Analytical description of the effects of melting practice and heat treatment on the creep properties of a 2 1/4 Cr-1 Mo steel

Conference · Sat Jan 01 04:00:00 EST 1977

OSTI ID:5282171

Booker, M K

2/sup 1///sub 4/ Cr-1 Mo steel is used worldwide as an elevated-temperature structural material, particularly in steam generation systems. Since this material is often used at service temperatures up to 600/sup 0/C, successful design requires a consideration of its creep properties. Unfortunately, the development of an analytical description of the creep behavior of 2/sup 1///sub 4/ Cr-1 Mo steel is complicated by two phenomena. First, the creep strength of this material is quite sensitive to heat treatment. Second, this material tends to exhibit nonclassical creep under some conditions. In addition, especially in nuclear applications, the material used may be air-melted, vacuum-arc remelted (VAR), or electroslag remelted (ESR). Available creep data from air-melted, VAR, and ESR material have been analyzed. Heat treatments included both annealed and isothermally annealed, with and without a subsequent ''postweld'' heat treatment. It has been found that the elevated-temperature ultimate tensile strength (UTS) is a useful indicator of creep strength for a given heat of material regardless of melting practice or heat treatment. Meanwhile, the nonclassical creep behavior has been attributed to a change in creep mechanism which has been mathematically modeled.

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5282171
• Report Number(s): CONF-771120-16
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
BUILDING MATERIALS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-MOLYBDENUM STEELS
CREEP
HEAT TREATMENTS
HIGH TEMPERATURE
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
MECHANICAL PROPERTIES
STEELS
TENSILE PROPERTIES