CN109338093A - A kind of electric pulse treating method reducing steel material fatigue crack growth rate - Google Patents
A kind of electric pulse treating method reducing steel material fatigue crack growth rate Download PDFInfo
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- CN109338093A CN109338093A CN201811364353.4A CN201811364353A CN109338093A CN 109338093 A CN109338093 A CN 109338093A CN 201811364353 A CN201811364353 A CN 201811364353A CN 109338093 A CN109338093 A CN 109338093A
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
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Abstract
The invention discloses a kind of electric pulse treating methods for reducing steel material fatigue crack growth rate, belong to high-strength steel material fatigue life technical field.This method is to carry out Electric Pulse Treatment to the steel material containing fatigue crack, the fatigue crack growth rate of steel material is reduced, to extend material fatigue life.During the Electric Pulse Treatment, pulse electro discharge waveform is damping waveform, discharge cycle 400ns；Number of processes is that twice, the operating voltage 9-10kV of processing, the operating voltage of second of processing are 10.5-12kV for the first time.The Research And Engineering application that the present invention can be used for crackle crack arrest, crack healing and its component fatigue injury repair of high-strength steel material and fatigue is lengthened the life.
Description
Technical field
The present invention relates to high-strength steel material fatigue life technical fields, and in particular to a kind of reduction steel material fatigue is split
The electric pulse treating method of line spreading rate.
Background technique
The failure of most of engineering metal component is derived from destruction caused by fatigue behaviour.Fatigue process includes fatigue crack
Germinating and crack Propagation two stages.Component cracked during being on active service be influence one of component security reliability it is important
Problem, how to inhibit fatigue crack is the problem of a reality and key during engineering component is on active service.Up to the present, it grinds
Study carefully personnel and attempts a variety of methods to improve threshold in fatigue crack propagation to inhibit crackle to generate and extend, therefore desirable for can prolong
The service life of long component.Common method is to improve material surface quality to inhibit fatigue crack to germinate from surface, for example spray
[M.A.S.Torres, H.J.C.Voorwald, An evaluation of shot such as ball, nitriding, carburizing, high-frequency quenching
peening,residual stress and stress relaxation on the fatigue life of AISI
4340steel,Int.J.Fatigue 24(2002)877-886.；K.Tokaji,K.Kohyama,M.Akita,Fatigue
behaviour and facture mechanism of a 316stainless steel hardened by
carburizing,Int.J.Fatigue 26(2004)543-551.；[3]S.Y.Sirin,K.Sirin,E.Kaluc,
Effect of the ion nitriding surface hardening process on fatigue behavior of
AISI 4340steel,Mater.Charact.59(2008)351-358.；J.Komotori,M.Shimizu,Y.Misaka,
K.Kawasaki,Fatigue strength and fracture mechanism of steel modified by
super-rapid induction heating and quenching,Int.J.Fatigue 23(2001)S225-
S230.].These methods are that Fatigue crack initiation is provided with first of obstacle.However, after component crackle generates, these
Preprocess method can all fail.And after component cracks, the usage service life often quickly shortens, or even can generate catastrophic
Consequence can delay crack propagation to make with member for prolonging by effective crack forming mechanism, crackle crack arrest technique in this case
Use as a servant the service life.If even healing fatigue crack can be passivated by external energy input come repair materials internal flaw and damage,
It will be helpful to delay the fatigue rupture of material to achieve the purpose that extend its usage service life.
About the reparation of Metal Material Fatigue crackle, there is document report to split using the method for high-temperature pressurizing to repair at present
Line [R.S.Xin, Q.X.Ma, W.Q.Li, Microstructure and mechanical properties of internal
crack healing in a low carbon steel,Mater.Sci.Eng:A 662(2016)65-71.].But it heats
Mode be easy change material entirety microstructure and mechanical property, in other words namely change original material
Become, this is often worthless in practical implementation.
Summary of the invention
The purpose of the present invention is to provide it is a kind of reduce steel material fatigue crack growth rate electric pulse treating method,
It acts on by the high energy pulse current flow devices of autonomous Design, and using the high-density current that single pulse discharges containing fatigue crack
Steel sample on, can efficiently realize fatigue crack crack arrest, crack growth rate decline and the purpose that locally heals of crackle,
And then it can realize the purpose that fatigue is lengthened the life.The present invention can be used for crackle crack arrest, crack healing and its component of high-strength steel material
The Research And Engineering application that fatigue damage reparation and fatigue are lengthened the life.
To achieve the above object, the technical solution adopted in the present invention is as follows:
A kind of electric pulse treating method reducing steel material fatigue crack growth rate, this method is split to containing fatigue
The steel material of line carries out Electric Pulse Treatment, the fatigue crack growth rate of steel material is reduced, to extend the fatigue of materials longevity
Life.
