In the process of casting boiler parts, the quality of products is also divided into good and bad. What are the requirements for products, how to define whether Boiler Steam Boiler Grate Bars are qualified or not, and what are the reasons for the unqualified products.
Tiny and incoherent shrinkage cavities in the Boiler Steam Boiler Grate Bars castings, 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. In the inside of the thick section of the casting, the inside of the two interfaces, and the inside or surface of the intersection of the thick section and the thin section, the shape is irregular, the hole is rough, and the grains are coarse. 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. Inside, on or near the surface of Boiler Steam Boiler Grate Bars, there are smooth perforations of varying sizes, round, long and irregular in shape, single or aggregated into sheets. 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 Boiler Steam Boiler Grate Bars.