GB2224514A - Steel and production thereof - Google Patents
Steel and production thereof Download PDFInfo
- Publication number
- GB2224514A GB2224514A GB8923306A GB8923306A GB2224514A GB 2224514 A GB2224514 A GB 2224514A GB 8923306 A GB8923306 A GB 8923306A GB 8923306 A GB8923306 A GB 8923306A GB 2224514 A GB2224514 A GB 2224514A
- Authority
- GB
- United Kingdom
- Prior art keywords
- max
- steel
- concentrations
- ppm
- stage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims description 43
- 239000010959 steel Substances 0.000 title claims description 43
- 238000004519 manufacturing process Methods 0.000 title claims description 4
- 238000005266 casting Methods 0.000 claims description 14
- 238000005275 alloying Methods 0.000 claims description 12
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 9
- 229910052799 carbon Inorganic materials 0.000 claims description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 8
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 7
- 239000007789 gas Substances 0.000 claims description 7
- 239000001257 hydrogen Substances 0.000 claims description 7
- 229910052739 hydrogen Inorganic materials 0.000 claims description 7
- 239000012535 impurity Substances 0.000 claims description 7
- 229910052748 manganese Inorganic materials 0.000 claims description 7
- 239000011572 manganese Substances 0.000 claims description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims description 5
- 238000010791 quenching Methods 0.000 claims description 5
- 230000000171 quenching effect Effects 0.000 claims description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 4
- 238000007664 blowing Methods 0.000 claims description 4
- 229910052804 chromium Inorganic materials 0.000 claims description 4
- 229910052750 molybdenum Inorganic materials 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 claims description 4
- 239000010703 silicon Substances 0.000 claims description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 3
- 229910052796 boron Inorganic materials 0.000 claims description 3
- 239000012467 final product Substances 0.000 claims description 3
- 239000000155 melt Substances 0.000 claims description 3
- 238000010309 melting process Methods 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 239000010955 niobium Substances 0.000 claims description 3
- 239000011574 phosphorus Substances 0.000 claims description 3
- 229910052717 sulfur Inorganic materials 0.000 claims description 3
- 239000011593 sulfur Substances 0.000 claims description 3
- 239000010936 titanium Substances 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 229910052726 zirconium Inorganic materials 0.000 claims description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 2
- 229910052786 argon Inorganic materials 0.000 claims description 2
- 239000011733 molybdenum Substances 0.000 claims description 2
- 229910052758 niobium Inorganic materials 0.000 claims description 2
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims description 2
- 239000000161 steel melt Substances 0.000 claims description 2
- 238000003756 stirring Methods 0.000 claims description 2
- 229910052720 vanadium Inorganic materials 0.000 claims description 2
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 2
- 229910001208 Crucible steel Inorganic materials 0.000 claims 3
- 229910045601 alloy Inorganic materials 0.000 claims 3
- 239000000956 alloy Substances 0.000 claims 3
- 101100129500 Caenorhabditis elegans max-2 gene Proteins 0.000 claims 1
- 239000011261 inert gas Substances 0.000 claims 1
- 239000007787 solid Substances 0.000 claims 1
- 238000003466 welding Methods 0.000 description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000011651 chromium Substances 0.000 description 3
- 230000001627 detrimental effect Effects 0.000 description 3
- 229910000734 martensite Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005496 tempering Methods 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000010891 electric arc Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000008595 infiltration Effects 0.000 description 2
- 238000001764 infiltration Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Heat Treatment Of Articles (AREA)
- Heat Treatment Of Steel (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Powder Metallurgy (AREA)
Description
- 1 222 45 4 STEEL AND A PROCESS FOR THE PRODUCTION OF STEEL
The invention relates to the field of metallurgy and concerns a low-alloy steel, its production, and its use. Tle steel is suitable for use in particular in thickwall structural units manufactured by casting which are connected to the rest of a construction by welding. Typical structural units of this sort are pipe joints in offshore equipment, slewing rings of ship and port cranes, bogies of railway wagons and coaches, and heavy cogwheels and shafts for hoisting gears.
