CN104508170B - Hardened steel pipe component, the automobile bloster employing hardened steel pipe component and the manufacture method of hardened steel pipe component - Google Patents
Hardened steel pipe component, the automobile bloster employing hardened steel pipe component and the manufacture method of hardened steel pipe component Download PDFInfo
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- CN104508170B CN104508170B CN201380038667.4A CN201380038667A CN104508170B CN 104508170 B CN104508170 B CN 104508170B CN 201380038667 A CN201380038667 A CN 201380038667A CN 104508170 B CN104508170 B CN 104508170B
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- 229910000760 Hardened steel Inorganic materials 0.000 title claims abstract description 39
- 238000004519 manufacturing process Methods 0.000 title claims description 27
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 89
- 239000010959 steel Substances 0.000 claims abstract description 89
- 239000011248 coating agent Substances 0.000 claims abstract description 59
- 238000000576 coating method Methods 0.000 claims abstract description 59
- 239000002184 metal Substances 0.000 claims abstract description 22
- 229910052751 metal Inorganic materials 0.000 claims abstract description 22
- 229910001297 Zn alloy Inorganic materials 0.000 claims abstract description 14
- 230000002093 peripheral Effects 0.000 claims abstract description 13
- 238000010438 heat treatment Methods 0.000 claims description 44
- 238000001816 cooling Methods 0.000 claims description 16
- 230000033228 biological regulation Effects 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 8
- 238000000465 moulding Methods 0.000 claims description 4
- 230000000694 effects Effects 0.000 description 33
- 230000001629 suppression Effects 0.000 description 24
- 238000010791 quenching Methods 0.000 description 13
- 238000001556 precipitation Methods 0.000 description 11
- 230000000171 quenching Effects 0.000 description 11
- 238000005261 decarburization Methods 0.000 description 10
- 239000000203 mixture Substances 0.000 description 9
- 230000014759 maintenance of location Effects 0.000 description 8
- 238000005275 alloying Methods 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- HCHKCACWOHOZIP-UHFFFAOYSA-N zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 7
- 229910052725 zinc Inorganic materials 0.000 description 7
- 239000011701 zinc Substances 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 229910000734 martensite Inorganic materials 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 238000003466 welding Methods 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N tin hydride Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 4
- 229910001335 Galvanized steel Inorganic materials 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- REDXJYDRNCIFBQ-UHFFFAOYSA-N aluminium(3+) Chemical class [Al+3] REDXJYDRNCIFBQ-UHFFFAOYSA-N 0.000 description 3
- 229910052796 boron Inorganic materials 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 3
- 238000005262 decarbonization Methods 0.000 description 3
- 230000004059 degradation Effects 0.000 description 3
- 238000006731 degradation reaction Methods 0.000 description 3
- 239000008397 galvanized steel Substances 0.000 description 3
- 229910052758 niobium Inorganic materials 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- 210000003491 Skin Anatomy 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium monoxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- 241000208199 Buxus sempervirens Species 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-N Carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 1
- 206010022979 Iron excess Diseases 0.000 description 1
- 230000000996 additive Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 230000000875 corresponding Effects 0.000 description 1
- 230000003111 delayed Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
- 101700018595 gp64 Proteins 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- TWXTWZIUMCFMSG-UHFFFAOYSA-N nitride(3-) Chemical compound [N-3] TWXTWZIUMCFMSG-UHFFFAOYSA-N 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 210000001519 tissues Anatomy 0.000 description 1
Abstract
The hardened steel pipe component of the present invention is formed by GI coating steel pipe, the cross section being perpendicular to described length direction of the central part of the length direction of described GI coating steel pipe has the substantially V-like shape of the contact site contacted between the inner peripheral surface containing described GI coating steel pipe, described contact site utilizes Fe Zn alloy phase that integration occurs, and is that the micro-vickers hardness of 50 μm depth locations is more than 95% apart from the micro-vickers hardness that described mother metal top layer is 200 μm depth locations apart from mother metal top layer.
Description
Technical field
The present invention relates to hardened steel pipe component, the automobile bloster employing hardened steel pipe component and hardened steel pipe component
Manufacture method.The Patent 2012-207249 CLAIM OF PRIORITY that the application files an application in Japan based on JIUYUE in 2012 on the 20th,
It is hereby incorporated its content.
Background technology
Automobile bloster is the component connected by left and right axletree, imposed load the most repeatedly, it is therefore desirable to high is tired
Labor characteristic.
Therefore, as Patent Document 1, it is proposed that carry out high-strength by implementing quenching after steel pipe is pressed
Degreeization is so that it is guaranteed that the scheme of manufacture method of automobile bloster of fatigue properties.
But, in the method owing to quenching in stove, therefore there is face, the top layer meeting of length heat time heating time, component
There is decarburization and the problem that softens, sufficient fatigue properties cannot be obtained.
It addition, in order to suppress this top layer to soften, it is proposed that by steel tube surface is being implemented as shown in patent documentation 2
The scheme of the technology that the top layer after carrying out heating after zinc-plated thus forming carbon denseization layer on steel surface, make quenching solidifies.
But, the method is also to heat in stove, it is therefore necessary to long-time heating, zinc volatilizees during this period.
Thus, the problem there is the zinc must paid close attention to extraordinarily also including the part of volatilization, spending the biggest cost.
It addition, patent document 3 discloses that by regulation pressing conditions under by compressing for steel pipe for cross section V shape
The bloster of the material of excellent fatigue characteristics obtained.
But, in this patent documentation 3, even if its object is to provide do not carry out the heat treatments such as quenching, also can play excellent
The bloster of fatigue properties, any mentioning be there is no for the most surface decarburization caused due to above-mentioned heat treatment.
Prior art literature
Patent documentation
Patent documentation 1: Japanese Unexamined Patent Publication 2005-171337 publication
Patent documentation 2: Japanese Unexamined Patent Publication 2006-45592 publication
Patent documentation 3: Japanese Unexamined Patent Publication 2009-274077 publication
Summary of the invention
The problem that invention is to be solved
Here, it is an object of the invention to, solve above-mentioned conventional problem, it is provided that quenching of material of excellent fatigue characteristics and low cost
Fire steel tube component, automobile bloster and the manufacture method of hardened steel pipe component.
For the method solving problem
The summary of the present invention is as described below.
(1) 1st aspect of the present invention is hardened steel pipe component, and it is formed by GI coating steel pipe, above-mentioned GI coating steel pipe
The cross section being perpendicular to above-mentioned length direction of the central part of length direction has between the inner peripheral surface containing above-mentioned GI coating steel pipe
The substantially V-like shape of the contact site contacted, above-mentioned contact site utilizes Fe-Zn alloy phase that integration occurs, distance mother metal table
Layer be the micro-vickers hardness of 50 μm depth locations be apart from the micro-vickers hardness that above-mentioned mother metal top layer is 200 μm depth locations
More than 95%.
(2) the hardened steel pipe component described in above-mentioned (1), wherein, the distance above-mentioned mother metal top layer of above-mentioned GI coating steel pipe is
The micro-vickers hardness of 50 μm depth locations can be more than 500Hv.
(3) above-mentioned (1) or (2) described in hardened steel pipe component, wherein, above-mentioned contact site can be throughout above-mentioned GI galvanized steel
The length of more than the 50% of the total length of pipe and formed.
(4) 2nd aspect of the present invention is automobile bloster, it uses quenching according to any one of above-mentioned (1)～(3)
Fire steel tube component.
(5) 3rd aspect of the present invention is the manufacture method of hardened steel pipe component, and it possesses following operation: compressing work
Sequence, this operation be the cross section being perpendicular to above-mentioned length direction of the central part of the length direction according to GI coating steel pipe have containing
The mode of the substantially V-like shape of the contact site contacted between the inner peripheral surface of above-mentioned GI coating steel pipe is come above-mentioned GI coating steel pipe
It is pressed；Heating keeps operation, and this operation is at zinc-plated amount A (g/m2), the maximum heating temperature T of more than 850 DEG C
(DEG C) and maximum heating temperature retention time t (hour) meet following (I) formula under conditions of, the above-mentioned GI of repressed molding is plated
Zinc steel pipe carries out heating and keeps；Refrigerating work procedure, this operation is by utilizing water-cooled to carry out the GI coating steel pipe of heated holding
Cool down thus utilize Fe-Zn alloy to make the integration of above-mentioned contact site mutually.
(T+273.15) × (logt+20)/A≤340 (I) formula
(6) manufacture method of the hardened steel pipe component described in above-mentioned (5), wherein, in above-mentioned cooling engineering, with 30 DEG C/s
Above rate of cooling by the above-mentioned GI coating steel pipe water-cooled of heated holding to less than 200 DEG C.
(7) above-mentioned (5) or (6) described in the manufacture method of hardened steel pipe component, wherein, above-mentioned zinc-plated amount A can be
60g/m2Above.
(8) manufacture method of the hardened steel pipe component described in above-mentioned (5)～any one of (7), wherein, above-mentioned compressing
In operation, can according to above-mentioned contact site throughout above-mentioned GI coating steel pipe total length more than 50% length and the mode that formed
Above-mentioned GI coating steel pipe is pressed.
