A kind of galvanochemistry the cannot-harm-detection device and method detecting cracks of metal surface
Technical field
The present invention relates to technical field of nondestructive testing, the electric potential signal particular by sensing electrode probe bundle collection metal surface carries out drawing and obtains the potential image on surface, and then the defect distribution on analytical sample surface.
Background technology
Non-Destructive Testing has been a proven technique now, mainly comprises (1) Liquid penetrant testing (PT); (2) EDDY CURRENT (ET); (3) ultrasound examination (UT); (4) ray detection (RT); (5) Magnetic memory testing.Each detection means has its merits and demerits.Such as: ultrasonic phase array detects: sweep velocity is fast, and degree of accuracy is higher, can carry out comprehensive scanning, be applicable to the surface imperfection measuring inherent vice and have certain depth, not only can record defective locations, the shape of defect, size can also be measured.But be subject to subjective and objective factor impact, working surface required level and smooth; Magnetic memory testing: surface, inherent vice all can be detected.Cleaning and other pre-service need not be carried out in the metal surface detecting position, highly sensitive and reproducible compared with ultrasound checking, tiny flaw area of stress concentration can be detected, therefore, to the early diagnosis of damaged metal and the eliminating of fault and prevention, there is higher susceptibility and reliability.But only can detect magnetic material.And above-mentioned detection means is all pure physical means.Mainly want herein to adopt a kind of corrosion electrochemistry method of testing to obtain Potential distribution to detect cracks of metal surface, these means are without the need to processing surface to be measured, simple to operate, can test various shape face, and want to coincide with above-mentioned physical means acquired results.
Summary of the invention
The object of the invention is to overcome the deficiencies in the prior art, provide a kind of galvanochemistry the cannot-harm-detection device detecting cracks of metal surface, it by detecting the Potential distribution on test button surface to be measured, thus judges size, the position of surface imperfection.
The object of the present invention is to provide a kind of new galvanochemistry lossless detection method detecting the defects such as metal surface fatigue and crackle.The method by detecting the Potential distribution of metal surface, thus judges size, the position of surface imperfection.
Object of the present invention is achieved by following technical proposals.
A kind of galvanochemistry the cannot-harm-detection device detecting cracks of metal surface, comprise test button to be measured, ion conductive membrane, contrast electrode, multi-channel electrode probe and electro-chemical measuring apparatus, described multi-channel electrode probe is arranged on the upper surface of described test button to be measured, described multi-channel electrode probe is made up of phenolics and metal electrode bar, described metal electrode bar is that the capable N of M arranges and equidistant is distributed in described phenolics, described M is more than or equal to 5 and is less than or equal to 20, described N is more than or equal to 5 and is less than or equal to 20, and described ion conductive membrane is provided with between the bottom that described multi-channel electrode is popped one's head in (test side of namely popping one's head in) and the upper surface of described test button to be measured, the upper surface close contact of the bottom that described ion conductive membrane is popped one's head in described multi-channel electrode respectively and described test button to be measured, described contrast electrode is arranged on the top of described test button to be measured and contacts with described ion conducting film close, the top (i.e. Signal connector end) of described multi-channel electrode probe, the bottom surface of described contrast electrode and described test button to be measured is respectively by the working end of wire and described electro-chemical measuring apparatus, demarcate contrast electrode end to be connected with earth terminal, operational amplifier or zero resistance circuit is provided with in described electro-chemical measuring apparatus.
In technique scheme, for the detection surface of surface configuration complexity, then the every root of electrode bar brushing phenolics respectively, enclosed electrode rod non-working surface, only expose head workplace, electrode cluster workplace is formed the curved surface bundle being suitable for test piece surface configuration.
In technique scheme, select saturated calomel electrode as contrast electrode.
In technique scheme, described ion conductive membrane is can conducting ion, but cannot conduct electrons, such as sponge, timber, filter paper, bamboo, is preferably soaked with the filter paper of 3.5%NaCl solution as ion conductive membrane.
In technique scheme, the metal electrode bar material of described multi-channel electrode probe is the carbon steel of Q235 model, and the diameter of the carbon steel rod of described Q235 model is 0.3-0.7mm, preferred 0.5mm.
