Assessment of AFA Stainless Steels for Tube Products

摘要

Oak Ridge National Laboratory (ORNL) and Carpenter Technology Corporation (Carpenter) participated in an in-kind cost share cooperative research and development agreement (CRADA) effort under the auspices of the Energy Efficiency and Renewable Energy (EERE) Technology Maturation Program to assess material properties of several potential AFA family grades and explore the feasibility of producing alumina-forming austenitic (AFA) stainless steels in tubular form needed for many power generation and chemical process applications. Carpenter's Research Laboratory successfully vacuum melted 30 lb heats of seven candidate AFA alloy compositions representing a wide range of alloy content and intended application temperatures. These compositions were evaluated by ORNL and Carpenter R&D for microstructure, tensile properties, creep properties, and oxidation resistance. In parallel, additional work was directed toward an initial tube manufacture demonstration of a baseline AFA alloy. Carpenter successfully manufactured a 10,000 lb production heat and delivered appropriate billets to a partner for extrusion evaluation. Tube product was successfully manufactured from the baseline AFA alloy, indicating good potential for commercially produced AFA tubular form material.