CN105466843A - Corrosion residual life prediction method of transmission line towers in coastal regions - Google Patents

Abstract

The invention discloses a corrosion residual life prediction method of transmission line towers in coastal regions. The method comprises the following steps: 1) measuring average thickness of tower material's residual zinc coating of a predicted tower; 2) measuring the minimal residual thickness of tower material's severely corroded regions of the predicted tower, and subtracting the minimal residual thickness from tower material's original thickness of the predicted tower so as to obtain the tower material's maximum corrosion depth of the predicted tower; 3) determining iron corrosion rate and zinc corrosion rate of the coastal region where the predicted tower resides; 4) obtaining the tower material's maximum allowable corrosion depth of the coastal region where the predicted tower resides; and 5) calculating corrosion residual safe life of the predicted tower. According to the invention, residual safe life of corroded transmission line towers in coastal regions can be predicted rapidly and accurately. Thus, measures can be taken timely so as to control and prevent accidents such as off-line, power failure, trip-out, etc. of transmission lines due to corrosion. The method of the invention has advantages of high accuracy and strong practicality.

Description

A kind of coastland electric power line pole tower Forecast of Remaining Life of Corrosive

Technical field

The invention belongs to power engineering field, be specifically related to a kind of coastland electric power line pole tower Forecast of Remaining Life of Corrosive.

Background technology

Transmission line of electricity is the skeleton of modern power network, and current ultra-high-tension power transmission line mainly adopts the pattern of overhead transmission line, is made up of shaft tower, wire and gold utensil.Shaft tower is the primary load bearing structure of transmission line of electricity, plays the fixing effect with supporting overhead transmission line.The safety of shaft tower directly affects line security, and shaft tower lost efficacy and will cause circuit directly to fall ground, caused line tripping, power failure, even generation personal safety accident.Because shaft tower is the class material that in transmission line of electricity, consumption is maximum, distribution is wide, and running environment is severe, suffers wind, Exposure to Sunlight for a long time, drenches with rain and the invasion and attack of corrosive contaminants in air, generally can corrode after operation.And electric power line pole tower many employings ferrous materials makes, surface adopts galvanizing by dipping anticorrosion, 30 years ~ 40 years general designed life, and clean clean atmospheric environment can meet the demands, but in coastland throughout the year by salt fog Chloride Attack, actual life is not by far up to the mark.Tower material rust is worn, disconnected accident of even falling tower of becoming rusty happens occasionally.But at present qualitative assessment means are lacked to the residual life after electric power line pole tower corrosion, be difficult to determine corrosion shaft tower whether safety, only assess serviceable life by individual perceptual experience, the time of Corrosion Maintenance maintenance is random and blindness is larger.A kind of quantitative means analysis of run unit active demand and prediction shaft tower corrosion residue safe life, to work out Corrosion Maintenance and turnaround plan in advance, timely application has a power failure and dispatches, by unsafe shaft tower transformation or replacing, avoid corroding the accident caused to occur, ensure power grid security.Therefore carrying out prediction tool to the residue safe life after shaft tower corrosion to be of great significance, is also a difficult point in current power transmission field.

Summary of the invention

The technical problem to be solved in the present invention: the backward situation lacking quantitative corrosion residual life prediction and evaluation means for current power transmission overhead line structures, there is provided a kind of and can predict the residue safe life of electric power line pole tower in coastland after corrosion rapidly and accurately, to take measures in time, the security incidents such as the transmission line of electricity that Control and prevention causes thus goes offline, have a power failure, tripping operation, accuracy is higher, practical coastland electric power line pole tower Forecast of Remaining Life of Corrosive.

