How to judge and accept the quality of cast iron platforms

How to judge and accept the quality of cast iron platforms

For the casting industry, damage to cast iron platform castings is quite common, but the consequences of different degrees of loss are different. So how to judge the quality of cast iron platforms? Below, the editor will briefly explain from the following aspects:

1、 The working face of the cast iron platform shall not have defects such as sand holes, air holes, cracks, slag inclusions, shrinkage porosity, scratches, bumps, rust spots, etc. that seriously affect the appearance and performance.

1. The casting surface of the cast iron platform should be cleaned of sand and leveled, and painted firmly.

2. On flat working surfaces with precision levels of 0-3, sand holes with a diameter less than 15mm are allowed to be blocked with the same material, and their hardness should be lower than that of the surrounding materials. The number of sand holes blocked in the working face should not exceed 4, and the spacing between sand holes should not be less than 80mm.

3. It should be made of fine grey cast iron or alloy materials, with a working face hardness of 170-220HB.

4. The working face should usually use scraping technology. The allowable surface roughness Ra for the 3-level flat working surface processed by scraping is 5um.

2、 Judgment of Scratching and Grinding Quality of Cast Iron Platform Working Face

1. Rough scraping: If the surface of the platform is relatively rough, the processing marks are deep, or the surface is severely rusted, uneven, or twisted, and the scraping allowance is above 0.005mm, rough scraping should be carried out first. The rough scraping point is achieved by using a long scraper with a stroke length (between 10mm and 15mm) and a wide blade mark (10mm). The scraper mark runs in the same direction and does not repeat in patches. After removing the knife marks from the machining of the cast iron platform, it can be polished and scraped according to the visible high points..

2. Fine scraping: Fine scraping is the process of scraping off the high points after rough scraping, using a short scraping method (with a knife mark width of about 6mm and a length of 5mm~10mm) to quickly disperse the grinding points. When fine scraping, it is necessary to scrape in a certain direction. After scraping once, the second time should be at a 45 degree or 60 degree angle to cross and scrape out the mesh pattern. When the average research point is 10-14 points per 25 ㎡ x 25 ㎡, the fine scraping can be ended.

3. Fine scraping: Fine scraping is carried out on the basis of fine scraping, using small scrapers or curved fine scrapers with a width of about 4mm and an average grinding point of 20-25 points per 25 ㎡ x 25 ㎡,

4. Scratching: Scratching has two functions: firstly, it is aesthetically pleasing, and secondly, it has the function of accumulating lubricating oil. Common patterns include diagonal patterns, swallow shaped patterns, and fish scale patterns.

3、 Weight deviation: During the production process, cast iron platforms may experience weight deviation. The design of cast iron platforms often takes into account casting errors and mechanical processing errors. The weight error of cast iron platforms should generally not exceed 10%. When it exceeds 10%, further evaluation of the quality of the cast iron platform is necessary to determine whether it can be put into use.