Microstructure and tensile behavior of nitrogen-alloyed, dual-phase stainless steels
- Ruhr Univ. Bochum (Germany). Lehrstuhl Werkstofftechnik
- ZF Friedrichshafen AG (Germany)
- Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering
- Illinois Inst. of Tech., Chicago, IL (United States). Dept. of Metallurgical and Materials Engineering
Two alloys of high-nitrogen stainless steel have been heat treated to produce dual-phase microstructures. The first alloy, N10CrNiMo17 1, a Ni-containing stainless steel, was processed conventionally. The second alloy, N20CrMo17, a Ni-free stainless steel, was processed to obtain a higher nitrogen content by pressurized electroslag remelting. The martensite in N10CrNiMo17 1 was homogeneously distributed in the ferrite and obtained a near-constant volume fraction as a function of intercritical annealing temperature. Microprobe analysis and microhardness measurements of the martensite constituent suggested that up to 0.4 pct N was dissolved in the austenite before quenching. Austenite formation, martensite transformation, undissolved nitrides, and retained austenite were evaluated by transmission electron microscopy (TEM). The Ni-containing alloy exhibited classic dual-phase tensile behavior in that continuous yielding was observed together with good combinations of ultimate tensile strength and total elongation. The martensite constituent in alloy N20CrMo17 was concentrated within bands. Comparison of tensile properties of the two alloys at similar volume fractions and hardness levels of martensite and ferrite showed that the microstructure containing banded martensite had inferior combinations of strength and ductility. The degradation of tensile ductility was accompanied by a fracture mode transition from microvoid coalescence to transgranular cleavage. The deformation and fracture behavior of both alloys were related to the microstructure.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 282234
- Journal Information:
- Metallurgical Transactions, A, Vol. 27, Issue 7; Other Information: PBD: Jul 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
A Composite Modeling Analysis of the Deformation Behavior of Medium Manganese Steels
Study of retained austenite and nano-scale precipitation and their effects on properties of a low alloyed multi-phase steel by the two-step intercritical treatment
Related Subjects
CHROMIUM-NICKEL-MOLYBDENUM STEELS
MICROSTRUCTURE
TENSILE PROPERTIES
FRACTURE PROPERTIES
CHROMIUM-MOLYBDENUM STEELS
NITROGEN
METALLURGICAL EFFECTS
HEAT TREATMENTS
FERRITE
AUSTENITE
MARTENSITE
ELECTRON MICROPROBE ANALYSIS
MICROHARDNESS
TRANSMISSION ELECTRON MICROSCOPY
ULTIMATE STRENGTH
ELONGATION
DUCTILITY