Achieving ultra-high strength friction stir welded joints of high nitrogen stainless steel by forced water cooling

Nitrogen alloying in steel may greatly increase the strength and corrosion resistance of the material. This paper introduced some research results of high nitrogen stainless steel (HNS) investigation via PM process. Nickel free high nitrogen stainless steels (17Cr12Mn2MoN) and superaustenitic high nitrogen stainless steels (28Cr6Mn2/6Mo10/20NiN) were investigated via gas atomization and HIP processes. Nitrogen alloying behavior during atomization and consolidation processes was investigated. Powders with nitrogen content up to 1% were manufactured by gas atomization process. Nickel free high nitrogen stainless steels with nitrogen up to 0.6% exhibits high strength and ductility at as-HIPed and solution annealed state, and superaustenitic HNS with nitrogen content up to 1% showed very high strength and good ductility at solution annealed state, with b at 1100 MPa, s at 810 MPa and elongation of 43%. PM HNS exhibited excellent corrosion resistance.

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Fabrication of High Strength High Nitrogen Stainless Steel with Excellent Corrosion Resistance and Its Mechanical Properties

Materials and Manufacturing Processes ◽

10.1081/amp-120027495 ◽

2004 ◽

Vol 19 (1) ◽

pp. 19-30 ◽

Cited By ~ 52

Author(s):

Y. Katada ◽

M. Sagara ◽

Y. Kobayashi ◽

T. Kodama

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Corrosion Resistance ◽

High Strength ◽

High Nitrogen ◽

Excellent Corrosion Resistance ◽

High Nitrogen Stainless Steel

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Production of High Nitrogen Stainless Steel X8CrMnN18-18 through EAF-AOD-LRF-CC-Steckel Mill Route and its Hot Deformation Study by Gleeble Thermomechanical Simulator

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.794.429 ◽

2013 ◽

Vol 794 ◽

pp. 429-440

Author(s):

Sudipta Patra ◽

Lokesh Kumar Singhal

Keyword(s):

Stainless Steel ◽

Grain Refinement ◽

Hot Deformation ◽

Microstructural Analysis ◽

High Strength ◽

Microstructural Characterization ◽

Mechanical Processing ◽

Compression Tests ◽

High Nitrogen ◽

High Nitrogen Stainless Steel

High nitrogen containing austenitic stainless steel X8CrMnN18-18 exhibits attractive combination of high strength, toughness and corrosion resistance.This grade containing more than 5000 ppm of nitrogen was produced commercially through EAF-AOD-LRF-CC-Steckel mill route and its microstructure and mechanical properties were studied. Excellent combination of strength,ductility and toughness is achieved in the entire range of 6mm to 50mm thick hot rolled plates. Uniaxial compression tests were carried out to understand the hot deformation behavior by varying temperature and strain rate. Softening behavior during deformation was analyzed from flow stress strain curves and microstructural analysis. Dynamic recrystallization (DRX) behavior of the material was observed during thermo mechanical processing. Critical strain related to DRX and Avrami kinetics of DRX was calculated by analyzing the flow curve data. Microstructural characterization was done by optical microscopy and EBSD analysis. Extensive grain refinement can be achieved by thermo-mechanical processing controlled by DRX. Keywords: High nitrogen stainless steel, Strength and toughness, DRX, Grain refinement, TMCP

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