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US3773500A
Expired / Lapsed
US
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High tensile steel for large heat-input automatic welding and production process therefor
Assignee: Nippon Steel Corp
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Filing: 1971-03-24
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Granted: 1973-11-20
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Expires: 1991-03-24
Abstract
Abstract A high tensile strength steel for a large heat-input welding more than 50,000J/cm which contains more than 0.004% by weight in respect to steel weight of titanium in TiN phase smaller than 0.05 Mu in the steel before welding and comprises 0.03-0.23% of carbon, 0.02 to 0.8% of sulphur, 0.5 to 2.0% of manganese, 0.004 to 0.07% of titanium 0.0005 to 0.10% of soluble aluminium, and 0.003 to 0.012% of total nitrogen, with addition of at least one selected from the group consisting of B, V, Ni, Cu, Cr and Mo.
Inventors
- 👤 S Kanazawa
- 👤 S Saito
- 👤 A Nakashima
- 👤 K Yamato
- 👤 K Okamoto
- 👤 K Tanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:46
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/04; C22C38/14
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
98 words
A high tensile strength steel for use in a welding process wherein the heat-input is greater than 50,000 J/cm, and which contains fine titanium compounds having a particle size of less than 1,000 A in an amount greater than 50 percent of the total amount of titanium compounds present and which comprises 0.03 to 0.23% carbon, 0.02 to 0.8% silicon, 0.5 to 2.0% manganese, 0.004 to 0,07% of titanium, 0.0005 to 0.10% of soluble aluminum, and 0.003 to 0.011% of total nitrogen, wherein the ratio Ti/N is < or = 3.5, with the balance being iron and impurities.
Claim 2
Dependent Claim
120 words
A high tensile strength steel for use in a welding process wherein the heat input is greater than 50,000 J/cm, and which contains fine titanium compounds having a particle size of less than 1,000 A in an amount greater than 50 percent of the total amount of titanium compounds present and which comprises 0.03 to 0.23% of carbon, 0.02 to 0.8% of silicon, 0.5 to 2.0% of manganese, 0.004 to 0.07% of titanium, 0.0005 to 0.10% of soluble aluminum, and 0.003 to 0.011% of total nitrogen, wherein the ratio Ti/N is < or = 3.5, with addition of at least one of 0.0005 to 0.006% of boron and 0.02 to 0.2% of vanadium with the balance being iron and impurities.
Claim 3
Dependent Claim
147 words
A high tensile strength steel for use in a welding process wherein the heat input is greater than 50,000 J/cm, and which contains fine titanium compounds having a particle size of less than 1,000 A in an amount greater than 50 percent of the total amount of titanium compounds present and which comprises 0.03 to 0.23% of carbon, 0.02 to 0.8% of silicon, 0.5 to 2.0% of manganese, 0.004 to 0.07% of titanium, 0.0005 to 0.10% soluble aluminum, 0.003 to 0.011% of total nitrogen, wherein the ratio Ti/N is < or = 3.5, with addition of at least one of 0.0005 to 0.006% of boron and 0.02 to 0.20% of vanadium and still further addition of at least one of less than 5% of nickel, less than 2.0% of copper, less than 0.35% of chromium, less than 0.35% of molybdenum, with the balance being iron and impurities.
Claim 4
Dependent Claim
156 words
A process for producing a high tensile strength steel for use in a welding process wherein the heat input is greater than 50, 000 J/cm, which comprises cooling to below 1,100* C, a steel ingot or cast billet which contains 0.03 to 0.23% of carbon, 0.02 to 0.8% of silicon, 0.5 to 2.0% of manganese, 0.004 to 0.07% of titanium, 0.0005 to 0.10% of soluble aluminum and 0.003 to 0.011% of total nitrogen, wherein the ratio of Ti/N is < or = 3.5 and at least one element selected from the group consisting of up to 0.006% boron, up to 0.2% vanadium, up to 5% nickel, up to 2% copper, up to 0.35% chromium, and up to 0.35% molybdenum, under a cooling condition such that the average cooling rate, from the temperature of the molten steel at pouring to 1,100* C is more than 5* C/min., and then hot working the steel ingot or cast billet.
Claim 5
Dependent Claim
90 words
A process for producing a high tensIle strength steel for use in a welding process wherein the heat input is greater than 50, 000 J/cm, comprising using a steel material containing 0.003 to 0.23% of carbon, 0.02 to 0.8% of silicon, 0.5 to 2.0% of manganese, 0.004 to 0.07% of titanium, 0.0005 to 0.10% of soluble aluminum and 0.003 to 0.011% of total nitrogen, wherein the ratio Ti/N is < or = 3.5 and heating the steel material between 1, 050* and 1,300* C only one time after the casting.
Claim 6
Dependent Claim
49 words
The process according to claim 6, in which the steel material further contains at least one element selected from the group consisting of up to 0.006% boron, up to 0.2% of vanadium, up to 5% nickel up to 2% copper, up to 0.35% chromium, and up to 0.35% molybdenum.
Claim 7
Dependent Claim
130 words
A process for producing a high tensile strength steel for use in a welding process wherein the heat input is greater than 50, 000 J/cm, comprising casting a steel material containing 0.03 to 0.23% of carbon, 0.02 to 0.8% of silicon, 0.5 to 2.0 % of manganese, 0.004 to 0.7% of titanium, 0.0005 to 0.10% of soluble aluminum and 0.003 to 0.011% of total nitrogen, wherein the ratio Ti/N is < or = 3.5, into the form of a steel ingot or cast billet, cooling said form to below 1,100* C such that the average cooling rate at the core portion, from the initial temperature of the molten steel at pouring to 1,100* C, is more than 5* C/min., and heating the form above 1,100* C only one time thereafter.
Claim 8
Dependent Claim
48 words
The process according to claim 8 in which the steel material further contains at least one element selected from the group consisting of up to 0.006% boron, up to 0.2% vanadium, up to 5% nickel, up to 2% copper, up to 0.35% chromium, and up to 0.35% molybdenum.
Claim 9
Dependent Claim
137 words
A process for producing a high tensile strength steel for use in a welding process wherein the heat input is greater than 50,000 J/cm, comprising casting a steel material containing 0.03 to 0.23% of carbon, 0.02 to 0.8% of silicon, 0.5 to 2.0% of manganese, 0.004 t0 0.007% of titanium, 0.0005 to 0.10% of soluble aluminum and 0.003 to 0.011% of total nitrogen wherein the ratio Ti/N < or = 3.5, into the form of a steel ingot or cast billet, cooling the form such that the average cooling rate at the core portion, from the temperature of the molten steel at pouring is less than 5* C/min., wherein the ingot or billet is not heated above 1,250* C and is heated to a temperature range from 1,050* to 1,250* C only one time after said cooling.
Claim 10
Dependent Claim
48 words
The process according to claim 10 in which the steel material further contains at least one element selected from the group consisting of up to 0.006% boron, up to 0.2% vanadium, up to 5% nickel, up to 2% copper, up to 0.35% chromium, and up to 0.35% molybdenum.
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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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |