JP2007138282A - Thermal spray material made from magnesium alloy having superior explosion proof in thermal spraying and imparting superior corrosion resistance to thermal-sprayed portion, and thermal spraying method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal spray material made from a magnesium alloy, which has superior explosion proof in a thermal spraying period and imparts superior corrosion resistance to a thermal-sprayed portion. <P>SOLUTION: The thermal spray material made from a magnesium alloy, which has superior explosion proof in a thermal spraying period and imparts superior corrosion resistance to a thermal-sprayed portion, comprises, by mass%, 13-42% Al, 1-5% Ca, and the balance Mg with unavoidable impurities. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a magnesium alloy that is used for modifying the surface of members for automobiles, steel pipes, building materials, home appliances, computers, and other equipment / machines by a thermal spraying method, and has excellent explosion resistance during thermal spraying and corrosion resistance of thermal sprayed parts. The present invention relates to a thermal spray material and a thermal spraying method using the same.

  In general, since magnesium has a low specific gravity and excellent corrosion resistance, it is used as a material or a surface modifying material for automobiles, steel pipes, building materials, home appliances, computers, and other devices that are required to be lightweight and corrosive.

  As an alloy material using magnesium, generally, a magnesium alloy containing Al: 11% or less is often used (for example, see Non-Patent Documents 1 and 2).

  Further, as a magnesium alloy material whose heat resistance is improved while maintaining the castability of the magnesium alloy material, for example, Al: 6 to 12%, Ca: 0.05 to 4%, rare earth element: 0.5 to 4%, Magnesium alloy containing Mn: 0.05 to 0.50%, Sn: 0.1 to 14% (see Patent Document 1, for example), Al: 4 to 25%, Ca: 1 to 15% A magnesium alloy (see, for example, Patent Document 2) has been proposed.

  Furthermore, as a magnesium alloy material whose flame retardancy is improved while maintaining the mechanical strength of the magnesium alloy material, for example, a magnesium alloy containing Ca: 0.1 to 15% and not more than twice the Al: Ca content is available. It has been proposed (for example, see Patent Document 3).

  In addition to being used as the bulk magnesium alloy material, magnesium is also used as a thermal spray material for improving the corrosion resistance of the member surface by utilizing the corrosion resistance of magnesium.

For example, as a wire-shaped spraying material used in arc spraying methods, etc., a coating wire (Al) containing Al and Mg in a coating part (pipe) and a coating material containing the filler in the coating part (pipe) is excellent in feedability. (For example, refer to Patent Document 4). Moreover, Mg: Corrosion-resistant treatment method (for example, see Patent Document 5) in which arc spraying is performed on the surface of the object to be sprayed using an Al—Mg alloy spray wire containing about 5% and a spray wire composed of Zn, After making a pipe using a Zn alloy-based plated steel sheet, the weld is sprayed with a frame of C ₂ H ₂ + O ₂ using an Al—Mg alloy wire and an Al wire, and the surface of the weld is made of an Al—Mg alloy. A method for improving the corrosion resistance by providing a thermal spray repair layer (see, for example, Patent Documents 7 and 9) has been proposed.

  Moreover, as a powder-form spraying material used for the plasma spraying method, Si: 26-80%, Mg: 0.05-10% and Cu: 5-10% are contained, and the balance is Al and inevitable impurities. There has been proposed a sprayed aluminum alloy powder for wear-resistant members having an average particle size of 1 to 200 μm produced by an atomizing method (see, for example, Patent Document 6).

  Also, Mg: 0.2% to less than 60% is contained on the surface of the base material by a thermal spraying method in which a powder or wire of the Mg-containing alloy is melted using a heat source such as a plasma jet, a fuel combustion flame, or an electric arc. A method for producing a halogen-resistant film-coated member that forms an Al—Mg alloy film having a thickness of 30 to 500 μm has been proposed (for example, see Patent Document 8).

  As described above, an Al-Mg alloy spray material such as a spray wire or spray powder used for the purpose of improving the corrosion resistance of the Al-Mg alloy surface on the metal surface by a thermal spraying method is a plasma jet, a fuel combustion frame, In order to prevent explosion when melting at a high temperature using a heat source such as an electric arc, the Mg content in the Al—Mg alloy sprayed material had to be limited to 20% or less (for example, And Patent Documents 5 and 6).

