High-niobium bearing steel for base material of CRA clad UOE pipe

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:398018

Terada, Y; Tamehiro, H ^[1]; Uemori, R; Maruyama, N; Ogawa, H ^[2]; Takahashi, A ^[3]

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1. Nippon Steel Corp., Kimitsu (Japan)
2. Nippon Steel Corp., Futtsu (Japan)
3. Nippon Steel Corp., Kitakyushu (Japan)

The manufacturing technology of corrosion resistant alloy (CRA) clad UOE pipe by applying thermomechanical control process (TMCP) has been studied. In order to obtain good pitting corrosion resistance in the Incoloy 825 layer, it is necessary to ensure complete recrystallization and suppress the precipitation of chromium carbides in the Incoloy 825 layer after rolling. To this end the clad plate was finish-rolled at high temperature and water-cooled after appropriate air cooling. However, in conventional steel, high temperature rolling considerably deteriorates the low-temperature toughness, therefore, it was found that increasing the niobium content causes the microstructure to refine remarkably and provides an excellent balance of strength and low-temperature toughness at a niobium content of about 0.1% even in high temperature rolling. The grain refinement by adding high niobium is attributable to suppression of austenite grain coarsening during slab-reheating by Nb(CN) particles, a rise in recrystallization stop temperature of austenite.

• OSTI ID: 398018
• Report Number(s): CONF-940409--; ISBN 1-880653-10-9
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
AUSTENITIC STEELS
CORROSION RESISTANT ALLOYS
MATERIALS TESTING
MECHANICAL PROPERTIES
MICROSTRUCTURE
PIPELINES