JP5070920B2 - Overlay wear-resistant iron-base alloy - Google Patents

Description

  The present invention relates to a built-up wear-resistant iron-based alloy. The overlay wear-resistant iron-based alloy of the present invention can be applied to, for example, a sliding material.

  Conventionally, as a build-up wear-resistant alloy, a copper-based alloy mainly composed of copper or an iron-based alloy mainly composed of iron is known.

  As a build-up wear-resistant copper-based alloy, for example, in Patent Document 1, by weight%, nickel: 5.0-20.0%, silicon: 0.5-5.0%, manganese: 3.0-30. Cu-Ni-Mn based alloy containing 0% and element that forms Laves phase by combining with manganese and forms silicide: 3.0 to 30.0% and unavoidable impurities, with the balance being copper Is described.

  On the other hand, as a build-up wear-resistant iron-based alloy, for example, in Patent Document 2, by weight%, chromium: 30-40%, nickel: 15-31%, molybdenum: 7-20%, carbon: 0.7-2 Fe-Cr-Ni alloys containing 2%, silicon: 1.5% or less and inevitable impurities with the balance being iron are described.

  A copper-based alloy has a melting point as low as about 400 ° C. as compared with an iron-based alloy, and therefore has low heat resistance and low wear resistance in a high temperature region. For this reason, there has been a limit from the viewpoint of high-temperature wear characteristics, for example, to apply a copper-based alloy as a build-up material for a valve seat part of an automobile engine cylinder head.

On the other hand, an iron-based alloy is advantageous in improving wear resistance in a high temperature region as compared with a copper-based alloy. However, iron-based alloys are less self-lubricating than copper-based alloys. Further, hard particles made of chromium carbide, molybdenum carbide, or the like dispersed in the iron-based matrix attack the sliding counterpart member. For this reason, for example, when an iron-based alloy is used as a build-up material for a valve seat portion of an automobile engine cylinder head, there is a problem that the amount of wear of an engine valve as a counterpart member increases.
JP 2005-256147 A Japanese Patent Laid-Open No. 2-17797

  By the way, in recent years, the overlay wear resistant alloy is being used in various environments, and the use conditions are becoming more severe. Particularly in the automobile industry, exhaust gas screen regulations are becoming stricter, and in order to cope with this, the combustion temperature is increased due to the dilution of fuel. For this reason, in automotive sliding parts, the requirement for wear resistance in a high temperature region has become more severe.

  Therefore, in the industry, particularly in the automobile industry, there is a demand for a built-up wear-resistant alloy that is further superior in wear resistance to the built-up wear-resistant alloy described in the above publication.

  This invention is made | formed in view of the above-mentioned situation, and it aims at improving the wear resistance in a high temperature area | region, and providing a built-up wear-resistant iron-base alloy which aimed at the fall of the other party aggression property. .

  1st invention specifies the build-up wear-resistant iron-base alloy of this invention from a composition surface. That is, the build-up wear-resistant iron-based alloy according to the first invention is an iron-based alloy containing iron as a main component, and is two-phase separated from iron in a liquid phase state and in an iron-based matrix in a solid phase state. It includes copper added at a blending ratio dispersed in a particulate form, a Laves phase particle-forming element that forms a Laves phase by combining with iron and forms a particulate silicide, nickel, and silicon. To do.

  The Laves phase particle forming element is preferably at least one selected from the group consisting of molybdenum, tungsten, and vanadium.

  The build-up wear-resistant iron-based alloy according to the first invention is, in mass%, iron: 50% or more, copper: 12.5 to 26.0%, Laves phase particle forming element: 8.0 to 10.0%, It is preferable to contain nickel: 8.0 to 10.0% and silicon: 2.0 to 2.5%.

  The build-up wear-resistant iron-based alloy according to the first invention preferably further contains niobium and carbon. These elements are preferably contained by mass%, containing niobium: 0.7 to 1.3% and carbon: 0.07 to 0.13%.

  2nd invention specifies the build-up wear-resistant iron-base alloy of this invention from the surface of a structure | tissue. That is, the build-up wear-resistant iron-based alloy according to the second invention is an iron-based alloy containing iron as a main component, an iron-based matrix containing iron as a main component, and dispersed in the iron-based matrix. And a hard Laves phase particle made of silicide having a Laves phase dispersed in the copper particle.

  The iron-based matrix preferably includes a Fe—Ni-based solid solution and a Fe—Ni-based silicide as main elements.

