Work Item
ASTM WK83562

Revision of A1091/A1091M-21 Standard Specification for Steel Castings, Creep-Strength Enhanced Ferritic Alloy, for Pressure-Containing Parts, Suitable for High-Temperature Service


This revision is for the addition of an additional grade of steel into the standard called C933, and alinement of terminolgy in relation from Cb and Nb as seen in other new standard revisions.

C933 has been developed over the past ten years by several major industrial companies and research organisations within and beyond the U.K., and is based in outline on the MarBN steel first proposed by Professor Fujio Abe of NIMS Japan. The material is a 9% chrome steel and is modified by additions of approximately 3% cobalt and tungsten with controlled additions of vanadium, niobium, boron and nitrogen which enhance creep performance.


Developed by Subcommittee: A01.18

Committee: A01

Staff Manager: W Scott Orthey

Work Item Status

Date Initiated: 09-27-2022

Technical Contact: Stephen Roberts

Item: 000