In order to solve the problems of the technologies described above, the technical solution used in the present invention is:

A kind of coastland electric power line pole tower Forecast of Remaining Life of Corrosive, step comprises:

1) the tower material residue zinc coat average thickness d of predicted shaft tower is measured _zn;

2) measure the least residue thickness t in the tower material seriously corroded region of predicted shaft tower, the tower material original thickness h of predicted shaft tower is deducted the tower material maximum corrosion depth d that described least residue thickness t obtains predicted shaft tower;

3) the iron rot speed v of coastland residing for predicted shaft tower is determined _fewith zine corrosion speed v _zn;

4) the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower is obtained _c;

5) the corrosion residue safe life of predicted shaft tower is calculated according to function expression formula (1) Suo Shi;

RL＝1000(d _C-d)÷v _Fe+d _Zn÷v _Zn(1)

In formula (1), RL is the corrosion residue safe life of predicted shaft tower, d _cthe maximum permission corrosion depth of the tower material of coastland residing for predicted shaft tower, d is the tower material maximum corrosion depth of predicted shaft tower, d _znfor the tower material residue zinc coat average thickness of predicted shaft tower, v _fethe iron rot speed of coastland residing for predicted shaft tower, v _znthe zine corrosion speed of coastland residing for predicted shaft tower.

Preferably, described step 1) detailed step comprise: first determine the multiple measurement points on predicted shaft tower, then measured the residue galvanized layer thickness of each measurement point on predicted shaft tower by magnetic cladding thickness measurer, and calculate the tower material residue zinc coat average thickness of predicted shaft tower according to the residue galvanized layer thickness of each measurement point.

Preferably, described step 2) in measure the tower material seriously corroded region of predicted shaft tower the detailed step of least residue thickness t comprise: first determine the measuring surface on predicted shaft tower, polishing measuring surface removes surperficial floating rust, paint film or oxide skin, then the size measurement instruments being not less than 0.1mm by precision detects the residual thickness of multiple position in measuring surface, and from the residual thickness of multiple position, get the least residue thickness t of minimum value as the tower material seriously corroded region of predicted shaft tower.

Preferably, described step 4) detailed step comprise:

4.1) the simulation salt fog solution of coastland residing for predicted shaft tower is prepared;

4.2) the tower material sample of predicted shaft tower is made pre-crackle tensile sample, by pre-crackle tensile sample by slow-drawing stress corrosion test machine carries out constant load tension test, and in the solution tank of slow-drawing stress corrosion test machine, place described simulation salt fog solution and make simulation salt fog solution soak the pre-crackle opening of pre-crackle tensile sample completely, record the tower material stress corrosion fracture toughness K of predicted shaft tower in residing coastland _iSCC;

4.3) based on the tower material design limit load σ of predicted shaft tower _c, stress corrosion fracture toughness K _iSCC, tower material original thickness h calculates the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower _c.

Preferably, described step 4.3) in the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower _ccomputing function expression formula such as formula shown in (2);

${\mathrm{\σ}}_c\sqrt{10{\mathrm{\πd}}_c}\·\sqrt{\frac{2h}{{\mathrm{\πd}}_c}tan\frac{{\mathrm{\πd}}_c}{2h}}\·\frac{0.752+2.02\frac{d_c}{h}+0.37{(1-sin\frac{{\mathrm{\πd}}_c}{2h})}^3}{cos\frac{{\mathrm{\πd}}_c}{2h}}=100K_{ISCC}---\left(2\right)$

In formula (2), σ _cfor the tower material design limit load of predicted shaft tower, d _cthe maximum permission corrosion depth of the tower material of coastland residing for predicted shaft tower, h is the tower material original thickness of predicted shaft tower, K _iSCCfor predicted shaft tower is in the tower material stress corrosion fracture toughness of residing coastland.

Preferably, described step 4.1) detailed step comprise: first collect the content that chlorion in the rainwater of year number is at least closely specified in coastland residing for predicted shaft tower, calculate chloride ion content annual mean in the rainwater obtaining local at least closely appointment year number, if this annual mean is c; Then villaumite and the deionized water of given mass is got, got villaumite is added in removed ionized water by amount, chloride ion content is equaled obtain and local at least closely specify chloride ion content annual mean c in the rainwater of year number, obtain the simulation salt fog solution of coastland residing for predicted shaft tower.

Preferably, described step 4.1) detailed step comprise: villaumite and the deionized water of getting given mass, got villaumite is added in removed ionized water by amount, if predicted shaft tower makes the massfraction of chloride ion content equal 5.0% when being positioned within the 10km of shore line, if predicted shaft tower makes the massfraction of chloride ion content equal 3.5% when being positioned at beyond the 10km of shore line, obtain the simulation salt fog solution of coastland residing for predicted shaft tower.

