In the casting process of Large Block Moving Chain Boiler Grate accessories, the quality of the products is also divided into good and bad. What are the requirements for the products? How to define whether the product is qualified or not? What are the reasons for product failure?
Shrinkage porosity is a small and incoherent shrinkage cavity inside the Large Block Moving Chain Boiler Grate casting, which is gathered in one or more places, the grains are coarse, there are small holes between the grains, and water seeps during the hydrostatic test.
Preventive measures: Minimize thermal joints at the connection between walls, and reduce pouring temperature and pouring speed as much as possible. Shrinkage cavity defects are irregular in shape, rough in the hole and coarse grains in the inside of the thick section of the casting, the inside of the two interfaces, and the inside or surface of the junction of the thick section and the thin section. Preventive measures: Castings with small and uniform wall thickness should be solidified at the same time, and castings with large and uneven wall thickness should be solidified sequentially from thin to thick, and chilled iron with a reasonable placement of risers. Stomatal defects, in the interior of the casting, on the surface or near the surface, have smooth holes of varying sizes, with round, long and irregular shapes, single or aggregated into pieces. The color is white or with a layer of dark color, sometimes covered with a layer of oxide skin. Precautionary measures: Reduce the suction of gossip metal when smelting. Reduce the amount of gas generated by the sand mold during the pouring process, improve the structure of the casting, improve the air permeability of the sand mold and the core, and enable the gas in the mold to be discharged smoothly.
The above are the reasons for possible product failure and preventive measures during the casting process of Large Block Moving Chain Boiler Grate accessories. Liaocheng Ningsen Machinery Parts Co., Ltd. sells its products with strict quality control.