KR20100006677A - Device for testing metal parts corrosion of vehicle - Google Patents

Abstract

PURPOSE: A corrosion testing device for a metal component of a vehicle is provided to arbitrarily control or to make the periodic environmental changes shorter according to the needs of a user. CONSTITUTION: A corrosion testing device for a metal component of a vehicle comprises a resistive heating device, an induction heater and a salt water spray unit. The resistive heating device consist of first and second heating boxes(12a,12b), first and second specimen holders(14a,14b), a power supply unit(18), a temperature control and a control unit(20). The first and second heating boxes are each other separately placed. The first and second specimen holders are installed in the first and second heating boxes. The induction heater is composed of a holder, an induction heating coil and a power supply unit. The salt water spray unit is composed of an etchant storage tank(36), salt water spray nozzles(38a,38b), and an air exhaust nozzle.

Description

Device for testing metal parts corrosion of vehicle

The present invention relates to a corrosion test apparatus for a metal component of an automobile, and more particularly, two processes (salt spray and drying + high temperature heat treatment process), such as salt spray and drying of the test piece, and simultaneously heating the test piece to a high temperature. The present invention relates to a corrosion test apparatus for a metal part of a vehicle, which can simultaneously simulate the environment similar to actual field conditions.

In general, as the engine is getting higher power, the problem of high temperature salt corrosion of engine peripheral parts has been continuously raised, and in addition to this, a quantitative measurement method for high temperature salt corrosion is needed experimentally. The device is in poor condition.

In view of this, there are conventional corrosion-promoting test equipments (salt spray testers, complex environmental corrosion testers, etc.) related to the corrosive environment, that is, the corrosion environment. There is a disadvantage that can not directly reproduce the high temperature salt corrosion environment occurs, and also has a disadvantage that does not meet the experimental conditions that require frequent cycle replacement similar to the running conditions.

The present invention has been made in view of the above point, in the test of sheet materials such as steel sheet, by directly applying heat to the test unit through a resistance heating device or an induction heating device to simulate the high temperature environment in the salt spray chamber, It is possible to quickly and accurately simulate periodic environmental changes (temperature changes), and to provide a corrosion test device for metal parts of automobiles which can shorten periodic environmental changes similar to driving conditions or can be arbitrarily adjusted according to the needs of the experimenter. The purpose is.

The present invention for achieving the above object is a heating device that can be heated while fixing the test piece; Brine spraying means for injecting brine to the test piece; Control means for controlling the temperature while supplying power to the heating apparatus; Air supply means for supplying compressed air to the heating device and the salt spraying means; It provides a corrosion test apparatus for metal parts of the vehicle, characterized in that configured to include.

In one preferred embodiment, the heating device is characterized in that any one of a resistance heating device for heating a test piece corresponding to a metal sheet of the vehicle body parts or an induction heating device for heating a test piece corresponding to a bulky metal part.

In a more preferred embodiment, the resistance heating device and the first and second heating boxes spaced apart from each other; First and second test piece holders rotatably mounted in the first and second heating boxes; A power supply device and a temperature control control unit which are the control means connected to the first and second test piece holders so that a current flows directly into the test piece; Characterized in that consisting of.

In addition, the induction heating device and a holder for fixing the test piece; An induction heating coil disposed at an outer diameter of a test piece fixed to the holder; A power supply device and a temperature control control unit which are the control means connected to supply current to the induction heating coil; Characterized in that consisting of.

In another preferred embodiment, the brine spraying means and the corrosion storage tank; A pump mounted to an outlet of the corrosive storage tank; A salt spray nozzle disposed at both sides of the test piece so as to spray the corrosion solution discharged from the pump; A salt spray body to which the salt spray nozzle is fixed; An air outlet installed at a lower end of the salt spray body to evenly eject the corrosion solution sprayed through the salt spray nozzle; Characterized in that consisting of.

In another preferred embodiment, the air supply means comprises: first and second air nozzles mounted on the bottom surfaces of the first and second heating boxes; An air saturator and an air compressor connected to the first and second air nozzles and the air ejection port to supply a compressed air; A predetermined portion of the air flow pipe includes an air pressure regulating valve; Characterized in that consisting of.

Through the above problem solving means, the present invention provides the following effects.

