting and recording the mould after it is unloaded.
3) Mould maintenance.
4) The service life of the die.
5. After the new mould is made, the quality management department is responsible for convening the mould design and manufacture personnel, the director of the die casting workshop and the inspector to discuss the acceptance of the mould. Qualified moulds can be put into production, and unqualified moulds are discussed and improved by designers and manufacturers.
6. Mould files should clearly record the number of products produced by the die casting, the problems caused by the die and the maintenance records of the die.
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