(9) manufacture method of the hardened steel pipe component described in above-mentioned (5)～any one of (8), wherein, keeps in above-mentioned heating
In operation, above-mentioned GI coating steel pipe can be carried out electrified regulation.
(10) manufacture method of the hardened steel pipe component described in above-mentioned (5)～any one of (9), wherein, protects in above-mentioned heating
Hold in operation, can protect under the above temperature province of the Ac3 point of steel according to by the above-mentioned GI coating steel pipe of repressed molding
Hold the mode of more than 3 seconds and less than 30 seconds to carry out electrified regulation.
(11) manufacture method of the hardened steel pipe component described in above-mentioned (5)～any one of (10), wherein, above-mentioned GI galvanized steel
Pipe can have the component system that Ac3 point is less than 850 DEG C.
Invention effect
According to above-mentioned hardened steel pipe component, owing to being formed by GI coating steel pipe, therefore by utilizing zinc-plated suppression top layer
Decarburization, it can be ensured that high surface hardness, improves fatigue properties.
It addition, the contact site come in contact between the inner peripheral surface of GI coating steel pipe utilizes Fe-Zn alloy phase that one occurs
Change, therefore can suppress the reduction of the fatigue life caused by the friction of contact site, improve fatigue properties.Therefore, it can reality
Existing thin-wall light-weighted, it is possible to achieve significantly cost degradation.
It addition, according to the manufacture method of above-mentioned hardened steel pipe component, by under conditions of meeting formula (I) to GI galvanized steel
Pipe carries out heating and keeps, and the decarburization on top layer, corresponding heating holding equipment can be suppressed to adjust with MIN zinc-plated amount
Zinc-plated amount, the decarburization on suppression top layer.It is thereby achieved that significantly cost degradation.
Accompanying drawing explanation
Figure 1A is the top view of the automobile bloster of present embodiment.
Figure 1B is the axonometric chart of above-mentioned automobile bloster.
Fig. 1 C is the IC-IC sectional view of Figure 1A.
Fig. 1 D is the ID-ID sectional view of Figure 1A
Fig. 2 is the specification figure of the hardened steel pipe component for manufacturing present embodiment.
Fig. 3 is the state diagram of Fe-Zn alloy.
Detailed description of the invention
Hereinafter, the automobile bloster (hereinafter referred to as bloster) of one embodiment of the present invention is described in detail.With
Under explanation in enumerated bloster as the object lesson of hardened steel pipe component, but the hardened steel pipe component of the present invention non-limiting
In this, also include the various hardened steel of the high fatigue properties of needs such as the structure component of industrial machine or structure component for building
Pipe component.
Figure 1A, Figure 1B are top view and the axonometric charts of the bloster 1 representing present embodiment.Fig. 1 C is that the IC-IC of Figure 1A cuts
Face figure, Fig. 1 D is the ID-ID sectional view of Figure 1A.
As shown in Figure 1A, Figure 1B, the bloster 1 of present embodiment is by long according to making to be perpendicular to it by GI coating steel pipe 10
The cross section (hereinafter referred to as vertical cross-section) in the degree direction mode in substantially V shape is pressed and is formed.
It addition, as shown in Figure 1 C, the bloster 1 of present embodiment has phase between inner peripheral surface at the central part of its length direction
The contact site 11 of contact.
Quench this contact site 11 is by contacting between zinc-plated at the inner peripheral surface of GI coating steel pipe 10
Process, thus utilize Fe-Zn alloy phase and integration occurs.
According to this composition, in addition to improving the effect of the rigidity of bloster 1, it is also possible to suppression is because of GI coating steel pipe 10
The reduction of the fatigue life that the friction between inner peripheral surface is caused, fatigue properties can be improved.
It addition, as shown in figure ip, on the position away from the length direction of central part, also can not contact between inner peripheral surface.
That is, contact site 11 only carries out contacting at the central part of the length direction of GI coating steel pipe 10.
But, in order to more suitably play the effect improving fatigue properties, preferably contact site 11 is throughout GI coating steel pipe 10
Total length more than 50% length and formed, more preferably formed throughout the length of more than 70%.
It addition, the bloster 1 of present embodiment is by implementing Quenching Treatment after being pressed GI coating steel pipe 10
And obtain, therefore can implement Quenching Treatment while suppressed the decarburization from top layer by zinc-plated effect, the most permissible
Improve the hardness of bloster 1 entirety.That is, decarburization is suppressed by the surface part at bloster 1, it can be ensured that with thickness of slab (wall thickness) center
The most equal hardness, thus can improve fatigue properties.
More specifically, in the bloster 1 of present embodiment, it is the micro-of 200 μm depth locations by distance mother metal top layer
Vickers hardness is set to X, the micro-vickers hardness that distance mother metal top layer is 50 μm depth locations is set to Y, the value of (Y/X) × 100
Reach more than 95.It addition, micro-vickers hardness is measured under load 50g.
