US4559090A
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Using a corrosion proof austenitic iron chromium nickel nitrogen alloy for high load components
Assignee: Vodafone GmbH
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Filing: 1985-02-22
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Granted: 1985-12-17
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Expires: 2005-02-22
Abstract
Abstract A corrosion proof austenitic alloy is proposed for use in components expected to experience also a high mechanical load; the alloy is to have a high yield strength. The alloy is to have a particular composition which is subjected to a heat treatment, subsequent cold working and recrystallization annealing such that nitrogen solid solution hardening, nitride precipitation hardening and strong grain-refinement synergistically combine to obtain high yield strength values beyond those compared to yield point enhancement calculated by only addition of the three hardening effects separately.
Inventors
- 👤 Gunther Grutzner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:01
CPC Classifications
C; C21; C21D; C21D8/00; C21D6/00; C21D6/02; C22; C22C; C22C38/00; C22C38/001; C22C38/18; C22C38/40
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
167 words
The Method of making components of structural material expected to be exposed to corrosion mediums in combination with high mechanical loads comprising the steps of providing an alloy consisting of not more than 0.12% C, from 0.075% to 0.55% N, not more than 0.75% niobium but not more than the 4-fold value of the nitrogen used in the alloy; from 16.0 to 32.0% Cr, from 7.0 to 55.0% Ni, not more than 8.5% Mn, not more than 6.5% molybdenum, not more than 3.0% silicon, not more than 4% copper, not more than 3,0% tungsten, the remainder being iron as well as unavoidable impurities (all percentages by weight); heat treating the alloy at a high temperature for obtaining a relatively large amount of nitrogen to go into solution; immediately cooling, subsequently cold working and recrystallization annealing the alloy so that precipations as well as an ultrafine grained structure with an average, linear intercept grain below 8.5 micrometers have formed so as to obtain a relatively high yield strength.
Claim 2
Independent Claim
167 words
The Method of making components of structural material expected to be exposed to corrosion mediums in combination with high mechanical loads comprising the steps of providing an alloy consisting of not more than 0.12% C, from 0.075% to 0.55% N, not more than 0.75% niobium but not more than the 4-fold value of the nitrogen used in the alloy; from 16.0 to 32.0% Cr, from 7.0 to 55.0% Ni, not more than 8.5% Mn, not more than 6.5% molybdenum, not more than 3.0% silicon, not more than 4% copper, not more than 3,0% tungsten, the remainder being iron as well as unavoidable impurities (all percentages by weight); heat treating the alloy at a high temperature for obtaining a relatively large amount of nitrogen to go into solution; immediately cooling, subsequently cold working and recrystallization annealing the alloy so that precipations as well as an ultrafine grained structure with an average, linear intercept grain below 8.5 micrometers have formed so as to obtain a relatively high yield strength.
Claim 3
Dependent Claim
37 words
The method as in claim 1, said temperature range of heat treatment being above 1000 degrees C.; said cold working amounting to 40-85 degree of deformation, said annealing being carried out between 800 and 1050 degrees C.
Claim 4
Dependent Claim
26 words
The method as in claim 1, wherein said heat treatment consists of a high temperature range run above 1000 degrees C. and immediately cooled to RT.
Claim 5
Dependent Claim
28 words
The method as in claim 1, wherein said heat treatment is or includes hot working steps above about 1000 degrees C.--preferably at 1150 degrees C.--and subsequently air cooled.
Claim 6
Dependent Claim
37 words
The method as in claim 1, wherein said heat treatment consists of a hot working step or a high temperature range run above 1000 degrees C. accompanied with subsequent solution annealing between 1000 and 1200 degrees C.
Claim 7
Dependent Claim
166 words
A structural material for use under corrosion conditions in combination with high mechanical load comprising an alloy of not more than 0.12% C., from 0.075% to 0.55% N, not more than 0.75% niobium but not more than the 4-fold value of the nitrogen used in the alloy; from 16.0 to 32.0% Cr, from 7.0 to 55.0% Ni, not more than 8.5% Mn, not more than 6.5% molybdenum, not more than 3.0% silicon, not more than 4% copper, not more than 3.0% tungsten, the remainder being iron as well as unavoidable impurities (all percentages by weight); said alloy having been heat treated above about 1000 degrees C. so as to obtain the highest possible degree of nitrogen to be in solution, said alloy being solution hardened accordingly; said alloy having been cooled and cold worked and recrystallization annealed so that nitride precipitation as well as an ultrafine grained structure with an average, linear intercept grain below 8.5 micrometers have formed in order to obtain high yield strength.
Claim 8
Dependent Claim
166 words
A structural material for use under corrosion conditions in combination with high mechanical load comprising an alloy of not more than 0.12% C., from 0.075% to 0.55% N, not more than 0.75% niobium but not more than the 4-fold value of the nitrogen used in the alloy; from 16.0 to 32.0% Cr, from 7.0 to 55.0% Ni, not more than 8.5% Mn, not more than 6.5% molybdenum, not more than 3.0% silicon, not more than 4% copper, not more than 3.0% tungsten, the remainder being iron as well as unavoidable impurities (all percentages by weight); said alloy having been heat treated above about 1000 degrees C. so as to obtain the highest possible degree of nitrogen to be in solution, said alloy being solution hardened accordingly; said alloy having been cooled and cold worked and recrystallization annealed so that nitride precipitation as well as an ultrafine grained structure with an average, linear intercept grain below 8.5 micrometers have formed in order to obtain high yield strength.
Claim 9
Dependent Claim
26 words
A structural material as in claim 6, said nitrogen content being from 0.22 to 0.45% and yield strength obtaining from 614 to 870 N/mm 2 .
Claim 10
Dependent Claim
23 words
A structural material as in claim 6, said high 0,2% offset yield strength in the temperature range up to about 550 degrees C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-16 | 1989-06-17 | 1989-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-16 | 1993-06-17 | 1993-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-16 | 1997-06-17 | 1997-12-17 | $7700.00 | Window Closed / Lapsed |