  In addition, in the manufacturing method of the halogen-resistant film coating | coated member of the said patent document 8, although it describes that some Mg content in an Al-Mg alloy film is accept | permitted to 60% in the said literature, actually The maximum Mg content in the Al—Mg alloy film shown in the implemented examples is 18.3%. The inventors may explode as shown in Table 1 below even when the Mg content in the Al—Mg alloy film is about 18%, and when the Mg content exceeds 20% As a result, it was confirmed that a molten film could not be formed.

  Particularly, the shape of the Al—Mg alloy sprayed material is likely to cause dust explosion when used as a sprayed powder having a flying particle (molten powder) size of about 20 to 400 μm at the time of spraying, as compared with a sprayed wire.

  Even in the case of bulk magnesium alloy, dust explosion caused by Mg metal may occur when processing such as cutting or cutting of the raw material. As a countermeasure against this, as described above, in order to enhance flame retardancy, Ca: 0 A magnesium alloy material containing 1 to 15% and not more than twice the Al: Ca content has been proposed (for example, Patent Document 3). However, when a magnesium alloy is used as a structural member, the upper limit of the Al content is limited in order to maintain mechanical strength, and the Al content is about 10% by mass at the maximum. However, as a result of the study by the present inventors, it is effective to suppress the dust explosion that occurs during processing such as cutting or cutting of the magnesium alloy material only by adding about 10% by mass of Al content in the magnesium alloy. However, it is not possible to reliably prevent dust explosion during thermal spraying under a condition where the Mg content exceeds 20%.

  That is, when spraying using magnesium as a thermal spray material, the flying particle size becomes a molten powder of about 20 to 400 μm, and the specific surface area is increased. Therefore, when the Mg content is higher than 20%, the melting point of the powder is higher than the melting point of the powder. As a result of the lower ignition point temperature, the possibility of explosion before melting is dramatically increased.

  Therefore, when using magnesium as the thermal spraying material, it is necessary to limit the Mg content in the thermal spraying material to be lower than the content in the bulk material, so that the corrosion resistance improvement merit of Mg metal can be fully enjoyed. Disappear.

  Therefore, it has been desired to develop a thermal spray material having an Mg content of 20% or more, which can further improve the corrosion resistance of the thermal spray portion without causing an explosion during thermal spraying.

JIS H 5203 JIS H 5303 JP 2005-68550 A JP2004-232060 JP2000-109963 JP2002-4025 JP2003-253419 JP 2003-286501 A JP 2003-328105 A JP 2004-269951 A JP-A-60-89559

  An object of the present invention is to provide a magnesium alloy thermal spray material that is excellent in corrosion resistance of a thermal sprayed part and excellent in explosion-proof property during thermal spraying in view of the current state of the prior art.

  The present invention solves the above technical problems, and the invention is as follows.

(1) By mass%, Al: 13 to 78%, Ca: 1 to 5%, and the total amount of Al and Ca is 79% or less, and the balance consists of Mg and inevitable impurities Magnesium alloy sprayed material with excellent explosion-proof properties during spraying and corrosion resistance of the sprayed part.
(2) Further, it is characterized by containing, by mass%, Zn: 65% or less, the total amount of Al and Zn being 78% or less, and the total amount of Al, Ca and Zn being 79% or less. The magnesium alloy thermal spray material excellent in the explosion-proof property at the time of thermal spraying and the corrosion resistance of the thermal spray part as described in the above (1).
(3) By mass%, Al: 13 to 42%, Ca: 1 to 5%, the total amount of Al and Ca is 47% or less, and the balance consists of Mg and inevitable impurities Magnesium alloy sprayed material with excellent explosion-proof properties during spraying and corrosion resistance of the sprayed part.

(4) Further, it is characterized by containing, by mass%, Zn: 65% or less, the total amount of Al and Zn being 42% or less, and the total amount of Al, Ca and Zn being 47% or less. The magnesium alloy thermal spray material excellent in the explosion-proof property at the time of thermal spraying and the corrosion resistance of the thermal spray part as described in (3) above.
(5) By mass%, Al: 42 to 78%, Ca: 1 to 5%, the total amount of Al and Ca is 79% or less, and the balance consists of Mg and inevitable impurities Magnesium alloy sprayed material with excellent explosion-proof properties during spraying and corrosion resistance of the sprayed part.
(6) Further, it is characterized by containing, by mass%, Zn: 65% or less, the total amount of Al and Zn being 78% or less, and the total amount of Al, Ca and Zn being 79% or less. The magnesium alloy thermal spray material excellent in the explosion-proof property at the time of thermal spraying and the corrosion resistance of the thermal sprayed portion according to any one of the above (1) to (6).

