In the last part, the quality control of the production process in the die casting workshop involves every link of the die casting process, from smelting to production debugging to inspection and control; From key process control to equipment and mold maintenance. Every link of omission may cause quality accidents.
Raw material testing, testing, batch number management and die casting timeliness
Raw material (aluminum ingot) test and die casting
- All incoming aluminum ingot must go through the laboratory, chemical room, only the test qualified aluminum ingot can enter the die casting workshop for trial die casting
- Newly arrived aluminum ingots that have not been tested can be put into the warehouse for temporary storage first. The warehouse keeper shall strictly distinguish this batch of newly put aluminum ingots from those currently in use, and mark this batch of newly put into the warehouse for temporary storage. The same batch of aluminum ingots with different piles shall be marked.
- Aluminum ingots temporarily stored in the new warehouse shall not be issued to the production workshop for use without permission. In the logo of this batch of aluminum ingots. There SHOULD be CLEAR material alloy code, quantity, purchase date and inspection status of aluminum ingots (new aluminum ingots without test and test casting must be hung with inspection signs).
- After testing qualified aluminum ingots, must be conducted in the die casting workshop try die-casting, try die-casting products cannot under small not less than 2000 pieces of big not less than 800 pieces, try die-casting products must pass a quality inspection by workshop director and quality management department, and must pass inspection after aging treatment, such as crack, cracking, deformation, etc.
- Aluminum ingot that PASS TEST, die CASTING TEST and aging treatment inspection can only be confirmed as qualified raw materials by QUALITY inspector of quality Management Department after filling in “Aluminum INgot Inspection Report”. According to the above test report, the quality management department signs and confirms on the Warehouse Receipt, and indicates that the aluminum ingots have passed the above two tests. At this time, the material can be formally put into the warehouse. The warehouse keeper formally hangs the inspection mark, indicating that the material can be formally put into production.
- The warehouse keeper shall compile material batch number for aluminum ingots that have passed the inspection.
Timeliness of die casting
- All die castings must be time-sensitive to eliminate die casting stress.
- The die castings produced in the die casting workshop must be stacked for 15-20 days after full inspection to eliminate the stress of the die casting products, and the die castings can be processed in the following process after timeliness treatment.
- Die castings for timeliness treatment must be clearly time marked.
- The quality inspector shall carry out spot inspection on the die castings with timeliness treatment. After confirming that the products fully meet the production requirements, they can be formally put into storage to enter the next process of production.
- If the PRODUCTS with UNcompleted timeliness treatment need to be used due to urgent production, the quality inspector of the die casting workshop should fill in the Concession Release Form, which must be approved by the inspection department of the company and the director of the die casting production workshop.
- When using products that have not completed timeliness treatment, the first product to be processed shall be shipped first.
Batch number management of raw materials (aluminum ingot)
- Because the composition of each batch of raw materials (aluminum ingots) is different, so the die-casting workshop must carry out the batch number management of raw materials during production.
- The batch number of aluminum ingot put into production must be the aluminum ingot that passes the above inspection.
- Products made from aluminum ingots of the same batch number must be strictly distinguished from those made from aluminum ingots of other batches and marked. The content of labeling includes: product model, material batch number, production time (time marking for timeliness processing), etc.
- Later machining, also need to be carried out according to the material batch number.
Control of return charge
- In the process of die casting production, the operator is strictly prohibited to privately put the return charge (such as: defective products, slag collection package, etc.) into the holding furnace. It is a serious violation of production operation rules to put return charge into the heat holding furnace without permission.
- In the process of production, the operator shall place the unqualified products and slag discharge materials in the special basket alone. It is forbidden to place the return charge directly on the ground. All return charges shall be stacked separately and marked.
- The slag discharge material of die casting and the waste material after sandblasting are strictly prohibited to be used in the heat preservation furnace. They must be used after melting, degassing, slag removal and refining.
- The return charge should be put into heavy smelting, whether the return charge is suitable for back furnace heavy smelting, can be decided after test. The return charge should be sorted before remixing to remove sundries and other irrelevant materials. The sorted return charge must be cleaned to remove impurities and dirt attached to it.
- The workshop director shall decide when to put the return charge into the smelting, which equipment to use for the processing of the return charge, and what kind of products to produce (mainly non-air-tight products and products with low strength requirements) for the returned charge that has passed the test. The PRODUCTION monitor and quality inspector shall monitor the input of return charge into the furnace, and strengthen the inspection of return charge die casting, including strengthening the inspection and sampling inspection of products.
- All return charge die castings must also be aged to eliminate the die casting stress of the product.
- All return charge die castings must be clearly identified.
- Treatment of the waste material that cannot be remelted: 1) The waste material is melted into aluminum ingot by the workshop. 2) After sorting, when the waste aluminum is sold.
Die casting equipment and mold maintenance and maintenance
Maintenance and maintenance of die casting equipment
All die casting equipment should be used in strict accordance with the equipment operating procedures.
For daily maintenance, secondary maintenance, intermediate repair and overhaul of all die casting equipment, please refer to Equipment Management Procedure
1) Daily maintenance and maintenance of die casting equipment, such as checking equipment and adding lubricating oil before going to work every day to ensure the normal operation of die casting equipment.
2) The die casting equipment will be maintained for 1000 hours.
3) The die casting equipment was operated for 6200H for intermediate repair.
4) The die casting equipment was overhauled after 18000H operation.
Set UP the daily maintenance instruction of equipment. Die casters shall carry out daily maintenance and maintenance according to the instruction before each shift. Each die casting machine shall establish an equipment file, and the monitor of each shift shall record the daily maintenance and maintenance of the equipment. Such as: the type and quantity of products produced by the equipment in this shift. All levels of maintenance, repair, overhaul and other records of die casting equipment, forming a related file of equipment.
Maintenance and maintenance of die casting mold:
(1) A mold file should be established for each set of die casting molds that are being used and newly made.
(2) the old mold files should clearly indicate the time when the mold is put into use, how many molds have been suppressed and other data, the above data can be estimated.
(3) Establish the daily maintenance and operation instructions for molds. Die casters, monitor, mold workers, maintenance workers and other workers shall carry out daily maintenance and maintenance of molds according to the requirements of the operation instructions.
Mold daily maintenance and maintenance operation instructions should be clear in the following aspects:
1) Who is responsible for installing the mould on the machine?
2) Who shall be responsible for cleaning, inspecting and recording the mold after unloading?
3) Maintenance of molds.
4) The service life of the mold.
After the new mold is made, the quality management department is responsible for convening the mold design and production personnel, the director of the die casting workshop, the inspector and so on to carry out the mold acceptance discussion. The qualified molds can be put into production, and the unqualified molds can be improved by the design and production personnel.
The mold file should clearly record how many products have been die-cast in the mold, what kind of problems have been caused by the mold, and the maintenance record of the mold.