According to the present invention, in a salt spray chamber, the test piece is directly heated by a resistance heating device (in case of a sheet material test such as steel sheet) or an induction heating device (large parts such as an exhaust system flexible pipe). By allowing salt spraying and drying, it is possible to quickly and accurately reproduce periodic environmental changes (temperature changes) according to driving conditions of the vehicle.

 Simultaneously perform two processes (salt spray and dry + high temperature heat treatment process) such as salt spray and drying the specimen and heat treatment to heat the specimen to a high temperature to simulate the actual field conditions This can greatly reduce the cost.

Hereinafter, the present invention will be described in more detail.

Corrosion test apparatus for metal parts of automobiles according to the present invention has been improved in a manner that proceeds in one cycle without separately performing the salt spray and dry + high temperature heat treatment process, because the two processes (salt spray) under the actual vehicle driving conditions And drying + high temperature heat treatment process) do not occur separately, but occur at the same time, thereby simulating the environment more similar to the actual field conditions.

In the present invention, a resistance heating device or an induction heating device is selected and used according to the shape and size of the automobile parts in order to simulate the high temperature salt environment of the automobile parts according to the driving conditions of the actual vehicle.

Here, the corrosion test apparatus for metal parts of automobiles according to the present invention will be described in more detail with reference to the following examples.

First embodiment

1 is a schematic diagram illustrating a case in which a resistance heating apparatus is adopted as an example of a corrosion test apparatus for a metal component of an automobile, and FIG. 2 is a schematic diagram illustrating the resistance heating apparatus in more detail.

According to the present invention, a corrosion test apparatus employing a resistance heating device is used when the test object is a sheet material such as a steel sheet or a bracket, and operates by applying heat to a metal part using the principle of resistance heating (direct resistance heating). do.

In one configuration of the resistance heating device, the first and second heating boxes 12a and 12b are spaced apart from each other in the salt spray chamber 10, and the first and second heating boxes 12a and 12b are at a high temperature. The first and second test piece holders 14a and 14b, each having austenitic stainless steel with corrosion resistance, and embedded therein, are connected to the power supply 18 while fixing the test pieces in the range of 0.5 to 3 mm. A conductive metal is used to allow direct current to flow through (direct heating temperature range ~ 500 ° C).

At this time, the power supply device 18 is composed of a control panel together with the temperature control control unit 20.

Test piece through-holes 16 are formed in each of the inner surfaces of the first and second heating boxes 12a and 12b, and the first and second test piece holders 14a and 14b are the first and second heating boxes 12a. And hinged to the front and rear surfaces of 12b).

More specifically, since the test piece may need to maintain a constant angle with respect to the salt spray during the corrosion test (salt spray test specification 15 to 30 degrees inclination) in some cases, the first and second test piece holders 14a, A rotating shaft is formed at 14b) to be mounted in the first and second heating boxes 12a and 12b so as to be rotatable, so as to set a tilt.

Therefore, one end of the test piece is fixed to the first test piece holder 14a in the first heating box 12a, and the other end of the test piece is fixed to the second test piece holder 14b in the second heating box 12b. do.

Meanwhile, first and second air nozzles 22a and 22b are mounted on bottom surfaces of the first and second heating boxes 12a and 12b, and the first and second air nozzles 22a and 22b are air flows. It is connected to the air saturator 26 and the air compressor 28 which is an air supply means along the pipe 24, and the air pressure control valve 30 is mounted in a predetermined portion of the air flow pipe 24.

More specifically, in order to minimize corrosion of the first and second heating box devices by salt spray in the resistance heating method, the through-holes to which the test pieces are exposed are minimized, in particular through the air nozzles 22a and 22b. Appropriate amount of air into the first and second heating boxes (12a, 12b) (do not affect the test specimen: adjusted to about 1/5 (0.3 ~ 0.5kgf / ㎠) of the salt spray pressure 1.5kgf / ㎠) Blow off to prevent brine from entering the first and second heating boxes 12a, 12b during the test.

The first and second air nozzles 22a and 22b for preventing the salt water intrusion have a nozzle diameter of 2 to 3 mm and control the pressure in the air pressure regulating valve 30 through the air saturator 26 in the air compressor 28. Air is injected, and the spray pressure is about 0.3 to 0.5 kgf / cm 2.