When cast structural units are used in large constructions assembled by welding to substitute for units composed of tubes and plates by welding, owing to the possibility of free shaping of the castings, e.g., the following advantages are obtained:
- 'ne joint seams can be removed from stress concentration regions to less heavily loaded regions.
- The joints can be shifted to areas where the welding work can be accomplished easily and reliably and where the welding work can be automated readily.
- In the planning of a casting, material can be added to highly stressed regions and reduced from less highly loaded areas. In this way the weight of a structural unit can be lowered and its operation be made more reliable.
-'ne castings have no risk of lamellar tearing.
- The casting can be shaped as of smooth geometry and so that stress concentrations are eliminated.
- It is possible to accomplish material thicknesses that are difficult to accomplish as plate/tube combinations.
In spite of the numerous advantages mentioned above, cast structural units have been used relatively scarcely. The principal reason has been that such cast steels not been available as equal the wrought products plates, tubes and forgoings - used for these applications in respect of the combination of strength/toughness/weldability.
The general object of the present invention is to provide a steel species whose toughness and fracture toughness properties equal those of wrought products of the same strength class in all temperature ranges, but in particular at low temperatures.
The means necessary to achieve the object of the invention are given in the patent claims.
The minimum yield strength of the steel in accordance with the invention is at least 540 MPa, and it can be adjusted up to 750 MPa by increasing the alloying degree. The toughness and fracture properties of the steel equal those of wrought products of the same strength class up to pieces of a thickness of about 200 mm.
Wrought products can be manufactured with corresponding properties up to a wall thickness of about 50 mm.
The steel can be welded without preheating, and heat treatment after welding is not necessary. On the other hand, the steel can also be welded with preheating, and after welding it can be stress-relief annealed or dehydration annealed without deteriorating its strength or toughness properties.
In the final product, the steel is characterized in a microstructure which consists of a uniform lath-marten-sitic/lower bainitic structure whose grain boundaries are practically free from precipitations and from non-metalic inclusions. No gas agglomerations or gas blows occur in the structure. Such a uniform microstructure is effective through the entire cross-section of the casting up to wall thicknesses of 200 mm.
An optimized microstructure, which provides the desired combination of strength/toughness/weldability, is achieved by choice of chemical composition and compatible beat treatment.
In the chemical composition it is essential that the carbon content shall be low - at the maximum 0.12%. As a rule, the carbon content of known steels of this strength class and intended for thick castings is remarkably higher. Owing to the low carbon content, the changes in specific volume on hardening remain little, and so also the deformation stresses, which are one prerequisite for cold tear, remain negligible. On the other hand, the carbon content has preferably a lower limit of 0.06%. This amount of carbon prevents atomic infiltration of impurities at the grain boundaries, which may promote temper brittleness in spite of low concentrations.
Attempts should be made to minimize the hydrogen content in steel. It is preferably 5 ppm, most appropriately at the maximum 2 ppm. In this way, no cold cracking occurs in connection with welding. Moreover, by means of this limitation of the hydrogen content, phenomena of hydrogen tear in the interior of thick castings are prevented.
The concentrations of sulfur and phosphorus are very low: Smax = 0.01 %, Pmax = 0.012 %. The nitrogen content is preferably also very low, at the maximum 100 ppm. By means of limitations of these impurities it is achieved that precipitations or infiltrations that endanger the toughness or weldability do not occur practically in any temperature range and that the steel also retains its 20 toughness after its varying metallurgical histories.
is To guarantee a uniform microstructure and, as a result of that, a uniform combination of strength/toughness/weldability throughout cross-sections of a thickness of up to 200 mm, relatively abundant alloying is required from the steel. The concentrations of silicon and manganese are limited to quite low levels in spite of their remarkable ability to increase the hardening capacity. The concentration of chromium is also quite low. On the contrary, nickel and molybdenum have been used abundantly.
