Low Temperature Stop Control Valve in Carbon Steel

The outstanding performance of LCB (ASTM A352 Grade LCB) low-temperature carbon steel castings not only stems from high-quality components, but also relies on precise control of casting and heat treatment processes. In the casting process, resin sand molding technology is adopted, combined with a bottom injection gating system, to ensure smooth filling of the molten metal, reduce defects such as pores and sand holes, and the density of the castings reaches over 98%. After non-destructive testing such as UT (ultrasonic testing) and MT (magnetic particle testing), the defect detection rate is less than 1%. After pouring, a stepped slow cooling process is adopted to prevent the casting from generating internal stress due to uneven cooling, laying a stable foundation for subsequent processing. The heat treatment process adopts the "normalizing (890-950℃ held for 2-3 hours) + tempering (620-680℃ held for 4-5 hours)" process, which enables the material to obtain a uniform ferrite + pearlite…