Cost Comparison of Cast Iron vs. Cast Steel for Grates
Choosing between cast iron and cast steel for grate material depends mainly on raw material cost, manufacturing and machining cost, and the size and working conditions of the boiler. The two materials differ clearly in cost structure, so they should be costed separately during selection.
Cost structure comparison
Cast iron takes pig iron as its main raw material, has a lower price and wide availability, and its casting process is relatively simple, with modest demands on casting equipment and skill. Cast iron also machines well afterwards, so manufacturing and machining cost is lower. Cast steel needs higher-grade steel, and some grades also require alloying elements, so raw material cost is usually well above cast iron. Its casting process is complex, with strict requirements on moulds, melting equipment and pouring practice, and the higher hardness makes later machining harder, so manufacturing and machining cost rises accordingly.
| Item | Cast iron | Cast steel |
|---|---|---|
| Raw material cost | Mainly pig iron, lower price, wide availability | Higher-grade steel with alloying elements, higher cost |
| Manufacturing and machining cost | Simple casting process, good machinability, lower cost | High casting and machining requirements, higher cost |
Selection considerations
Cast iron suits ordinary duties where performance requirements are not high, while cast steel holds reasonable cost performance in applications that match its higher performance. Actual selection has to weigh boiler size, working conditions and cost before the grate material is fixed.