The following combination of alloying elements is typical of the steel:
Si max 0.6 % Mn max 1 % Cr 0.5 1.5% Ni 2 5 % Mo 0.3 1 % With the chosen combination of alloying elements, the strengthening to the desired strength level takes place in the first place through the solution strengthening and not so much by means of the martensitic conversion. This latter mechanism is typical of the prior-art cast steels of this strength class.
Owing to the relatively abundant alloying the steel requires quenching and tempering as heat treatment, wherein the hardening requires solution annealing followed by water quenching. However, with this steel, this can be carried out without a risk of tearing even when pieces of complicated shapes are treated, for, owing to the low carbon content, the changes in specific volume on formation of martensite remain very little, and the stresses that arise do not even nearly approach the braking point of the steel.
In the steel now invented, microconstituents of alloying, such as titanium, vanadium, niobium, boron, or zirconium, which are typical of the prior-art weldable wrought steels of the corresponding strength class, are not used to a 20 substantial extent.
Ile concentrations of the microconstituents are lirnited to the following maximum values: Nb Ti v Zr B 0.02% 0.02% 0.03% 0.02% 0.003% All of the concentrations given above refer to the concentrations in the final product.
The steel in accordance with the invention can be produced by means of a two-stage melting process:
1. Tle first stage of the melting is carried out in a normal air-are furnace, wherein, by means of a normal slagging process and by means of oxygen blowing advanced further than in a conventional melting process, sulfur, phosphorus, silicon, and manganese are removed from the molten steel to very low contents. At the same time, significant amounts of carbon and chromium are also removed. In this electric-arc furnace stage the gas content of the steel, in particular in respect of nitrogen and oxygen, may be very high.
2. In the second stage, after the steel that was melted in the electricarc furnace has been transferred into a vacuum converter, it is subjected to a short oxygen blowing stage, by means of which a low concentration of detrimental impurities is ensured. Hereupon the concentrations of the desired elements are adjusted to the limits aimed at by addition of pure alloying elements. At this stage the gas content in the steel may be high.
After the alloying and the removal of detrimental impurities, the detrimental gases are removed from the melt by into the converter chamber sucking a deep vacuum (lower than 5 mbars, preferably lower than 2 mbars) and by, at the same time, stirring the steel melt by means of blowing of pure argon taking place from underneath the melt. During this process stage, oxygen, nitrogen, and hydrogen are eliminated from the steel down to equilibrium concentrations, which are so low that they have no weakening effect on the properties of solidified steel.
The casting is subjected to a quenching and tempering treatment, which includes water quenching at about 900 OC, tempering at about 600 OC, and air cooling to the room temperature. In this way, an impact toughness of typically 100 to 300 J KV- at -40 OC and -60 'c is obtained for the casting up to wall thicknesses of 200 mm. The microstructure is uniformly lath-martensitic- lowerbanitic through the entire wall.
Ile steel can be welded as cold, and it need not be heat treated after welding when the welding energy is kept within the range of 10 to 35 kj/cm. The weld deformation zone meets the minimum requirement of the base material, and in the deformation zone no cold cracking occurs unless the hydrogen level of the weld itself is higher than 10 ppm.
Claims (14)
1. Low alloy cast steel, characterized in that the alloying elements proper are nickel, molybdenum, and chromiurn, and their concentrations are Ni
2 to 5 % Mo 0.