When the value of (Y/X) × 100 is less than 95, due to the fatigue cracking started from top layer, therefore there is reduction fatigue life
Probability.(Y/X) value of × 100 is preferably more than 96, more preferably more than 97.
It addition, in order to ensure high fatigue properties, preferred distance mother metal top layer is that the micro Vickers of 50 μm depth locations is hard
Degree Y with micro Vickers as 500Hv more than, more preferably more than 540Hv.
So, according to the bloster 1 of present embodiment, it is formed by GI coating steel pipe 10, therefore can be by zinc-plated
The effect that surface hardness improves, fatigue properties improve is obtained, due to GI coating steel pipe 10 while the decarburization on effect suppression top layer
Inner peripheral surface between the contact site 11 that comes in contact utilize Fe-Zn alloy phase that integration occurs, therefore can suppress because of inner circumferential
The reduction of the fatigue life that the friction between face is caused, can improve fatigue properties with doubling.It is thereby achieved that thin-walled is light
Quantify, significantly cost degradation can be realized.
It addition, in the present invention, though the chemical composition of the steel of GI coating steel pipe 10 is not particularly limited, but to preferably becoming
It is grouped into and illustrates.% relevant with the content of chemical composition below refers to quality %.
The chemical composition of the steel of GI coating steel pipe 10 can contain C, Si, Mn, Ti, B with following ranges.
C:0.15～0.30%
C is the element of the intensity determining bloster 1.In order to ensure the intensity for having abundant fatigue properties, C is preferably made to contain
Amount is more than 0.15%, more preferably more than 0.20%.In order to make hardness be more than Hv500, preferably reach more than 0.24%.Separately
Outward, in order to suppress the generation of hardening crack, preferably making C content is less than 0.30%, more preferably less than 0.25%.
Si:0.05～0.35%
Si is deoxidant element, and contributes to solution strengthening.In order to obtain these effects, preferably comprise more than 0.05%.
It addition, be less than 0.35% by making Si, it can be ensured that toughness.The lower limit of Si content is more preferably 0.20%, Si content upper
Limit more preferably 0.30%.
Mn:0.5～2.0%
Mn is the element improving hardenability, by making Mn content be more than 0.5%, can guarantee carrying of hardenability fully
High effect, the most preferably.It addition, be less than 2.0% by making Mn content, the deterioration of delayed fracture characteristic, permissible can be suppressed
The precipitation of suppression MnS, the reduction of fatigue strength near electric welding portion can be avoided, the most preferably.
The lower limit of Mn content is more preferably 1.0%, the upper limit of Mn content is more preferably less than 1.7%.
Ti:0.005～0.05%
Ti by being fixed, suppress the precipitation of BN by N in steel with the form of TiN, thus to stably and effectively improving
Added brought hardenability by B to play a role.Therefore, the mode matched according to the stoichiometry with TiN, preferably contain with N
3.42 times of interpolations carried out above of amount, the most automatically determine the preferred scope of Ti content from the scope of N content.
But, due to also as the part of Carbide Precipitation, therefore to the most reliably carry out the fixing, preferably of N
For 0.005～the scope of 0.05% higher than theoretical value.More preferably 0.01～0.02%.
B:0.0005～0.005%
B is the element that the interpolation by trace is significantly increased the hardenability of steel.By making the content of B be
More than 0.0005%, can compatibly obtain the effect improving hardenability, the most preferably, more preferably more than 0.001%.
It addition, when to make B be less than 0.005%, the thick generation containing B precipitate can be suppressed, additionally can suppress
Embrittlement, the most preferably, more preferably less than 0.002%.
It addition, Al, P, S, N, O can be limited in following ranges by the chemical composition of the steel of GI coating steel pipe 10.
Below Al:0.08%
Al is the element that the deoxidation material as molten steel is useful, preferably adds more than 0.01%.It addition, Al still fixes N
Element, therefore Al amount crystal particle diameter or engineering properties are brought big impact.By making Al content be less than 0.08%, permissible
The generation of the product surface defect that suppression is caused because of non-metallic inclusion, the most preferably.Al content be more preferably 0.05% with
Under.
Below P:0.05%
P is that proper alignment cracking behavior and toughness are brought dysgenic element, the most preferably less than 0.05%, more preferably
It is less than 0.03%.
S: less than 0.0030%
S makes toughness deterioration, can reduce the fatigue strength near electric welding portion, therefore preferably S by the precipitation of MnS simultaneously
Content is less than 0.0030%, more preferably less than 0.0026%.
