Production Practice of Cupola Furnace Smelting RQTSi5 Heat-Resistant Ductile Iron Castings

The spheroidization rate is 2, the ball diameter is 6 and the base 268 is our factory adopting the 944188 ductile iron metallographic standard. 26; refers to the number of pearlite in the matrix is ​​10, that is, the matrix structure is ferrite + 10 spheroids. Phosphorus eutectic. Carburizing body 13 heat treatment and furnace application 3.I heat treatment silicon spheroidal graphite cast iron metallurgical structure is ferrite + spheroidal graphite, pearlite 兮 quantity is less than buckle original leisure is the production process of pearlite content in silicon ductile iron as-cast structure Control is relatively successful, and also meets the requirements of 1; 98478 light heat-resistant ductile iron body, but in the use of heat-resistant casting, in order to improve its initiality, it is necessary to lower the pearlite content in order to improve the plasticity, so low-temperature graphite is carried out. Annealing to decompose the pearlite. The final organization is ferrite + a small amount of pearlite. In order to obtain a ferrite matrix with high plastic toughness, it must be annealed by low temperature graphitization. Since there is almost no free cementite in the structure, it is not necessary to heat graphitization annealing, and the casting is heated to a range of 720,760, and the temperature is kept at 4 ratios. Cool to 600 air-cooled.

3.2 Furnace application Under the same conditions of use, after more than 2 years of operation, each roasting box can be used for half a year, and the life of the furnace floor is more than one year.

4 Economic effect After using the village material, the life of the roasting crucible is extended by one time, the annual saving cost is more than 35,000 yuan, the furnace floor exceeds the original life, the annual saving cost is more than 15,000 yuan, and the total annual saving cost is more than 50,000 yuan. Received date 19990 car 13; revised date 199 Shift 1210. Male, Shaanxi Liquan, engineer.