  The hard Laves layer particles are preferably made of at least one selected from the group consisting of Fe—Mo based silicide, Fe—W based silicide and Fe—V based silicide.

  The build-up wear-resistant iron-based alloy according to the second invention is dispersed in the copper particles, and hard carbide particles made of at least one selected from the group consisting of niobium carbide, molybdenum carbide, and composite carbide of niobium and molybdenum. Furthermore, it is preferable to provide.

  In the built-up wear-resistant iron-based alloy of the present invention, high wear resistance can be ensured even in a high temperature region by an iron-based matrix mainly composed of iron having higher heat resistance than copper.

  Moreover, the copper added in the compounding ratio which is separated into two phases from iron in the liquid phase state and dispersed in the iron base matrix in the solid phase is dispersed as copper particles in the iron base matrix. The copper particles dispersed in the iron-based matrix have a lower hardness than the iron-based matrix. That is, in the overlay wear-resistant iron-based alloy of the present invention, soft copper particles are dispersed in a hard iron-based matrix.

  Here, a Laves phase particle forming element such as molybdenum, tungsten, or vanadium forms a Laves phase by combining with iron and forms silicide by combining with silicon. The hard Laves phase particles made of silicide having the Laves phase thus formed enhance the wear resistance at high temperatures. And in the build-up wear-resistant iron-based alloy of the present invention, the hard Laves phase particles are dispersed not in the hard iron-based matrix but in the soft copper-based particles.

  Thus, in the build-up wear-resistant iron-based alloy of the present invention, soft copper particles are dispersed in a hard iron-based matrix, and hard Laves phase particles are dispersed in the soft copper particles. According to such a structure, as shown in the data of the examples described later, for example, a conventional overlay wear-resistant iron-based alloy in which hard particles harder than the iron-based matrix are dispersed in a hard iron-based matrix. Compared to, the wear resistance at high temperature is high and the opponent attack is low.

  In the present specification, unless otherwise specified,% means mass%. Moreover, in the build-up wear-resistant iron-based alloy of the present invention, the remaining iron mass% obtained by subtracting the total amount of additive elements from 100 mass% exceeds the individual mass% of each additive element.

  Therefore, according to the build-up wear-resistant iron-based alloy of the present invention, it is possible to further improve the wear resistance in the high temperature region and reduce the opponent attack.

  The build-up wear-resistant iron-based alloy of the present invention is an iron-based alloy containing iron as a main component, and has a composition containing copper, Laves phase particle forming elements, nickel, and silicon. Further, the overlay wear-resistant iron-based alloy of the present invention includes an iron-based matrix mainly composed of iron, dispersed in the iron-based matrix, copper particles mainly composed of copper, and dispersed in the copper particles. And a structure having hard Laves phase particles made of silicide having Laves phase.

  The iron-based matrix has iron as a main component, and can be formed with a Fe—Ni-based solid solution and a Fe—Ni-based silicide as main elements. Fe-Ni-based silicide is a columnar eutectic component and contributes to the improvement of buildup.

  In the build-up wear-resistant iron-based alloy of the present invention, copper is added in such a blending ratio that it is two-phase separated from iron in the liquid phase and is dispersed in the form of particles in the iron-based matrix in the solid phase. That is, copper is dispersed as copper particles in the iron matrix.

  The blending ratio of copper is preferably 12.5 to 26.0%, preferably 12.5 to 26.0% when the entire build-up wear-resistant iron-based alloy of the present invention is taken as 100%. % Is more preferable, and 12.5 to 15.0% is particularly preferable. When there are too few compounding ratios of copper, the copper particle disperse | distributed in an iron-base matrix will run short. Insufficient copper particles dispersed in the iron-based matrix reduces the Laves phase and drastically reduces the lubricating wear properties. On the other hand, when there are too many compounding ratios of copper, copper will not be disperse | distributed in a particulate form in an iron-based matrix, but will become a lump and homogeneously separate. When copper is homogeneously separated in the iron matrix, copper and iron are largely separated, and the dispersion effect disappears.

  The size of the copper particles dispersed in the iron-based matrix is influenced by the composition and solidification rate of the build-up wear-resistant iron-based alloy, but is preferably about 30 to 1000 μm, and about 50 to 250 μm. More preferably. If the copper particles are too large, the heat resistance is insufficient, and conversely if the copper particles are too small, the lubricity is insufficient.

