US2343481A - Permanent magnet steel - Google Patents
Permanent magnet steel Download PDFInfo
- Publication number
- US2343481A US2343481A US440875A US44087542A US2343481A US 2343481 A US2343481 A US 2343481A US 440875 A US440875 A US 440875A US 44087542 A US44087542 A US 44087542A US 2343481 A US2343481 A US 2343481A
- Authority
- US
- United States
- Prior art keywords
- carbon
- alloy
- permanent magnet
- iron
- steel
- 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.)
- Expired - Lifetime
Links
- 229910000831 Steel Inorganic materials 0.000 title description 14
- 239000010959 steel Substances 0.000 title description 14
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 38
- 229910045601 alloy Inorganic materials 0.000 description 23
- 239000000956 alloy Substances 0.000 description 23
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 19
- 229910052799 carbon Inorganic materials 0.000 description 19
- 229910052742 iron Inorganic materials 0.000 description 19
- 238000010791 quenching Methods 0.000 description 12
- 238000001816 cooling Methods 0.000 description 11
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 9
- 229910052804 chromium Inorganic materials 0.000 description 9
- 239000011651 chromium Substances 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 8
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 7
- 229910052748 manganese Inorganic materials 0.000 description 7
- 239000011572 manganese Substances 0.000 description 7
- QFGIVKNKFPCKAW-UHFFFAOYSA-N [Mn].[C] Chemical compound [Mn].[C] QFGIVKNKFPCKAW-UHFFFAOYSA-N 0.000 description 6
- 238000005336 cracking Methods 0.000 description 6
- 229910000617 Mangalloy Inorganic materials 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 150000001247 metal acetylides Chemical class 0.000 description 4
- 230000000171 quenching effect Effects 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 3
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 238000005266 casting Methods 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000000161 steel melt Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
- H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
Definitions
- This invention relates to permanent magnet steel and a method of making such steel, and more particularly to permanent magnets of such steel and a method of making the same.
- Carbon manganese steel is well known as a permanent magnet material, although other steels such as chromium, cobalt, or tungsten have been more commonly used in recent years.
- other steels such as chromium, cobalt, or tungsten have been more commonly used in recent years.
- carbon manganese steel is again being pro-posed as a permanent magnet material.
- a small percentage of chromium is added to the carbon manganese'steel melt and then the alloy is quenched in oil.
- An oil quench affords a substantially slower cooling rate than that afforded by a water quench, thus reducing warping or cracking of the steel.
- Carbon manganese steel as used for permanent magnets heretofore had in general the composition of .5% to 1% carbon. .5% to 1.25% man-' ganese and the rest iron. While this composition produced a permanent magnet steel having satisfactory magnetic properties, the steel had to be water quenched to prevent rapid precipitation of carbides and consequent loss of magnetic properties. Because of the physical properties of this composition, rapid cooling had the undesirable effect of causing cracking and warping of the steel. By adding .2% to .'75% chromium to a melt of carbon manganese steel of the composition just described, it appears that the former rate of precipitation of carbides is sufi'iciently reduced so that slower cooling in an oil quench is feasible. Slower cooling reduces greatly the warping and cracking of the steel heretofore encountered. It further appears that an alloy comprising .5% chromium, .6% carbon, .85% manganese and the rest iron, gives satisfactory magnetic and physical properties for many purposes.
- the carbon, manganese, chromiumand iron may be first melted together and the .alloy thus produced cast into ingots and fabricated into the desired shapes. During casting and fabrication, the alloy cools slowly and carbides are precipitated in an excessive amount with a consequent loss of magnetic properties. The fabricated alloy is therefore reheated sufliciently to cause the carbon to reenter solution with the iron. With an alloy of the composition indicated above as satisfactory, a temperature of about 1450 F. appears to be slightly above the critical point and sufiicient to cause the carbon to reenter solution with the iron. It will be understood that with other alloys having different proportions, the
- critical temperature may also be different.
- the I temperature is maintained long. enough to permit substantially all of the carbon to reenter solution with the iron.
- the alloy is quenched in an oil quench, thus providing a rate of cooling enough lower than tha afiorded by water to pre-' vent warping and cracking,while at the time 'mium, .5% to 1% carbon, .5% to 1.25% manganes and the rest iron together to form an alloy, heating the alloy to cause the carbon to enter solution with the iron and then cooling the alloy in an oil quench.
- a method of making a permanent magnet comprising the steps of melting .5% chromium, .60% carbon, .85% manganese and the rest iron together to form an alloy, heating the alloy to cause the carbon to enter solution with the iron, and then cooling the alloy in an oil quench.
- a method of making a permanent magnet comprising melting .2% to 375% chromium, .5% to 1% carbon, .5% to 1.25% manganese and the rest iron together to form an alloy, fabricating a magnet, reheating the alloy to cause the carbon to enter solution with the iron, and then cooling the alloy in an oil quench.
- a method of making a permanent magnet which comprises heating an alloy of .2% to 175% chromium, .5% to 1% carbon, .5% to 1.25% manganese and the balance iron, to cause the carbon to enter solution with the iron and then quenching the alloy in oil.
- a method of making a permanent magnet which comprises heating an alloy of .5% chromium, .60% carbon, 35% manganese and the balance iron, to cause the carbon to enter solution with the iron and then quenching the alloy in oil.