Wherein, equidistantly be fixed in phenolics for the carbon steel rod of multi-channel electrode by 100 Q235 models, metal electrode bar is that 10 row 10 arrange, and 3mm is arranged in described phenolics at equal intervals, and the signals collecting end of electro-chemical measuring apparatus comprises 100 signals collecting contacts.
The top of multi-channel electrode probe with the concrete connected mode of the signals collecting end of electro-chemical measuring apparatus is: 100 metal electrode bars that multi-channel electrode is popped one's head in are connected with 100 signals collecting contacts of the working end of electro-chemical measuring apparatus respectively by 100 wires.
Electro-chemical measuring apparatus by the Single-chip Controlling embedded wherein, according to the position of 100 metal electrode bars, the electric potential signal of acquisition order 100 signal acquisition point successively.
The course of work of the present invention is as follows:
After connecting whole device, make test button to be measured and the conducting of electrochemical testing device earth terminal, the demarcation contrast electrode end conducting of contrast electrode and electro-chemical measuring apparatus, by the Single-chip Controlling that electro-chemical measuring apparatus is embedded, each metal electrode bar that multi-channel electrode is popped one's head in is not being connected with electro-chemical measuring apparatus working end in the same time and is becoming isopotential point with test button to be measured respectively, electro-chemical measuring apparatus gathers electric potential signal successively by contrast electrode, now electrochemical workstation is the current potential of the test button surface location to be measured that corresponding metal electrode bar points to by the electric potential signal that contrast electrode gathers, recycling electro-chemical measuring apparatus also carries out analyzing and processing to the electric potential signal gathered, output potential distribution plan.Well can find electrode by potential image coordinate, thus determine the position that this electrode is tested, the place that electrode potential is low, represent and easily serve as anode, for the possibility of defect is large, and then determine the defect of specimen surface.
Detect a galvanochemistry lossless detection method for cracks of metal surface, carry out according to following step:
Step 1: the ion conductive membrane being soaked with electrolyte solution is placed in be made up of phenolics and metal electrode bar multi-channel electrode probe and test button to be measured between, the upper surface close contact of the bottom that described ion conductive membrane is popped one's head in described multi-channel electrode respectively and described test button to be measured, described metal electrode bar by described ion conductive membrane orderly be emitted on described test button upper surface to be measured, described metal electrode bar is that the capable N of M arranges and equidistant is distributed in described phenolics, described M is more than or equal to 5 and is less than or equal to 20, described N is more than or equal to 5 and is less than or equal to 20, contrast electrode surface treatment is for subsequent use,
Step 2: described contrast electrode contacts with described ion conducting film close, the described electro-chemical measuring apparatus with operational amplifier or zero resistance circuit is adopted to gather electric potential signal, wherein said multi-channel electrode probe is connected with described electro-chemical measuring apparatus working end, described contrast electrode is connected with the contrast electrode end arranged in described electrochemical testing device, and described test button lower surface to be measured is connected with described electrochemical testing device earth terminal, after connecting whole device, make test button to be measured and the conducting of electrochemical testing device earth terminal, the demarcation contrast electrode end conducting of contrast electrode and electro-chemical measuring apparatus, by the Single-chip Controlling that electro-chemical measuring apparatus is embedded, each metal electrode bar that multi-channel electrode is popped one's head in is not being connected with electro-chemical measuring apparatus working end in the same time and is becoming isopotential point with test button to be measured respectively, electro-chemical measuring apparatus gathers electric potential signal successively by contrast electrode, now electrochemical workstation is the current potential of the test button surface location to be measured that corresponding metal electrode bar points to by the electric potential signal that contrast electrode gathers,
Step 3: analyzing and processing is carried out, output potential distribution plan to the electric potential signal gathered.In potential image, each root electrode all correspond to a two-dimensional coordinate, namely potential image represents the Potential distribution that the capable N in M arranges the test button surface to be measured corresponding to metal electrode bar array be equally spaced, differentiated the position on test button surface to be measured corresponding to the low coordinate of electrode potential by potential image coordinate, be specimen surface defect; As first electrode correspond to coordinate (1,1), second electrode respective coordinates (1,2), until the tenth electrode respective coordinates (1,10); But horizontal ordinate changes from the ten electrode, correspond to coordinate (2,1), in like manner until the 20 electrode respective coordinates (2,10), then horizontal ordinate changes again.Namely every ten electrodes, horizontal ordinate changes once, until the 100th electrode pair answers (10,10).Current potential coordinate, according to the adjustment of testing sample situation, well can find electrode by potential image coordinate, thus determine the position that this electrode is tested, the place that electrode potential is low, represent and easily serve as anode, for the possibility of defect is large, and then determine the defect of specimen surface.