  The Laves phase particle-forming element combines with iron to form a Laves phase and forms a particulate silicide, thereby generating hard Laves phase particles made of silicide having a Laves phase. The hard Laves phase particles are dispersed in copper particles dispersed in an iron-based matrix. The hard Laves phase particles are higher in hardness than the iron-based matrix.

  The type of Laves phase particle-forming element is particularly selected as long as it forms hard Laves phase particles made of silicide having Laves phase by forming Laves phase by combining with iron and forming particulate silicide. Although not limited, it is preferably at least one selected from the group consisting of molybdenum, tungsten and vanadium.

  The blending ratio of the Laves phase particle forming element is preferably 8.0 to 10.0% when the entire build-up wear-resistant iron-based alloy of the present invention is 100%. When the mixing ratio of Laves phase particle forming elements is too small, the hard Laves phase particles dispersed in the copper particles are insufficient, and the effect of increasing the wear resistance at high temperatures is lowered. On the other hand, when the mixing ratio of Laves phase particle forming elements is too large, the toughness of the build-up wear-resistant iron-based alloy becomes low, and cracking is likely to occur when building up on an object.

  Nickel is mainly present in the iron-based matrix and forms an Fe—Ni-based solid solution or Fe—Ni-based silicide.

  The mixing ratio of nickel is preferably 8.0 to 10.0% when the entire build-up wear-resistant iron-based alloy of the present invention is defined as 100%. When the mixing ratio of nickel is too small, the heat resistance is lowered, and the effect of increasing the wear resistance at high temperatures is lowered. On the other hand, if the proportion of nickel is too large, the toughness of the build-up wear-resistant iron-based alloy becomes low, and cracking is likely to occur when depositing on an object.

  Silicon is present in an iron-based matrix to form a Fe—Ni-based silicide, or silicon is present in copper particles to be Fe—Mo-based silicide, Fe—W-based silicide and / or Fe—V-based. The silicide is formed.

  The blending ratio of silicon is preferably 2.0 to 2.5% when the entire build-up wear-resistant iron-based alloy of the present invention is 100%. If the blending ratio of silicon is too small, the Laves phase is insufficient, and the effect of increasing the wear resistance at high temperatures is reduced. On the other hand, if the blending ratio of silicon is too large, a large amount of silicide is crystallized, the toughness of the built-up wear-resistant iron-based alloy is lowered, and cracking is likely to occur when building up on an object.

  The overlay wear-resistant iron-based alloy of the present invention preferably has a composition further containing niobium and carbon. Niobium and carbon together with molybdenum produce hard carbide particles composed of at least one selected from the group consisting of niobium carbide, molybdenum carbide, and composite carbide of niobium and molybdenum. The hard carbide particles are dispersed in the copper particles dispersed in the iron-based matrix, like the hard Laves phase particles. That is, the build-up wear-resistant iron-based alloy of the present invention is selected from the group consisting of niobium carbide, molybdenum carbide, and composite carbide of niobium and molybdenum dispersed in copper particles by adding niobium and carbon. It is preferable to further include at least one kind of hard carbide particles. Thereby, the wear resistance at high temperatures can be further increased. The hard carbide particles are higher in hardness than the iron-based matrix.

  The mixing ratio of niobium is preferably 0.7 to 1.3% when the entire build-up wear-resistant iron-based alloy of the present invention is 100%. When the mixing ratio of niobium is too small, the hard carbide particles dispersed in the copper particles are insufficient, so that the effect of increasing the wear resistance at high temperatures is lowered. On the other hand, when the mixing ratio of niobium is too large, a large amount of niobium carbide is crystallized, the toughness of the built-up wear-resistant iron-based alloy is lowered, and cracking is likely to occur when building up on an object.

  The blending ratio of carbon is preferably 0.07 to 0.13% when the entire build-up wear-resistant iron-based alloy of the present invention is 100%. When the blending ratio of carbon is too small, the hard carbide particles dispersed in the copper particles are insufficient, and the effect of increasing the wear resistance at high temperatures is reduced. On the other hand, when the mixing ratio of carbon is too large, a large amount of carbides are crystallized, the toughness of the build-up wear-resistant iron-based alloy is lowered, and cracking is likely to occur when building up on the object.

  The size of the hard carbide particles is influenced by the composition and solidification rate of the build-up wear-resistant iron-based alloy, but is preferably about 5 to 750 μm, and more preferably about 10 to 350 μm. If the hard carbide particles are too large, cracks are likely to be induced. Conversely, if the hard carbide particles are too small, the effect of increasing wear resistance at high temperatures is reduced.