Preferably, described step 3) detailed step comprise: the carbon steel identical with predicted shaft tower material and zinc are made dressing plate sample respectively, 1 year is tanned by the sun under dressing plate sample is placed on coastland residing for predicted shaft tower respectively, detect the thickness difference before and after carbon steel dressing plate specimen test or corrosion weight loss, if what detect is corrosion weight loss, convert corrosion weight loss the thickness difference obtained before and after carbon steel dressing plate specimen test, thickness difference before and after carbon steel dressing plate specimen test is obtained the iron rot speed v of coastland residing for predicted shaft tower divided by the time _fedetect the thickness difference before and after zinc dressing plate specimen test or corrosion weight loss, if what detect is corrosion weight loss, convert corrosion weight loss the thickness difference obtained before and after carbon steel dressing plate specimen test, the thickness difference before and after zinc dressing plate specimen test obtained the zine corrosion speed v of coastland residing for predicted shaft tower divided by the time _zn.

Or preferably, described step 3) detailed step comprise: first obtain coastland residing for predicted shaft tower corrosion environment classification, then according to the corrosion environment maximum corrosion rate table of comparisons that corrosion environment classified inquiry is preset, the iron rot speed v of coastland residing for predicted shaft tower is obtained _fewith zine corrosion speed v _zn.

Or preferably, described step 3) detailed step comprise: the iron rot speed v first directly calculating coastland residing for predicted shaft tower according to formula (3) _fe, the then iron rot speed v of coastland residing for predicted shaft tower _fesearch the default corrosion environment maximum corrosion rate table of comparisons, obtain the zine corrosion speed v of coastland residing for predicted shaft tower _zn;

v _Fe＝1000(h-t)÷T(3)

In formula (3), v _fethe iron rot speed of coastland residing for predicted shaft tower, h is the tower material original thickness of predicted shaft tower, and t is the least residue thickness in the tower material seriously corroded region of predicted shaft tower, and T is putting into operation the time of predicted shaft tower.

Coastland of the present invention electric power line pole tower Forecast of Remaining Life of Corrosive has following advantage: the present invention is by measuring the tower material residue zinc coat average thickness d of predicted shaft tower _znmeasure the least residue thickness t in the tower material seriously corroded region of predicted shaft tower, the tower material original thickness h of predicted shaft tower is deducted the tower material maximum corrosion depth d that described least residue thickness t obtains predicted shaft tower, determines the iron rot speed v of coastland residing for predicted shaft tower _fewith zine corrosion speed v _zn, obtain the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower _c, the corrosion residue safe life of predicted shaft tower is finally calculated according to aforementioned value, the operation instructing transmission line of electricity can be become, safeguard, maintenance and a set of effective method changed, break traditional shaft tower corrosion lifetime evaluation only by the restriction of individual perceptual experience, the assessment to coastland electric power line pole tower corrosion residual life can be realized, physical meaning is clear, the residue safe life of electric power line pole tower in coastland after corrosion can be predicted rapidly and accurately, to take measures in time, the transmission line of electricity that Control and prevention causes thus goes offline, have a power failure, the security incidents such as tripping operation, there is accuracy higher, practical advantage.

Accompanying drawing explanation

Fig. 1 is the basic procedure schematic diagram of embodiment of the present invention method one.

Fig. 2 is the system architecture schematic diagram carrying out constant load tension test in the embodiment of the present invention one.

Embodiment

Embodiment one:

As shown in Figure 1, the step of the present embodiment coastland electric power line pole tower Forecast of Remaining Life of Corrosive comprises:

1) the tower material residue zinc coat average thickness d of predicted shaft tower is measured _zn, unit μm;

2) measure the least residue thickness t in the tower material seriously corroded region of predicted shaft tower, the tower material original thickness h of predicted shaft tower is deducted the tower material maximum corrosion depth d that least residue thickness t obtains predicted shaft tower, unit mm; In the present embodiment, the tower material original thickness h of predicted shaft tower is 8mm, and least residue thickness t is 5mm, and tower material maximum corrosion depth d is 3mm;

3) the iron rot speed v of coastland residing for predicted shaft tower is determined _fewith zine corrosion speed v _zn;

