Quick answer: cast bodies are made by pouring molten steel into a mould, which allows complex shapes and large sizes at lower cost. Forged bodies are shaped from solid steel under pressure, which gives a denser, more uniform structure and suits small, high pressure valves. Neither is automatically better.
Comparison
| Point | Cast body | Forged body |
|---|---|---|
| Size range | Suits medium and large valves | Usually small valves |
| Shape freedom | Complex internal geometry possible | Simpler geometry |
| Structure | Grain structure depends on casting and heat treatment quality | Dense and uniform |
| Cost | Lower per kilogram at larger sizes | Higher for the same weight |
| Inspection | Casting defects must be controlled by process and NDT where specified | Fewer internal defect risks |
Where each route belongs
- Large pipeline and process valves: cast bodies
- Small high pressure valves, instrument and manifold duty: forged bodies
- Where the specification calls for a forged design in small sizes, follow the specification
- Where a complex shape is needed, casting is usually the only economic route
Why casting quality is a process question
Casting quality is decided before the valve is machined: by the charge chemistry, the pouring temperature, the mould and the heat treatment. A foundry that controls those steps produces bodies with predictable mechanical properties, and can show the traceability behind them.
待补内容位：待补：工厂可提供的铸件材质清单、热处理工艺说明、可执行的探伤项目（另可考虑将本页与锻钢阀产品页互链）。