  (7) The magnesium alloy thermal spray material excellent in the explosion-proof property at the time of thermal spraying and the corrosion resistance of the thermal sprayed portion according to any one of (1) to (6), further containing, by mass%, Si: 10% or less.

  (8) The magnesium alloy thermal spray material excellent in the explosion-proof property at the time of thermal spraying and the corrosion resistance of the thermal sprayed part according to any one of (1) to (7), further comprising, in mass%, Mn: 4% or less.

  (9) The magnesium alloy thermal spray material excellent in explosion-proof property and thermal corrosion resistance during thermal spraying according to any one of the above (1) to (8), wherein the thermal spray material is a wire or powder.

  (10) The thermal sprayed material surface is sprayed using the magnesium alloy sprayed material according to any one of (1) to (9) above, and the explosion resistance during spraying is excellent, and the corrosion resistance of the sprayed portion is excellent. Spraying method.

  According to the present invention, when the surface of a member to be sprayed is sprayed by a spraying method to improve the surface, it is possible to provide a magnesium alloy sprayed material having excellent explosion resistance during spraying and excellent corrosion resistance of the sprayed portion. . Further, by using the thermal spray material, it is possible to provide a thermal spraying method that is excellent in explosion-proof property during thermal spraying and excellent in corrosion resistance of the thermal sprayed portion.

  Details of the present invention will be described below.

  The present inventors examined the component composition of the magnesium alloy thermal spray material for preventing explosion during thermal spraying under the condition that the Mg content in the magnesium alloy thermal spray material was increased as compared with the prior art.

  Conventionally, when cutting or cutting a magnesium alloy material (bulk material), in order to prevent dust explosion due to a face, etc., a method of improving the flame retardancy of the magnesium alloy material by adding Al to the magnesium alloy Is known (for example, Patent Document 3).

  However, according to the examination by the confirmation test of the present invention, in order to suppress the explosion at the time of thermal spraying using the magnesium alloy thermal spray material, about 10% or less added to the magnesium alloy material (bulk material). No significant effect was observed with the Al content. This is because, when spraying using a thermal spray material of a magnesium alloy, the flying particle size becomes a molten powder having a size of about 20 to 400 μm, and the specific surface area is increased, so the ignition point temperature is lower than the melting point of the Mg alloy powder. It was found that this was the cause of the explosion before the sprayed material melted during spraying.

  Therefore, the present inventor contains 3% or more of Al in order to lower the melting point of the magnesium alloy spray material, and contains a predetermined amount of Ca in order to increase the ignition temperature. The component composition of the magnesium alloy sprayed material so that it can be maintained lower than the above was studied earnestly.

  The basic concept of the present invention will be described with reference to FIG. FIG. 1 shows the relationship between the Al content in the magnesium alloy sprayed material and the ignition temperature and melting point of the magnesium alloy sprayed material. In the magnesium alloy sprayed material, the balance other than Al and Ca is Mg and inevitable impurities.

  In general, the thermal spraying method uses a heat source such as a plasma jet, a fuel combustion flame, or an electric arc, and raises the temperature of the thermal spray material to a temperature higher than the melting point (preferably a liquid phase temperature, but a solid phase temperature under the thermal spraying pretreatment conditions). However, it is necessary to weld the sprayed material to the surface of the member to be sprayed while melting. For this reason, when the ignition temperature of the thermal spray material (≈the temperature at which explosion occurs) is lower than the melting point, it is difficult to perform thermal spraying satisfactorily.

  As shown in FIG. 1, the melting point of the magnesium alloy sprayed material decreases as the Al content increases in the range where the Al content in the magnesium alloy sprayed material is about 50% or less, and the Al content decreases to about 50%. In the exceeding range, it tends to increase as the Al content increases. The relationship curve between the melting point of the magnesium alloy sprayed material and its Al content hardly changes under the condition of Ca: 1 to 5%.

  On the other hand, the ignition temperature of the magnesium alloy spray material is such that when the Al content in the magnesium alloy spray material is about 50% or less, the Al content increases, and the Al content exceeds about 50% to about 80. However, it becomes almost constant regardless of the Al content, and tends to increase as the Al content increases in a range exceeding about 80%.

