US3674468A - High-strength silicon steel - Google Patents
High-strength silicon steel Download PDFInfo
- Publication number
- US3674468A US3674468A US92144A US3674468DA US3674468A US 3674468 A US3674468 A US 3674468A US 92144 A US92144 A US 92144A US 3674468D A US3674468D A US 3674468DA US 3674468 A US3674468 A US 3674468A
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- United States
- Prior art keywords
- steel
- less
- silicon steel
- strength
- toughness
- Prior art date
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- 229910000976 Electrical steel Inorganic materials 0.000 title abstract description 12
- 229910052799 carbon Inorganic materials 0.000 abstract description 4
- 230000009466 transformation Effects 0.000 abstract description 4
- 229910052720 vanadium Inorganic materials 0.000 abstract description 2
- 229910000831 Steel Inorganic materials 0.000 description 13
- 239000010959 steel Substances 0.000 description 13
- 229910000746 Structural steel Inorganic materials 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 238000005242 forging Methods 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 239000000460 chlorine Substances 0.000 description 3
- 229910052804 chromium Inorganic materials 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000004615 ingredient Substances 0.000 description 3
- 238000005272 metallurgy Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 238000005495 investment casting Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 229910001149 41xx steel Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 229910017082 Fe-Si Inorganic materials 0.000 description 1
- 229910017133 Fe—Si Inorganic materials 0.000 description 1
- 101100409194 Rattus norvegicus Ppargc1b gene Proteins 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
Definitions
- the present invention relates to a new high-strength silicon steel possessing improved and unusual combinations of metallurgical and mechanical properties.
- silicon is an effective alloying element for increasing strength and toughness of ferrite and also that the upper limit of silicon for structural steel is about 2%, since larger amounts cause an unacceptable lowering of toughness.
- Another object of this invention is to provide a novel structural steel which has a high toughness in the as-cast condition.
- Still another object of this invention is to provide a new structural steel having excellent forging properties and which may be subjected to electric welding in open air vw'thout preliminary heating.
- a further object of this invention is to provide a new structural steel which has very high corrosion resistance to various acids.
- the product of this invention is characterized by consisting of, by weight: less than 0.03% C, 4-6% -Si, 5l0% Ni, 6-18% Cr, less than 4% each of Mn, Mo and Cu, less than 2% V, the residue being essentially Fe.
- the amount of C, Si, Mn, Ni and Cr be provided within the above ranges.
- the amount of C should not exceed about 0.03% because more carbon impairs the toughness of the product to some degree.
- the amount of Si employed has been found to be most important. When the Si content is less than about 3%, the strength is adversely affected; whereas with Si content above 7%, the toughness is impaired. For the best combination of strength and toughness, it has been found that the Si content should be within the range of 4% to 6%.
- Ni and Mn The total amount of Ni and Mn (Mn is usually held to about 2%) is varied soas to approach 2 times the Si content, and the Cr varied about 2.5 times the Si content, so that the Ac transformation point is lowered to less than 1400 F., thereby preventing the alloy from suffering grain-gross, which imparts toughness thereto.
- the characteristics of the high-strength silicon steel according to the invention are illustrated by the data in Tables 2 and 3, setting forth the mechanical properties of round bars with diameter of 1 inch. These round bars have been prepared in such a way that the raw materials are melted in a high frequency electric furnace in open air to produce ingots of 0.5 ton weight which are taken place witha hot-roll to obtain those round bars.
- Hv 325 350 350 S., lb./s in 150,000 165, 000 160, 000
- the high-strength silicon steel A according to the invention is compared with the 'NiCrMo structure steel (4337) and comparing these values of elongation, R.A., Charpy impact value and quality factors. It
- steel A has a very high toughness approximately 2 times higher than that of the quench-andtempered NiCrMo steel.
- this data shows that steel A does not have practically any mass-effect on heat-treatment and this enables massive steel forgings, such as rotor-shafts, to have uniform and high strength and toughness even over the core thereof.
- Table 3 illustrates the mechanical and corrosion-resisting properties of the high-strength silicon steel B according to the invention in comparison with those of 18-8 stainless steel (30.4). It will be appreciated that the steel B has overcome the poor resistance of 18-8 stainless steel against chlorine and hydrochloric acid and many new uses in the field of chemical industry therefore become possible.
