Design of low alloy steels for thick walled pressure vessels. Final technical report, February 1, 1980-May 30, 1985. [2-1/4Cr-1Mo with minor additions of Cr, Ni, Mo and V]

Technical Report · Sat Jun 01 04:00:00 EDT 1985

OSTI ID:5603058

Ritchie, R O; Todd, J A; Spencer, P N; Parker, E R

This report presents results of the five year research program ''Design of Low Alloy Steels for Thick Walled Pressure Vessels.'' The objective of the program was to modify existing commercial low alloy steels and to develop new alloys to satisfy the material requirements for thick section plate up to 400 mm (16 in.) to be used for construction of the large pressure vessels envisioned for second and third generation coal conversion systems. A new series of experimental 3Cr-Mo-Ni steels were produced and investigated for suitability as improved materials for large thick section coal conversion pressure vessels. These new steels rely on minor alloy modifications to commercial 2-1/4Cr-1Mo (ASTM A387 Grade 22 Class 2) steel. Hardenability, yield strength, tensile ductility, Charpy V-notch impact toughness, hydrogen attack resistance, and creep rupture and temper embrittlement resistance were investigated. Initial studies on fatigue crack propagation in hydrogen attacked steel, and fracture toughness (K/sub Ic/) studies were carried out. It was found that the new steels are superior to 2-1/4Cr-1Mo steel with respect to hardenability, room temperature strength, impact toughness and resistance to hydrogen attack, and wre comparable with respect to room and elevated temperature ductility, creep strength and rupture ductility and temper embrittlement resistance. Moreover, their mechanical properties compare very favorably with other 3Cr-Mo steels recently developed by Climax Molybdenum Company and the Japan Steel Works. Of the Berkeley experimental steels, the 3Cr-1-1/2Mo-1/2Ni composition is considered to have the best combination of properties for thick section coal conversion applications and has been recommended for further testing in larger heats and for eventual commercial certification. 58 refs., 69 figs., 20 tabs.

• Research Organization: California Univ., Berkeley (USA). Dept. of Materials Science and Mineral Engineering
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5603058
• Report Number(s): ORNL/Sub-80-7843/01; UCB/RP-85/D1034; ON: DE86011748
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404 -- Coal
Lignite
& Peat-- Gasification
36 MATERIALS SCIENCE
360100* -- Metals & Alloys
ALLOYS
CHARPY TEST
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-MOLYBDENUM STEELS
CONTAINERS
CRACK PROPAGATION
CREEP
DATA
DESTRUCTIVE TESTING
DUCTILITY
ELEMENTS
ELONGATION
EMBRITTLEMENT
EXPERIMENTAL DATA
FABRICATION
FATIGUE
FRACTURE PROPERTIES
HARDENING
HEAT TREATMENTS
HYDROGEN
IMPACT TESTS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
JOINING
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
METALLOGRAPHY
METALLURGICAL EFFECTS
NONMETALS
NUMERICAL DATA
PRESSURE VESSELS
RECOMMENDATIONS
STEEL-ASTM-A387
STEELS
TEMPERATURE DEPENDENCE
TENSILE PROPERTIES
TESTING
WELDING
YIELD STRENGTH