  Further, the relationship curve between the ignition temperature of the magnesium alloy spray material and its Al content shifts upward as the Ca content increases. As a result, when the Ca content in the magnesium alloy sprayed material is less than 1%, the melting point of the magnesium alloy sprayed material becomes higher than the ignition temperature regardless of the Al content, and before the spraying (before the welding) The possibility that the magnesium alloy sprayed material will explode increases.

  On the other hand, when the Ca content in the magnesium alloy sprayed material exceeds 1%, the melting point of the magnesium alloy sprayed material is kept lower than the ignition temperature under the condition that the Al content in the magnesium alloy sprayed material is 13% or more. It is possible to perform good thermal spraying while preventing explosion during thermal spraying.

  The increase in Al content and Ca content reduces the melting point of the magnesium alloy thermal spray material, and the increase in ignition temperature increases the effect of preventing explosion during spraying. However, excessive addition of Al and Ca is caused by the remaining Mg. Causes the corrosion resistance to be hindered. That is, according to the examination results of the inventors, when the Ca content in the magnesium alloy sprayed material exceeds 5% or when the Al content exceeds 78%, the surface of the magnesium alloy sprayed material is oxidized. It was found that a physical layer is formed and the sprayed coating becomes a mixture of oxide and metal, which causes a decrease in corrosion resistance. In particular, since the oxide formed on the surface of the thermal spray material has a melting point higher than that of the metal, a coating is formed on the thermal sprayed part in a state where the thermal spray particles are not sufficiently melted during thermal spraying, thereby inhibiting the formation of a dense coating. This is considered to be the cause of the decrease in the corrosion resistance of the sprayed part. Further, when the total amount of Al and Ca exceeds 79%, the remaining Mg content decreases, so that the effect of improving the corrosion resistance of the sprayed portion by Mg cannot be obtained.

  The present invention has been made based on these findings, and the magnesium alloy sprayed material contains, by mass%, Al: 13 to 78%, Ca: 1 to 5%, and the total amount of Al and Ca. Is 79% or less, and the balance consists of Mg and inevitable impurities.

  The reason for limiting the component composition in the magnesium alloy sprayed material specified in the present invention will be described below. Note that “%” shown below means “% by mass” unless otherwise specified.

Al: Al has an effect of lowering the melting point of the magnesium alloy. In order to sufficiently improve the explosion-proof property at the time of thermal spraying, the Al content in the magnesium alloy thermal spray material needs to be 13% or more. On the other hand, if the Al content exceeds 78%, an oxide layer is formed on the surface of the magnesium alloy sprayed material, and the sprayed coating becomes a mixture of oxide and metal, so the effect of improving the corrosion resistance of the sprayed portion is reduced. In order to maintain the corrosion resistance of the target sprayed part, the upper limit of the Al content needs to be 78%.
In order to make the melting point of the magnesium alloy sprayed material the lowest, it is preferable that the Al content is in the range of 32 to 34%, which is an eutectic region of Al-Mg.

  In addition, as the Al content in the magnesium alloy sprayed material increases, the melting point of the magnesium alloy sprayed material decreases, and the effect of preventing explosion during spraying increases more, but the Mg that contributes to the remaining corrosion resistance decreases, In addition, since the corrosion resistance of the sprayed portion during spraying is reduced, in order to maximize the corrosion resistance of the sprayed portion and to ensure a certain level of dust explosiveness, the upper limit of the Al content is 42%, the Al content Is preferably 13 to 42%.

In addition, when the Al content in the magnesium alloy sprayed material increases, the amount of intermetallic compounds increases, so that it becomes hard and the workability may deteriorate. When the form of the magnesium alloy sprayed material is powder, no problem arises. However, in the case of a wire, there is a concern about the workability (drawing workability) during wire production, so it is preferable to work warmly. .
In addition, the higher the Al content in the magnesium alloy spray material, the lower the melting point of the magnesium alloy spray material, and the more effective it is to prevent explosion during spraying, thus preventing dust explosion during spraying more stably. In order to do so, it is preferable that the lower limit of the Al content is 42% and the Al content is 42 to 78.

  Ca: It has the effect of raising the ignition temperature of the magnesium alloy, and in order to sufficiently improve the explosion-proof property at the time of thermal spraying, the Ca content in the magnesium alloy thermal spray material needs to be 1% or more. On the other hand, if the Ca content exceeds 5%, an oxide layer is formed on the surface of the magnesium alloy sprayed material, and the sprayed coating becomes a mixture of oxide and metal, so the effect of improving the corrosion resistance of the sprayed portion is reduced. In order to maintain the corrosion resistance of the target sprayed portion, the upper limit of the Ca content needs to be 5%.

