EP1871917A1 - Boron steel grade for induction hardening and shaft - Google Patents
Boron steel grade for induction hardening and shaftInfo
- Publication number
- EP1871917A1 EP1871917A1 EP06717138A EP06717138A EP1871917A1 EP 1871917 A1 EP1871917 A1 EP 1871917A1 EP 06717138 A EP06717138 A EP 06717138A EP 06717138 A EP06717138 A EP 06717138A EP 1871917 A1 EP1871917 A1 EP 1871917A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- induction hardening
- molybdenum
- nickel
- boron steel
- boron
- 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.)
- Withdrawn
Links
- 230000006698 induction Effects 0.000 title claims abstract description 25
- 229910000712 Boron steel Inorganic materials 0.000 title claims abstract description 20
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 53
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 26
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims abstract description 24
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 24
- 239000011733 molybdenum Substances 0.000 claims abstract description 24
- 239000012535 impurity Substances 0.000 claims abstract description 6
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 7
- 229910052796 boron Inorganic materials 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 5
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 5
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 5
- 239000005864 Sulphur Substances 0.000 claims description 5
- 239000004411 aluminium Substances 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- 229910052799 carbon Inorganic materials 0.000 claims description 5
- 239000011572 manganese Substances 0.000 claims description 5
- 239000010936 titanium Substances 0.000 claims description 5
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 239000011574 phosphorus Substances 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
- 239000010703 silicon Substances 0.000 claims description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims 2
- 229910052742 iron Inorganic materials 0.000 claims 1
- 239000000203 mixture Substances 0.000 abstract description 14
- 229910000831 Steel Inorganic materials 0.000 abstract description 11
- 239000010959 steel Substances 0.000 abstract description 11
- 239000000956 alloy Substances 0.000 abstract description 6
- 229910045601 alloy Inorganic materials 0.000 abstract description 5
- 230000003068 static effect Effects 0.000 abstract description 5
- 230000001965 increasing effect Effects 0.000 abstract description 4
- 230000000750 progressive effect Effects 0.000 abstract description 4
- 238000000034 method Methods 0.000 abstract description 2
- 230000000694 effects Effects 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- CADICXFYUNYKGD-UHFFFAOYSA-N sulfanylidenemanganese Chemical compound [Mn]=S CADICXFYUNYKGD-UHFFFAOYSA-N 0.000 description 3
- 239000006104 solid solution Substances 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 238000002604 ultrasonography Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229920001515 polyalkylene glycol Polymers 0.000 description 1
- 229920002959 polymer blend Polymers 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
- C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
-
- 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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
Definitions
- the present invention relates to a boron steel grade according to the introductory part of the attached claim 1.
- the invention also relates to a shaft made of boron steel according to the introductory part of the attached claim 6.
- Low-alloy boron steel is used inter alia for shafts which by induction hardening of a surface zone are provided with increased fatigue and static strength but also a wear-resistant surface layer.
- Induction hardening of this kind causes in the surface zone compressive stresses which counteract the occurrence of fatigue cracks in this surface zone and thereby have a positive effect on fatigue strength.
- the relationship between the magnitude of the compressive stresses and the fatigue strength is unambiguous. The greater the compressive stresses, the higher the fatigue strength.
- the compressive stresses in the surface zone are balanced by tensile stresses in central portions (the core).
- Tensile stresses in the core do not normally affect strength, since the level of stresses arising from imposed loads is low in specifically the core.
- stationary induction hardening also called single-shot hardening, i.e. a hardening operation where the total volume to be hardened is first heated to the hardening temperature and is thereafter cooled immediately or after a certain delay
- the compressive stresses in the surface zone become particularly high and the fatigue strength becomes better than is achieved by progressive induction hardening where heating and subsequent cooling are effected during continuous mutual movement between inductor/cooling shower and the workpiece which is to be hardened.
- the stresses, not least the tensile stresses in the core in the case of stationary induction hardening may become so great during the actual hardening process that cracks (central cracks) occur in the core.
- a typical and representative ratio is about 20,000 load cycles at 20 kNm torsional fatigue for progressive induction hardening as against about 80,000 load cycles at 20 kNm torsional fatigue for stationary induction hardening.
