A kind of sacrificial anode based on through mode eddy current core detection system of breakingTechnical field
The utility model belongs to non-ferrous metal functional material technical field of nondestructive testing, relates in particular to a kind of system of utilizing through mode eddy current method to carry out Non-Destructive Testing to the disconnected core defect of sacrificial anode.
Background technology
Sacrificial anode (mainly referring to Ribbon sacrificial anode in the application) is widely used in fields such as long distance pipeline, large-scale storage tank, grounded screen and shipping industrys.Sacrificial anode forms electrical link with protective, leans on the dissolving of self that cathodic protection current is provided, thereby reaches the function that prevents or slow down protective corrosion.
Ribbon sacrificial anode has flexible feature, can be applicable to be subject to the special occasions of space or shape restriction.There are the shapes such as square and rhombus in its cross section, and center is iron core, outer coated sacrificial anode, and length can reach km.But in its manufacture process, the core material of central part is subject to larger stress, under extreme conditions, iron core can produce constriction, crackle even ruptures.While applying with the sacrificial anode of disconnected core defect, corrosion often first betides fault location, has greatly shortened the life cycle of sacrificial anode, has weakened its protective capability, causes the wasting of resources and economic loss.
At present, the mode that main employing is inspected by random samples is carried out quality evaluation to the sacrificial anode of same batch.The detection method adopting in corresponding examination criteria is Electrochemical Detection and chemical composition analysis, and the deficiency of the mode of this detection is to consume tested material and sense cycle is longer.Non-Destructive Testing aspect, the same mode of sampling observation that adopts is carried out ray detection to sacrificial anode, with reach to batch the quality of material assess.The security of ray and convenience are the principal elements that affects detection efficiency.
No matter be to adopt electrochemical method or ray detection, all have very important problem, cannot or be difficult to make the tested rate of sacrificial anode to reach 100%, and this index day by day becomes the emphasis that client pays close attention to.
Eddy detection technology has now been widely used in the nondestructive examination of metal tube, rod, silk thread, plate, band and mechanical component, it is to use electromagnetic induction principle, by sine-wave current incentive probe coil, when probe approaches metal surface, coil alternating magnetic field around produces induction current in metal surface.For flat metal, the faradic flow direction is with the concentric circle of coil, and likeness in form vortex, is called eddy current.Eddy current also produces same frequency simultaneously magnetic field, its direction and coil magnetic field opposite direction.The loss resistance of swirl channel, and the anti-magnetic flux of eddy current generation, reflex to again probe coil, changed size of current and the phase place of coil, changed the impedance of coil.Therefore, probe moves in metal surface, while running into the variations such as defect or material, size, makes eddy current magnetism different to the retroaction of coil, cause that coil impedance changes, and measures this variable quantity by eddy detecting instrument and just can differentiate that there are zero defect or other change in physical in metal surface.How to utilize this technology further to overcome the defect of above-mentioned prior art, be the inventor endeavour institute to.
Utility model content
Fundamental purpose of the present utility model is to provide the disconnected core detection system of a kind of sacrificial anode based on through mode eddy current, utilize it to detect the disconnected core of sacrificial anode, can overcome the shortcoming of prior art detection means, system is by setting suitable detection frequency, make eddy current testing signal after seeing through outsourcing material, still can produce eddy current at core, thereby the defect in sacrificial anode central core is detected and located.
For achieving the above object, the utility model is taked following design proposal:
The disconnected core detection system of sacrificial anode based on through mode eddy current, it includes:
Article one, in order to correct and to support the roller-way of sacrificial anode;
An eddy current testing instrument, with a through mode eddy current probe, has the through hole passing for tested sacrificial anode at the center of eddy current probe;
One can, at the multiple degrees of freedom probe fixing device of z direction of principal axis vibration, have one and can in the plane axial perpendicular to eddy current probe, realize the translation along x axle, the probe servo mechanism that z axle rotates on it;
Described eddy current probe is placed on the probe servo mechanism of multiple degrees of freedom probe fixing device.