- a permanent magnet comprising .2% to .75% chromium, .5% to 1% carbon, .5% to 1.25%
- the alloy having 10 mium, .60% carbon, .85% manganese and the rest iron, the alloy having been heated to cause the carbon to enter solution with the iron, and cooled in an oil quench.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Hard Magnetic Materials (AREA)
Description
Patented Mar. 7, 1944 PERMANENT MAGNET STEEL Kenneth L. Scott, Western Springs, 111., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York No Drawing. Application April 28, 1942, Serial No. 440,875
7 Claims.
This invention relates to permanent magnet steel and a method of making such steel, and more particularly to permanent magnets of such steel and a method of making the same.
Carbon manganese steel is well known as a permanent magnet material, although other steels such as chromium, cobalt, or tungsten have been more commonly used in recent years. However, now because of restrictions on the quantity which may be used of certain critical'materials, many of the ordinary magnet steels are nolonger generally available and therefore resort must be had to combinations involving the use of smaller quantities of the restricted materialsv or to materials not restricted. Thus, carbon manganese steel is again being pro-posed as a permanent magnet material.
Some difliculties have been experienced with carbon manganese steel due to the necessity of water quenching and the consequent rapid cooling of the steel, which sometimes causes serious cracking and warping. It is generally understood that by rapid cooling through water quenching the precipitation of carbides is held at an incipient stage and that this produces the desired magnetic properties. However, rapid cooling tends to cause cracking and warping.
It is an object of the present invention to provide an improved permanent magnet steel and an improved method of making the same.
In accordance with one embodiment of this invention, a small percentage of chromium is added to the carbon manganese'steel melt and then the alloy is quenched in oil. An oil quench affords a substantially slower cooling rate than that afforded by a water quench, thus reducing warping or cracking of the steel.
The above described and other objects and advantages of this invention will be apparent from the following detailed description:
Carbon manganese steel as used for permanent magnets heretofore had in general the composition of .5% to 1% carbon. .5% to 1.25% man-' ganese and the rest iron. While this composition produced a permanent magnet steel having satisfactory magnetic properties, the steel had to be water quenched to prevent rapid precipitation of carbides and consequent loss of magnetic properties. Because of the physical properties of this composition, rapid cooling had the undesirable effect of causing cracking and warping of the steel. By adding .2% to .'75% chromium to a melt of carbon manganese steel of the composition just described, it appears that the former rate of precipitation of carbides is sufi'iciently reduced so that slower cooling in an oil quench is feasible. Slower cooling reduces greatly the warping and cracking of the steel heretofore encountered. It further appearsthat an alloy comprising .5% chromium, .6% carbon, .85% manganese and the rest iron, gives satisfactory magnetic and physical properties for many purposes.
The carbon, manganese, chromiumand iron may be first melted together and the .alloy thus produced cast into ingots and fabricated into the desired shapes. During casting and fabrication, the alloy cools slowly and carbides are precipitated in an excessive amount with a consequent loss of magnetic properties. The fabricated alloy is therefore reheated sufliciently to cause the carbon to reenter solution with the iron. With an alloy of the composition indicated above as satisfactory, a temperature of about 1450 F. appears to be slightly above the critical point and sufiicient to cause the carbon to reenter solution with the iron. It will be understood that with other alloys having different proportions, the
critical temperature may also be different. The I temperature is maintained long. enough to permit substantially all of the carbon to reenter solution with the iron. Then the alloy is quenched in an oil quench, thus providing a rate of cooling enough lower than tha afiorded by water to pre-' vent warping and cracking,while at the time 'mium, .5% to 1% carbon, .5% to 1.25% manganes and the rest iron together to form an alloy, heating the alloy to cause the carbon to enter solution with the iron and then cooling the alloy in an oil quench.
2. A method of making a permanent magnet comprising the steps of melting .5% chromium, .60% carbon, .85% manganese and the rest iron together to form an alloy, heating the alloy to cause the carbon to enter solution with the iron, and then cooling the alloy in an oil quench.
3. A method of making a permanent magnet comprising melting .2% to 375% chromium, .5% to 1% carbon, .5% to 1.25% manganese and the rest iron together to form an alloy, fabricating a magnet, reheating the alloy to cause the carbon to enter solution with the iron, and then cooling the alloy in an oil quench.
4. A method of making a permanent magnet which comprises heating an alloy of .2% to 175% chromium, .5% to 1% carbon, .5% to 1.25% manganese and the balance iron, to cause the carbon to enter solution with the iron and then quenching the alloy in oil.
5. A method of making a permanent magnet which comprises heating an alloy of .5% chromium, .60% carbon, 35% manganese and the balance iron, to cause the carbon to enter solution with the iron and then quenching the alloy in oil.
6. A permanent magnet comprising .2% to .75% chromium, .5% to 1% carbon, .5% to 1.25%
5 manganese and the rest iron, the alloy having 10 mium, .60% carbon, .85% manganese and the rest iron, the alloy having been heated to cause the carbon to enter solution with the iron, and cooled in an oil quench.
KENNETH L. SCO'I'I.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US440875A US2343481A (en) | 1942-04-28 | 1942-04-28 | Permanent magnet steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US440875A US2343481A (en) | 1942-04-28 | 1942-04-28 | Permanent magnet steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2343481A true US2343481A (en) | 1944-03-07 |
Family
ID=23750530
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US440875A Expired - Lifetime US2343481A (en) | 1942-04-28 | 1942-04-28 | Permanent magnet steel |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2343481A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10857432B2 (en) * | 2017-05-15 | 2020-12-08 | Neo-Sync Llc | Putter head |
-
1942
- 1942-04-28 US US440875A patent/US2343481A/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10857432B2 (en) * | 2017-05-15 | 2020-12-08 | Neo-Sync Llc | Putter head |
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