4) the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower is obtained _c;

5) the corrosion residue safe life of predicted shaft tower is calculated according to function expression formula (1) Suo Shi;

RL＝1000(d _C-d)÷v _Fe+d _Zn÷v _Zn(1)

In formula (1), RL is the corrosion residue safe life of predicted shaft tower, d _cthe maximum permission corrosion depth of the tower material of coastland residing for predicted shaft tower, d is the tower material maximum corrosion depth of predicted shaft tower, d _znfor the tower material residue zinc coat average thickness of predicted shaft tower, v _fethe iron rot speed of coastland residing for predicted shaft tower, v _znthe zine corrosion speed of coastland residing for predicted shaft tower.

In the present embodiment, predicted shaft tower tower material material used is Q235 steel, conveniently measures, take off an intact Q235 head tower material, length 1m from shaft tower, and follow-up measurement is and completes based on this sampling.

In the present embodiment, step 1) detailed step comprise: first determine the multiple measurement points on predicted shaft tower, then measured the residue galvanized layer thickness of each measurement point on predicted shaft tower by magnetic cladding thickness measurer, and calculate the tower material residue zinc coat average thickness of predicted shaft tower according to the residue galvanized layer thickness of each measurement point.The quantity of the multiple measurement points on the predicted shaft tower determined in the present embodiment is specially 10, also can carry out as required increasing or reducing in addition, but comparatively speaking, measurement point is more, then tower material residue zinc coat average thickness is more accurate.

In the present embodiment, step 2) in measure the tower material seriously corroded region of predicted shaft tower the detailed step of least residue thickness t comprise: first determine the measuring surface on predicted shaft tower, polishing measuring surface removes surperficial floating rust, paint film or oxide skin, then the size measurement instruments being not less than 0.1mm by precision detects the residual thickness of multiple position in measuring surface, and from the residual thickness of multiple position, get the least residue thickness t of minimum value as the tower material seriously corroded region of predicted shaft tower.Gauging instrument implement body can the instrument such as select tape tailpin vernier caliper, milscale, supersonic thickness meter as required, and 10 data are at least measured in each region in the present embodiment, minimum value in all measured values of same parts is the least residue thickness of tower material, is designated as t, unit mm.

In the present embodiment, step 3) detailed step comprise: the carbon steel identical with predicted shaft tower material and zinc are made dressing plate sample respectively, 1 year is tanned by the sun under dressing plate sample is placed on coastland residing for predicted shaft tower respectively, detect thickness difference before and after carbon steel dressing plate specimen test (or corrosion weight loss, if what detect is corrosion weight loss, convert corrosion weight loss the thickness difference obtained before and after carbon steel dressing plate specimen test), thickness difference before and after carbon steel dressing plate specimen test is obtained the iron rot speed v of coastland residing for predicted shaft tower divided by the time _fedetect thickness difference before and after zinc dressing plate specimen test (or corrosion weight loss, if what detect is corrosion weight loss, convert corrosion weight loss the thickness difference obtained before and after carbon steel dressing plate specimen test), the thickness difference before and after zinc dressing plate specimen test is obtained the zine corrosion speed v of coastland residing for predicted shaft tower divided by the time _zn.By a term coupon corrosion test in the present embodiment, method of testing is pressed GB/T19292.4-2003 " the corrosive atmosphere corrosivity of metal and alloy is for assessment of the mensuration of the corrosion rate of corrosive standard sample " and is performed, the carbon steel identical with tower material material to be measured and zinc are made dressing plate sample, size is generally 150mm length × 100mm, and wide × 1mm is thick, 1 year is tanned by the sun under being placed on local atmospheric corrosion environment, obtain average annual corrosion depth data, recording local iron rot speed is v _fe=220 μm/a, zine corrosion speed is v _zn=5.6 μm/a.