In the disconnected core detection system of the described sacrificial anode based on through mode eddy current, described multiple degrees of freedom probe fixing device include one can up-down vibration compliant platform and be placed in the probe servo mechanism on compliant platform;
Described compliant platform has a pair of group of support longitudinally, installs upper and lower a pair of slide rail between this pack support, and this compliant platform is connected with the horizontal table elasticity of below;
Described probe servo mechanism is constituted by three grades of square support frames and middle rotation axis, and wherein, the one-level framework at interior center directly carries eddy current probe, and this one-level framework is connected by z direction rotation axis with the secondary framework of its outer ring; Secondary framework is connected by x direction rotation axis with three grades of frameworks of its outer ring again; Three grades of frameworks are by being set in slide block on slide rail along the horizontal slip on slide rail of x direction of principal axis.
In the disconnected core detection system of the described sacrificial anode based on through mode eddy current, described horizontal table height is adjustable.
In the disconnected core detection system of the described sacrificial anode based on through mode eddy current, described detection system is positioned at the rear end of sacrificial anode production line, the roller-way straight line UNICOM of the roller-way of this detection system and sacrificial anode production line.
In the application, mentioned through mode eddy current detection method has noncontact, safety coefficient and detection efficiency high, is convenient to be integrated on production equipment to realize the online detection to sacrificial anode.On the almost not impact of the production efficiency of sacrificial anode, can to whole piece sacrificial anode, detect efficiently.
The utility model has the advantages that:
The first, the EDDY CURRENT mode that the utility model adopts is a kind of lossless detection method, can not damage material, can realize the detection completely of sacrificial anode is improved to production cost with exceeding, and safe and reliable;
Second, multiple degrees of freedom probe fixing device in the utility model can be realized along translation and the rotation of x, y axle in the plane axial perpendicular to eddy current probe, eddy current probe can be swung along with the sacrificial anode of flexing, the object of aiming at all the time with sacrificial anode axle center to reach eddy current probe axle center, can realize accurate and accurate test;
The 3rd, the eddy current detection method that the utility model adopts, without the tested test specimen of contact, can be integrated in production line, realizes efficient online detection the to sacrificial anode.
Accompanying drawing explanation
Fig. 1 is that the disconnected core detection system of the sacrificial anode of the utility model based on through mode eddy current forms schematic diagram.
Fig. 2 is that the disconnected core detection system of the sacrificial anode of the utility model based on through mode eddy current forms schematic diagram (overlooking).
Fig. 3 is multiple degrees of freedom probe fixing device structural representation of the present utility model.
In figure: 1--sacrificial anode; 2--roller-way; 3--milling train; 4--through mode eddy current probe; 5--multiple degrees of freedom probe fixing device; 6--eddy current testing instrument; 7--horizontal table;
50--spring; 51--compliant platform; 52--support; 53--slide rail; 54--one-level framework; 55--secondary framework; 56--z direction rotation axis; Tri-grades of frameworks of 57--; 58--x direction rotation axis; 59--slide block.
Below in conjunction with drawings and the specific embodiments, the utility model is described in further details.
Embodiment
Consult Fig. 1, shown in Fig. 2, the disconnected main utility model point of core detection system of the sacrificial anode of the utility model based on through mode eddy current is to utilize an eddy current testing instrument to carry out on-line measurement: the rear end that whole detection system is integrated in to sacrificial anode production line, the roller-way 2 ' of detection system and the roller-way 2 straight line UNICOMs of sacrificial anode production line, sacrificial anode 1 is delivered to milling train 3 by roller-way 2 and first forms processing, then by being installed on the central through hole of the through mode eddy current probe 4 on multiple degrees of freedom probe fixing device 5, the detection being connected to sacrificial anode with eddy current testing instrument 6 by eddy current probe 4.
Shown in Figure 3, be to realize more accurately and measuring, the utility model system special design be applicable to detect the multiple degrees of freedom probe fixing device 5 of sacrificial anode.
This multiple degrees of freedom probe fixing device 5 can vibrate at z direction of principal axis: have one can up-down vibration compliant platform mechanism and be placed in the probe servo mechanism in compliant platform mechanism.