Select saturated calomel electrode as contrast electrode.
Select the filter paper being soaked with 3.5%NaCl solution as ion conductive membrane.
The metal electrode bar material of described multi-channel electrode probe is the carbon steel of Q235 model, and the diameter of the carbon steel rod of described Q235 model is 0.3-0.7mm, preferred 0.5mm.
The present invention obtains the current potential in each region, metal surface by electrochemical means, obtains metal surface potential image intuitively, analyzes current potential height and confirms negative and positive polar region, and then determine position and the shape of defect.The advantages such as compared with the device of traditional Non-Destructive Testing cracks of metal surface, the present invention uses electrochemical means, without the need to processing surface to be measured, has result simple, easy to operate, measuring accuracy is high, accuracy is high, intuitive measurement results is clear.
A kind of corrosion electrochemistry lossless detection method detecting cracks of metal surface that the present invention proposes, for Non-Destructive Testing provides a kind of new method.The method obtains the corrosion potential in each region, metal surface by electrochemical means, obtains metal surface potential image intuitively, analyzes current potential height and confirms negative and positive polar region, and then determine position and the shape of defect.Compared with the method for traditional Non-Destructive Testing cracks of metal surface, the method is electrochemical means, can be more visual and clear, simple to operate, measuring accuracy is high, accuracy is high, and does not limit by surface configuration.
Accompanying drawing explanation
Fig. 1 is structural representation of the present invention;
Fig. 2 is the cross sectional representation of multi-channel electrode probe in the present invention;
Fig. 3 tests 30min gained potential image in the specific embodiment of the invention;
Fig. 4 be in Fig. 3 region 1 place by the three-dimensional appearance figure measured by three-dimensional microscope;
Fig. 5 is the Ultrasonic Nondestructive figure that the present invention is used for proving this method feasibility.
In figure: 1 is test button to be measured, 2 is ion conductive membrane, and 3 is multi-channel electrode probe, and 3-1 is phenolics, and 3-2 is metal bar, and 4 is contrast electrode, and 5 is electro-chemical measuring apparatus.
Embodiment
Below by specific embodiment, technical scheme of the present invention is further described.
As shown in Fig. 1 to 5, in figure: 1 is test button to be measured, 2 is ion conductive membrane, and 3 is multi-channel electrode probe, and 3-1 is phenolics, and 3-2 is metal bar, and 4 is contrast electrode, and 5 is electro-chemical measuring apparatus.
Embodiment 1
A kind of galvanochemistry the cannot-harm-detection device detecting cracks of metal surface, comprise test button to be measured, ion conductive membrane, contrast electrode, multi-channel electrode probe and electro-chemical measuring apparatus, multi-channel electrode probe is arranged on the upper surface of test button to be measured, multi-channel electrode probe is made up of phenolics and metal electrode bar, and ion conductive membrane is provided with between the bottom (test side of namely popping one's head in) and the upper surface of test button to be measured of multi-channel electrode probe, the upper surface close contact of the bottom that ion conductive membrane is popped one's head in multi-channel electrode respectively and test button to be measured, contrast electrode is arranged on the top of test button to be measured and contacts with ion conducting film close, the top (i.e. Signal connector end) of multi-channel electrode probe, the bottom surface of contrast electrode and test button to be measured is respectively by the working end (not marking in figure) of wire and electro-chemical measuring apparatus, demarcate contrast electrode end (not marking in figure) to be connected with earth terminal (not marking in figure), operational amplifier or zero resistance circuit is provided with in electro-chemical measuring apparatus.