In the present embodiment, step 4) detailed step comprise:

4.1) the simulation salt fog solution of coastland residing for predicted shaft tower is prepared;

4.2) the tower material sample of predicted shaft tower is made pre-crackle tensile sample (regulation according to GB/T15970.6 " corrosion stress corrosion test the 6th part of metal and alloy: the Synthesis and applications of pre-precracked specimen under constant load or permanent displacement "), by pre-crackle tensile sample by slow-drawing stress corrosion test machine carries out constant load tension test, and in the solution tank of slow-drawing stress corrosion test machine, place simulation salt fog solution and make simulation salt fog solution soak the pre-crackle opening of pre-crackle tensile sample completely, record the tower material stress corrosion fracture toughness K of predicted shaft tower in residing coastland _iSCC,

4.3) based on the tower material design limit load σ of predicted shaft tower _c, stress corrosion fracture toughness K _iSCC, tower material original thickness h calculates the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower _c.

In the present embodiment, described step 4.1) detailed step comprise: first collect the content that chlorion in the rainwater of year number is at least closely specified in coastland residing for predicted shaft tower, calculate chloride ion content annual mean in the rainwater obtaining local at least closely appointment year number, if this annual mean is c; Then villaumite and the deionized water of given mass is got, got villaumite is added in removed ionized water by amount, chloride ion content is equaled obtain and local at least closely specify chloride ion content annual mean c in the rainwater of year number, obtain the simulation salt fog solution of coastland residing for predicted shaft tower.In the present embodiment, villaumite adopts the NaCl (sodium chloride) of SILVER REAGENT or chemical pure (wt% >=99.5%), and deionized water specifically adopts the deionized water of resistivity 18M more than Ω cm, to improve the accuracy of simulation salt fog solution.In addition, in addition also other villaumites can be adopted as required, can also the aqueous solution of other types be adopted as required realize modulation simulation salt fog solution, desirable 1000 ~ 10000 grams of desirable 100 ~ 1000 grams of the quality of villaumite, deionized water, as long as meet its proportioning and constant load tension test demand.In the present embodiment, collect coastland residing for predicted shaft tower when at least closely specifying the content of chlorion in the rainwater of year number, specifically refer to the content collecting chlorion the rainwater of local at least nearly 10 years from shaft tower target on-site environmental monitoring center or meteorological department.

In the present embodiment, step 4.2) in slow-drawing stress corrosion test machine adopt YYF-50 type slow-drawing stress corrosion test machine, the simulation salt fog solution prepared is placed in solution tank, ensure that solution soaks pre-crackle opening completely, record the tower material stress corrosion fracture toughness K of predicted shaft tower in residing coastland _iSCC.As shown in Figure 2, the arm 11 of extending of the upside of slow-drawing stress corrosion test machine 1 is provided with fixture 12, downside is fixed with lower clamp 13, pre-crackle tensile sample 2 is separately fixed in fixture 12, lower clamp 13, the middle part of pre-crackle tensile sample 2 is plugged in solution tank 3, and solution tank 3 is placed simulation salt fog solution 31 and made simulation salt fog solution 31 soak the pre-crackle opening 21 of pre-crackle tensile sample 2 completely; Measure the tower material stress corrosion fracture toughness K of predicted shaft tower in residing coastland _iSCCtime, the fracture toughness of tower material in simulation salt fog solution is measured by the regulation of GB/T21143-2007 " the uniform tests method of metal material quasistatic fracture toughness ", measure 3 times and average above, this numerical value is the tower material stress corrosion fracture toughness of predicted shaft tower in residing coastland, is designated as K _iSCC, unit

In the present embodiment, step 4.3) in the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower _ccomputing function expression formula such as formula shown in (2);

${\mathrm{\σ}}_c\sqrt{10{\mathrm{\πd}}_c}\·\sqrt{\frac{2h}{{\mathrm{\πd}}_c}tan\frac{{\mathrm{\πd}}_c}{2h}}\·\frac{0.752+2.02\frac{d_c}{h}+0.37{(1-sin\frac{{\mathrm{\πd}}_c}{2h})}^3}{cos\frac{{\mathrm{\πd}}_c}{2h}}=100K_{ISCC}---\left(2\right)$

In formula (2), σ _cfor the tower material design limit load of predicted shaft tower, d _cthe maximum permission corrosion depth of the tower material of coastland residing for predicted shaft tower, h is the tower material original thickness of predicted shaft tower, K _iSCCfor predicted shaft tower is in the tower material stress corrosion fracture toughness of residing coastland.

