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347/347H

UNS S34700/S34709

Description

347/347H is an austenitic chromium steel containing columbium often used in refineries, high temperature chemical processing, and high temperature steam service. This columbium bearing steel not sensitive to intergranular corrosion after heating within the range of carbide precipitation but elevated properties may be achieved through cold reduction.

Forms in Stock

Specifications

Smls Pipe ½”-12″ 40s, 80s, 120, 160, XXH ASTM/ASME 312
B/W Fittings ½”-8″ 40s, 80s ASTM/ASME 403
Flanges ½”-8″ 150#, 300#, 600# ASTM/ASME 182

Limiting Chemical Composition, %

Ni…9.0-13.0 Si…0.75 max.
Cr…17.0-19.0 S…..0.03 max.
C…..0.08 max. P…..0.045 max.
Mo…3.0-4.0 Co + Ta…8 x C min. 1.00 max.
Fe…Balance
Mn…2.0 max.