It addition, for the precipitation suppressing MnS, the most only suppression S content, relation also by S with Mn content is carried out
Suppression, the most preferably making Mn content is less than 0.0025 with the long-pending value of S content.By making Mn content and S content long-pending
Value be less than 0.0025, the fatigue strength near electric welding portion can be guaranteed fully.
Below N:0.006%
N is the element with the effect making nitride or Carbonitride Precipitation thus improve intensity.But, add steel at B
In have the reduction of the hardenability caused because of the precipitation of BN, brought by the Ti added to prevent the precipitation of BN as mentioned above
The problem that hot-workability that the precipitation of TiN is caused or the reduction of fatigue strength and toughness reduce.On the other hand, TiN also has
There is the coarsening of γ particle diameter when suppressing high temperature, improve the effect of toughness.Therefore, in order to make hot-workability, fatigue strength and tough
The balance of property reaches optimal, and preferably N content is less than 0.006%.It addition, N content more preferably 0.001～0.005%, enter one
Step is preferably 0.002～0.004%.
Below O:0.004%
O is the element of the additive effect becoming CaO, infringement Ca, and therefore O content is preferably limited to less than 0.004%.
It addition, the chemical composition of the steel of GI coating steel pipe 10 can as required with following ranges contain Mo, Cr, Nb,
More than one in V, Ni are as selecting element.
Mo:0.05～0.5%
Mo is the element with the effect improving hardenability.When Mo content is less than 0.05%, it is impossible to expect this fully
A little effects, on the other hand, when Mo content is more than 0.5%, cost of alloy improves, and therefore Mo content is preferably 0.05～0.5%
Scope.
Cr:0.05～1.0%
Cr is not necessary addition element, is the element added for the purpose of improving hardenability.In order to obtain fully
Obtaining the raising effect of hardenability, preferably making Cr content is more than 0.05%, more preferably more than 0.10%.It addition, from suppression electricity
The aspect that defect during weldering welding occurs is set out, preferably makes Cr content be less than 1.0%, is more preferably less than 0.8%.
Nb:0.01～0.1%
Nb, in addition to having the effect by precipitation strength produced by Nb carbonitride, also has the crystal grain to steel
Footpath carries out miniaturization, improves the effect of toughness.When Nb content is more than 0.01%, carrying of intensity-toughness can be obtained fully
High effect.On the other hand, i.e. box lunch Nb content is more than 0.1% containing sometimes, also cannot expect more to improve effect, only
Being the raising causing cost, therefore Nb content is preferably the scope of 0.01～0.1%.
V:0.01～0.1%
V is the element of the effect with the precipitation strength produced by V carbonitride.By making V content be more than 0.01%,
Can compatibly play these effects, the most preferably.On the other hand, even if V content contains sometimes more than 0.1%, also cannot the phase
Treating more to improve effect, only cause the raising of cost of alloy, therefore V content is preferably less than 0.1%.
Ni:0.1～1.0%
Ni is the element with the effect improving hardenability and toughness.By making Ni content be more than 0.1%, can be suitable for
Ground plays its effect, the most preferably.On the other hand, when Ni content is more than 1.0%, cost of alloy improves, and therefore Ni content is excellent
Elect less than 1.0% as.
As long as that is, the following chemical composition of chemical composition of the steel of GI coating steel pipe 10: contain with above-mentioned scope
C, Si, Mn, Ti, B, limit Al, P, S, N, O within the above range, contain Mo, Cr, Nb, V, Ni with above-mentioned scope as required
In more than one as select element, remainder contains Fe and inevitable impurity.
It addition, in the present invention, in order to the tissue of bloster 1 being made martensite by quenching, need to guarantee fully raw material
Hardenability.As the index of hardenability, such as use according to " ferrum and steel, 74 (1988) P.1073 " all the time known to face
Boundary chilling temperature Vc90 (DEG C/s).It is the index shown in following (formula A), refer to the volume fraction of martensite reach 90% with
Rate of cooling time upper.Therefore, Vc90 is the lowest, then hardenability is the highest, even if rate of cooling is slack-off, it is possible to obtain martensite group
Knit.
LogVc90=2.94-0.75 β (formula A)
Wherein, β=2.7C+0.4Si+Mn+0.8Cr+2.0Mo+0.45Ni.
It addition, when without B (boron), (formula A) becomes (formula A ').
LogVc90=2.94-0.75 (β '-1) (formula A ')
Wherein, β '=2.7C+0.4Si+Mn+0.8Cr+Mo+0.45Ni.
Then, the manufacture method of above-mentioned bloster 1 is described in detail.
As shown in the flowchart of figure 2, the manufacture method of the bloster 1 of present embodiment at least has compressing operation, adds
Heat keeps operation and refrigerating work procedure.Hereinafter each operation is described in detail.
