1. Parts of the casting are incomplete, often appearing in the thin-walled part, the part farthest from the runner or the upper part of the casting. The incomplete corners are smooth and shiny without sticking sand.
1.1 Reasons:
1.11The pouring temperature is low, the pouring speed is too slow or the pouring is intermittent
1.12 The cross-sectional area of the runner and inner runner is small
1.13 The content of carbon and silicon in molten iron is too low
Excessive moisture and pulverized coal content in the molding sand, large gas generation, or too high mud content, poor air permeability
1.14 The height of the upper sand mold is not enough, and the pressure of the molten iron is insufficient
1.2 Prevention method:
1.21 Increase the pouring temperature, speed up the pouring speed, and prevent intermittent pouring
1.22 Increase the cross-sectional area of the runner and inner runner
1.23 Adjust the ingredients after the furnace, and appropriately increase the carbon and silicon content
1.24 Strengthen the exhaust gas in the casting mold, reduce the amount of coal powder and organic matter added in the molding sand
1.25 Increase the height of the upper sand box
2. The castings are all incomplete. The level of the molten iron in Zhide Road is the same as the level of the molten iron of the castings.
The edges are slightly rounded.
2.1 Reasons:
2.11 The amount of molten iron in the ladle is not enough
2.12 The pouring speed is too fast, when the molten iron overflows from the pouring cup, the operator mistakenly thinks that the wrong type has been first
full, stop pouring too early
2.2 Prevention method:
2.21 Correctly estimate the amount of molten iron in the ladle
2.22 For the narrow casting mold, slow down the pouring speed appropriately to ensure that the casting mold is full
3. The casting is damaged and broken.
3.1 Reasons:
3.11 The castings are shaken too violently, or the castings are damaged by impact during handling
3.12 When the drum is cleaned, the casting is improperly loaded, and the weak part of the casting is broken during rolling
3.13 The size of the riser and the riser neck section is too large; the riser neck has no knock section (groove). Or the method of knocking out the pouring riser is incorrect, so that the casting body is damaged and incomplete
3.2 Prevention method:
3.21 When the castings are cleaned and transported by falling sand, pay attention to avoid various forms of excessive collision and vibration, and avoid unreasonable throwing
3.22 Strictly follow the process rules and requirements when cleaning the drum
3.23 Modify the dimensions of the riser and the riser neck, make a knock section of the riser neck, and correctly grasp the direction of the pouring riser
4. Sticky sand and rough surface
Sticky sand is a kind of surface defect of castings, which means that the surface of castings adheres to the sand that is difficult to remove.
4.1 Causes:
4.11 The sand is too coarse and the sand mold is not compact enough
4.12 The moisture in the molding sand is too high, so that the molding sand is not easy to be compacted, the pouring speed is too fast, the pressure is too high, and the temperature is too high
4.13 There is too little pulverized coal in the molding sand, and it is broken and pulled away. Causes the surface sand to dry out. The low drying level of the glass mold is too low, and the mold is attached to the display board in seconds
4.2 Prevention method:
4.21 In the case of sufficient air permeability, use finer raw sand and appropriately increase the compactness of molding sand
4.22 Ensure stable and effective pulverized coal content in molding sand and strictly control sand moisture
4.23 Improve the pouring system, improve the pouring operation,
4.24 Reduce the pouring temperature and control the baking temperature of the template, which is generally equal to or slightly higher than the temperature of the molding sand.
5. Sand holes are holes filled with molding sand inside or on the surface of the casting.
5.1 Reasons:
5.11 The surface strength of molding sand is not enough
5.12 There is no rounded corners or small draft angle on the pattern, which leads to the hook sand, the mold is damaged and the box is closed without repairing or repairing it.
5.13 The sand mold is placed for too long before pouring, and the surface strength decreases after air-drying
5.14 The mold is damaged when closing the box or during handling
5.15 When the box is closed, the floating sand in the mold is not removed. After the box is closed, the sprue cup is not covered, and the broken sand falls into the mold.
5.2 Prevention method:
5.21 Increase the viscosity of the molding sand, add new sand in time, and improve the surface strength of the molding sand
5.22 The finish of the pattern should be high, and the draft angle and casting fillet should be reasonably made. The damaged mold should be repaired before closing the box
5.23 Shorten the placement time of the sand mold before pouring
5.24 Be careful when closing the box or handling the mold to avoid damage or sand particles falling into the mold cavity
5.25 Before closing the box, remove the floating sand in the mold and cover the gate
Qingdao Sanzhuji Equipment Manufacturing Co., Ltd. specializes in the production of Green Sand Molding Line,Self-hardening sand molding line,foundry machines,Sand molding machine,Sand casting equipment,sand mixer,GS high efficiency rotary mixer,Resin sand mixer,no-bake resin sand mixer,Jolt squeeze molding machine/Jolt-squeezing moulding machines,Multi- Piston Moulding Machine/Hydraulic multi-piston moulding machine,sand casting molding machine,sand reclamation equipment，foundry molding machine,flaskless moulding machine,shot blasting machine,dust collector,according to the amount of old sand recovered Carry out plan customization, and provide sand reclamation equipment installation, commissioning, and training. Welcome guests to visit the factory.