- the highstrength silicon steel according to this invention has the following excellent characteristics and properties:
- the present invention may be applied to the manufacture of a wide variety of ferrous products and articles T which will be apparent to those skilled in the metallurgy of steel from the properties of the ferrous alloy provided by the invention.
- These products and articles include machine parts such as reaction vessels for chemical engineering, turbine-discs of jet engines, exhaust valves of internal combustion engines, chassis of cars, bulletproof plates of tanks, protecting covers for missiles, wire ropes for suspension bridges and marine use, many kinds of springs and various rust-resisting instruments for medical and home uses.
- a high-strength silicon steel consisting essentially of:
- a high-strength silicon steel according to claim 1 which also includes less than about 1% of any one of Al, Ti, Cb and B.
- a high-strength machine structural silicon steel according to claim 1 consisting essentially of:
- Mo-i-V' l-3 Cu Up to 1. Fe Essentially the remainder.
- a high-strength corrosion resisting silicon steel according to claim 1 consisting essentially of:
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
A HIGH-STRENGTH SILICON STEEL CONSISTING OF LESS THAN 0.03% C, 4-6% SI, 5-10% NI, 6-18% CR, LESS THAN 4% EACH OF MN, MO AND CU, LESS THAN 2% V AND RESIDUE ESSENTIALLY FE, IN WHICH THE TOTAL AMOUNT OF NI AND MN IS VARIED SO AS TO APPROACH 2 TIMES THE SI CONTENT AND THE CR VARIED ABOUT 2.5 TIMES TO THE SI CONTENT, SO THAT THE AC3 TRANSFORMATION POINT IS LOWERED TO LESS THAN 1400*F.
Description
United States Patent 3,674,468 HIGH-STRENGTH SILICON STEEL Keiichi Ota, 54 Nakagawara-cho, Sakyo-ku,
Kyoto, Japan I No Drawing. Continuation-impart of application Ser. No. 708,530, Feb. 27, 1968. This application Nov. 23, 1970, Ser. No. 92,144
Int. Cl. C22c 39/20, 39/44 U.s. cl. 7s-'-12s A 4 Claims ABSTRACT OF THE DISCLOSURE CROSS REFERENCES This application is a continuation-in-part of copending application, Ser. No. 708,530 filed Feb. 27, 1968 and now abandoned.
BACKGROUND OF THE INVENTION.
The present invention relates to a new high-strength silicon steel possessing improved and unusual combinations of metallurgical and mechanical properties.
It is well known by anyone skilled in the metallurgy of steel that silicon is an effective alloying element for increasing strength and toughness of ferrite and also that the upper limit of silicon for structural steel is about 2%, since larger amounts cause an unacceptable lowering of toughness.
SUMMARY OF THE INVENTION It is thus a principal object of the present invention to obviate the above drawback and to provide a new structural steel possessing a high strength and toughness which is characterized in that Fe-Si alloy containing 46% Si is alloyed witha suitable amount of Mn, Ni and Cr to lower the Ac transformation point to less than 1400" F., thereby preventing the alloy from suifering grain-gross while successfully imparting toughness thereto.
It is another objectof this invention to provide a new structural steel having a high degree of castability and which is well suited for the precision casting of thin and complex machine parts.
Another object of this invention is to provide a novel structural steel which has a high toughness in the as-cast condition.
Still another object of this invention is to provide a new structural steel having excellent forging properties and which may be subjected to electric welding in open air vw'thout preliminary heating.
A further object of this invention is to provide a new structural steel which has very high corrosion resistance to various acids.
The product of this invention is characterized by consisting of, by weight: less than 0.03% C, 4-6% -Si, 5l0% Ni, 6-18% Cr, less than 4% each of Mn, Mo and Cu, less than 2% V, the residue being essentially Fe.
It is important that the amount of C, Si, Mn, Ni and Cr be provided Within the above ranges. For example, the amount of C should not exceed about 0.03% because more carbon impairs the toughness of the product to some degree. The amount of Si employed has been found to be most important. When the Si content is less than about 3%, the strength is adversely affected; whereas with Si content above 7%, the toughness is impaired. For the best combination of strength and toughness, it has been found that the Si content should be within the range of 4% to 6%.