The steel material can be 4340 high-strength steel of AISI.
During the Electric Pulse Treatment, pulse electro discharge waveform is damping waveform, discharge cycle 400ns；Processing time
Number is twice, the operating voltage 9-10kV of processing, the operating voltage of second of processing is 10.5-12kV for the first time.
The advantages of the present invention are as follows:
1, the present invention repairs the fatigue crack on steel component by the pulse current of high-energy, has high efficiency, nothing
Need to detect crack position, on matrix substantially without influence the advantages that, can achieve the crack arrest of metal component localized cracks and crackle
The purpose of healing.
2, the present invention is the difference and electricity using damage location and intact matrix conductivity during pulsed current annealing
Stream joule heating effect different caused by streaming etc. and thermal stress effect result in crackle crack arrest, localized cracks healing, crackle
Phenomena such as deviation, realizes the purpose for reducing its fatigue crack growth rate, and then is beneficial to its fatigue and lengthens the life effect.
3, the electroporation can be used for steel material and the crackle crack arrest of component, crack healing, fatigue life etc.
Research and application it is upper.
Detailed description of the invention
Fig. 1 is Electric Pulse Treatment sample pictorial diagram of the present invention.
Fig. 2 is AISI 4340 steel compact tension specimen (CT) specimen size (unit: mm).
Fig. 3 is prefabricating fatigue crack and Electric Pulse Treatment precrack in compact tensile specimen.
Fig. 4 is pulse electro discharge waveform and crack Propagation parameter；Wherein: (a) electric pulse equipment discharge waveform；(b)
Crack Propagation experiment parameter.
Fig. 5 is that Electric Pulse Treatment realizes that fatigue crack growth rate reduces schematic diagram.
Fig. 6 is the crack growth rate variation without Electric Pulse Treatment sample and through Electric Pulse Treatment sample；Wherein:
(a) without the da/dN of reference sample S1, S2 of Electric Pulse Treatment and S3~Δ K curve；(b) at 9kV+10kV electric pulse
Da/dN~Δ K the curve and reference sample for managing sample S4, S5 compare；(c) da/ of 9kV+11kV Electric Pulse Treatment sample S6, S7
DN~Δ K curve and reference sample compare；(d) between Δ K=13MPam1/2~16MPam1/2, before and after Electric Pulse Treatment
Crack growth rate.
Fig. 7 is crack surface entirety SEM observation after crack propagation；Wherein: (a) S1 sample；(b) S3 sample；(c)S4-E
Sample, (d) S5-E sample, (e) S6-E sample；(f) S7-E sample.
Fig. 8 is that laser co-focusing observes crack surface deflection phenomenon；Wherein: (a) S1 sample；(b) S3 sample；(c) S4-E is tried
Sample；(d) S6-E sample.
Fig. 9 is the careful SEM observation of crack surface after crack propagation；Wherein: (a) crack surface overall schematic；(b) notch
Place's healing sign (a-quadrant)；(c) part healing bridging and fusing sign (B area)；(d) sign (B area) is melted；(e) it leans on
Boundary region (region C) before and after nearly electric pulse；(f) boundary region before and after the electric pulse amplified.
Specific embodiment
The present invention is described in detail below in conjunction with attached drawing.
By high energy pulse current flow devices, the huge energy using the release of single high energy pulse electric current passes through containing pre- the present invention
Compact tension specimen (CT) sample (Fig. 1) of crackle processed, makes its crackle crack arrest, reduces its crack growth rate and to a certain extent
Achieve the purpose that crack healing.The electroporation can be used for carrying out crackle crack arrest and crackle to high-strength steel material and its component
The Research And Engineerings applications such as reparation.
Using above-mentioned apparatus to compact tensile specimen (4340 steel of AISI) carry out Electric Pulse Treatment, and with without electric arteries and veins
The sample (4340 steel of AISI) of punching processing carries out effect comparison and analysis, and detailed process is as follows:
(a) compact tension specimen (CT) sample of 4340 steel of AISI is prepared, specimen size is as shown in Figure 2.