In the present embodiment, select saturated calomel electrode as contrast electrode.
In the present embodiment, select the filter paper being soaked with 3.5%NaCl solution as ion-conducting membrane.
In the present embodiment, the metal electrode bar material of multi-channel electrode probe is the carbon steel of Q235 model, wherein multi-channel electrode is equidistantly fixed in phenolics by the carbon steel rod of 25 Q235 models, 5 row 5 are become to arrange, 5mm is arranged in phenolics at equal intervals, and the diameter of the carbon steel rod of described Q235 model is 0.3mm.
In the present embodiment, the signals collecting end of electro-chemical measuring apparatus comprises 25 signals collecting contacts (not marking in figure).
In the present embodiment, the top of multi-channel electrode probe with the concrete connected mode of the signals collecting end of electro-chemical measuring apparatus is: 25 metal electrode bars that multi-channel electrode is popped one's head in are connected with 25 signals collecting contacts of the working end of electro-chemical measuring apparatus respectively by 25 wires.
In the present embodiment, electro-chemical measuring apparatus by the Single-chip Controlling embedded wherein, according to the position of 25 metal electrode bars, the electric potential signal of acquisition order 25 signal acquisition point successively.
Detect a galvanochemistry lossless detection method for cracks of metal surface, carry out according to following step:
Step 1: saturated calomel electrode that what this experiment was selected is is as contrast electrode, and be soaked with the filter paper of 3.5%NaCl solution as ion-conducting membrane, probe is 25 independently sensing electrode bundles, material is as far as possible close with test sample, and this example selects Q235 carbon steel.
Step 2: Experimental equipment as shown in Figure 1: first smooth for the filter paper being soaked with 3.5%NaCl solution is covered gear surface to be measured, use magnet that orderly for contrast electrode bundle electrode is fixed on gear surface to be measured, reference saturated calomel electrode is also fixed on surface to be measured in the lump.
Step 3: adopt the device with zero resistance circuit to gather electric potential signal, wherein each electrode of sensing electrode bundle is not being connected with electro-chemical measuring apparatus working end respectively in the same time, test sample is connected with electrochemical testing device earth terminal, and reference saturated calomel electrode is connected with electro-chemical test equipment and instrument contrast electrode end.
Step 4: analyzing and processing is carried out, output potential distribution plan to the electric potential signal gathered.Can determine by potential image coordinate the position that this electrode is tested, and then determine the defect area of specimen surface.
Embodiment 2
A kind of galvanochemistry the cannot-harm-detection device detecting cracks of metal surface, comprise test button to be measured, ion conductive membrane, contrast electrode, multi-channel electrode probe and electro-chemical measuring apparatus, multi-channel electrode probe is arranged on the upper surface of test button to be measured, multi-channel electrode probe is made up of phenolics and metal electrode bar, and ion conductive membrane is provided with between the bottom (test side of namely popping one's head in) and the upper surface of test button to be measured of multi-channel electrode probe, the upper surface close contact of the bottom that ion conductive membrane is popped one's head in multi-channel electrode respectively and test button to be measured, contrast electrode is arranged on the top of test button to be measured and contacts with ion conducting film close, the top (i.e. Signal connector end) of multi-channel electrode probe, the bottom surface of contrast electrode and test button to be measured is respectively by the working end (not marking in figure) of wire and electro-chemical measuring apparatus, demarcate contrast electrode end (not marking in figure) to be connected with earth terminal (not marking in figure), operational amplifier or zero resistance circuit is provided with in electro-chemical measuring apparatus.
In the present embodiment, select saturated calomel electrode as contrast electrode.
In the present embodiment, select the filter paper being soaked with 3.5%NaCl solution as ion-conducting membrane.
In the present embodiment, the metal electrode bar material of multi-channel electrode probe is the carbon steel of Q235 model, wherein multi-channel electrode is equidistantly fixed in phenolics by the carbon steel rod of 400 Q235 models, 20 row 20 are become to arrange, 1mm is arranged in phenolics at equal intervals, and the diameter of the carbon steel rod of described Q235 model is 0.7mm.