- The total amount of Ni and Mn (Mn is usually held to about 2%) is varied soas to approach 2 times the Si content, and the Cr varied about 2.5 times the Si content, so that the Ac transformation point is lowered to less than 1400 F., thereby preventing the alloy from suffering grain-gross, which imparts toughness thereto.
'By using Cu, the corrosion resistance of this alloy to various acids has been elevated remarkably, especially with respect to sulfuric and hydrochloric acid, while at the same time the forging property is lowered. Therefore, it is recommended to add 1-2% Cu for rust-resisting forging and 34% for stainless casting.
For the purposes of deoxidation and refining of austenite grain-size, it is preferable to add less than 1% each of Al, Ti, Cb and B.
DESCRIPTION OF THE PREFERRED EMBODIMENT In order that those skilled in the metallurgy of steel have a better understanding of the properties which can be obtained by the present invention, the standard composition ranges suitable for certain uses are set forth in the following Table 1.
The characteristics of the high-strength silicon steel according to the invention are illustrated by the data in Tables 2 and 3, setting forth the mechanical properties of round bars with diameter of 1 inch. These round bars have been prepared in such a way that the raw materials are melted in a high frequency electric furnace in open air to produce ingots of 0.5 ton weight which are taken place witha hot-roll to obtain those round bars.
TABLE 2 Chemical composition of steel A tested, percent :0 0.018, Si 4.6, Mn 2.8, Ni 6.6, Cr 10.4, Mo plus V 2.2
Ni CrMo steel Steel A Steel A (4337) Heat treatment Mechanical properties:
Hardness, Hv 325 350 350 S., lb./s in 150,000 165, 000 160, 000
Elongation in 2 inch, perc 52. 48. 2 25. 3
R A., percent 68. 3 74. 4 46. 3
Charpy I.V., kg. m./sq. cm..." 28.1 32. 4 16.2
In the above Table 2, the high-strength silicon steel A according to the invention is compared with the 'NiCrMo structure steel (4337) and comparing these values of elongation, R.A., Charpy impact value and quality factors. It
will be appreciated that steel A has a very high toughness approximately 2 times higher than that of the quench-andtempered NiCrMo steel. On the other hand this data shows that steel A does not have practically any mass-effect on heat-treatment and this enables massive steel forgings, such as rotor-shafts, to have uniform and high strength and toughness even over the core thereof.
Table 3 illustrates the mechanical and corrosion-resisting properties of the high-strength silicon steel B according to the invention in comparison with those of 18-8 stainless steel (30.4). It will be appreciated that the steel B has overcome the poor resistance of 18-8 stainless steel against chlorine and hydrochloric acid and many new uses in the field of chemical industry therefore become possible.
TABLE 3 Chemical composition of steel B tested, percent: 0.022, Si 1.8, Mn 1.8, Ni 7.3, Cr 16.8, Cu 3.4, Mo plus V 1.6
18-8 Stainless Steel In addition to the foregoing mechanical and corrosionresisting properties, it has been confirmed that the highstrength silicon steel according to this invention has the following excellent characteristics and properties:
(a) It is rich in castability and well adapted for precision casting of thin and complex machine parts such as turbine blades.
(b) It has excellent forging properties and permits the manufacture of a music string having a tensile strength of 350,000 lb./s'q. inch and 38 turns in twisting.
(c) It has a very high toughness of more than 8 kg. m./sq. cm. of Charpy impact value in the as-cast condition.
(d) Reduction of toughness is negligible even at temperatures below 32 F., and an impact value of "kg. m./sq. cm. may be obtained in liquid nitrogen.
The present invention may be applied to the manufacture of a wide variety of ferrous products and articles T which will be apparent to those skilled in the metallurgy of steel from the properties of the ferrous alloy provided by the invention. These products and articles include machine parts such as reaction vessels for chemical engineering, turbine-discs of jet engines, exhaust valves of internal combustion engines, chassis of cars, bulletproof plates of tanks, protecting covers for missiles, wire ropes for suspension bridges and marine use, many kinds of springs and various rust-resisting instruments for medical and home uses.
I claim: 1. A high-strength silicon steel consisting essentially of:
Ingredient: Wt. percent C Less than 0.03. 5 Si 4-6.
Ni 5-10. Cr 6-18 and about 2.5 times Si content. Mn Less than 4.
