HP's are austenitic Fe, Cr, Ni (Ni at ~33%) castings intended for creep rupture high temp oxidizing and carburizing resistance.
They rely most often on alloying from Nb and W and are commonly used for petrochem applications such as heat treat fixtures.
shane,
i remember that i've encountered EN or DIN material spec for 9Cr but our tpi don't want to consider it as P5,
he said EN or DIN is unlisted which is not in asme 9. i guess this is what joey mean.
i ask your opinion, if i have wps for EN 10025 GR S275 (comparable to A36), will you consider it as P1 material if you're reviewing
the wps against asme 9? if acceptable, i think this will save a lot of time and money for not re-doing the welding procedure qualification test.
bert