In the present embodiment, the signals collecting end of electro-chemical measuring apparatus comprises 400 signals collecting contacts (not marking in figure).
In the present embodiment, the top of multi-channel electrode probe with the concrete connected mode of the signals collecting end of electro-chemical measuring apparatus is: 400 metal electrode bars that multi-channel electrode is popped one's head in are connected with 400 signals collecting contacts of the working end of electro-chemical measuring apparatus respectively by 400 wires.
In the present embodiment, electro-chemical measuring apparatus by the Single-chip Controlling embedded wherein, according to the position of 400 metal electrode bars, the electric potential signal of acquisition order 400 signal acquisition point successively.
Detect a galvanochemistry lossless detection method for cracks of metal surface, carry out according to following step:
Step 1: saturated calomel electrode that what this experiment was selected is is as contrast electrode, and be soaked with the filter paper of 3.5%NaCl solution as ion-conducting membrane, probe is 400 independently sensing electrode bundles, material is as far as possible close with test sample, and this example selects Q235 carbon steel.
Step 2: Experimental equipment as shown in Figure 1: first smooth for the filter paper being soaked with 3.5%NaCl solution is covered gear surface to be measured, use magnet that orderly for contrast electrode bundle electrode is fixed on gear surface to be measured, reference saturated calomel electrode is also fixed on surface to be measured in the lump.
Step 3: adopt the device with zero resistance circuit to gather electric potential signal, wherein each electrode of sensing electrode bundle is not being connected with electro-chemical measuring apparatus working end respectively in the same time, test sample is connected with electrochemical testing device earth terminal, and reference saturated calomel electrode is connected with electro-chemical test equipment and instrument contrast electrode end.
Step 4: analyzing and processing is carried out, output potential distribution plan to the electric potential signal gathered.Can determine by potential image coordinate the position that this electrode is tested, and then determine the defect area of specimen surface.
Embodiment 3
A kind of galvanochemistry the cannot-harm-detection device detecting cracks of metal surface, comprise test button to be measured, ion conductive membrane, contrast electrode, multi-channel electrode probe and electro-chemical measuring apparatus, multi-channel electrode probe is arranged on the upper surface of test button to be measured, multi-channel electrode probe is made up of phenolics and metal electrode bar, and ion conductive membrane is provided with between the bottom (test side of namely popping one's head in) and the upper surface of test button to be measured of multi-channel electrode probe, the upper surface close contact of the bottom that ion conductive membrane is popped one's head in multi-channel electrode respectively and test button to be measured, contrast electrode is arranged on the top of test button to be measured and contacts with ion conducting film close, the top (i.e. Signal connector end) of multi-channel electrode probe, the bottom surface of contrast electrode and test button to be measured is respectively by the working end (not marking in figure) of wire and electro-chemical measuring apparatus, demarcate contrast electrode end (not marking in figure) to be connected with earth terminal (not marking in figure), operational amplifier or zero resistance circuit is provided with in electro-chemical measuring apparatus.
In the present embodiment, select saturated calomel electrode as contrast electrode.
In the present embodiment, select the filter paper being soaked with 3.5%NaCl solution as ion-conducting membrane.
In the present embodiment, the metal electrode bar material of multi-channel electrode probe is the carbon steel of Q235 model, wherein multi-channel electrode is equidistantly fixed in phenolics by the carbon steel rod of 225 Q235 models, 15 row 15 are become to arrange, 2mm is arranged in phenolics at equal intervals, and the diameter of the carbon steel rod of described Q235 model is 0.4mm.
In the present embodiment, the signals collecting end of electro-chemical measuring apparatus comprises 225 signals collecting contacts (not marking in figure).
In the present embodiment, the top of multi-channel electrode probe with the concrete connected mode of the signals collecting end of electro-chemical measuring apparatus is: 225 metal electrode bars that multi-channel electrode is popped one's head in are connected with 225 signals collecting contacts of the working end of electro-chemical measuring apparatus respectively by 225 wires.
