In the consumption of copper castings, the common casting defects are pores, pinholes, casts showing worm-like or partially black, tin sweat and lead sweat, slag inclusion, segregation, shrinkage, shrinkage, lack of pouring (lack of meat), Cold separation and so on. <<<<<< Chromium ore procurement bidding, bidding quantity: 6000-10000 tons / year

In general, the cause of these defects is not only the problem of smelting and casting, but also the problems of many consumer processes such as external core making, sand quality, falling sand clearing, etc., and therefore detailed analysis is required. In order to take appropriate reasonable measures to deal with.

When consuming copper castings, the common defects and their causes are analyzed and avoided as follows:

Stomata

Analysis of the reasons:

1. Alloy liquid inhalation is serious

2. The pouring temperature is too high

3. The content of moisture, clay or fine sand in the molding sand is too high, or the sputum is too solid and the gas permeability is poor.

4. Oil sands are too high in oil

5. Sand and core are not dried

6. Pouring the system into improper design, or improper operation when pouring, entrained in air

7. Pouring water

8. The appearance of cold iron is rust, wet or dressing

9. Excessive metal coating oil

10. Metal mold temperature is too high or too low, poor ventilation

11. The vent is infarcted or lacking in quantity

Ways to avoid:

1. Strictly control the charge and appearance of the data, pay special attention to control the moisture content

2. Improve the design and leave enough vents

3. Dry type should be dried

4. Control the pouring temperature

5. When pouring from time to time, the liquid column should be short

6. Cold iron derusting and drying

7. Metal type temperature should be appropriate, tin bronze 80~120°C, brass and Wuxi bronze 150~200°C

8. Excessive ventilation on the metal parting surface, the gas is not easily discharged, and the gas is taken out by the vent plug.