US4406698A
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Martensitic stainless cast steel having high cavitation erosion resistance
Assignee: Toshiba Corp
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Filing: 1981-04-21
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Granted: 1983-09-27
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Expires: 2001-04-21
Abstract
Abstract Martensitic stainless cast steel suitable for use as turbine elements for water power plants having high cavitation erosion resistance and consisting essentially of carbon of 0.1 wt % or less, silicon of 1.0 wt % or less, manganese of 2.0-9.0 (exclusive of 2.0) wt %, nickel of 0.5-8.0 wt %, chromium of 11.0-14.0 wt %, and the balance of essentially iron.
Inventors
- 👤 Takashi Yebisuya
- 👤 Masao Yamamoto
- 👤 Mituo Kawai
- 👤 Koichi Tajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:14
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/58
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
52 words
Martensitic stainless cast steel having high cavitation erosion resistance and consisting essentially of carbon of 0.1 wt% or less, silicon of 1.0 wt% or less, manganese of 2.0-9.0 (exclusive of 2.0) wt%, nickel of 0.5-8.0 wt%, chromium of 11.0-14.0 wt%, molybdenum of 2.0 wt% or less and the balance of essentially iron.
Claim 2
Dependent Claim
52 words
Martensitic stainless cast steel having high cavitation erosion resistance and consisting essentially of carbon of 0.1 wt% or less, silicon of 1.0 wt% or less, manganese of 2.0-9.0 (exclusive of 2.0) wt%, nickel of 0.5-8.0 wt%, chromium of 11.0-14.0 wt%, molybdenum of 2.0 wt% or less and the balance of essentially iron.
Claim 3
Dependent Claim
50 words
Martensitic stainless cast steel having high cavitation erosion resistance and consisting essentially of carbon of 0.1 wt% or less, silicon of 1.0 wt% or less, manganese of 2.0-9.0 (exclusive of 2.0) wt%, nickel of 0.5-8.0 wt%, chromium of 11.0-14.0 wt%, niobium of 0.01-0.1 wt% and the balance of essentially iron.
Claim 4
Dependent Claim
50 words
Martensitic stainless cast steel having high cavitation erosion resistance and consisting essentially of carbon of 0.1 wt% or less, silicon of 1.0 wt% or less, manganese of 2.0-9.0 (exclusive of 2.0) wt%, nickel of 0.5-8.0 wt%, chromium of 11.0-14.0 wt%, niobium of 0.01-0.1 wt% and the balance of essentially iron.
Claim 5
Dependent Claim
50 words
Martensitic stainless cast steel having high cavitation erosion resistance and consisting essentially of carbon of 0.1 wt% or less, silicon of 1.0 wt% or less, manganese of 2.0-9.0 (exclusive of 2.0) wt%, nickel of 0.5-8.0 wt%, chromium of 11.0-14.0 wt%, copper of 0.1-0.5 wt% and the balance of essentially iron.
Claim 6
Dependent Claim
50 words
Martensitic stainless cast steel having high cavitation erosion resistance and consisting essentially of carbon of 0.1 wt% or less, silicon of 1.0 wt% or less, manganese of 2.0-9.0 (exclusive of 2.0) wt%, nickel of 0.5-8.0 wt%, chromium of 11.0-14.0 wt%, copper of 0.1-0.5 wt% and the balance of essentially iron.
Claim 7
Dependent Claim
50 words
Martensitic stainless cast steel having high cavitation erosion resistance and consisting essentially of carbon of 0.1 wt% or less, silicon of 1.0 wt% or less, manganese of 2.0-9.0 (exclusive of 2.0) wt%, nickel of 0.5-8.0 wt%, chromium of 11.0-14.0 wt%, nitrogen of 0.02-0.15 wt% and the balance of essentially iron.
Claim 8
Dependent Claim
50 words
Martensitic stainless cast steel having high cavitation erosion resistance and consisting essentially of carbon of 0.1 wt% or less, silicon of 1.0 wt% or less, manganese of 2.0-9.0 (exclusive of 2.0) wt%, nickel of 0.5-8.0 wt%, chromium of 11.0-14.0 wt%, nitrogen of 0.02-0.15 wt% and the balance of essentially iron.
Claim 9
Dependent Claim
23 words
Martensitic stainless cast steel according to claim 4 wherein the amount sum of nitrogen and carbon is in the range of 0.02-0.15 wt%.
Claim 10
Dependent Claim
17 words
Martenistic stainless cast steel according to claim 1 wherein molybdenum is in the range of 0.5-2.0 wt%.
Claim 11
Dependent Claim
17 words
Martensitic stainless cast steel according to claim 6 wherein molybdenum is in the range of 0.5-1.6 wt%.
Claim 12
Dependent Claim
32 words
Martensitic stainless cast steel according to claim 1, 6, 7, 5, 2, 3, or 4 wherein carbon is in the range of 0.05-0.1 wt% and silicon in the range of 0.3-1.0 wt%.
Claim 13
Dependent Claim
32 words
Martensitic stainless cast steel according to claim 4 wherein manganese is in the range of 2.5-6.0 wt%, nickel in the range of 1.0-6.0 wt%, and chromium in the range of 12.0-13.5 wt%.
Claim 14
Dependent Claim
17 words
Martensitic stainless cast steel according to claim 3 wherein nickel is in the range of 3.0-4.0 wt%.
Claim 15
Dependent Claim
20 words
Martensitic stainless cast steel according to claim 5, 2, 3, 4 further containing molybdenum which is 2.0 wt% or less.
Claim 16
Dependent Claim
22 words
Martensitic stainless cast steel according to claim 5, 3, 4 further containing niobium in the range of 0.01-0.1 (exclusive of 0.1) wt%.
Claim 17
Dependent Claim
17 words
Martensitic stainless cast steel according to claim 5-4 further containing copper in the range of 0.1-0.5 wt%.
Claim 18
Dependent Claim
24 words
A turbine element for water power plants made of martensitic stainless cast steel according to claim 1, 6, 7, 5, 2, 3 or 4.
Claim 19
Dependent Claim
19 words
A turbine element according to claim 14 wherein said said turbine element is runner, stay vane or guide vane.
Claim 20
Dependent Claim
17 words
Martensitic stainless cast steel according to claim 1 wherein molybdenum is in the range of 0.5-2.0 wt%.
Claim 21
Dependent Claim
17 words
Martensitic stainless cast steel according to claim 16 wherein molybdenum is in the range of 0.5-1.6 wt%.
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GB1236698A
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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) | 1986-09-26 | 1987-03-28 | 1987-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-26 | 1991-03-28 | 1991-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-26 | 1995-03-28 | 1995-09-27 | $7700.00 | Window Closed / Lapsed |