Total amount of Al and Ca:
By containing Al and Ca as described above, the ignition temperature of the magnesium alloy sprayed material can be made relatively higher than the melting point, and the magnesium alloy can be prevented from exploding before spraying (before welding). However, if the total amount of Al and Ca exceeds 79%, the remaining Mg is reduced, and the effect of improving the corrosion resistance of the sprayed portion due to Mg described later is lowered. Therefore, the upper limit of the total amount of Al and Ca is 79%. .
Moreover, in order to increase Mg which contributes to the corrosion resistance of the remainder and further enhance the corrosion resistance improving effect of the sprayed portion with Mg, the upper limit of the total amount of Al and Ca is preferably 47%.

  Mg: Mg content in the magnesium alloy sprayed material has the effect of improving the corrosion resistance, and is the remaining metal of the magnesium alloy sprayed material. In the present invention, the upper limit of the Al content and the Ca content, and the upper limit of the total amount of Al and Ca can maintain the intended corrosion resistance of the magnesium alloy sprayed material, and therefore need to be particularly limited. There is no. However, in order to stably maintain the corrosion resistance when components other than Al and Ca are contained, the content of each component is set so that the remaining Mg content is 21% or more, more preferably 53% or more. It is preferable to adjust.

  The magnesium alloy thermal spray material of the present invention contains Al, Ca and the balance Mg as basic components, but may further contain the following component elements for the following purposes depending on the application.

  Zn: Since Zn is less susceptible to oxidation than Mg and Al, the inclusion of Zn has the effect of improving the adhesion of the sprayed portion and improving its strength, and can be contained at 65% or less. If the Zn content in the magnesium alloy sprayed material exceeds 65%, the corrosion resistance deterioration of the sprayed portion cannot be ignored. In order to increase the adhesion of the sprayed part and further increase its strength, it is preferable to contain 0.5 or more in the magnesium alloy sprayed material.

Total amount of Al and Zn:
If the total amount of Al and Zn exceeds 78%, the remaining Mg is reduced, resulting in a problem that the effect of improving the corrosion resistance of the sprayed portion due to Mg, which will be described later, is reduced. Therefore, the upper limit of the total amount of Al and Zn is set to 78%. Is preferred. Further, from this point, it is more preferable that the upper limit of the total amount of Al and Zn is 42%.

Total amount of Al, Ca and Zn:
If the total amount of Al, Ca, and Zn exceeds 79%, the remaining Mg is reduced, and the effect of improving the corrosion resistance of the sprayed portion due to Mg, which will be described later, decreases, so the upper limit of the total amount of Al, Ca, and Zn is 79%. And
Moreover, in order to increase Mg which contributes to the corrosion resistance of the balance and further enhance the corrosion resistance improvement effect of the sprayed portion with Mg, the upper limit of the total amount of Al, Ca and Zn is preferably 47%.

  Si: Si has an effect of improving the corrosion resistance of the sprayed portion, particularly in a corrosive environment having a high basicity, and can be contained at 10% or less. When the content exceeds 10%, the degree of decrease in ductility of the sprayed portion is large. In order to dramatically improve the corrosion resistance of the magnesium alloy sprayed material by the action of Si, the Si content is preferably set to 2.0 or more. On the other hand, if the Si content in the magnesium alloy sprayed material exceeds 8%, the brittleness of the sprayed portion cannot be ignored, so the upper limit of the content is preferably 8%.

  Mn: Mn removes Fe or the like that enters by diffusion or the like when iron is contained in the material to be sprayed or the material to be sprayed, for example, when a corrosion resistant coating is formed on the surface of the steel material with a magnesium alloy sprayed material. It is an effective element and can be contained at 4% or less. When the content exceeds 4%, the degree of decrease in ductility of the sprayed portion is large. This effect becomes remarkable when 0.1 or more Mn is contained in the magnesium alloy sprayed material. Therefore, the Mn content is preferably 0.1% or more. On the other hand, if the Mn content exceeds 2% in the magnesium alloy sprayed material, the brittleness of the sprayed part cannot be ignored, so the upper limit of the Mn content is preferably 2%.

  The form (shape) of the magnesium alloy sprayed material of the present invention is preferably a wire or powder generally used as a sprayed material.