- the object of the present invention is to provide low-alloy boron steel which can be induction-hardened statically without central cracks occurring.
- Fig. 1 depicts a compilation in tabular form concerning Hie incidence of cracks as a function of composition, where primarily the molybdenum and nickel contents clearly vary
- Fig. 2 depicts in diagram form the incidence of cracks as a function of molybdenum and nickel contents
- FIG. 3 depicts in an axial section a driveshaft for which experiments with steel grades according to the present invention were carried out.
- the steel grades according to the invention are low-allow boron steel, and steel grades according to the invention with the range of composition according to the invention appear in Table 1 together with a corresponding known steel grade.
- Carbon which has a substantial influence on induction hardening characteristics, is present in contents of between 0.30 and 0.50%, resulting in desired strength after hardening. A carbon content amounting to 0.38-0.45% is preferred.
- Silicon is present in an amount of 0.15-0.40%, preferably more than 0.15% up to 0.40%, and is primarily added as a carrier for other alloying elements, but also has some strengthening effect.
- Manganese is present in an amount of 1.10 up to 1.50%, preferably more than 1.10% up to 1.50%, and has strengthening effects partly by increasing the hardenability, which, where there is great hardness depth, may affect the hardness depth in induction hardening. Manganese is also added in order to bind sulphur which would otherwise have adverse effects on impact strength.
- the phosphorus content, ⁇ 0.035%, has to be kept low to prevent brittleness and hardness cracks due to grain boundary weakening.
- MnS manganese sulphide
- Chrome is present in an amount ⁇ 0.5%, preferably more than 0.2% and less than 0.5%. Chrome increases hardenability and reduces the risk of decarburisation.
- Molybdenum in an amount of 0.030% and up to 0.15% has according to the invention proved to be able, together with certain contents of nickel as below, to prevent the occurrence of central cracks, inter alia in static induction hardening.
- the molybdenum content is normally not even specified for boron steel of this kind. It is also likely that such an addition of molybdenum in combination with nickel also reduces the risk of hardness cracks in other grades.
- Molybdenum in a quantity of 0.05 up to 0.15% is preferred.
- Nickel in an amount of 0.15% up to 0.40% has proved, together with molybdenum as above, according to the invention, to be able to prevent the occurrence of central cracks, inter alia in static induction hardening.
- the nickel content is likewise not usually specified.
- Nickel is regarded as an impurity. It is also likely that such an addition of molybdenum in combination with nickel also reduces the risk of hardness cracks in other grades.
- Nickel in an amount of more than 0.20 up to 0.40% is preferred.
- Titanium in certain contents is needed for keeping a certain content of boron in solid solution in the steel with a view to improving the hardening characteristics. Titanium should therefore be present in an amount of 0.020-0.050%. Aluminium is a deoxidant and is therefore present in low contents. Aluminium impairs the fatigue strength by forming aluminium oxide, and aluminium contents should be kept ⁇ 0.050%.
- the desirable content in solid solution is at least 0.0005%, while the total content should be limited to less than 0.004%.
- molybdenum and nickel constitute impurities which are not even specified in a standard composition.
- the composition ranges for molybdenum and nickel which result in the crack-eliminating effect according to the invention nevertheless comprise contents which clearly exceed prevailing impurity levels.
- Fig. 1 shows the incidence of cracks on a large number of driveshafts from a large number of charges with mutual varying chemical composition
- "No.” denotes the number of shafts in which cracks were detected
- “Tot.” the total number of shafts examined for each steel charge
- “Incid. %” the ratio between "No.” and “Tot”, i.e. the proportion of shafts with detected cracks.
- Fig. 2 shows the incidence of cracks, "Crack Incidence %", as a function of molybdenum content and nickel content, although for manufacturing reasons the effect of molybdenum content or nickel content would be isolated.
- the minimum contents indicated have been adjusted by a small margin to the respective content combinations of 0.035% molybdenum/0.167% nickel and 0.038 molybdenum/0.188% nickel, which resulted in no cracks.