  The build-up wear-resistant iron-based alloy of the present invention undergoes two-liquid phase separation between iron and copper in the melt state. Further, in the melt state, Laves phase particle forming elements, nickel and silicon are each in one layer. When niobium and carbon are added, niobium and carbon are in a single layer in the melt state. And a particle | grain is formed from a liquid phase by cooling and solidifying from a melt state. In this cooling and solidification process from the melt state, first, hard Laves phase particles are formed (when niobium and carbon are added, hard carbide particles are also formed almost simultaneously), and then iron is cooled and solidified. The iron matrix is formed, and the liquid phase of copper is dispersed in the iron matrix (the hard Laves phase particles and hard carbide particles generated earlier are present in this copper liquid phase), and finally It is thought that copper particles containing hard Laves phase particles and hard carbide particles are formed by cooling and solidifying the liquid phase of copper. When the iron matrix is formed, the hard Laves phase particles and carbide particles are not taken into the iron matrix and are present in the copper liquid phase because of the formation ability (energy of formation tendency). .

  The build-up wear-resistant iron-based alloy of the present invention can employ at least one of the following embodiments.

  The build-up wear-resistant iron-based alloy of the present invention is used as a build-up alloy built on an object. Examples of the overlaying method include a method of depositing by welding using a high-density energy heat source such as a laser beam, an electron beam, or an arc. In this case, the build-up wear-resistant iron-based alloy of the present invention is used as a material for build-up as a powder or a bulk body, and the above-described laser beam, electron, and the like are assembled in the build-up portion. It can be welded and deposited using a heat source typified by a high-density energy heat source such as a beam or an arc. Moreover, the above-described build-up wear-resistant iron-based alloy is not limited to a powder or a bulk body, and may be a material for building-up that is formed into a wire or a rod. Examples of the laser beam include those having a high energy density such as a carbon dioxide laser beam and a YAG laser beam. Examples of the material of the object to be built up include aluminum, an aluminum-based alloy, iron, an iron-based alloy, copper, a copper-based alloy, and the like, but are not limited thereto. Examples of the basic composition of the aluminum alloy constituting the object include aluminum alloys for casting, such as Al—Si, Al—Cu, Al—Mg, and Al—Zn, but are not limited thereto. It is not a thing. Examples of the object include engines such as an internal combustion engine and an external combustion engine, but are not limited thereto. In the case of an internal combustion engine, valve system materials are exemplified. In this case, the present invention may be applied to a valve seat that constitutes an exhaust port, or may be applied to a valve seat that constitutes an intake port. In this case, the valve seat itself may be composed of the built-up wear-resistant iron-based alloy according to the present invention, or the build-up wear-resistant iron-based alloy according to the present invention may be built up on the valve seat. good. However, the build-up wear-resistant iron-based alloy according to the present invention is not limited to the valve train material of an engine such as an internal combustion engine, but to other types of sliding build-up materials that require wear resistance. Can also be used.

  Moreover, as the build-up wear-resistant iron-based alloy according to the present invention, a build-up layer after build-up may be formed, or a build-up alloy before build-up may be used.

  Examples of the present invention will be specifically described below.

(Example)
Table 1 shows the composition (analytical composition) of the sample according to the build-up wear-resistant iron-based alloy of the examples. The analytical composition is basically consistent with the formulation composition. The composition of the sample according to the build-up wear-resistant iron-based alloy of the example includes copper, molybdenum, nickel, silicon, niobium and carbon, and the balance is made of iron. As shown in Table 1, iron: 50% or more , Copper: 12.5 to 26.0%, molybdenum as Laves phase particle forming element: 8.0 to 10.0%, nickel: 8.0 to 10.0%, silicon: 2.0 to 2.5 %, Niobium: 0.7 to 1.3%, and carbon: 0.07 to 0.13%.

  That is, the composition of the examples is as follows: iron: balance (52.7%), copper: 25.0%, molybdenum as Laves phase particle forming element: 9.0%, nickel: 9.0%, silicon: 2. 3%, niobium: 1.0%, carbon: 0.1%.

  The sample is a powder having a particle size of 5 μm to 300 μm manufactured by gas atomizing a molten alloy melted in a high vacuum. This gas atomization treatment was performed by ejecting a high-temperature molten metal from a nozzle into a non-oxidizing atmosphere (argon gas or nitrogen gas atmosphere). The powder formed by the gas atomization process has high component uniformity.