  When the form of the magnesium alloy thermal spray material is a wire, the wire diameter of the thermal spray wire is φ0.8 to 2.0 mm in order to perform thermal spraying using a normal wire thermal sprayer without changing the nozzle diameter of the thermal sprayer. It is preferable that

  In the case of producing a thermal spray wire, since the strength of the material increases as the amount of Al added increases, the wire workability decreases. Therefore, it is preferable to perform warm processing in order to improve the wire workability.

  The method for producing the thermal spray wire from the magnesium alloy material is not particularly limited. For example, a bulk material having a diameter of 30 to 50 mm is once extruded to be formed into a diameter of 4 to 12 mm, and then drawn warmly (300 ° C. or less). By processing, a magnesium alloy spray wire of φ0.8 to 2.0 mm can be produced.

  When the magnesium alloy thermal spray material is in the form of powder, if the particle size of the thermal spray powder is less than 20 μm, the supply of the powder during thermal spraying is reduced and dust explosion during thermal spraying is likely to occur. Therefore, it is preferable to set it as 20 micrometers or more. On the other hand, if the particle size of the thermal spray powder exceeds 400 μm, the thermal capacity of the thermal spray powder becomes large and it becomes difficult to melt to the inside of the particle, so the upper limit of the particle size of the thermal spray powder is preferably 400 μm.

  The method for producing the thermal spray powder from the magnesium alloy material is not particularly limited. For example, the raw material melted in the molten metal in a vacuum is discharged from a hole having a diameter of several millimeters, and an inert gas is discharged from the nozzle here. A method of spraying and atomizing (gas atomization) or the like is used.

  In the case where the magnesium alloy spray material of the present invention is any of the above-mentioned wire and powder, the surface of the sprayed material is sprayed using this to form a sprayed layer having excellent corrosion resistance on the surface of the sprayed material. It can be formed without the danger of explosion.

  After manufacturing welded structures, molded products, cast products, etc. using materials with good weldability, workability, and castability, corrosion resistance is applied to these surfaces by the thermal spraying method using the magnesium alloy thermal spray material of the present invention. By forming an excellent thermal sprayed layer, it is possible to manufacture welded structures, molded products, and cast products that are compatible with material properties and corrosion resistance at low cost and high productivity.

  In particular, since the plated layer disappears or deteriorates due to welding heat input in the welded part after pipe forming using a Zn-plated steel sheet or a Zn alloy-based plated steel sheet, the welded part is sprayed using the magnesium alloy sprayed material of the present invention. In addition, the corrosion resistance of the welded steel pipe product can be improved by forming a sprayed layer having excellent corrosion resistance on the surface of the welded portion.

  In addition, when the surface of a welded structure or molded product using a Zn-plated steel sheet or a Zn alloy-based plated steel sheet deteriorates or is damaged in the usage environment, the corrosion resistance of the deteriorated or damaged part is improved. As the repair method, the thermal spraying method using the magnesium alloy thermal spray material of the present invention can be applied.

  An embodiment of a method for spraying the surface of a sprayed material using the magnesium alloy sprayed material of the present invention can be performed as follows, for example.

  For example, using a plasma spray gun (made by PRAXAIR, MODEL2086A, argon + hydrogen plasma + argon shield gas), the spraying material supply rate is 5-30 g / min, the spraying distance is 100-300 mm, and plasma spraying is performed on the substrate surface. A film having a predetermined thickness can be formed by scanning the gun. As the thermal spraying method of the present invention, a thermal spraying method for melting a thermal spray wire or thermal spray powder using a heat source such as a plasma jet, a fuel combustion flame, or an electric arc can be applied.

  In addition, as a special spraying method, it is also possible to spray the molten metal in the magnesium alloy bath (hereinafter referred to as molten metal) in addition to the above-mentioned sprayed wire and sprayed powder directly onto the sprayed body (Ospray type). . This lowers the processing cost of the material, so the running cost can be suppressed compared to the wire or powder material (however, the equipment cost becomes higher).

  Next, the effects of the present invention will be described using examples. In addition, the conditions of the Example shown below are one conditions employ | adopted in order to confirm the feasibility and effect of this invention, and are not limited only to the following conditions. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

  Spraying is performed using a plasma spray gun (PRAXAIR, MODEL 2086A, argon + hydrogen plasma + argon shield gas), the spraying material supply rate is 15 g / min, the spraying distance is 200 mm, and the plasma spray gun is scanned over the substrate surface. As a result, thermal spraying was performed at a film formation thickness of about 500 μm. The substrate is made of SS400 or AZ612 alloy (6% Al, 1% Zn, 2% Ca, remaining Mg), and is cut into a size of 20 mm thickness x 500 mm length x 100 mm width. did.

