Mechanical properties and microstructures of dual phase steels containing silicon, aluminum and molybdenum

Technical Report · Thu Mar 01 00:00:00 EST 1979

OSTI ID:5688645

O'Neill, Jr, T J

An investigation concerning the heat treatment of duplex ferritic-martensitic low carbon steels containing silicon, aluminum and molybdenum was carried out. Tensile properties of intermediately quenched and directly annealed specimens were characterized and microstructural correlations established. The two-phase mixture rule is used as a fairly good approximation of the mechanical behavior of the duplex system, but it has been recognized that the properties of both the ferrite and martensite depend on the volume fraction of martensite produced in the final morphology. Thus, although the volume fraction of martensite appears to be the most influentuial factor in controlling the behavior of the duplex steel, ferrite strengthening may occur by precipitation hardening, and the strength of martensite may increase due to carbon enrichment as its volume fraction is decreased. Utilization of both of these factors results in a composite whose properties do not depend upon the martensite volume fraction (up to about .4). Greater leeway can be achieved in controlling the heat treatment temperatures of the alloy. Such a steel, a Fe/.06C/.93A1 alloy, has been investigated in this study.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5688645
• Report Number(s): LBL-9047
• Resource Relation: Other Information: Thesis
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
IRON BASE ALLOYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
STEELS
CARBON ADDITIONS
FERRITE
HEAT TREATMENTS
MARTENSITE
MOLYBDENUM ADDITIONS
PRECIPITATION HARDENING
QUANTITY RATIO
ALLOYS
CRYSTAL STRUCTURE
HARDENING
IRON ALLOYS
MOLYBDENUM ALLOYS
360102* - Metals & Alloys- Structure & Phase Studies
360103 - Metals & Alloys- Mechanical Properties