- the preferred minimum contents have been provided with a margin upwards relative to the minimum contents extracted.
- An upper content limit has also been set for both molybdenum and nickel. This is partly for cost reasons and for preventing disadvantages, e.g. impaired machinability, which occur at increasing molybdenum and nickel contents.
- Scania boron steel TB 1639 as a low-alloy material is specified in Table 1 below.
- Low-alloy compositions are usually stated without contents of molybdenum and nickel, which substances are to be regarded as common impurities.
- a general composition according to the invention, a preferred composition and a detailed composition which in experiments resulted in lack of cracks are also specified.
- Table 1 Composition of boron steel according to the state of the art and the invention.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
- Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
Abstract
Low-alloy boron steel grade, e.g. for shafts, which by induction hardening of a surface zone are given an improved fatigue and static strength. The greatest improvement in fatigue strength is obtained by stationary (single shot) induction hardening, due to higher compressive stresses in the surface compared to those obtained by progressive (scanning method) induction hardening. High corresponding tensile stresses in the shaft centre have, however, proved to be able to cause central cracks for these steel grades. The invention means that by using slightly increased contents of molybdenum and nickel as compared with those which as a rule appear as impurities in boron steel of standard composition without specification of the molybdenum and nickel content, the occurrence of central cracks is eliminated.
Description
BORON STEEL GRADE FOR INDUCTION HARDENING5 AND SHAFT
1. Background
1.1 Technical field
The present invention relates to a boron steel grade according to the introductory part of the attached claim 1.
The invention also relates to a shaft made of boron steel according to the introductory part of the attached claim 6.
1.2 Brief presentation of the state of the art
Low-alloy boron steel is used inter alia for shafts which by induction hardening of a surface zone are provided with increased fatigue and static strength but also a wear- resistant surface layer.
Induction hardening of this kind causes in the surface zone compressive stresses which counteract the occurrence of fatigue cracks in this surface zone and thereby have a positive effect on fatigue strength. The relationship between the magnitude of the compressive stresses and the fatigue strength is unambiguous. The greater the compressive stresses, the higher the fatigue strength.
The compressive stresses in the surface zone are balanced by tensile stresses in central portions (the core). Tensile stresses in the core do not normally affect strength, since the level of stresses arising from imposed loads is low in specifically the core.
In stationary induction hardening, also called single-shot hardening, i.e. a hardening operation where the total volume to be hardened is first heated to the hardening temperature and is thereafter cooled immediately or after a certain delay, the compressive stresses in the surface zone become particularly high and the fatigue strength becomes better than is achieved by progressive induction hardening where
heating and subsequent cooling are effected during continuous mutual movement between inductor/cooling shower and the workpiece which is to be hardened. However, the stresses, not least the tensile stresses in the core, in the case of stationary induction hardening may become so great during the actual hardening process that cracks (central cracks) occur in the core. If central cracks can be avoided, however, stationary induction hardening of a shaft results in very good fatigue strength. A typical and representative ratio is about 20,000 load cycles at 20 kNm torsional fatigue for progressive induction hardening as against about 80,000 load cycles at 20 kNm torsional fatigue for stationary induction hardening.
Low-allow boron steel has proved to be very sensitive to the phenomena described above, which under certain conditions give rise to central cracks, which are of course unacceptable in the hardened product. Cracks of this kind are normally difficult to detect when they do not reach the surface of the product concerned. It has nevertheless proved possible to detect them by examination with ultrasound.
The object of the present invention is to provide low-alloy boron steel which can be induction-hardened statically without central cracks occurring.
2. Summary of the invention
The object as above is achieved with boron steel and shafts according to the attached claims 1 and 6.
Further advantages are achieved by what is specified in the dependent claims.
3. Brief description of the drawings
The invention is described below in more detail with reference to examples of embodiments and the attached drawings, in which
- Fig. 1 depicts a compilation in tabular form concerning Hie incidence of cracks as a function of composition, where primarily the molybdenum and nickel contents clearly vary,
- Fig. 2 depicts in diagram form the incidence of cracks as a function of molybdenum and nickel contents,
- Fig. 3 depicts in an axial section a driveshaft for which experiments with steel grades according to the present invention were carried out.
