Abnormal magnetic behaviour of powder metallurgy austenitic stainless steels sintered in nitrogen

Duplex austenitic- ferritic stainless steels (DSS) offer significant advantages when compared to standard austenitic stainless steels, in several areas of industrial applications, due to their higher mechanical strength, superior resistance to corrosion and a lower price because of their lower nickel content. Despite the extensive research carried out so far in the area of DSS the characterisation of their magnetic properties, under stress or under a static field, has attracted significantly less attention. This is contrary to the fact that in certain naval constructions the suitability of a given type of steel is judged not only by its tensile, impact, and corrosion properties but also by its magnetic behaviour.A 2205 type austenitic- ferritic DSS has been cold rolled to different cold rolling reductions, with an aim of achieving a 0.2 % proof strength of at least 700 MPa with an elongation value of greater than 20%.

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Fabrication of High Nitrogen Austenitic Stainless Steels by Powder Metallurgy.

Journal of the Japan Society of Powder and Powder Metallurgy ◽

10.2497/jjspm.46.1249 ◽

1999 ◽

Vol 46 (12) ◽

pp. 1249-1255 ◽

Cited By ~ 4

Author(s):

Kota Kataoka ◽

Toshihiro Tsuchiyama ◽

Hideto Goto ◽

Setsuo Takaki

Keyword(s):

Powder Metallurgy ◽

Stainless Steels ◽

Austenitic Stainless Steels ◽

High Nitrogen

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On the Machinability of Powder Metallurgy Austenitic Stainless Steels

Journal of Engineering for Industry ◽

10.1115/1.3187892 ◽

1988 ◽

Vol 110 (4) ◽

pp. 339-343 ◽

Cited By ~ 9

Author(s):

J. S. Agapiou ◽

G. W. Halldin ◽

M. F. DeVries

Keyword(s):

Powder Metallurgy ◽

Stainless Steels ◽

Single Phase ◽

High Strength Steels ◽

Austenitic Stainless Steels ◽

High Strength ◽

Technical Literature ◽

Bulk Properties ◽

Point Temperature ◽

Drill Point

Powder Metallurgy (P/M) materials, especially those made of high strength steels, are often reported in the technical literature to have poor machinability when compared to their wrought or cast counterparts. In order to characterize the machinability of single phase P/M materials and to identify the influence of porosity on that behavior, the machinability of P/M 304L austenitic stainless steel was evaluated as a function of porosity, in the range of 64 to 90 percent of theoretical density. Machinability was defined in terms of the average drill point temperature. It was found that the drill temperature increased with porosity to a point. Further increases in porosity produced decreasing levels of average drill point temperature. The nonlinear machinability response was attributed to the offsetting contributions of the thermal conductivity, the work-hardening, and the bulk properties of the P/M material.

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Radiation Damage Studies with the HVEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100096655 ◽

1972 ◽

Vol 30 ◽

pp. 680-681

Author(s):

J. J. Laidler ◽

B. Mastel

Keyword(s):

Radiation Damage ◽

Stainless Steels ◽

Volume Expansion ◽

Austenitic Stainless Steels ◽

Test Facility ◽

Fast Breeder Reactors ◽

Breeder Reactors ◽

Under Construction ◽

Development Laboratory ◽

Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

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Strain-induced martensite effects on transgranular carbide precipitation in type 304 stainless steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087331 ◽

1991 ◽

Vol 49 ◽

pp. 604-605

Author(s):

A.H. Advani ◽

L.E. Murr ◽

D. Matlock

Keyword(s):

Heat Treatment ◽

Grain Boundary ◽

Stress Corrosion Cracking ◽

Stainless Steels ◽

Deformation Twin ◽

Austenitic Stainless Steels ◽

Carbide Precipitation ◽

Strain Induced Martensite ◽

Type 304

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.

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