  And the base | substrate formed with the aluminum alloy (material: AC2C) which is a build-up target object was prepared, and the said sample (powder form) was mounted on the build-up part of the base | substrate, and the sample layer was formed. In this state, while blowing shield gas (argon gas) from the gas supply pipe to the build-up location, the laser beam of the carbon dioxide laser is swung by the beam oscillator, and the laser beam and the substrate are moved relative to each other. The sample layer was irradiated with a laser beam. At this time, the laser beam was swung in the width direction of the sample layer by a beam oscillator. In this irradiation treatment, the laser output of the carbon dioxide laser is 3.5 kW, the spot diameter of the laser beam on the sample layer is 1.0 mm, the relative traveling speed between the laser beam and the substrate is 15 mm / sec, and the shielding gas flow rate Was 10 liters / min. Thereafter, the sample was melted and solidified to form a build-up layer (build-up thickness: 1.8 mm, build-up width: 5.5 mm) on the build-up portion of the substrate.

(Microscopic observation)
About the built-up layer formed in this way, the built-up structure | tissue was observed with the microscope. As the micrograph (100 times) is shown in FIG. 1, the copper particles were uniformly dispersed throughout the iron-based matrix. The particle size of the copper particles was about 20 to 100 μm. The hard Laves phase particles and the hard carbide particles were dispersed not in the iron matrix but in the copper particles. The fact that the hard Laves phase particles and the hard carbide particles are dispersed not in the iron matrix but in the copper particles can be confirmed by observation with a magnified microscope. Moreover, the particle size of the hard carbide particles was about 5 to 50 μm.

  Moreover, the above-mentioned build-up structure | tissue was investigated with the EPMA analyzer. As a result, the iron-based matrix was formed mainly with Fe-Ni-based solid solution and network Fe-Ni-based silicide having nickel as a main component. Further, the hard Laves phase particles dispersed in the copper particles were made of Fe-Mo based silicide. Further, the hard carbide particles dispersed in the copper particles were composed of niobium carbide, molybdenum carbide, and composite carbide of niobium and molybdenum.

  Furthermore, when the above-mentioned build-up structure was examined with an X-ray diffraction analyzer, it was confirmed that the Fe-Mo-based silicide that is the hard Laves phase particles dispersed in the copper particles was Laves phase.

(Comparative Example 1)
As shown in Table 1 together with the composition of the sample according to the overlay wear-resistant iron-based alloy of Comparative Example 1, the composition of Comparative Example 1 contains chromium instead of copper in the composition of the example, and molybdenum and nickel. , Silicon, niobium and carbon, with the balance being iron. This sample corresponds to the conventional material (building-up wear-resistant iron-based alloy) described in Patent Document 2.

  That is, the composition of Comparative Example 1 is iron: remainder (32.5%), chromium: 35.0%, molybdenum: 10.0%, nickel: 20.0%, silicon: 1.0%, carbon: 1 .5%.

  The said sample is the powder manufactured by the gas atomizing process similar to an Example.

(Comparative Example 2)
As shown in Table 1, the composition of the overlay wear-resistant copper-based alloy of Comparative Example 2 is shown in Table 1. The composition of Comparative Example 2 includes nickel, cobalt, molybdenum, iron, silicon, and chromium, with the balance being copper. It becomes more. This sample corresponds to a build-up wear-resistant copper-based alloy of a conventional material (model: CuLS50).

  That is, the composition of Comparative Example 2 is as follows: balance: copper (%), nickel: 15.0%, cobalt: 7.0%, molybdenum: 6.0%, iron: 5.0%, silicon: 2.8% , Chromium: 1.5%.

  The said sample is the powder manufactured by the gas atomizing process similar to an Example.

(Comparative Example 3)
As shown in Table 1 together with the composition of the sample of Comparative Example 3, the sample of Comparative Example 3 is an iron-based sintered material. The composition of Comparative Example 3 is as follows: Fe: balance, Co: 7.5 to 10.5%, Mo: 5.0 to 8.0%, Ni: 5.0 to 6.0%, C: 0.25 -0.50%.

(Abrasion test)
For each build-up layer formed using the sample related to the build-up wear-resistant iron-based alloy of the example and the samples of Comparative Examples 1 to 3, a wear test was performed to examine the wear amount.