  Thermal spray powder with a particle size of 20 to 80 μm was used as the thermal spray material, and the melting point (solid phase line, liquid phase line) and ignition temperature of the thermal spray powder were measured and evaluated with a differential thermometer to examine dust explosion (sprayability). . In the evaluation of dust explosion (sprayability), spraying is impossible when the measured value of the ignition temperature of the sprayed material is lower than the measured value of the melting point, and spraying is possible when the measured value is higher than the melting point. However, since the solidus line and liquidus line of the alloy are different, here, when the measured value of the ignition temperature is higher than the liquidus line, thermal spraying is easy (◎), and the measured value of the ignition temperature is the liquidus line and solid phase. In the case of between the lines, thermal spraying is possible because the thermal spray material can be partially melted (○), and when the ignition temperature is lower than the solidus, thermal spraying is not possible ( X).

  The ductility of the coating is evaluated by forming a coating of 0.5 mm on a SS400 material having a thickness of 2 mm, producing a test piece of 1/5 size of a JIS No. 13 B test piece, and conducting a tensile test using this. did.

  In addition, the corrosion resistance of the sprayed coating is evaluated with a salt spray test (SST test: JIS standard Z2371) that has 80% or more of the corrosion resistance of AZ612 alloy (for repairing magnesium alloy or for surface modification of steel materials) Therefore, it is not always necessary to show corrosion resistance of 100% or more), 50% or more is ○, 30% or more is △, and less than 30% is × (all coatings are protective coatings of SS400 material) Although there was an effect of corrosion resistance, the effect cost was almost the same as the order of ◎ to ×).

  Table 1 shows the component content of the magnesium alloy spray material, the dust explosion (sprayability) and the evaluation results of the sprayed coating when spraying using this.

  In the table, 1 to 7 are comparative examples, and 8 to 28 are invention examples.

  No. The comparative example 1 was pure Mg, and the Al content and the Ca content deviated from the lower limits specified in the present invention, so that a dust explosion occurred and thermal spraying was impossible.

  No. In Comparative Example 2, since the Al content and the Ca content deviate from the lower limits defined in the present invention, a dust explosion occurred and the result was that spraying was impossible.

  No. In Comparative Example 3, the Al content is 32%, which is within the range defined by the present invention, but the Ca content is 0.5%, which deviates from the lower limit defined by the present invention. As a result, thermal spraying was impossible.

  No. In Comparative Example 4, since the Ca content was 21% and deviated from the upper limit specified in the present invention, the corrosion resistance was not suitable.

No. In Comparative Example 5, the Mg content was 18%, but the Ca content deviated from the lower limit defined in the present invention (Ca was not contained), so a dust explosion occurred.

  No. In Comparative Examples 6 and 7, the total amount of Al + Zn + Ca was 82%, exceeding the upper limit defined in the present invention, and the corrosion resistance was unacceptable.

  No. The invention examples of 8 to 14 have a Ca content of 5% and are within the range defined by the present invention, and each Al content is also within the range defined by the present invention, so the explosion resistance during thermal spraying is improved. Good thermal spraying is possible and the corrosion resistance of the thermal spray coating is also good. In particular, no. In the invention example of 8, the composition range of the eutectic region of Al—Mg is the lowest, the liquidus is the lowest, and the risk of dust explosion is the lowest. However, the corrosion resistance gradually decreases as the Al content increases.

  No. 15 invention examples have a Ca content of 1% and an Al content of 33%, both of which are within the range specified in the present invention, so that the explosion resistance during thermal spraying is improved and good thermal spraying is possible. The corrosion resistance of the thermal spray coating is also good.

  No. Inventive Example No. 16 In contrast to the eleventh invention example, 4% of Zn is contained in the thermal spray material, and the explosion resistance during thermal spraying and the corrosion resistance of the thermal spray coating are good.

  No. The invention example of No. This is an example in which 40% of Zn is contained in the thermal spray material with respect to the eleventh invention example, the explosion-proof property and adhesion at the time of thermal spraying are good, and the corrosion resistance of the thermal spray coating is relatively good.

  No. The 18th invention example is No. 8 is an example in which a part of Al in the thermal spray material is replaced with Zn and 59% of Zn is contained, and the explosion resistance and adhesion at the time of thermal spraying are good, and the corrosion resistance of the thermal spray coating is relatively It is good.

