Nickel–molybdenum alloys for hydrochloric acid — any concentration, any temperature within the practical range.
B-2 and B-3 are almost pure nickel–molybdenum. That chemistry gives them near-immunity to hydrochloric acid and to other reducing acids, but it also means they have no chromium and therefore no resistance to oxidising species. Ferric or cupric ions in the stream will attack them quickly, so they must not be used where the acid has picked up iron or copper contamination.
B-3 is the modern version: the composition was adjusted to delay the formation of the Ni4Mo β phase at grain boundaries, which gives it much better thermal stability and weld-zone resistance than B-2.
ASTM B564, B574, B575, B622
The default alloy for mixed acids, chlorides and wet chlorine — and the grade most often specified when no one is sure what the stream will do.
Alloy detailChromium-rich cousins of C-276: better in oxidising media and in wet chlorine, with C-4 for hot ductility.
Alloy detailOne alloy for seawater, sour gas and 600 °C strength — the workhorse of offshore and supercritical service.
Alloy detailQuotes within one business day. Send grade, size, pressure class, face type and quantity — a drawing works better than a description.