  In this wear test, as shown in FIG. 2, a build-up layer 11 was formed on the surface of a thick disc-shaped test piece 10 made of a valve seat material (aluminum alloy AC2C) using each sample. And the test piece 10 in which this build-up layer 11 was formed was hold | maintained at the 1st holder 12. FIG. On the other hand, a cylindrical mating member 20 made of a valve material (the surface of a JIS-SUE3 equivalent material is coated with a JIS-SUH35 equivalent material) is prepared, and an induction coil 21 is wound around the outer periphery of the mating material 20 Two holders 22 were held. Then, the mating material 20 was rotated while being induction-heated by the induction coil 21, and the test was performed by pressing the shaft end surface of the mating material 20 against the build-up layer 11 of the test piece 10. As test conditions, the load was 563.5 kPa, the friction sliding speed was 0.3 m / sec, the friction time was 1800 sec, and the surface temperature of the test piece 10 was 250 to 400 ° C.

  Then, the wear amount of the built-up layer 11 and the counterpart material 20 after the friction test was examined. As shown in FIG. 3, in the build-up layer formed with the sample according to the example, the valve seat wear amount (wear amount of the build-up layer 11) is the sample according to Comparative Example 1 (conventional material: Fe Compared with the base alloy), it was greatly reduced. Further, in the built-up layer formed with the sample according to the example, the valve wear amount (wear amount of the counterpart material 20) is reduced to the same level or lower than that of the sample according to Comparative Example 2 (conventional material: Cu-based alloy). did.

(Effect / influence of Cu content)
In the composition of the example, the blending ratio of additive components other than copper is Fe: balance, Mo: 9.0%, Ni: 9.0%, Si: 2.3%, Nb: 1.0%, C: 1 Samples with various changes in the blending ratio of copper were prepared while being fixed at 0.0%.

  And the overlaying layer was formed in the surface of the base | substrate which consists of aluminum alloys (material: AC2C) by the method similar to an Example using each sample.

  About the obtained build-up layer, particle | grain dispersion rate (when the whole build-up layer was made into 100 volume%), the volume ratio of the copper particle which occupies for the build-up layer was investigated.

  As shown in FIG. 4 and FIG. 5, if the copper content in the build-up wear-resistant iron-based alloy is in the range of 12.5 to 26.0%, the particle dispersion rate of the copper particles is 2 Within the range of 0.5 to 24.5% by volume, the copper particles were uniformly dispersed in the iron-based matrix in the build-up layer. On the other hand, when the mixing ratio of copper in the build-up wear-resistant iron-based alloy was less than 12.5%, there were very few copper particles dispersed in the iron-based matrix. Moreover, when the compounding ratio of copper in the build-up wear-resistant iron-based alloy exceeded 26.0%, the copper was not dispersed in the form of particles in the iron-based matrix but became a lump and homogeneously separated.

  FIG. 5 is a cross-sectional view schematically showing the dispersion state of the copper particles in the built-up layer, and (a) is a schematic cross-sectional view when the proportion of copper in the built-up wear-resistant iron-based alloy is 5%. , (B) is a schematic cross-sectional view when the proportion of copper in the built-up wear-resistant iron-based alloy is 20%, and (c) is when the proportion of copper in the built-up wear-resistant iron-based alloy is 30%. FIG.

  Therefore, it was confirmed that the preferable range of the mixing ratio of copper in the build-up wear-resistant iron-based alloy is 12.5 to 26.0%.

(Effect / effect of Ni content)
In the composition of the example, the blending ratio of additive components other than nickel is Fe: balance, Cu: 25.0%, Mo: 9.0%, Si: 2.3%, Nb: 1.0%, C: 0 Samples were prepared with various mixing ratios of nickel while being fixed at 1%.

  And the abrasion test mentioned above was implemented about each sample, and the valve seat abrasion amount was measured. Moreover, about each sample, the crack generation rate at the time of overlaying was investigated.

  As shown in FIG. 6 and FIG. 7, if the mixing ratio of nickel in the build-up wear-resistant iron-based alloy is in the range of 8.0 to 10.0%, the wear amount and crack of the valve seat The occurrence rate could be effectively reduced, and the wear resistance and crack resistance at high temperatures could be improved in a well-balanced manner.

(Effect / influence of Mo amount)
In the composition of the example, the blending ratio of additive components other than molybdenum is Fe: balance, Cu: 25.0%, Ni: 9.0%, Si: 2.3%, Nb: 1.0%, C: 0 Samples were prepared in which the mixing ratio of molybdenum was variously changed while being fixed at 1%.

  And the abrasion test mentioned above was implemented about each sample, and the valve seat abrasion amount was measured. Moreover, about each sample, the crack generation rate at the time of overlaying was investigated.

