Processing characteristics of seamless steel pipe

Processing characteristics of seamless steel pipe fine casting: Since the shortening of seamless pipe steel pipe fine casting greatly exceeds the shortening of cast iron, in order to avoid the disadvantages of shrinkage and shrinkage of seamless pipe steel pipe, most of the casting process uses risers, cold irons and subsidies to complete the sequential condensation.

In order to avoid shrinkage, shrinkage holes, porosity and cracks in seamless steel pipe castings, seamless steel pipe should have uniform wall thickness, avoiding sharp corners and right-angle structures, adding sawdust in the molded sand and adding coke in the core. And use hollow sand core and oil sand core to improve the concession and air permeability of sand mold or sand core.

Processing characteristics of seamless pipe castings:

Due to the poor fluidity of steel, in order to avoid cold segregation and seamless pipe castings pouring, the wall thickness of steel castings should not be less than 8mm. Use dry casting or hot casting; Appropriately increase the pouring temperature, generally 1520° ~ 1600°C. Due to the high pouring temperature, the steel superheat is high and the liquidity of the steel is long time, which can improve the fluidity. Seamless Steel Pipe Factory, Seamless Steel Pipe Manufacturer suggests you that if the pouring temperature is too high, then the seamless pipe will cause defects such as coarse grains, thermal cracks, porosity and sand adhesion. Therefore, usually smaller, thinner and messy shape of the fine casting casting temperature is about 150 ℃ of the melting point of steel.

The main reason why the conflict torque of thick-walled seamless steel tubes decreases as the speed of movement increases is the change in smoothness conditions. Seamless steel pipe when the object stops, will be between the two smooth surfaces of the smooth oil extrusion, showing a dry conflict or close to dry conflict, until the speed increases to point 3, it is completely transformed into a wet conflict, and the oil film formation is established between the two metal surfaces. The moment of conflict is separated by the oil molecules, showing positive damping characteristics, which prevents the object from vibrating at high speeds.