In particular, the corrosion solution storage tank 32 storing the brine to be sprayed on the test piece is disposed in a predetermined position, the salt spray means for spraying the brine to the test piece in the outlet of the corrosion solution storage tank 32 is shown in FIG. As shown, the pump 34 mounted to the outlet of the corrosive storage tank 32, the corrosive liquid discharge line 36 extending in two from the pump, and at each end of the corrosive liquid discharge line 36 First and second salt spray nozzles 38a and 38b mounted therein, an air jet 40 disposed directly below the first and second salt spray nozzles 38a and 38b, and the first and second spray nozzles 38a and 38b. The salt spray nozzles 38a and 38b and the air blowing holes 40 are fixed to the lower end, and the upper end is composed of a predetermined volume of the salt spray body 42 in an open form.

At this time, the first and second saline spray nozzles (38a, 38b) and the air ejection port is sprayed by the atomizer (mistomizer) to uniform salt water.

Salt water spraying means having such a configuration is in a state disposed in the outer position of the first and second heating box, respectively.

Test Example 1

436 (SUS), 304 (SUS), and 316 (SUS) which are a kind of sheet metal parts of a vehicle were fixed to the said 1st and 2nd test piece holder.

Corrosion liquid ejected through the corrosive discharge line 36 by driving the pump 34 of the salt spray means is spray pressure: 1.5kgf / ㎠, spraying amount: 1.5 through the first and second salt spray nozzles (38a, 38b) Injected at a ml / hr, at this time, by the air pressure supplied to the air ejection port 40 it was sprayed so that the corrosion solution evenly spread over the test piece.

At this time, 5% NaCl solution was used as the corrosion solution composition stored in the corrosion solution storage tank 32.

In particular, the brine spray phase (5 hours at 95% relative humidity), the forced drying phase (stop the salt spray for 3 hours to 30% relative humidity), and the wet phase (again 3 hours to 95% relative humidity again) Spraying) and the forced drying step (salt spray interruption for 2 hours to 30% relative humidity) in one cycle, during which the current applied from the power supply 18 receives the first and second specimen holders. (14a, 14b) were simultaneously supplied to the test piece, and the test piece was heated to 400 ° C., and another test piece was heated to 600 ° C., and the test results are shown in FIG. 5.

That is, to simulate an environment very similar to the actual field conditions, as a result of the simultaneous salt spray, drying, and high temperature heat treatment as described above, after 10 days and 80 days, the corrosion degree of each specimen was observed, 80 It was found that holes due to corrosion occurred in the test piece within days.

Second embodiment

The second embodiment of the corrosion test apparatus for a metal component of an automobile according to the present invention is the same as the configuration according to the first embodiment, except that the configuration for heat treatment of the test piece is different.

That is, in the case of bulky parts (such as bellows or exhaust pipes), the resistance heating method is not appropriate, which is characterized by using an induction heating device for heating the whole part.

3 is a block diagram showing a second embodiment of a corrosion test apparatus for a metal component of an automobile according to the present invention.

The induction heating device is composed of a heating coil 44 connected to the power supply device 18, and a holder 46 for mounting the test piece so that the test piece is located inside the heating coil 44, the heating temperature range is Within about 700 ° C.

On the other hand, the induction heating device is designed to be detachable structure using a clamp or a bracket well known in the art so that it can be used as a resistance heating device and a power source.

At this time, it is preferable that the heating coil 44 used for induction heating uses a surface treated with high temperature corrosion resistance as necessary in order to secure corrosion resistance to salt water.

As in the first embodiment, together with the power supply device 18 for supplying power to the heating coil 44, a temperature control control unit 20 having a constant temperature and temperature control function according to time is configured as one control panel, Allow the experimenter to optionally control the heating conditions and time for the specimen.

That is, since the resistance varies depending on the metal type of the test piece, in order to set the proper temperature, the resistance value according to the metal part must be measured first and the appropriate voltage must be selected accordingly. A function of setting an appropriate voltage value is input, and the measured temperature is transmitted to the temperature control control unit 20 in real time from the temperature sensor 48 installed near the specimen under test so as to maintain constant temperature.

Test Example 2

The exhaust system flexible pipe was fixed to the holder holding the test piece.

Corrosion liquid ejected through the corrosive discharge line 36 by driving the pump 34 of the salt spray means is spray pressure: 1.5kgf / ㎠, spraying amount: 1.5 through the first and second salt spray nozzles (38a, 38b) Injected at a ml / hr, at this time, by the air pressure supplied to the air ejection port 40 it was sprayed so that the corrosion solution evenly spread over the test piece.