4. Detailed description of preferred embodiments
In the description, all percentage figures given for elements in the steel grades indicated are by weight.
The steel grades according to the invention are low-allow boron steel, and steel grades according to the invention with the range of composition according to the invention appear in Table 1 together with a corresponding known steel grade.
Carbon, which has a substantial influence on induction hardening characteristics, is present in contents of between 0.30 and 0.50%, resulting in desired strength after hardening. A carbon content amounting to 0.38-0.45% is preferred.
Silicon is present in an amount of 0.15-0.40%, preferably more than 0.15% up to 0.40%, and is primarily added as a carrier for other alloying elements, but also has some strengthening effect.
Manganese is present in an amount of 1.10 up to 1.50%, preferably more than 1.10% up to 1.50%, and has strengthening effects partly by increasing the hardenability, which, where there is great hardness depth, may affect the hardness depth in induction hardening. Manganese is also added in order to bind sulphur which would otherwise have adverse effects on impact strength.
The phosphorus content, < 0.035%, has to be kept low to prevent brittleness and hardness cracks due to grain boundary weakening.
Sulphur improves machinability by formation of manganese sulphide (MnS) but at the same time reduces strength because MnS constitutes in the stronger steel matrix weak regions which may act as crack notches. The sulphur content needs here to be kept within the range 0.020-0.050%.
Chrome is present in an amount < 0.5%, preferably more than 0.2% and less than 0.5%. Chrome increases hardenability and reduces the risk of decarburisation.
Molybdenum in an amount of 0.030% and up to 0.15% has according to the invention proved to be able, together with certain contents of nickel as below, to prevent the occurrence of central cracks, inter alia in static induction hardening. The molybdenum content is normally not even specified for boron steel of this kind. It is also likely that such an addition of molybdenum in combination with nickel also reduces the risk of hardness cracks in other grades. Molybdenum in a quantity of 0.05 up to 0.15% is preferred.
Nickel in an amount of 0.15% up to 0.40% has proved, together with molybdenum as above, according to the invention, to be able to prevent the occurrence of central cracks, inter alia in static induction hardening. The nickel content is likewise not usually specified. Nickel is regarded as an impurity. It is also likely that such an addition of molybdenum in combination with nickel also reduces the risk of hardness cracks in other grades. Nickel in an amount of more than 0.20 up to 0.40% is preferred.
Titanium in certain contents is needed for keeping a certain content of boron in solid solution in the steel with a view to improving the hardening characteristics. Titanium should therefore be present in an amount of 0.020-0.050%.
Aluminium is a deoxidant and is therefore present in low contents. Aluminium impairs the fatigue strength by forming aluminium oxide, and aluminium contents should be kept < 0.050%.
Boron in low contents improves hardening characteristics, e.g. hardenability, which where there is great hardness depth may affect the hardening depth in induction hardening. The desirable content in solid solution is at least 0.0005%, while the total content should be limited to less than 0.004%.
5. Applying the invention
In normal circumstances, molybdenum and nickel constitute impurities which are not even specified in a standard composition. The composition ranges for molybdenum and nickel which result in the crack-eliminating effect according to the invention nevertheless comprise contents which clearly exceed prevailing impurity levels.
However, said ranges correspond to relatively small amounts of the alloy substances molybdenum and nickel and probably have an extremely marginal effect on the steel cost of the low-allow boron steels here concerned.
On the oilier hand, a substantial increase in strength is achieved by being able to apply static induction hardening without central cracks occurring, which in itself is likely in certain cases to mean that material can be economised in workpieces concerned without affecting performance as regards such aspects as fatigue strength.
6. Examples and experiments
Driveshafts (Fig. 3) made of boron steel TB 1639 with various molybdenum and nickel contents were hardened by stationary induction hardening as follows:
1. Induction heating in about 40 seconds to a surface temperature of about 10000C.
2. Cooling by water-based polymer mixture (polyalkylene glycol).
3. Tempering (reheating, about 90 seconds) by inductive stationary heating to a surface temperature of about 3000C.
The occurrence of cracks was detected by ultrasound from shaft end surface.