(compressing operation)
First, in compressing operation, given by the length direction outside-in along GI coating steel pipe 10
Displacement, by compressing for GI coating steel pipe 10 one-tenth substantially V-like shape, makes the shape of bloster 1.That is, according to its length direction
The cross section being perpendicular to length direction of central part has the contact site 11 contacted between the inner peripheral surface containing GI coating steel pipe 10
The mode of substantially V-like shape GI coating steel pipe 10 is pressed.
Concrete shape, as shown in Figure 1A～Fig. 1 D, is formed with steel pipe inner face as shown in Figure 1 C at the central part of length direction
Between the contact site 11 that contacts.It addition, both ends are steel pipe is squeezed into flat shape.
(heating keeps operation)
In heating keeps operation, to the most compressing GI coating steel pipe 10 under conditions of meeting following (1) formula
Carry out heating to keep.
(T+273.15) × (logt+20)/A≤340 (1) formula
(1), in formula, A is the zinc-plated amount (g/m of GI coating steel pipe 102), T be more than 850 DEG C maximum heating temperature (DEG C),
T is the maximum heating temperature retention time (hour).It addition, in this specification by (T+273.15) relevant with heating condition ×
(logt+20) it is referred to as heat treatment parameter B.
By according to meeting and should design zinc-plated amount A and heat treatment parameter B by the way of (1) formula, being apart from mother metal top layer
The micro-vickers hardness of 200 μm depth locations is set to X, is made by the micro-vickers hardness that distance mother metal top layer is 50 μm depth locations
It is set to Y, the value of (Y/X) × 100 can be made to reach more than 95.
Further, since making maximum heating temperature is more than 850 DEG C, quenching structure therefore can be made to become martensite.Another
Aspect, when the low temperature that maximum heating temperature is less than 850 DEG C, can become 2 phase regions, produce unhardened part, fatigue properties
Drastically reduce.
That is, by GI coating steel pipe 10 being carried out heating holding under conditions of meeting above-mentioned (1) formula, by by suppression table
Produced by pull-up carbon fatigue properties improve effect and by produced by the alloying of contact site 11 fatigue properties improve effect
Really, fatigue properties can be made to improve with doubling.
From the aspect of the superficial decarbonization can being more reliably suppressed in heating holding operation, preferably GI coating steel pipe
Zinc-plated amount A of 10 is 60g/m2Above.
Keep the heating means in operation as heating, such as, can be switched on heating, sensing heating, stove heating.But work as
During in view of productivity ratio, more preferably electrified regulation.
The upper limit of maximum heating temperature is not particularly limited, and when for superfluous high temperature, has zinc to volatilize from the surface of steel pipe
Probability.Therefore, in order to more be reliably suppressed superficial decarbonization, 1100 DEG C can be made as the upper limit.
Retention time is preferably more than 3 seconds in the above temperature province of Ac3 point.When being more than 3 seconds when making the retention time,
It is uneven by being more reliably suppressed temperature, such that it is able to it is uneven to reduce the hardness after quenching.Further, since ferrum can be made reliable
Ground spreads to zinc coat, therefore can stably utilize Fe-Zn alloy by contact site 11 integration.
It addition, the retention time is preferably less than 30 seconds.Its reason is, by making the retention time be less than 30 seconds, permissible
Suppression iron excess ground spreads to zinc coat.
It addition, when GI coating steel pipe 10 being heated by electrified regulation, have electric current generation bias current, cause temperature not
Equal probability, when being 3～30 seconds when making the retention time, it is thus identified that can be heated to the temperature range quenched equably.
As it has been described above, in the manufacture method of the bloster 1 of present embodiment, due to the maximum heating temperature more than 850 DEG C
Under carry out heating and keep, therefore, it is possible to keep the temperature province of Ac3 point reducing steel as best one can to broaden, become prone to production,
Therefore the steel pipe of component system that Ac3 point be less than 850 DEG C is preferably used.
Here, available following (2) formula of Ac3 point calculates.
Ac3=910-203 (C1/2)-15.2 × Ni+44.7 × Si+104 × V+31.5 × Mo+13.1 × W (2) formula
Wherein, hardenability (Vc90) is that the component system of steel of less than 70 DEG C/sec can be by following (3) formula and (4) formula
Represent.Vc90 refers to more than 90% rate of cooling when becoming martensite.