In the present embodiment, the tower material design limit load of predicted shaft tower is 180MPa, at the tower material stress corrosion fracture toughness K of residing coastland _iSCCvalue be after substitution formula (2), calculate the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower _cvalue be 3.6mm.In the present embodiment, the tower material surface of predicted shaft tower covers red rust, therefore tower material residue zinc coat average thickness d _znbe 0 μm, the tower material maximum corrosion depth d of predicted shaft tower is 3mm, the iron rot speed v of coastland residing for predicted shaft tower _febe 220 μm/a, the zine corrosion speed v of coastland residing for predicted shaft tower _znbe 5.6 μm/a, therefore the corrosion residue safe life calculating predicted shaft tower is RL=1000 × (3.6-3) ÷ 220+0 ÷ 5.6=2.7 (year), namely this corrosion shaft tower can continue the residual life of safe operation is 2.7 years, and anticorrosion maintenance or the engineering that renovates should be arranged before this to guarantee power grid security.

Embodiment two:

The present embodiment is substantially identical with embodiment one, and its main difference point is step 3) with step 4.1) implementation different.

In the present embodiment, step 3) detailed step comprise: first obtain coastland residing for predicted shaft tower corrosion environment classification, then according to the corrosion environment maximum corrosion rate table of comparisons (referring to table 1) that corrosion environment classified inquiry is preset, the iron rot speed v of coastland residing for predicted shaft tower is obtained _fewith zine corrosion speed v _zn.

Table 1: the corrosion environment maximum corrosion rate table of comparisons.

The corrosion environment classification of coastland residing for predicted shaft tower can be classified to local corrosion environment according to the on-site environmental monitoring center of predicted shaft tower target or atmospheric corrosion station for acquiring, this classification meets the regulation of GB/T19292.1-2003 " the corrosive atmosphere corrosion forms of metal and alloy ", has C1, C2, C3, C4, C5 five corrosive grades.

Within in the present embodiment, predicted shaft tower is positioned at shore line 10km, step 4.1) detailed step comprise: villaumite and the deionized water of getting given mass, got villaumite is added in removed ionized water by amount, make the massfraction of chloride ion content equal 5.0%, obtain the simulation salt fog solution of coastland residing for predicted shaft tower.

In the present embodiment, the tower material residue zinc coat average thickness d of predicted shaft tower _znbe 21 μm, the maximum permission corrosion depth d of the tower material of coastland residing for predicted shaft tower _cfor 3.6mm, the tower material maximum corrosion depth d of predicted shaft tower is 3mm, the iron rot speed v of coastland residing for predicted shaft tower _febe 220 μm/a, the zine corrosion speed v of coastland residing for predicted shaft tower _znbe 5.6 μm/a, therefore the corrosion residue safe life calculating predicted shaft tower is RL=1000 × (3.6-3) ÷ 220+21 ÷ 5.6=6.5 (year), namely this corrosion shaft tower can continue the residual life of safe operation is 6.5 years, and anticorrosion maintenance or the engineering that renovates should be arranged before this to guarantee power grid security.

Embodiment three:

The present embodiment is substantially identical with embodiment one, and its main difference point is step 3) with step 4.1) implementation different.

In the present embodiment, step 3) detailed step comprise: the iron rot speed v first directly calculating coastland residing for predicted shaft tower according to formula (3) _fe, the then iron rot speed v of coastland residing for predicted shaft tower _fesearch the default corrosion environment maximum corrosion rate table of comparisons (referring to table 1), obtain the zine corrosion speed v of coastland residing for predicted shaft tower _zn;

v _Fe＝1000(h-t)÷T(3)

In formula (3), v _fethe iron rot speed of coastland residing for predicted shaft tower, h is the tower material original thickness of predicted shaft tower, and t is the least residue thickness in the tower material seriously corroded region of predicted shaft tower, and T is putting into operation the time of predicted shaft tower.In the present embodiment, time of the putting into operation T of predicted shaft tower is 8a.Embodiment one, embodiment two, embodiment three determine the iron rot speed v of coastland residing for predicted shaft tower _fewith zine corrosion speed v _zncycle shorten successively, but computational accuracy reduces successively, therefore, preferentially adopts the method come above when the evaluation time is abundant.