Described compliant platform mechanism has a compliant platform 51 and a pair of group of support 52 longitudinally placed on it, between this pack support, install upper and lower a pair of slide rail 53, in the present embodiment, this compliant platform 51 is connected with adjustable for height horizontal table 7 elasticity, compliant platform is supported by the spring 50 of 4 reference columns and upper and lower surface, can be along z direction of principal axis up-down vibration.
Described probe servo mechanism is constituted by three grades of square support frames and middle rotation axis:
One-level framework 54 is connected by z direction rotation axis 56 with secondary framework 55, between one-level framework and secondary framework, can relatively rotate around z axle;
Secondary framework 55 is connected by x direction rotation axis 58 with three grades of frameworks 57, between secondary framework and three grades of frameworks, can relatively rotate around x axle;
Three grades of frameworks 57 are fixed on slide block 59, and three grades of frameworks can be along the horizontal slip on slide rail 53 of x direction of principal axis.
This device can in perpendicular to the axial plane of probe, realize along the translation of x axle and x axle, z axle rotate and z direction of principal axis can slight vibration, the object of aiming at all the time with sacrificial anode axle center to reach probe axle center.
The disconnected core detection system of the sacrificial anode of the utility model based on through mode eddy current is by setting suitable detection frequency, so that probe is surperficial at sacrificial anode or the skin depth of the eddy current of sub-surperficial formation changes, thereby the defect in sacrificial anode central core is detected and located.
When concrete detection, adjustment eddy current testing instrument first: choose detection frequency, carry out zero potential, phasing degree and detection sensitivity adjustment, then detect in real time.Concrete steps are:
(1) choose detection frequency: according to the detection signal of artificial defect in tested sacrificial anode master body, determine and detect frequency, under selected detection frequency, should be able to stably detect the artificial defect of iron core position processing;
(2) zero potential adjustment: by the master body of tested sacrificial anode without position, traumatic part in probe, keep to aim at axle center, steady, static, adjust the initial potential of probe, to guarantee to measure dynamic range;
(3) phasing degree is adjusted: observe detection signal polar plot, upper and lower, left and right shake master body, observes the situation that dither signal waveform occurs, and jittering noise waveform is adjusted to level;
(4) detection sensitivity adjustment: axially repeatedly pull master body along probe, allow artificial defect repeatedly by probe, the speed pulling and speed of production approach, the sensitivity of adjusting instrument is reported to the police artificial defect just, increases on this basis by 8～10dB as the detection sensitivity in production run.
(5) after the good instrument of adjustment, through mode eddy current probe is installed in the one-level framework on multiple degrees of freedom probe fixing device, allows tested anode along y axle, pass the central through hole of through mode eddy current probe; By predetermined speed, advance, carried out the detection to whole piece sacrificial anode.
A specific embodiment of the present utility model below: it is example that 16 * 22mm rhombus of take extruding zinc anode belt detects.
This type of extruding zinc anode becomes band, and its xsect is rhombus, size conforms standard GB/T/T17848-1999.Tested sacrificial anode sample is Type B, major axis 22.23mm, and minor axis 15.88mm, is about 1m, has disconnected core defect at middle part.
First, at the iron core place of end, process an artificial defect (vertically boring, bore diameter 1mm, degree of depth 30mm), because this model anode coated high purity zinc thickness iron core outside is larger, when choosing detection frequency, should choose lower frequency.Here select 4kHz as detecting frequency, detect frequency and whether meet detection demand, can be verified by the detection signal of end artificial defect.
Flawless part on sacrificial anode is positioned in probe, adjusts zero potential and phasing degree.Sacrificial anode is pulled vertically repeatedly, make end artificial defect repeatedly by probe, finding critical warning sensitivity is 35dB, improve sensitivity to 45dB as detection sensitivity.
Tested sacrificial anode, at the uniform velocity through center probe, is completed to detection.Testing result shows in the middle part of tested sacrificial anode, there is a disconnected core defect, occurs reporting to the police.
The various embodiments described above can not depart from some variations in addition under scope of the present utility model, thus above explanation comprises and accompanying drawing shown in structure should be considered as exemplary, but not in order to limit the protection domain of the application's patent.