(b) compact tension specimen (compact tension-CT) sample prefabricated crackle is made by La-drawing fatigue loading mode
Crack propagation after i.e. Paris sections and keeps extension 1mm, stablizes extended mode to determine to reach to steady propagation section；In test
The crackle that crack Propagation tests the prefabricated steady propagation stage is carried out particular by fatigue tester Instron E10000,
Stress ratio R=0.1, frequency f=10HZ；
(c) select two samples S1, S2 as reference coupon, it is original to measure the material by crack Propagation experiment
Fatigue crack growth rate curve, i.e. da/dN~Δ K curve；
(d) under identical experiment condition, materials S3, takes in crack propagation to Paris sections and after continuing to extend 1mm
Under, then be installed on fatigue tester and carry out subsequent crack propagation to sample fracture, with confirmation handling sample to da/dN~Δ K
The influence of curve is negligible；
(e) under identical experiment condition, two samples S4, S5 are taken, after precasting crackle by step (b), carry out electric arteries and veins
Punching handles (as shown in Figure 3), and twice, first time operating voltage is 9kV for processing, and second of operating voltage is 10kV；At electric pulse
Continue crack Propagation after reason to test to sample fracture, obtains da/dN~Δ K curve；
(f) under identical experiment condition, two samples S6, S7 are taken, after step (b) precasts crackle, carry out electric pulse
Processing, twice, first time operating voltage is 9kV for processing, and second of operating voltage is 11kV, then proceeds by fatigue crack expansion
Exhibition experiment obtains da/dN~Δ K curve to sample fracture；
(g) Electronic Speculum (SEM) and laser are scanned in post-rift fracture apperance and section fluctuating quantity to S1-S7 sample
Laser Scanning Confocal Microscope (LSCM) observation obtains the experimental evidence of crackle crack arrest, crack deflection and the healing of crackle local melting.
Crack Propagation experiment condition in the above process are as follows: stress ratio R=0.1, frequency f=10HZ；Electric pulse is put
Electrical waveform is damping waveform, discharge cycle about 400ns；As shown in Figure 4.Make sample crack Propagation by Electric Pulse Treatment
The schematic diagram that rate reduces is as shown in Figure 5.
The rested on a scientific basis principle of the present invention are as follows: electric current joule heating effect and thermal stress
Since damaged portion is different from the resistivity of the not damaged part of matrix in metal material, and damaged portion resistivity is big
In undamaged resistivity, when electric current contains the material haveing damage by one, can distribute in the high pars affecta of resistivity
Raw current convergence, generates the Temperature Distribution effect for causing localization compared with the higher joule heating effect of matrix.Especially work as damage zone
Local melting phenomenon is occurred into for (1) when the localized hyperthermia in domain is increased to certain value, (2), which expand with heat and contract with cold, causes thermal expansion, is limited to
The lower matrix of temperature causes compression to damage field in turn, promotes damage field under the synergistic effect of these two aspects reason
Healing.(this damage refers generally to hole and crackle.)
The energy being input in material during pulsed current annealing can be calculated by following formula (1):
In formula (1): j (t) is the current density of any time t, and ρ is resistivity, and V is the volume of sample.Due to pulse
The action time of electric current is extremely short, and temperature rise process can be as adiabatic process, and maximum average temperature rising can be calculated by following formula:
Δ T=E/ (CpDV), wherein CpIt is the specific heat capacity of material, d is sample rate, and V is sample volume.Mistake of the sample in rapid warm raising
Cheng Zhong, different zones expansion rate is inconsistent, and obviously lags behind the rate of temperature rise, can generate in the sample hot pressing in this way and answer
Power.The thermal stress maximum value possible can be calculated by following formula (2):
σmax=E α Δ Tmax(2)；
In formula (2): E is elasticity modulus, and α is thermal expansion coefficient.
Above-mentioned S1-S7 sample after processing, by test and compare it can be seen that the invention has the following beneficial effects:
Technical effect one: the present invention is handled using electroporation so that fatigue crack growth rate is substantially reduced.
Fig. 6 is shown to be changed without the crack growth rate of Electric Pulse Treatment sample and Electric Pulse Treatment sample, by Fig. 6
(c) as can be seen that da/dN~Δ K curve of 9kV+11kV Electric Pulse Treatment sample S6, S7 and reference sample compare, crackle expands
Exhibition rate has obvious reduction；By it can be seen from Fig. 6 (d) between Δ K=13MPam1/2~16MPam1/2, electricity
Crack growth rate is substantially reduced before and after the processing for pulse.
Technical effect two: pass through Electric Pulse Treatment crackle forward position clear-cut, and have deviation, crack arrest phenomenon.
Fig. 7 show crack surface entirety SEM observation situation after crack propagation, S1 sample crack surface macroscopic view in Fig. 7 (a)
It is upper smooth；Fig. 7 (b) S3 sample crackle has slight line of demarcation；Fig. 7 (e) S6-E sample and Fig. 7 (f) S7-E sample crack surface
On have line of demarcation before and after apparent Electric Pulse Treatment.
Fig. 8 is that laser co-focusing observes crack surface deflection phenomenon, the crackle of Fig. 8 (a) S1 sample and Fig. 8 (b) S3 sample
Face does not have apparent deviation；There is apparent deviation on the crack surface of Fig. 8 (c) S4-E sample and Fig. 8 (d) S6-E sample.
Technical effect three: acting on by pulse current, there is healing sign in part on crack surface.