3 to 1 % Cr 0.5 to 1.5% the concentrations of silicon and manganese are Si max 0.6 % Mn max 1 % the carbon content is C max 0.12 % the concentrations of the microconstituents niobium, titanium, vanadium, zirconium, and boron are Nb Ti v Zr B max 0.02 % max 0.02 % max 0.03 % max 0.02 % max 0.003% the concentrations of the impurities sulfur and phosphorus are S max 0.01 % P max 0.012 % 2. Steel as claimed in claim 1, characterized in that the concentrations of hydrogen and nitrogen are H max 5 ppm N max 100 ppm 3. Steel as claimed in claim I or 2, characterized in that the concentrations of the alloying elements are Ni 2.3 to 2.7 Mo 0.3 to 0.5 Cr 1 to 1.5
4. Steel as claimed in claim 1 or 2, characterized in that the concentrations of the alloying elements are Ni 4.2 to
5 Mo 0.5 to 0.7 Cr 0.5 to 1 5. Steel as claimed in any of the claims 1 to 4, characterized in that the 10 concentrations of silicon and manganese are Si max 0.3 % Mn max 0. 05 %
6. Steel as claimed in any of the claims 1 to 5, characterized in that the concentrations of the microconstituents are Nb max 0.01 % Ti max 0.01 % v max 0.02 % Zr max 0.01 % B max 0.002%
7. Steel as claimed in any of the claims 1 to 6, characterized in that the concentrations of the impurities are
S max 0.005 % P max 0.01 % 8. Steel as claimed in any of the claims 1 to 7, characterized in that the carbon content is C max 0.10 %
9. Steel as claimed in any of the claims 1 to 8, characteiized in that the concentration of hydrogen and nitrogen are H max 2 ppm N max 60 ppm
10. Process for the production of low-alloy cast steel, characterized in that steel as claimed in any of the claims 1 to 6 is produced by means of a two stage melting process, wherein in the first stage, the impurities that occur as solid in the solidified state are removed while permitting an intensive increase in the gas content of the steel, and in the second stage, after adjustment of the alloying, gases are removed by means of deep vacuum and stirring by means of an inert gas.
11. Process as claimed in claim 10, characterized in that the vacuum is lower than 5 mbars.
12. Process as claimed in claim 11, characterized in that the vacuum is lower than 2 mbars.
13. Process as claimed in any of the claims 10 to 12, characterized in that in the second stage the steel melt is stirred by blowing argon into the melt from below.
14. Process for casting of steel castings out of low-alloy cast steel, characterized in that a casting is cast out of a steel as claimed in any of the claims 1 to 9 or out of a steel produced in accordance with any of the claims 10 to 13, the casting is hardened at a temperature of about 900 'C by water quenching, tempered at a temperature of about 600 OC, and air-cooled to the room temperature so that the microstructure of the final product is substantially lath martensitic-lower-bainitic.
1 Hcblbmz.l MMER4TP Pup oWn may tobt&om The patent office Rmn M111t1C14M t ltd. At M07 CMY. lnt. COn 1 f87 Mpn Mdtllftl&y MCIM ltd. At M07 CrU. MnyWn A r07
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI884779A FI84370C (en) | 1988-10-17 | 1988-10-17 | Steel |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8923306D0 GB8923306D0 (en) | 1989-12-06 |
| GB2224514A true GB2224514A (en) | 1990-05-09 |
| GB2224514B GB2224514B (en) | 1993-05-26 |
Family
ID=8527215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8923306A Expired - Fee Related GB2224514B (en) | 1988-10-17 | 1989-10-16 | Steel and a process for the production of steel |
Country Status (6)
| Country | Link |
|---|---|
| CH (1) | CH679781A5 (en) |
| DE (1) | DE3934435A1 (en) |
| FI (2) | FI84370C (en) |
| FR (1) | FR2637915B1 (en) |
| GB (1) | GB2224514B (en) |