  As shown in FIG. 8 and FIG. 9, when the molybdenum content in the build-up wear-resistant iron-based alloy is within the range of 8.0 to 10.0%, the wear amount and cracking of the valve seat are observed. The occurrence rate could be effectively reduced, and the wear resistance and crack resistance at high temperatures could be improved in a well-balanced manner.

(Effects / influences of Si content)
In the composition of the example, the blending ratio of additive components other than silicon is Fe: balance, Cu: 25.0%, Mo: 9.0%, Ni: 9.0%, Nb: 1.0%, C: 0 Samples were prepared with various blending ratios of silicon while being fixed at 1%.

  And the abrasion test mentioned above was implemented about each sample, and the valve seat abrasion amount was measured. Moreover, about each sample, the crack generation rate at the time of overlaying was investigated.

  As shown in FIGS. 10 and 11, these results show that the wear amount and cracking of the valve seat are within the range of 2.0 to 2.5% of silicon in the build-up wear-resistant iron-based alloy. The occurrence rate could be effectively reduced, and the wear resistance and crack resistance at high temperatures could be improved in a well-balanced manner.

(Effects / influences of Nb content)
In the composition of the examples, the blending ratio of additive components other than niobium is Fe: balance, Cu: 25.0%, Mo: 9.0%, Ni: 9.0%, Si: 2.3%, C: 0 Samples were prepared in which the mixing ratio of niobium was variously changed while being fixed at 1%.

  And the abrasion test mentioned above was implemented about each sample, and the valve seat abrasion amount was measured. Moreover, about each sample, the crack generation rate at the time of overlaying was investigated.

  As shown in FIGS. 12 and 13, these results show that the wear amount and cracking of the valve seat can be achieved if the niobium content in the build-up wear-resistant iron-based alloy is in the range of 0.7 to 1.3%. The occurrence rate could be effectively reduced, and the wear resistance and crack resistance at high temperatures could be improved in a well-balanced manner.

(Effect / influence of C amount)
In the composition of the examples, the blending ratio of additive components other than carbon is Fe: balance, Cu: 25.0%, Mo: 9.0%, Ni: 9.0%, Si: 2.3%, Nb: 1 Samples were prepared with various blending ratios of carbon while being fixed at 0.0%.

  And the abrasion test mentioned above was implemented about each sample, and the valve seat abrasion amount was measured. Moreover, about each sample, the crack generation rate at the time of overlaying was investigated.

  As shown in FIGS. 14 and 15, these results show that the amount of wear and cracking of the valve seat is within the range of 0.07 to 0.13% of carbon in the build-up wear-resistant iron-based alloy. The occurrence rate could be effectively reduced, and the wear resistance and crack resistance at high temperatures could be improved in a well-balanced manner.

  Therefore, if the build-up layer of the build-up wear-resistant iron-based alloy according to the present invention is laminated on the valve seat that is a valve system component of the internal combustion engine, the wear resistance of the valve seat can be improved, and the opponent attack is also improved. It can be seen that the amount of wear of the counterpart material can be reduced. It is also advantageous to improve crack resistance when building up.

(Other)
In the above-described embodiment, an example in which molybdenum is used as the Laves phase forming element has been described. However, instead of molybdenum, tungsten or vanadium is used, and Fe-W type silicide or Fe-V type silicide is used as hard Laves phase particles. Even if formed, the same effect is considered to be obtained.

  In addition, in the above embodiment, the overlay wear-resistant copper-based alloy powder is formed by gas atomization treatment, but is not limited to this, powderization treatment such as mechanical atomization treatment that pulverizes the molten metal against the rotating body, Alternatively, the overlay wear-resistant copper-based alloy powder for overlaying may be formed by mechanical pulverization using a pulverizer.

  The build-up wear-resistant iron-based alloy of the present invention is built up on the valve seat constituting the valve system of the internal combustion engine, or in some cases, on the material constituting the valve that is the counterpart material of the valve seat, or on the valve. It can be applied to any material. The internal combustion engine may be a gasoline engine or a diesel engine.

  In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within a range not departing from the gist. The description of the words and phrases described in the embodiments and examples can be described in each claim even if a part of the description.