  No. The 19th invention example is No. Although it is an example in which 1% of Si is contained in the thermal spray material with respect to the invention example of 10, the corrosion resistance of the thermal spray coating is No. 1 because it deviates from the lower limit of the preferable Si content. It was about the same as 10.

  No. No. 20 has a Si content of 10%, which deviates from the preferable upper limit of the Si content, and the ductility of the sprayed coating is reduced, but the explosion-proof property during spraying and the corrosion resistance of the sprayed coating are good.

  No. No. 21 has a Mn content of 4% and deviates from the preferable upper limit of the Mn content. Therefore, the ductility of the sprayed coating is lowered, but the explosion resistance during spraying and the corrosion resistance of the sprayed coating are good.

  No. 22-23 is the range which Zn quantity prescribes | regulates by this invention, and a film strength can improve rather than No. 10.

  No. Nos. 24 to 25 are within the range defined by the present invention in the amount of Si. Corrosion resistance in an environment having a basicity higher than 10 can be increased.

  Nos. 26 to 27 have a Mn content within the range defined in the present invention, and the corrosion resistance when impurities are contained is No. 26. Can be higher than 10.

  No. No. 28 contains all elements of Zn, Si and Mn, and these are all within the preferred range of the present invention, so that the corrosion resistance is No. 28. It can be expected to improve over 10 materials.

As described above, according to the present invention, repair of a magnesium alloy and surface modification of a steel material in various halogen gas environments can be provided at low cost.
Therefore, this invention expands the use as a raw material for motor vehicles, steel pipes, building materials, home appliances, computers, and other equipment / machines, and has great industrial applicability.

The addition amount conceptual diagram of Al and Ca of this invention is shown.

Claims (10)

  Thermal spraying characterized by containing Al: 13 to 78% and Ca: 1 to 5% in mass%, the total amount of Al and Ca being 79% or less, and the balance being composed of Mg and inevitable impurities Magnesium alloy sprayed material with excellent explosion resistance and corrosion resistance of the sprayed part.   Further, the composition contains, by mass%, Zn: 65% or less, the total amount of Al and Zn is 78% or less, and the total amount of Al, Ca and Zn is 79% or less. 1. Magnesium alloy sprayed material having excellent explosion-proof properties during spraying and corrosion resistance of the sprayed portion.   Thermal spraying characterized by containing Al: 13 to 42% and Ca: 1 to 5% by mass%, the total amount of Al and Ca being 47% or less, and the balance being composed of Mg and inevitable impurities Magnesium alloy sprayed material with excellent explosion resistance and corrosion resistance of the sprayed part.   Further, the composition contains, in mass%, Zn: 65% or less, the total amount of Al and Zn is 42% or less, and the total amount of Al, Ca, and Zn is 47% or less. 3. Magnesium alloy spray material excellent in explosion-proof property during spraying and corrosion resistance of the sprayed portion.   Thermal spraying characterized by containing Al: 42 to 78% and Ca: 1 to 5% in mass%, the total amount of Al and Ca being 79% or less, and the balance being Mg and inevitable impurities Magnesium alloy sprayed material with excellent explosion resistance and corrosion resistance of the sprayed part.   Further, the composition contains, by mass%, Zn: 65% or less, the total amount of Al and Zn is 78% or less, and the total amount of Al, Ca and Zn is 79% or less. 5. A magnesium alloy sprayed material having excellent explosion-proof properties during spraying and corrosion resistance of the sprayed portion.   Furthermore, the magnesium alloy thermal spray material excellent in the explosion-proof property at the time of thermal spraying and the corrosion resistance of the thermal spray part according to any one of claims 1 to 6, characterized by containing Si: 10% or less in mass%.   Furthermore, the magnesium alloy thermal spray material excellent in the explosion-proof property at the time of thermal spraying and the corrosion resistance of the thermal spray part according to any one of claims 1 to 7, characterized by containing Mn: 4% or less.   The said thermal spray material is a wire or powder, The magnesium alloy thermal spray material excellent in the explosion-proof property at the time of thermal spraying, and the corrosion resistance of the thermal spray part.   A thermal spraying method having excellent explosion resistance at the time of thermal spraying and excellent corrosion resistance of the thermal sprayed portion, wherein the surface of the thermal sprayed material is thermally sprayed using the magnesium alloy thermal spray material according to any one of claims 1 to 9.

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