WCB, which is an abbreviation of Weldable Cast B-Grade Carbon Steel, is a cast steel with carbon as the main alloying element. Cast steel is a general term for iron-based casting alloys used to produce castings that do not undergo eutectic transformation during the solidification process. WCB is a common material number for valves and their fittings.
WCB cast carbon steel (UNS Code J03002) is covered by ASTM A216/A216M standard (ASTM A216/A216M Steel Castings, Carbon, Suitable for Fusion Welding, for High-Temperature Service ), which specification covers carbon steel castings for valves, fittings, flanges and other pressure-containing parts for high temperature service and the quality required for assembly with other castings or wrought steel parts by fusion welding. The equivalent grade of WCB in China standard is ZG280-520.
There are three grades of carbon steel covered in specification of ASTM A216/A216M, WCA (UNS J02502), WCB and WCC (UNS J02503). Selection will depend upon design and service conditions, mechanical properties, and the high temperature characteristics.
Castings of WCB shall be furnished in the annealed, or normalized, or normalized and tempered according to the end usage. WCB have a good weldability, so the weld repairs shall be inspected to the same quality standards that are used to inspect the WCB castings.
Carbon steel is an iron-based casting alloy with carbon as the main alloying element and a small amount of other elements. Cast low-carbon steels with carbon content less than 0.2%, cast medium-carbon steels with carbon content of 0.2% to 0.5%, and cast high-carbon steels with carbon content greater than 0.5%. As the carbon content increases, the strength and hardness of cast carbon steel increase. Cast carbon steel has high strength, plasticity and toughness, and low cost. It is used in heavy machinery to manufacture parts that bear heavy loads, such as rolling mill stands, hydraulic press bases, etc. It is used on railway vehicles to manufacture parts that are subject to great force and impact, such as bolsters, side frames, wheels and couplers.