Fig. 9 is the careful SEM observation of crack surface after crack propagation, by Fig. 9 (b) it can be seen that the indentation, there healing sign (area A
Domain)；There is part healing bridging and fusing sign (B area) in Fig. 9 (c)；There is fusing sign (B area) in Fig. 9 (d).
To sum up, electroporation (Electropulsing treatment, EPT) is a kind of high energy, instantaneous, efficient side
Method has the characteristics that selective injury reparation, and is not required to detect damage location in advance.The present invention is according to intact matrix and damage
The difference of position conductivity can stream concentration in damage location by the pulse current of material and cause local heat effect,
On the other hand the compression for combining the anisotropic split split plot domain of thermal expansion difference to generate, realizes the wound healing inside material structure, from
And reach crackle crack arrest and crack forming mechanism.Suitable electric pulse is selected under the premise of not changing the matrix and performance of material
Treatment process parameter can be used as the new technology of a kind of efficient crackle crack arrest and crack forming mechanism to extend the fatigue of engineering component
Service life, to play energy-saving and environment-friendly meaning in national economy.
Claims (3)
1. a kind of electric pulse treating method for reducing steel material fatigue crack growth rate, it is characterised in that: this method is pair
Steel material containing fatigue crack carries out Electric Pulse Treatment, the fatigue crack growth rate of steel material is reduced, to extend
Material fatigue life.
2. the electric pulse treating method according to claim 1 for reducing steel material fatigue crack growth rate, feature
Be: the steel material is 4340 high-strength steel of AISI.
3. the electric pulse treating method according to claim 1 for reducing steel material fatigue crack growth rate, feature
Be: during the Electric Pulse Treatment, pulse electro discharge waveform is damping waveform, discharge cycle 400ns；Number of processes is
Twice, the operating voltage 9-10kV of processing, the operating voltage of second of processing are 10.5-12kV for the first time.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110174309A (en) * | 2019-06-12 | 2019-08-27 | 宁波大学 | The sample design method of metal material fracture partial melting under fatigue load |
| CN111763816A (en) * | 2020-06-17 | 2020-10-13 | 上海海事大学 | Technological parameter optimization method of high-energy electric pulse technology for preventing crack propagation |
| CN113579451A (en) * | 2021-07-02 | 2021-11-02 | 武汉理工大学 | Electric shock regulation and control method for metal construction forming structure state |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101215630A (en) * | 2007-12-26 | 2008-07-09 | 燕山大学 | Electromagnetic thermal effect welding seam crack arresting and soldering structure strengthening device |
| CN102839277A (en) * | 2012-09-21 | 2012-12-26 | 安徽工业大学 | Method for improving low-carbon aluminum killed steel blank hot cracks by adopting low-voltage pulse current |
| CN104439887A (en) * | 2014-12-15 | 2015-03-25 | 大连理工大学 | Metal part internal crack repairing method |
| CN106167885A (en) * | 2016-08-08 | 2016-11-30 | 武汉晶泰科技股份有限公司 | The restorative procedure of metal material interior microscopic defect |
| CN107900507A (en) * | 2017-11-14 | 2018-04-13 | 哈尔滨工业大学 | The pulse current prosthetic device and method of micro-crack in a kind of metal tube |
-
2018
- 2018-11-16 CN CN201811364353.4A patent/CN109338093A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101215630A (en) * | 2007-12-26 | 2008-07-09 | 燕山大学 | Electromagnetic thermal effect welding seam crack arresting and soldering structure strengthening device |
| CN102839277A (en) * | 2012-09-21 | 2012-12-26 | 安徽工业大学 | Method for improving low-carbon aluminum killed steel blank hot cracks by adopting low-voltage pulse current |
| CN104439887A (en) * | 2014-12-15 | 2015-03-25 | 大连理工大学 | Metal part internal crack repairing method |
| CN106167885A (en) * | 2016-08-08 | 2016-11-30 | 武汉晶泰科技股份有限公司 | The restorative procedure of metal material interior microscopic defect |
| CN107900507A (en) * | 2017-11-14 | 2018-04-13 | 哈尔滨工业大学 | The pulse current prosthetic device and method of micro-crack in a kind of metal tube |
Non-Patent Citations (1)
| Title |
|---|
| 付宇明 等: "带有疲劳裂纹的35CrMo构件电磁热止裂强化", 《机械工程学报》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110174309A (en) * | 2019-06-12 | 2019-08-27 | 宁波大学 | The sample design method of metal material fracture partial melting under fatigue load |
| CN111763816A (en) * | 2020-06-17 | 2020-10-13 | 上海海事大学 | Technological parameter optimization method of high-energy electric pulse technology for preventing crack propagation |
| CN113579451A (en) * | 2021-07-02 | 2021-11-02 | 武汉理工大学 | Electric shock regulation and control method for metal construction forming structure state |
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Application publication date: 20190215 |