10α≤ 70 (3) formulas
α=2.94-0.75 × (2.7 × C+0.4 × Si+Mn+0.45 × Ni+0.8 × Cr+2 × Mo) (4) formula
When keeping GI coating steel pipe 10 under these conditions, the zinc-plated phase of steel tube surface enters in the state diagram of Fig. 3 and carries
There is hatched region, thus carry out being quenched, become Fe-Zn alloy phase, by contact site 11 one at V word cross sectional shape position
Change.Should improve as a result, it is possible to the reduction of fatigue life that caused because of the friction between GI coating steel pipe 10 inner peripheral surface of suppression
Fatigue strength.As it has been described above, when ferrum is to the diffusion deficiency of plating phase, then the region than hatched area more left side can be moved to,
Even if being quenched, the mixed phase of ferrum-kirsite phase and ferrum also can be become, thus the most preferred.
(refrigerating work procedure)
In refrigerating work procedure, by the GI coating steel pipe 10 of heated holding is carried out water-cooled, utilize Fe-Zn alloy will connect mutually
Contact portion 11 integration.
In refrigerating work procedure, when being cooled to below 200 DEG C with the rate of cooling of 30 DEG C/more than s, can by formation of martensite
To improve fatigue properties further, the most preferably.More preferably making rate of cooling is 50 DEG C/more than s.
As cooling means, can be spray cooling, immersion cooling, soda pop cooling etc., when considering productivity ratio, preferably spray
Fog cooling.
About the bloster 1 of the present embodiment so obtained, contact site 1 utilizes Fe-Zn alloy phase that integration occurs, and
Distance mother metal top layer be the micro-vickers hardness of 50 μm depth locations be distance mother metal top layer be the dimensional microstructure of 200 μm depth locations
More than the 95% of family name's hardness, therefore by being improved effect and by contact site 11 by fatigue properties produced by suppression superficial decarbonization
Fatigue properties produced by alloying improve effect, and fatigue properties can be made to improve with doubling.
It addition, do not make zinc-plated for GA but be that GA has been carried out due to alloying for the reason of GI, so even carry out
The heating of short time, also can become the state identical with long-time heating GI, ferrum-kirsite phase and ferrum can be become after the cooling period
Mixed phase, utilizes Fe-Zn alloy to make the effect of contact site 11 integration become insufficient mutually.
Embodiment
Embodiment described below.
As example 1～6 and comparative example 1～3, by 0.24%C-0.2%Si-1.2%Mn-0.02%Ti-10ppmB
The GI steel plate of composition carry out electric welding after, carry out press process, electrified regulation and spray cooling, thus manufacture bloster,
Determine distance mother metal top layer be 50 μm depth locations micro-vickers hardness, distance mother metal top layer be 200 μm depth locations
Micro-vickers hardness and fatigue properties.It addition, about example 1～6 and comparative example 1,2, make contact site one by alloying
Change.
Table 1 illustrates various imposing a condition and measurement result.A is weight per unit area (g/m2), T be maximum heating temperature
(DEG C), t are to maintain the time (hour), B is heat treatment parameter, X be distance mother metal top layer be the micro Vickers of 200 μm depth locations
Hardness, Y be distance mother metal top layer be the micro-vickers hardness of 50 μm depth locations.
Table 1
In the value of B/A meets the example 1～6 of the scope of the invention, by the effect of the suppression de-C from top layer, permissible
The value making Y/X is more than 95%, by with by produced by the alloying of contact site fatigue properties improve effect synergy,
High fatigue properties can be obtained.In example 1～6, about the micro-vickers hardness that distance mother metal top layer is 50 μm depth locations
It is the example 1～5 of more than 500Hv, compared with example 6, the best fatigue properties can be obtained.
On the other hand, the value at B/A is unsatisfactory in the comparative example 1,2 of the scope of the invention, due to from the decarburization on top layer thus
The hardness of skin section reduces, it is impossible to the collaborative effect obtaining with being improved effect by fatigue properties produced by the alloying of contact site
Really, it is impossible to obtain high fatigue properties.
It addition, in the comparative example 3 that plating is not carried out, be not only due to the hardness reduction of the decarburization from top layer and skin section,
And cannot obtain by the raising effect of fatigue properties produced by the alloying of contact site, therefore still cannot obtain high
Fatigue properties.
From the above results, according to the present invention it is possible to obtain material of excellent fatigue characteristics and the bloster of low cost.
Probability is utilized in industry
According to the present invention, it is possible to provide the hardened steel pipe component of material of excellent fatigue characteristics and low cost, automobile bloster and quench
The manufacture method of fire steel tube component.