The table in Fig. 1 shows the incidence of cracks on a large number of driveshafts from a large number of charges with mutual varying chemical composition, hi the table, "No." denotes the number of shafts in which cracks were detected, "Tot." the total number of shafts examined for each steel charge and "Incid. %" the ratio between "No." and "Tot", i.e. the proportion of shafts with detected cracks. Fig. 2 shows the incidence of cracks, "Crack Incidence %", as a function of molybdenum content and nickel content, although for manufacturing reasons the effect of molybdenum content or nickel content would be isolated.
From the compositions of the shafts (testpieces) in which no cracks were detected ("Incid. 0%" in Fig. 1), minimum contents of about 0.030% molybdenum and about 0.15% nickel, for prevention of cracks, can be extracted.
The minimum contents indicated have been adjusted by a small margin to the respective content combinations of 0.035% molybdenum/0.167% nickel and 0.038 molybdenum/0.188% nickel, which resulted in no cracks. The preferred minimum contents have been provided with a margin upwards relative to the minimum contents extracted.
An upper content limit has also been set for both molybdenum and nickel. This is partly for cost reasons and for preventing disadvantages, e.g. impaired machinability, which occur at increasing molybdenum and nickel contents.
Within the scope of the experimental investigation described above, it was also possible to verify by both measurements and calculations that stationary induction hardening results in both higher compressive stresses in the surface and higher tensile stresses in the centre than progressive induction hardening of shafts.
7. Chemical compositions
Scania boron steel TB 1639 as a low-alloy material is specified in Table 1 below. Low-alloy compositions are usually stated without contents of molybdenum and nickel, which substances are to be regarded as common impurities. A general composition according to the invention, a preferred composition and a detailed composition which in experiments resulted in lack of cracks are also specified.
Table 1 Composition of boron steel according to the state of the art and the invention.
Chemical composition
Basic TB 1639 Invention Preferred Example substance basis generally embodiment from Fig. 1
C 0.38-0.45 0.30-0.50 0.30-0.50 0.417
Si 0.15-0.40 0.15-0.40 > 0.15-0.40 0.282
Mn 1.10-1.50 1.10-1.50 > 1.10-1.50 1.323
P < 0.035 < 0.035 < 0.035 0.011
S 0.020-0.050 0.020-0.050 0.020-0.050 0.028
Cr < 0.50 < 0.50 < 0.20-0.50 0.297
Mo 0.030-0.15 0.05-0.15 0.038
Ni 0.15-0.40 > 0.20-0.40 0.188
Ti 0.020-0.050 0.020-0.050 0.020-0.050 0.039
Al < 0.050 < 0.050 < 0.050 0.032
B (total) < 0.0040 < 0.0040 < 0.0040 < 0.0040
B (soluble) > 0.005 > 0.005 > 0.005 > 0.005
Claims
1. A boron steel, preferably for stationary induction hardening, comprising, in wt%,
0.30-0.50% carbon 0.15-0.40% silicon 1.10-1.50% manganese
< 0.035% phosphorus 0.020-0.050% sulphur < 0.50% chrome
0.030-0.15% molybdenum 0.15-0.40% nickel 0.020-0.050% titanium
< 0.050% aluminium < 0.0040% total boron
> 0.0005% soluble boron
and the remainder iron and impurities.
2. A boron steel according to claim 1 , comprising in wt%,
0.30-0.50% carbon more than 0.15 up to 0.40% silicon more than 1.10 up to 1.50% manganese < 0.035% phosphorus 0.020-0.050% sulphur
< 0.50% chrome 0.05-0.15% molybdenum 0.20-0.40% nickel 0.020-0.050% titanium
< 0.050% aluminium
< 0.0040% total boron
> 0.0005% soluble boron
3. A boron steel according to claim 1 or 2, characterised in that the proportion of carbon is 0.38-0.45%.
4. A boron steel according to claim 1, 2 or 3, characterised in that the proportion of nickel is more than 0.20 up to 0.40%.
5. A boron steel according to claim 1, 2, 3 or 4, characterised in that the proportion of chrome is more than 0.20 up to 0.50%.