It is a microscope picture which shows the build-up structure of the build-up layer formed with the build-up wear-resistant iron-based alloy of an Example. It is a block diagram which shows typically a mode that the abrasion resistance test is performed with respect to the test piece which has a build-up layer. It is a graph which shows the abrasion loss of the built-up layer which concerns on an Example and Comparative Examples 1-3. It is a graph which shows the relationship between the Cu compounding quantity in a build-up wear-resistant iron-base alloy, and the copper particle dispersion rate in a build-up layer. It is sectional drawing which shows typically the dispersion state of the copper particle in an overlaying layer, (a) is a schematic sectional view when the compounding ratio of copper in an overlay wear-resistant iron-base alloy is 5%, (b) is Schematic cross-sectional view when the proportion of copper in the build-up wear-resistant iron-based alloy is 20%, (c) is a schematic cross-sectional view when the proportion of copper in the build-up wear-resistant iron-based alloy is 30%. is there. It is a graph which shows the relationship between the Ni compounding amount in the build-up wear-resistant iron-based alloy, and the wear amount of the build-up layer. It is a graph which shows the relationship between the Ni compounding quantity in a build-up wear-resistant iron-based alloy, and the crack incidence of a build-up layer. It is a graph which shows the relationship between Mo compounding amount in a build-up wear-resistant iron-base alloy, and the wear amount of a built-up layer. It is a graph which shows the relationship between Mo compounding amount in a build-up wear-resistant iron-base alloy, and the crack generation rate of a build-up layer. It is a graph which shows the relationship between the Si compounding amount in a build-up wear-resistant iron-based alloy, and the wear amount of a built-up layer. It is a graph which shows the relationship between Si compounding amount in a build-up wear-resistant iron-base alloy, and the crack incidence rate of a build-up layer. It is a graph which shows the relationship between the Nb compounding quantity in a build-up wear-resistant iron-base alloy, and the wear amount of a built-up layer. It is a graph which shows the relationship between the Nb compounding quantity in a build-up wear-resistant iron-base alloy, and the crack incidence of a build-up layer. It is a graph which shows the relationship between C compounding quantity in a build-up wear-resistant iron-base alloy, and the wear-amount of a built-up layer. It is a graph which shows the relationship between C compounding quantity in a build-up wear-resistant iron-base alloy, and the crack incidence of a build-up layer.

Explanation of symbols

10 ... Test piece (valve seat) 11 ... Overlay layer 20 ... Counterpart material (valve)

Claims (8)

An iron-base alloy containing iron as a main component, two-phase separated from iron in a liquid phase state, and added in a blending ratio that is dispersed in the form of particles in an iron-base matrix in a solid phase state; It contains Laves phase particle forming elements that combine to form Laves phases and form particulate silicide, nickel, and silicon, and the content of these elements is mass%, iron: 50% or more, copper: 12 0.5-26.0%, Laves phase particle forming elements: 8.0-10.0%, nickel: 8.0-10.0% and silicon: 2.0-2.5% Overlay wear-resistant iron-based alloy.   The build-up wear-resistant iron-based alloy according to claim 1, wherein the Laves phase particle forming element is at least one selected from the group consisting of molybdenum, tungsten, and vanadium. The build-up wear-resistant iron-based alloy according to claim 1 or 2, further comprising niobium and carbon. The build-up wear-resistant iron-based alloy according to claim 3, characterized by containing niobium: 0.7 to 1.3% and carbon: 0.07 to 0.13% by mass. An iron-based alloy containing iron as a main component, an iron-based matrix containing iron as a main component, dispersed in the iron-based matrix, copper particles containing copper as a main component, and dispersed in the copper particles And hard Laves phase particles made of silicide having Laves phase , and the element content is mass%, iron: 50% or more, copper: 12.5 to 26.0%, Laves phase particle forming element: 8 A build-up wear-resistant iron-base alloy characterized by 0.0 to 10.0%, nickel: 8.0 to 10.0% and silicon: 2.0 to 2.5% . 6. The build-up wear-resistant iron-based alloy according to claim 5, wherein the iron-based matrix is mainly composed of a Fe—Ni-based solid solution and a Fe—Ni-based silicide. It said hard Laves phase particles, Fe-Mo system silicides, according to claim 5 or 6, characterized in that comprises at least one selected from the group consisting of silicide of silicide and Fe-V-based Fe-W system , Built-up wear-resistant iron-based alloy. The copper particles are dispersed in, niobium carbide, claims 5 to 7, characterized in that it further comprises a hard carbide particles consisting of at least one selected from the group consisting of complex carbide and molybdenum carbide and niobium and molybdenum The build-up wear-resistant iron-based alloy according to any one of the above .

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