In the present embodiment, electro-chemical measuring apparatus by the Single-chip Controlling embedded wherein, according to the position of 225 metal electrode bars, the electric potential signal of acquisition order 225 signal acquisition point successively.
Detect a galvanochemistry lossless detection method for cracks of metal surface, carry out according to following step:
Step 1: saturated calomel electrode that what this experiment was selected is is as contrast electrode, and be soaked with the filter paper of 3.5%NaCl solution as ion-conducting membrane, probe is 225 independently sensing electrode bundles, material is as far as possible close with test sample, and this example selects Q235 carbon steel.
Step 2: Experimental equipment as shown in Figure 1: first smooth for the filter paper being soaked with 3.5%NaCl solution is covered gear surface to be measured, use magnet that orderly for contrast electrode bundle electrode is fixed on gear surface to be measured, reference saturated calomel electrode is also fixed on surface to be measured in the lump.
Step 3: adopt the device with zero resistance circuit to gather electric potential signal, wherein each electrode of sensing electrode bundle is not being connected with electro-chemical measuring apparatus working end respectively in the same time, test sample is connected with electrochemical testing device earth terminal, and reference saturated calomel electrode is connected with electro-chemical test equipment and instrument contrast electrode end.
Step 4: analyzing and processing is carried out, output potential distribution plan to the electric potential signal gathered.Can determine by potential image coordinate the position that this electrode is tested, and then determine the defect area of specimen surface.
Embodiment 4
A kind of galvanochemistry the cannot-harm-detection device detecting cracks of metal surface, comprise test button to be measured, ion conductive membrane, contrast electrode, multi-channel electrode probe and electro-chemical measuring apparatus, multi-channel electrode probe is arranged on the upper surface of test button to be measured, multi-channel electrode probe is made up of phenolics and metal electrode bar, and ion conductive membrane is provided with between the bottom (test side of namely popping one's head in) and the upper surface of test button to be measured of multi-channel electrode probe, the upper surface close contact of the bottom that ion conductive membrane is popped one's head in multi-channel electrode respectively and test button to be measured, contrast electrode is arranged on the top of test button to be measured and contacts with ion conducting film close, the top (i.e. Signal connector end) of multi-channel electrode probe, the bottom surface of contrast electrode and test button to be measured is respectively by the working end (not marking in figure) of wire and electro-chemical measuring apparatus, demarcate contrast electrode end (not marking in figure) to be connected with earth terminal (not marking in figure), operational amplifier or zero resistance circuit is provided with in electro-chemical measuring apparatus.
In the present embodiment, select saturated calomel electrode as contrast electrode.
In the present embodiment, select the filter paper being soaked with 3.5%NaCl solution as ion-conducting membrane.
In the present embodiment, the metal electrode bar material of multi-channel electrode probe is the carbon steel of Q235 model, wherein multi-channel electrode is equidistantly fixed in phenolics by the carbon steel rod of 100 Q235 models, 10 row 10 are become to arrange, 3mm is arranged in phenolics at equal intervals, and the diameter of the carbon steel rod of described Q235 model is 0.5mm.
In the present embodiment, the signals collecting end of electro-chemical measuring apparatus comprises 100 signals collecting contacts (not marking in figure).
In the present embodiment, the top of multi-channel electrode probe with the concrete connected mode of the signals collecting end of electro-chemical measuring apparatus is: 100 metal electrode bars that multi-channel electrode is popped one's head in are connected with 100 signals collecting contacts of the working end of electro-chemical measuring apparatus respectively by 100 wires.
In the present embodiment, electro-chemical measuring apparatus by the Single-chip Controlling embedded wherein, according to the position of 100 metal electrode bars, the electric potential signal of acquisition order 100 signal acquisition point successively.
