WCB vs WC6 vs WC9
Steam temperature drives chromium-moly cast grades. Mis-stating WCB for hot steam is a common RFQ error.
Side-by-side
| Topic | WCB | WC6 / WC9 |
|---|---|---|
| Alloy | Carbon steel | Cr-Mo alloy steels |
| Temp | Lower steam / process | Higher temperature steam |
| RFQ cue | A216 WCB | A217 WC6 or WC9 |
| Cost | Lower | Higher |
| Docs | MTC 3.1 typical | MTC + heat treat notes |
RFQ tip
Always state design temperature next to the cast grade on steam RFQs.