Symbol description
1 bloster
10 GI coating steel pipes
11 contact sites
A zinc weight per unit area
B heat treatment parameter
The T retention time
T maximum heating temperature
X distance mother metal top layer is the micro-vickers hardness of 200 μm depth locations
Y distance mother metal top layer is the micro-vickers hardness of 50 μm depth locations
Claims (11)
1. a hardened steel pipe component, it is characterised in that
It is formed by GI coating steel pipe,
The cross section being perpendicular to described length direction of the central part of the length direction of described GI coating steel pipe has containing described GI
The V-shape of the contact site contacted between the inner peripheral surface of coating steel pipe,
Described contact site utilizes Fe-Zn alloy phase that integration occurs,
Distance mother metal top layer be the micro-vickers hardness of 50 μm depth locations be to be 200 μm depth locations apart from described mother metal top layer
Micro-vickers hardness more than 95%.
Hardened steel pipe component the most according to claim 1, it is characterised in that
Mother metal top layer described in the distance of described GI coating steel pipe be the micro-vickers hardness of 50 μm depth locations be more than 500Hv,
Described micro-vickers hardness is measured under load 50g.
Hardened steel pipe component the most according to claim 1 and 2, it is characterised in that described contact site is zinc-plated throughout described GI
The length of more than the 50% of the total length of steel pipe and formed.
4. an automobile bloster, it is characterised in that employ the hardened steel pipe component according to any one of claims 1 to 3.
5. a manufacture method for hardened steel pipe component, it possesses following operation:
Compressing operation, this operation be the central part of the length direction according to GI coating steel pipe be perpendicular to described length direction
The mode of the cross section V-shape with the contact site contacted between the inner peripheral surface containing described GI coating steel pipe come described
GI coating steel pipe is pressed；
Heating keeps operation, and this operation is to keep at zinc-plated amount A, the maximum heating temperature T of more than 850 DEG C and maximum heating temperature
Carry out heating under conditions of time t meets following (1) formula, to the described GI coating steel pipe of repressed molding to keep；
Refrigerating work procedure, this operation is to utilize Fe-by utilizing water-cooled to cool down the GI coating steel pipe of heated holding
Zn alloy makes the integration of described contact site mutually,
(T+273.15)×(log10T+20)/A≤340 (1) formula
Wherein, the unit of A is g/m2, the unit of T be DEG C, the unit of t for hour.
The manufacture method of hardened steel pipe component the most according to claim 5, it is characterised in that in described cooling engineering,
With the rate of cooling of 30 DEG C/more than s by the described GI coating steel pipe water-cooled of heated holding to less than 200 DEG C.
7. according to the manufacture method of the hardened steel pipe component described in claim 5 or 6, it is characterised in that described zinc-plated amount A is
60g/m2Above.
8. according to the manufacture method of the hardened steel pipe component described in claim 5 or 6, it is characterised in that described compressing
In operation, according to described contact site throughout described GI coating steel pipe total length more than 50% length and the mode that formed to institute
State GI coating steel pipe to be pressed.
9. according to the manufacture method of the hardened steel pipe component described in claim 5 or 6, it is characterised in that keep in described heating
In operation, described GI coating steel pipe is carried out electrified regulation.
10. according to the manufacture method of the hardened steel pipe component described in claim 5 or 6, it is characterised in that keep in described heating
In operation, according to the described GI coating steel pipe of repressed molding is kept under the above temperature province of the Ac3 point of steel 3 seconds with
Upper and less than 30 seconds modes carry out electrified regulation.
11. the manufacture method according to the hardened steel pipe component described in claim 5 or 6, it is characterised in that described GI coating steel pipe
There is the component system that Ac3 point is less than 850 DEG C utilizing following (2) formula to calculate.
Ac3=910-203 (C1/2)-15.2 × Ni+44.7 × Si+104 × V+31.5 × Mo+13.1 × W (2) formula
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012207249 | 2012-09-20 | ||
| JP2012-207249 | 2012-09-20 | ||
| PCT/JP2013/074687 WO2014046007A1 (en) | 2012-09-20 | 2013-09-12 | Hardened steel tube member, automobile axle beam using hardened steel tube member, and method for manufacturing hardened steel tube member |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104508170A CN104508170A (en) | 2015-04-08 |
| CN104508170B true CN104508170B (en) | 2016-11-30 |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101713045A (en) * | 2005-04-01 | 2010-05-26 | Bpw(梅州）车轴有限公司 | High-strength ultrafine grain alloy structural steel, production method and application thereof |
| CN102174684A (en) * | 2006-08-11 | 2011-09-07 | 新日本制铁株式会社 | Automobile undercarriage component having irregular cross-sectional shape and excellent in fatigue performance |
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101713045A (en) * | 2005-04-01 | 2010-05-26 | Bpw(梅州）车轴有限公司 | High-strength ultrafine grain alloy structural steel, production method and application thereof |
| CN102174684A (en) * | 2006-08-11 | 2011-09-07 | 新日本制铁株式会社 | Automobile undercarriage component having irregular cross-sectional shape and excellent in fatigue performance |
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