At this time, 5% NaCl solution was used as the corrosion solution composition stored in the corrosion solution storage tank 32.

In particular, 10 cycles of 5% NaCL salt spray (5 hours at 95% relative humidity) and forced drying (3 hours off the salt spray for 30% relative humidity) are performed. A current applied from the power supply was supplied to the induction heating coil 44 to heat the test piece in the induction heating coil 44, that is, the exhaust system flexible pipe to 500 ° C, and another test piece to 700 ° C.

As a result, as shown in FIG. 6, corrosion was generated on the outer surfaces of the exhaust system flexible pipe heated to 500 ° C. and the exhaust system flexible pipe heated to 700 ° C., and also shown in FIG. 7. As a result of observing the microstructure of each specimen through an electron microscope, it was confirmed that the high temperature salt boundary corrosion occurred.

1 is a configuration diagram showing a first embodiment of a corrosion test apparatus for a metal component of an automobile according to the present invention;

Figure 2 is a schematic diagram showing in more detail the configuration for the resistance heating device of FIG.

3 is a configuration diagram showing a second embodiment of a corrosion test apparatus for a metal component of an automobile according to the present invention;

Figure 4 is a schematic diagram showing in more detail the salt spray and air spray means of the corrosion test apparatus for metal parts of the vehicle according to the present invention;

5 is an electron micrograph showing the results of the corrosion test using the corrosion test apparatus for metal parts of a vehicle according to the first embodiment of the present invention,

6 and 7 are photographs showing the results of the corrosion test using the corrosion test apparatus for metal parts of the vehicle according to the second embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: salt spray chamber 12a: the first heating box

12b: second heating box 14a: first specimen holder

14b: second specimen holder 16: specimen through-hole

18: power supply unit 20: temperature control unit

22a: 1st air nozzle 22b: 2nd air nozzle

24: air flow pipe 26: air saturator

28: air compressor 30: air pressure control valve

32: corrosive storage tank 34: pump

36: corrosive discharge line 38a: the first salt spray nozzle

38b: 2nd salt spray nozzle 40: air jet

42: salt spray body 44: heating coil

46: holder 48: temperature sensor

Claims (6)

A heating apparatus capable of fixing and simultaneously heating the test piece; Brine spraying means for injecting brine to the test piece; Control means for controlling the temperature while supplying power to the heating apparatus; Air supply means for supplying compressed air to the heating device and the salt spraying means; Corrosion test device for metal parts of the vehicle, characterized in that comprises a. The method according to claim 1, The heating apparatus is any one of a resistance heating device for heating a test piece corresponding to a metal sheet of a vehicle body part or an induction heating device for heating a test piece corresponding to a bulky metal part. Device. The method of claim 2, wherein the resistance heating device: First and second heating boxes spaced apart from each other; First and second test piece holders rotatably mounted in the first and second heating boxes; A power supply device and a temperature control control unit which are the control means connected to the first and second test piece holders so that a current flows directly into the test piece; Corrosion test device for metal parts of the vehicle, characterized in that consisting of. The method of claim 2, wherein the induction heating apparatus: A holder for mounting and fixing the test piece; An induction heating coil disposed at an outer diameter of a test piece fixed to the holder; A power supply device and a temperature control control unit which are the control means connected to supply current to the induction heating coil; Corrosion test device for metal parts of the vehicle, characterized in that consisting of. The method according to claim 1, wherein the salt spray means: A corrosive storage tank; A pump mounted to an outlet of the corrosive storage tank; A salt spray nozzle disposed at both sides of the test piece so as to spray the corrosion solution discharged from the pump; A salt spray body to which the salt spray nozzle is fixed; An air outlet installed at a lower end of the salt spray body to evenly eject the corrosion solution sprayed through the salt spray nozzle; Corrosion test device for metal parts of the vehicle, characterized in that consisting of. The method of claim 1 or 5, wherein the air supply means: First and second air nozzles mounted on bottom surfaces of the first and second heating boxes; An air saturator and an air compressor connected to the first and second air nozzles and the air ejection port to supply a compressed air; A predetermined portion of the air flow pipe includes an air pressure regulating valve; Corrosion test device for metal parts of the vehicle, characterized in that consisting of.

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