Phase transformations in a manganese-alloyed austenitic stainless steel

Journal Article · Sun May 01 00:00:00 EDT 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90345-X· OSTI ID:5188706

Jargelius-Pettersson, R F.A. ^[1]

---

1. Swedish Inst. for Metals Research, Stockholm (Sweden)

The increasing demands placed on the corrosion resistance of stainless steels has led to the successive development of more highly alloyed materials. In this context nitrogen has shown considerable value as an alloying element but its use is restricted by a solubility limit of approximately 0.2 wt% in conventional austenitic stainless steel grades. Manganese increases the nitrogen solubility appreciably and for this reason there has also been an increased interest in its use as an alloying addition but numerous questions remain to be answered about the effect of both nitrogen and manganese on structural stability. Although much work has been published on the precipitation of secondary phases in CrNi(Mo) stainless steels, there is a relative paucity of information available on manganese-alloyed steels. Brandis et al. investigated precipitation in a 25Cr 17Ni 3Mo 6Mn 0.2Nb steel and found no manganese-enriched phases to occur. Sigma phase was the predominant intermetallic precipitate at low nitrogen contents while higher nitrogen contents retarded the onset of sigma phase precipitation but caused the appearance of chi phase. Boothby et al. investigated a 12Cr 11-35Ni (3Mo) steel in which the nickel was partially replaced by 20 or 30% manganese and found the precipitation of the intermetallic sigma, chi and Laves phases to be promoted by manganese, although again no manganese-enriched phases were observed. Fritscher demonstrated however the existence in the Fe-Cr-Ni system of a brittle ternary Y phase containing 30--60% manganese which was destabilized by nitrogen. The present work represents part of a study designed to gain greater understanding of the precipitation and sensitization behavior of highly alloyed austenitic stainless steels and concentrates on the influence of nitrogen additions up to 0.5wt% on precipitation of secondary phases in a 20Cr 18Ni 4.5Mo 10Mn steel.

• OSTI ID: 5188706
• Journal Information: Scripta Metallurgica et Materialia; (United States), Vol. 30:9; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHROMIUM-NICKEL-MOLYBDENUM STEELS
CRYSTAL-PHASE TRANSFORMATIONS
NITROGEN
METALLURGICAL EFFECTS
CORROSION RESISTANT ALLOYS
EXPERIMENTAL DATA
MICROSTRUCTURE
TRANSMISSION ELECTRON MICROSCOPY
ALLOYS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
DATA
ELECTRON MICROSCOPY
ELEMENTS
HIGH ALLOY STEELS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
MICROSCOPY
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NONMETALS
NUMERICAL DATA
PHASE TRANSFORMATIONS
STAINLESS STEELS
STEELS
360102* - Metals & Alloys- Structure & Phase Studies