Mo Do. 10 Cu Do.
V Less than 2. 7 Fe Essentially the remainder. Ni-l-Mn About 2 times Si content.
wherein the Ac transformation point of said steel is less than l400 F.
2. A high-strength silicon steel according to claim 1 which also includes less than about 1% of any one of Al, Ti, Cb and B.
3. A high-strength machine structural silicon steel according to claim 1 consisting essentially of:
Ingredient: Wt. percent C Up to 0.03. Si 4-5. Mn 1-3.
Mo-i-V' l-3. Cu Up to 1. Fe Essentially the remainder.
4. A high-strength corrosion resisting silicon steel according to claim 1 consisting essentially of:
Ingredient: p Wt. percent C Up to 0.03. Si 4.5-5.5.
Mn l-3.
Cr 12-18. Mo-]V 1 3. Cu 1-4. Fe Essentially the remainder.
References Cited UNITED STATES PATENTS 2,747,989 5/ 1956 Kirkby 75-128 C 2,839,392 6/1958 Streicher 75-128 3,337,331 8/1967 Ljungberg 75l28 C 1,555,395 9/1925 Armstrong -428 3,294,527 12/ 1966 Floreen 75-l23 2,7 50,283 6/1956 Loveless 75l24 L. DEWAYNE RUTLEDGE, Primary Examiner J. E. LEGR-U, Assistant Examiner US. Cl. XJR.
75l25, 128 C, 128 F, 128G, 128 T, 128 W
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US9214470A | 1970-11-23 | 1970-11-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3674468A true US3674468A (en) | 1972-07-04 |
Family
ID=22231841
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US92144A Expired - Lifetime US3674468A (en) | 1970-11-23 | 1970-11-23 | High-strength silicon steel |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3674468A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3839100A (en) * | 1973-04-16 | 1974-10-01 | K Ota | Low nickel high-strength silicon steel |
| US3926620A (en) * | 1970-07-14 | 1975-12-16 | Sumitomo Metal Ind | Low carbon ni-cr alloy steel having an improved resistance to stress corrosion cracking |
| US4050928A (en) * | 1976-02-17 | 1977-09-27 | The International Nickel Company, Inc. | Corrosion-resistant matrix-strengthened alloy |
| US5051233A (en) * | 1989-01-14 | 1991-09-24 | Bayer Aktiengesellschaft | Stainless wrought and cast materials and welding additives for structural units exposed to hot, concentrated sulfuric acid |
| US5306477A (en) * | 1992-04-23 | 1994-04-26 | Bayer Aktiengesellschaft | Use of wrought and cast materials and welding fillers for making and using hot concentrated sulphuric acid or oleum |
| US20040234409A1 (en) * | 2003-02-27 | 2004-11-25 | Francois Ropital | Use of low alloy anticoking steels with an increased silicon and manganese content in refining and petrochemicals applications, and novel steel compositions |
-
1970
- 1970-11-23 US US92144A patent/US3674468A/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3926620A (en) * | 1970-07-14 | 1975-12-16 | Sumitomo Metal Ind | Low carbon ni-cr alloy steel having an improved resistance to stress corrosion cracking |
| US3839100A (en) * | 1973-04-16 | 1974-10-01 | K Ota | Low nickel high-strength silicon steel |
| US4050928A (en) * | 1976-02-17 | 1977-09-27 | The International Nickel Company, Inc. | Corrosion-resistant matrix-strengthened alloy |
| US5051233A (en) * | 1989-01-14 | 1991-09-24 | Bayer Aktiengesellschaft | Stainless wrought and cast materials and welding additives for structural units exposed to hot, concentrated sulfuric acid |
| US5306477A (en) * | 1992-04-23 | 1994-04-26 | Bayer Aktiengesellschaft | Use of wrought and cast materials and welding fillers for making and using hot concentrated sulphuric acid or oleum |
| US20040234409A1 (en) * | 2003-02-27 | 2004-11-25 | Francois Ropital | Use of low alloy anticoking steels with an increased silicon and manganese content in refining and petrochemicals applications, and novel steel compositions |
| US7442264B2 (en) * | 2003-02-27 | 2008-10-28 | Institute Francais Du Petrole | Method of using low alloy anticoking steels with an increased silicon and manganese content in refining and petrochemicals applications |
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