| NO (1) | NO173945C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001036698A1 (en) * | 1999-11-17 | 2001-05-25 | Dt Vyhybkárna A Mostárna, Spol. S R.O. | Steel for railway crossing points |
| CN101905244A (en) * | 2010-08-05 | 2010-12-08 | 中原特钢股份有限公司 | Method for producing mandrel by utilizing 28NiCrMoV steel as raw material |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1026735A (en) * | 1963-09-03 | 1966-04-20 | Int Nickel Ltd | Low-alloy steel |
| GB1248434A (en) * | 1967-10-17 | 1971-10-06 | Mitsubishi Heavy Ind Ltd | Steel with high notch toughness, high yield point and high tensile strength |
| GB1253552A (en) * | 1968-01-31 | 1971-11-17 | Mitsubishi Heavy Ind Ltd | Heat treatment of high tensile steel |
| GB1253740A (en) * | 1968-01-31 | 1971-11-17 | Mitsubishi Heavy Ind Ltd | Heat treatment of high tensile bainitic steel |
| GB1306410A (en) * | 1969-12-30 | 1973-02-14 | Teledyne Inc | Stress relievable steel weld deposit |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3368887A (en) * | 1965-08-17 | 1968-02-13 | Union Carbide Corp | Consumable wire for improving mechanical properties of weld metal |
| CH524684A (en) * | 1967-11-11 | 1972-06-30 | Mitsubishi Heavy Ind Ltd | Process for the production of an ultra-high strength steel |
| US3655366A (en) * | 1969-10-13 | 1972-04-11 | Int Nickel Co | Low alloy structural steel |
| US3759706A (en) * | 1972-02-23 | 1973-09-18 | Us Navy | High toughness alloy ateel with improved weldability |
| GB8320622D0 (en) * | 1983-07-30 | 1983-09-01 | British Steel Corp | Alloy steels |
-
1988
- 1988-10-17 FI FI884779A patent/FI84370C/en not_active IP Right Cessation
-
1989
- 1989-10-09 CH CH367989A patent/CH679781A5/de not_active IP Right Cessation
- 1989-10-13 FR FR8913412A patent/FR2637915B1/en not_active Expired - Fee Related
- 1989-10-14 DE DE19893934435 patent/DE3934435A1/en not_active Withdrawn
- 1989-10-16 GB GB8923306A patent/GB2224514B/en not_active Expired - Fee Related
- 1989-10-16 NO NO894119A patent/NO173945C/en not_active IP Right Cessation
-
1990
- 1990-02-26 FI FI900964A patent/FI87240C/en not_active IP Right Cessation
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1026735A (en) * | 1963-09-03 | 1966-04-20 | Int Nickel Ltd | Low-alloy steel |
| GB1248434A (en) * | 1967-10-17 | 1971-10-06 | Mitsubishi Heavy Ind Ltd | Steel with high notch toughness, high yield point and high tensile strength |
| GB1253552A (en) * | 1968-01-31 | 1971-11-17 | Mitsubishi Heavy Ind Ltd | Heat treatment of high tensile steel |
| GB1253740A (en) * | 1968-01-31 | 1971-11-17 | Mitsubishi Heavy Ind Ltd | Heat treatment of high tensile bainitic steel |
| GB1306410A (en) * | 1969-12-30 | 1973-02-14 | Teledyne Inc | Stress relievable steel weld deposit |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001036698A1 (en) * | 1999-11-17 | 2001-05-25 | Dt Vyhybkárna A Mostárna, Spol. S R.O. | Steel for railway crossing points |
| CN101905244A (en) * | 2010-08-05 | 2010-12-08 | 中原特钢股份有限公司 | Method for producing mandrel by utilizing 28NiCrMoV steel as raw material |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2637915A1 (en) | 1990-04-20 |
| GB2224514B (en) | 1993-05-26 |
| FR2637915B1 (en) | 1993-07-30 |
| FI87240C (en) | 1992-12-10 |
| NO894119D0 (en) | 1989-10-16 |
| FI900964A0 (en) | 1990-02-26 |
| GB8923306D0 (en) | 1989-12-06 |
| FI84370B (en) | 1991-08-15 |
| FI87240B (en) | 1992-08-31 |
| CH679781A5 (en) | 1992-04-15 |
| NO894119L (en) | 1990-04-18 |
| FI84370C (en) | 1991-11-25 |
| NO173945B (en) | 1993-11-15 |
| DE3934435A1 (en) | 1990-04-19 |
| FI884779A (en) | 1990-04-18 |
| NO173945C (en) | 1994-02-23 |
| FI884779A0 (en) | 1988-10-17 |
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Effective date: 20001016 |