In the present embodiment, predicted shaft tower is positioned at beyond the 10km of shore line, step 4.1) detailed step comprise: villaumite and the deionized water of getting given mass, got villaumite is added in removed ionized water by amount, make the massfraction of chloride ion content equal 3.5%, obtain the simulation salt fog solution of coastland residing for predicted shaft tower.

The above is only the preferred embodiment of the present invention, protection scope of the present invention be not only confined to above-described embodiment, and all technical schemes belonged under thinking of the present invention all belong to protection scope of the present invention.It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principles of the present invention, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (10)

1. a coastland electric power line pole tower Forecast of Remaining Life of Corrosive, is characterized in that step comprises:

1) the tower material residue zinc coat average thickness d of predicted shaft tower is measured _zn;

2) measure the least residue thickness t in the tower material seriously corroded region of predicted shaft tower, the tower material original thickness h of predicted shaft tower is deducted the tower material maximum corrosion depth d that described least residue thickness t obtains predicted shaft tower;

3) the iron rot speed v of coastland residing for predicted shaft tower is determined _fewith zine corrosion speed v _zn;

4) the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower is obtained _c;

5) the corrosion residue safe life of predicted shaft tower is calculated according to function expression formula (1) Suo Shi;

RL＝1000(d _C-d)÷v _Fe+d _Zn÷v _Zn(1)

In formula (1), RL is the corrosion residue safe life of predicted shaft tower, d _cthe maximum permission corrosion depth of the tower material of coastland residing for predicted shaft tower, d is the tower material maximum corrosion depth of predicted shaft tower, d _znfor the tower material residue zinc coat average thickness of predicted shaft tower, v _fethe iron rot speed of coastland residing for predicted shaft tower, v _znthe zine corrosion speed of coastland residing for predicted shaft tower.

2. coastland according to claim 1 electric power line pole tower Forecast of Remaining Life of Corrosive, it is characterized in that, described step 1) detailed step comprise: first determine the multiple measurement points on predicted shaft tower, then measured the residue galvanized layer thickness of each measurement point on predicted shaft tower by magnetic cladding thickness measurer, and calculate the tower material residue zinc coat average thickness of predicted shaft tower according to the residue galvanized layer thickness of each measurement point.

3. coastland according to claim 2 electric power line pole tower Forecast of Remaining Life of Corrosive, it is characterized in that, described step 2) in measure the tower material seriously corroded region of predicted shaft tower the detailed step of least residue thickness t comprise: first determine the measuring surface on predicted shaft tower, polishing measuring surface removes the floating rust on surface, paint film or oxide skin, then the size measurement instruments being not less than 0.1mm by precision detects the residual thickness of multiple position in measuring surface, and from the residual thickness of multiple position, get the least residue thickness t of minimum value as the tower material seriously corroded region of predicted shaft tower.

4. coastland according to claim 3 electric power line pole tower Forecast of Remaining Life of Corrosive, is characterized in that, described step 4) detailed step comprise:

4.1) the simulation salt fog solution of coastland residing for predicted shaft tower is prepared;

4.2) the tower material sample of predicted shaft tower is made pre-crackle tensile sample, by pre-crackle tensile sample by slow-drawing stress corrosion test machine carries out constant load tension test, and in the solution tank of slow-drawing stress corrosion test machine, place described simulation salt fog solution and make simulation salt fog solution soak the pre-crackle opening of pre-crackle tensile sample completely, record the tower material stress corrosion fracture toughness K of predicted shaft tower in residing coastland _iSCC;

4.3) based on the tower material design limit load σ of predicted shaft tower _c, stress corrosion fracture toughness K _iSCC, tower material original thickness h calculates the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower _c.