The course of work of the present embodiment is as follows:
After connecting whole device, make test button to be measured and the conducting of electrochemical testing device earth terminal, the demarcation contrast electrode end conducting of contrast electrode and electro-chemical measuring apparatus, each metal electrode bar that multi-channel electrode is popped one's head in is not being connected with electro-chemical measuring apparatus working end respectively in the same time, gather electric potential signal successively, analyzing and processing is carried out, output potential distribution plan to the electric potential signal gathered.In potential image, each root electrode all correspond to a two-dimensional coordinate, and as first electrode correspond to coordinate (1,1), second electrode respective coordinates (1,2), until the tenth electrode respective coordinates (1,10); But horizontal ordinate changes from the ten electrode, correspond to coordinate (2,1), in like manner until the 20 electrode respective coordinates (2,10), then horizontal ordinate changes again.Namely every ten electrodes, horizontal ordinate changes once, until the 100th electrode pair answers (10,10).Current potential coordinate adjusts according to testing sample situation, well electrode can be found by potential image coordinate, thus determine the position that this electrode is tested, accompanying drawing 3 is test 30min gained potential image, current potential lower region 1,2 can be identified very clearly from figure, the place that electrode potential is low, easily serves as anode, and corrosion will be serious.Illustrate that these two regions there occurs comparatively serious corrosion, causing compared with the reason of heavy corrosion may be the existence of surface imperfection.
For verifying the reliability of Electrochemical Detection, to Fig. 3 region 1, place carries out three-dimensional microscopic examination, Fig. 4 be in Fig. 3 region 1 place by the three-dimensional appearance figure measured by three-dimensional microscope, the defect that existence one is larger under its smooth surface can be seen from Fig. 4 3-d photographs, the place that electrode potential is low, represent and easily serve as anode, for the possibility of defect is large, and then determine the defect of specimen surface.
Detect a galvanochemistry lossless detection method for cracks of metal surface, carry out according to following step:
Step 1: saturated calomel electrode that what this experiment was selected is is as contrast electrode, and be soaked with the filter paper of 3.5%NaCl solution as ion-conducting membrane, probe is 100 independently sensing electrode bundles, material is as far as possible close with test sample, and this example selects Q235 carbon steel.
Step 2: Experimental equipment as shown in Figure 1: first smooth for the filter paper being soaked with 3.5%NaCl solution is covered gear surface to be measured, use magnet that orderly for contrast electrode bundle electrode is fixed on gear surface to be measured, reference saturated calomel electrode is also fixed on surface to be measured in the lump.
Step 3: adopt the device with zero resistance circuit to gather electric potential signal, wherein each electrode of sensing electrode bundle is not being connected with electro-chemical measuring apparatus working end respectively in the same time, test sample is connected with electrochemical testing device earth terminal, and reference saturated calomel electrode is connected with electro-chemical test equipment and instrument contrast electrode end.
Step 4: analyzing and processing is carried out, output potential distribution plan to the electric potential signal gathered.Can determine by potential image coordinate the position that this electrode is tested, and then determine the defect area of specimen surface.
With Origin software to electric potential signal process, obtain potential image.From Fig. 3 potential image, current potential comparatively negative region 1,2 can be identified very clearly.The place that electrode potential is low, easily serves as anode, and corrosion will be serious.Illustrate that these two regions there occurs comparatively serious corrosion, causing compared with the reason of heavy corrosion may be the existence of surface imperfection.
For verifying the reliability of Electrochemical Detection, to region 1, place carries out three-dimensional microscopic examination and ultrasonic phase array, the defect that existence one is larger under its smooth surface can be seen from Fig. 4 3-d photographs, can see from Fig. 5 ultrasonic phase array, a large echo (right figure is near initial ripple position) is there is, the reaction of defect that Here it is between initial ripple (right figure red line topmost) and reflection wave (right figure red line bottom).
In sum, the method in the embodiment of the present invention obtains the corrosion potential in each region, metal surface by electrochemical means, obtains metal surface potential image intuitively, analyzes current potential height and confirms seriously corroded district, and then determine position and the shape of defect.The method is corrosion electrochemistry means, can be more visual and clear, simple to operate, measuring accuracy is high, accuracy is high, and does not limit by surface configuration.
Above to invention has been exemplary description; should be noted that; when not departing from core of the present invention, any simple distortion, amendment or other those skilled in the art can not spend the equivalent replacement of creative work all to fall into protection scope of the present invention.