6. A shaft, characterised in that it is made of a boron steel according to claim 1, 2, 3, 4 or 5.
7. A shaft according to claim 6, characterised by a hardened layer caused by stationary induction hardening.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE0500812A SE0500812L (en) | 2005-04-12 | 2005-04-12 | Brush steel for induction hardening and shaft |
| PCT/SE2006/050059 WO2006110100A1 (en) | 2005-04-12 | 2006-04-06 | Boron steel grade for induction hardening and shaft |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP1871917A1 true EP1871917A1 (en) | 2008-01-02 |
Family
ID=35653953
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP06717138A Withdrawn EP1871917A1 (en) | 2005-04-12 | 2006-04-06 | Boron steel grade for induction hardening and shaft |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP1871917A1 (en) |
| JP (1) | JP2008537982A (en) |
| CN (1) | CN101155941B (en) |
| BR (1) | BRPI0608675A2 (en) |
| SE (1) | SE0500812L (en) |
| WO (1) | WO2006110100A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101624675B (en) * | 2009-07-30 | 2011-02-16 | 莱芜钢铁股份有限公司 | 45BM steel for caterpillar track pin roll and manufacturing method thereof |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2725747B2 (en) * | 1990-11-16 | 1998-03-11 | 大同特殊鋼株式会社 | Steel for induction hardening |
| JP2916069B2 (en) * | 1993-09-17 | 1999-07-05 | 新日本製鐵株式会社 | High-strength induction hardened shaft parts |
| JP3432944B2 (en) * | 1995-03-16 | 2003-08-04 | 新日本製鐵株式会社 | Steel material for induction hardened shaft parts with excellent torsional fatigue strength |
| JP3432950B2 (en) * | 1995-04-17 | 2003-08-04 | 新日本製鐵株式会社 | Steel material for induction hardened shaft parts that has both cold workability and torsional fatigue strength characteristics |
| JPH10195589A (en) * | 1996-12-26 | 1998-07-28 | Nippon Steel Corp | High torsional fatigue strength induction hardened steel |
| JPH11181542A (en) * | 1997-12-16 | 1999-07-06 | Nippon Steel Corp | Steel for induction hardening excellent in cold workability and induction hardening and its manufacturing method |
| ES2292836T3 (en) * | 2002-10-18 | 2008-03-16 | Jfe Steel Corporation | STEEL MATERIAL FOR MECHANICAL STRUCTURE, EXTREMELY APPROPRIATE FOR LAMINATION, TEMPERATURE FISSURE RESISTANCE AND TORSION PROPERTY AND MOTOR SHAFT. |
| JP3774697B2 (en) * | 2002-12-04 | 2006-05-17 | 新日本製鐵株式会社 | Steel material for high strength induction hardening and method for manufacturing the same |
| JP2005048211A (en) * | 2003-07-30 | 2005-02-24 | Jfe Steel Kk | Manufacturing method of steel material with excellent fatigue characteristics |
-
2005
- 2005-04-12 SE SE0500812A patent/SE0500812L/en not_active IP Right Cessation
-
2006
- 2006-04-06 EP EP06717138A patent/EP1871917A1/en not_active Withdrawn
- 2006-04-06 WO PCT/SE2006/050059 patent/WO2006110100A1/en not_active Ceased
- 2006-04-06 JP JP2008506416A patent/JP2008537982A/en active Pending
- 2006-04-06 CN CN2006800116181A patent/CN101155941B/en not_active Expired - Fee Related
- 2006-04-06 BR BRPI0608675-6A patent/BRPI0608675A2/en not_active IP Right Cessation
Non-Patent Citations (1)
| Title |
|---|
| See references of WO2006110100A1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2006110100A1 (en) | 2006-10-19 |
| SE527221C2 (en) | 2006-01-24 |
| JP2008537982A (en) | 2008-10-02 |
| SE0500812L (en) | 2006-01-24 |
| CN101155941A (en) | 2008-04-02 |
| BRPI0608675A2 (en) | 2010-01-19 |
| CN101155941B (en) | 2010-09-08 |
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