5. coastland according to claim 4 electric power line pole tower Forecast of Remaining Life of Corrosive, is characterized in that, described step 4.3) in the maximum permission corrosion depth d of tower material of coastland residing for predicted shaft tower _ccomputing function expression formula such as formula shown in (2);

${\mathrm{\σ}}_c\sqrt{10{\mathrm{\πd}}_c}\·\sqrt{\frac{2h}{{\mathrm{\πd}}_c}tan\frac{{\mathrm{\πd}}_c}{2h}}\·\frac{0.752+2.02\frac{d_c}{h}+0.37{(1-sin\frac{{\mathrm{\πd}}_c}{2h})}^3}{cos\frac{{\mathrm{\πd}}_c}{2h}}=100K_{ISCC}---\left(2\right)$

In formula (2), σ _cfor the tower material design limit load of predicted shaft tower, d _cthe maximum permission corrosion depth of the tower material of coastland residing for predicted shaft tower, h is the tower material original thickness of predicted shaft tower, K _iSCCfor predicted shaft tower is in the tower material stress corrosion fracture toughness of residing coastland.

6. coastland according to claim 4 electric power line pole tower Forecast of Remaining Life of Corrosive, it is characterized in that, described step 4.1) detailed step comprise: first collect the content that chlorion in the rainwater of year number is at least closely specified in coastland residing for predicted shaft tower, calculate chloride ion content annual mean in the rainwater obtaining local at least closely appointment year number, if this annual mean is c; Then chemical pure villaumite and the deionized water of given mass is got, got chemical pure villaumite is added in removed ionized water by amount, chloride ion content is equaled obtain and local at least closely specify chloride ion content annual mean c in the rainwater of year number, obtain the simulation salt fog solution of coastland residing for predicted shaft tower.

7. coastland according to claim 4 electric power line pole tower Forecast of Remaining Life of Corrosive, it is characterized in that, described step 4.1) detailed step comprise: chemical pure villaumite and the deionized water of getting given mass, got chemical pure villaumite is added in removed ionized water by amount, if predicted shaft tower makes the massfraction of chloride ion content equal 5.0% when being positioned within the 10km of shore line, if predicted shaft tower makes the massfraction of chloride ion content equal 3.5% when being positioned at beyond the 10km of shore line, obtain the simulation salt fog solution of coastland residing for predicted shaft tower.

8. according to the coastland electric power line pole tower Forecast of Remaining Life of Corrosive in claim 1 ~ 7 described in any one, it is characterized in that, described step 3) detailed step comprise: the carbon steel identical with predicted shaft tower material and zinc are made dressing plate sample respectively, 1 year is tanned by the sun under dressing plate sample is placed on coastland residing for predicted shaft tower respectively, detect the thickness difference before and after carbon steel dressing plate specimen test or corrosion weight loss, if what detect is corrosion weight loss, convert corrosion weight loss the thickness difference obtained before and after carbon steel dressing plate specimen test, thickness difference before and after carbon steel dressing plate specimen test is obtained the iron rot speed v of coastland residing for predicted shaft tower divided by the time _fedetect the thickness difference before and after zinc dressing plate specimen test or corrosion weight loss, if what detect is corrosion weight loss, convert corrosion weight loss the thickness difference obtained before and after carbon steel dressing plate specimen test, the thickness difference before and after zinc dressing plate specimen test obtained the zine corrosion speed v of coastland residing for predicted shaft tower divided by the time _zn.

9. according to the coastland electric power line pole tower Forecast of Remaining Life of Corrosive in claim 1 ~ 7 described in any one, it is characterized in that, described step 3) detailed step comprise: first obtain coastland residing for predicted shaft tower corrosion environment classification, then according to the corrosion environment maximum corrosion rate table of comparisons that corrosion environment classified inquiry is preset, the iron rot speed v of coastland residing for predicted shaft tower is obtained _fewith zine corrosion speed v _zn.

10. according to the coastland electric power line pole tower Forecast of Remaining Life of Corrosive in claim 1 ~ 7 described in any one, it is characterized in that, described step 3) detailed step comprise: the iron rot speed v first directly calculating coastland residing for predicted shaft tower according to formula (3) _fe, the then iron rot speed v of coastland residing for predicted shaft tower _fesearch the default corrosion environment maximum corrosion rate table of comparisons, obtain the zine corrosion speed v of coastland residing for predicted shaft tower _zn;

v _Fe＝1000(h-t)÷T(3)

In formula (3), v _fethe iron rot speed of coastland residing for predicted shaft tower, h is the tower material original thickness of predicted shaft tower, and t is the least residue thickness in the tower material seriously corroded region of predicted shaft tower, and T is putting into operation the time of predicted shaft tower.