Modified 14Cr-16Ni stainless steels with improved creep resistance at 700/sup 0/C due to tailored precipitate microstructures

Conference · Tue Sep 01 04:00:00 EDT 1987

OSTI ID:6253577

Maziasz, P J; Swindeman, R W

The compositions of several 14Cr-16Ni (2.5Mo,2Mn) austenitic stainless steels were modified with combinations of minor and residual alloying elements to produce excellent creep strength based on unique precipitate microstructures. These modifications produce fine MC and FeTiP precipitate particles in the matrix for strength, and combinations of coarser M/sub 23/C/sub 6/, M/sub 6/C and MC, particles along the grain boundaries for improved ductility and rupture resistance. The creep-rupture resistance of these modified 14 to 16 steels is superior to that of type 316 or alloy 800H and better than that of 17 to 14CuMo at 700/sup 0/C in the mill-annealed condition. These new steels approach the creep resistance of alloy 617 at 700 to 760/sup 0/C. Analysis of microstructure and correlation with creep properties suggests that precipitate effects are primarily responsible for the improvement in mechanical properties. The design of the novel precipitate microstructures is based on microcompositional information obtained using state-of-the-art analytical electron microscopy (AEM). 7 refs., 8 figs., 1 tab.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6253577
• Report Number(s): CONF-870980-1; ON: DE87014788
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
COBALT ALLOYS
COMPARATIVE EVALUATIONS
CORRELATIONS
CORROSION RESISTANT ALLOYS
CREEP
CRYSTAL STRUCTURE
ELECTRON MICROSCOPY
FOSSIL-FUEL POWER PLANTS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INCOLOY 800H
INCOLOY ALLOYS
INCONEL 617
INCONEL ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
MANGANESE ADDITIONS
MANGANESE ALLOYS
MATERIALS
MECHANICAL PROPERTIES
MICROSCOPY
MICROSTRUCTURE
MODIFICATIONS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
POWER PLANTS
SILICON ADDITIONS
SILICON ALLOYS
STAINLESS STEEL-316
STAINLESS STEELS
STEELS
SUPERHEATERS
THERMAL POWER PLANTS
TITANIUM ADDITIONS
TITANIUM ALLOYS