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Boron stainless steel powder and rapid solidification method

Assignee: Marko Materials Inc
•
Filing: 1980-05-27
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Granted: 1984-02-07
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Expires: 2000-05-27
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Abstract

Abstract Alloys having composition similar to commercial precipitation-hardenable stainless steels, but modified by the addition of 1.4 to 2.4 wt % boron, are disclosed. The alloys are subjected to a rapid solidification processing (RSP) technique which produces cooling rates between ˜10 5 -10 7 °C./sec. The as-quenched RSP ribbon or powder, etc., consists primarily of a metastable crystalline solid solution phase. The metastable crystalline phases are subjected to suitable heat treatments so as to produce a transformation to a stable multiphase microstructure, which includes borides; this heat treated alloy exhibits superior mechanical properties and thermal stability in conjunction with good corrosion and oxidation resistance.

Inventors

  • 👤 Ranjan Ray
  • 👤 Donald E. Polk
  • 👤 Bill C. Giessen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 23:32
CPC Classifications
C; C22; C22C; C22C45/00; C22C45/02; B; B22; B22F; B22F9/00; B22F9/002; B22F9/008; C22C33/00; C22C33/02; C22C33/0257; C22C33/0278; C22C33/0285

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 174 words
An alloy in powder form wherein said powders have an average particle size of less than 60 mesh (U.S. Standard) comprising platelets having an average thickness of less than 0.1 mm and each platelet being characterized by an irregularly shaped outline resulting from fracture thereof and having the composition represented by the general formula Fe Bal Cr 10-30 (Ni,Co) 3-15 (Mo,W,Al,Cu,Ti,Cb,V,Ta,N) 0 .7-6 (Mn,Si) <3 C 0 .03-0.30 where the iron is present at a level of more than 50 wt% and may contain incidental impurities, said composition additionally alloyed with between 1.4 to 2.4 wt% boron, said alloy being prepared by the method comprising the steps: (a) forming a melt of said alloy (b) depositing said melt against a rapidly moving quench surface so as to quench said melt at a rate in the range of approximately 10 5 ° to 10 7 ° C./sec and thereby form a rapidly solidified strip of said alloy characterized by predominantly body centered cubic or face centered cubic structure and (c) comminuting said strip into powders.
Claim 2
Dependent Claim 174 words
An alloy in powder form wherein said powders have an average particle size of less than 60 mesh (U.S. Standard) comprising platelets having an average thickness of less than 0.1 mm and each platelet being characterized by an irregularly shaped outline resulting from fracture thereof and having the composition represented by the general formula Fe Bal Cr 10-30 (Ni,Co) 3-15 (Mo,W,Al,Cu,Ti,Cb,V,Ta,N) 0 .7-6 (Mn,Si) <3 C 0 .03-0.30 where the iron is present at a level of more than 50 wt% and may contain incidental impurities, said composition additionally alloyed with between 1.4 to 2.4 wt% boron, said alloy being prepared by the method comprising the steps: (a) forming a melt of said alloy (b) depositing said melt against a rapidly moving quench surface so as to quench said melt at a rate in the range of approximately 10 5 ° to 10 7 ° C./sec and thereby form a rapidly solidified strip of said alloy characterized by predominantly body centered cubic or face centered cubic structure and (c) comminuting said strip into powders.
Claim 3
Independent Claim 178 words
The method of making an alloy in powder form wherein said powders have an average particle size of less than 60 mesh (U.S. Standard) comprising platelets having an average thickness of less than 0.1 mm and each platelet being characterized by an irregularly shaped outline resulting from fracture thereof and having the composition represented by the general formula Fe Bal Cr 10-30 (Ni,Co) 3-15 (Mo,W,Al,Cu,Ti,Cb,V,Ta,N) 0 .7-6 (Mn,Si) <3 C 0 .03-0.30 where the iron is present at a level of more than 50 wt% and may contain incidental impurities, said composition additionally alloyed with between 1.4 to 2.4 wt% boron, said alloy being prepared by the method comprising the steps: (a) forming a melt of said alloy (b) depositing said melt against a rapidly moving quench surface so as to quench said melt at a rate in the range of approximately 10 5 ° to 10 7 ° C./sec and thereby form a rapidly solidified strip of said alloy characterized by predominantly body centered cubic or face centered cubic structure and (c) comminuting said strip into powders.
Claim 4
Independent Claim 178 words
The method of making an alloy in powder form wherein said powders have an average particle size of less than 60 mesh (U.S. Standard) comprising platelets having an average thickness of less than 0.1 mm and each platelet being characterized by an irregularly shaped outline resulting from fracture thereof and having the composition represented by the general formula Fe Bal Cr 10-30 (Ni,Co) 3-15 (Mo,W,Al,Cu,Ti,Cb,V,Ta,N) 0 .7-6 (Mn,Si) <3 C 0 .03-0.30 where the iron is present at a level of more than 50 wt% and may contain incidental impurities, said composition additionally alloyed with between 1.4 to 2.4 wt% boron, said alloy being prepared by the method comprising the steps: (a) forming a melt of said alloy (b) depositing said melt against a rapidly moving quench surface so as to quench said melt at a rate in the range of approximately 10 5 ° to 10 7 ° C./sec and thereby form a rapidly solidified strip of said alloy characterized by predominantly body centered cubic or face centered cubic structure and (c) comminuting said strip into powders.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-02-06 1987-08-08 1988-02-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-02-06 1991-08-08 1992-02-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-02-06 1995-08-08 1996-02-07 $7700.00 Window Closed / Lapsed

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