JPS6354773B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a carbon-based amorphous iron alloy that has high strength, high hardness, high crystallization temperature, and excellent embrittlement resistance. Normally, solid metals and alloys are in a crystalline state,
If the liquid is cooled extremely rapidly (the cooling rate is approximately 10 ⁴ to 10 ⁶ °C/sec, depending on the composition of the alloy), a solid with an amorphous structure similar to that of a liquid without a periodic atomic arrangement can be obtained. Such metals are called amorphous metals or amorphous metals. Generally, this type of metal is an alloy consisting of two or more elements;
Usually, it consists of a combination of both transition metal elements and non-metal elements, and the semimetal content is about 15 to 30 atomic percent. In addition, the present inventors have previously developed an amorphous iron alloy for high strength, fatigue resistance, general corrosion resistance, pitting corrosion resistance, crevice corrosion resistance, stress corrosion cracking resistance, and hydrogen embrittlement resistance (Japanese Patent Application Laid-Open No. 51-4017
No.) and applied for a patent. This alloy has the following composition. As atomic %, Cr1~40%, P, C and B
Contains 7 to 35% of one or more of the following as a main component, and as subcomponents: (1) 0.01 to 35% of one or two of Ni and Co.
40%, (2) 0.01 to 20% of one or more of Mo, Zr, Ti, Si, Al, Pt, Mn and Pd, (3) V, Nb, Ta, W, Ge and Be. Any one
0.01-10% of one or more species; (4) 0.01-5% of one or more of Au, Cu, Zn, Cd, Sn, As, Sb, Bi, and S; High strength, fatigue resistant, general corrosion resistant,
Amorphous iron alloy for pitting corrosion resistance, crevice corrosion resistance, stress corrosion cracking resistance, and hydrogen embrittlement resistance. The amorphous alloy disclosed in JP-A-51-4017 was a new alloy that had improved strength and heat resistance through the addition of chromium, as well as excellent corrosion resistance. What is also noteworthy is that these alloys have novel corrosion-resistant properties, and are not only resistant to general corrosion, but also resistant to pitting and crevice corrosion that cannot be avoided with modern stainless steels (304 steel, 316 steel, etc.). corrosion,
It also has an excellent feature of high resistance to stress corrosion cracking. However, because these alloys have a wide range of compositions,
For practical and new uses, the composition range is easy to manufacture and inexpensive while maintaining various properties such as high heat resistance, high hardness and strength, and high embrittlement temperature. It was previously unknown. An object of the present invention is to provide a carbon-based amorphous iron alloy that is easy to manufacture and inexpensive while having various properties such as high strength, high hardness, high crystallization temperature, and high embrittlement temperature. It is. That is, the present invention is a carbon-based amorphous iron alloy having high strength, high hardness, high crystallization temperature, and high embrittlement temperature, which is characterized by having a composition substantially represented by the following formula.
Fe _a M _c Q _d (In the formula, Fe _a is a atomic % of Fe, M _c is one or two selected from Mo and W containing d atomic %, and Q _d is d atomic % of C. a is in the range of 48 to 82, c is in the range of 4 to 26, and d is in the range of 15 to 26, and the sum of a, c, and d is substantially 100.However, if M is only W ) The present inventors have discovered that an iron alloy containing only carbon as a nonmetallic element easily becomes amorphous over a wide composition range, and has excellent properties in terms of strength, hardness, corrosion resistance, and heat resistance. The present invention was completed based on the new finding that Next, the present invention will be explained in detail. Among the well-known amorphous alloys, inexpensive ones are mainly iron-based; for example,
Fe ₈₀ P ₂₀ , Fe ₈₀ B ₂₀ , Fe ₈₀ P ₁₂ B ₈ , Fe ₇₅ Si ₁₅ B ₁₀ ,
It was a combination of iron and nonmetallic elements P, B, Si, and C, such as Fe ₇₅ Si ₁₅ P ₁₀ and Fe ₈₀ P ₁₃ C ₇ . However, the present inventors have discovered that these metalloid elements, which are necessary additives for making the material amorphous, each have advantages and disadvantages. The effects are summarized in Table 1. In the same table, the characteristics are ◎ (excellent), 〇 (good), ×
(Acceptable) However, it has been evaluated.

[Table] From the same table, Ge is unfavorable in all respects, and P
has good properties such as raw material cost, amorphous formation ability, and corrosion resistance, but other properties are unfavorable. In particular, it is a problematic element because it generates harmful gases during melting and promotes embrittlement of the material during heating. Si in the same table
and B are unfavorable since they have the effect of reducing corrosion resistance, and B also has the disadvantage of high raw material costs. As is clear from the table, C was found to be an element having preferable properties in all respects with respect to the above-mentioned elements. Thus, the present inventors completed the present invention by conducting detailed research on amorphous iron alloys containing only C in the semimetal, which contributes to amorphization. Generally, amorphous alloys are obtained by rapid cooling from a liquid state, and various cooling methods have been considered for this purpose. For example, liquid metal is continuously jetted onto the outer circumferential surface of one disc rotating at high speed (Fig. 1 a) or between two rolls rotating counter-rotating at high speed (Fig. 1 b). A method is known in which the material is rapidly solidified on the surface of twin rolls at a rate of about 10 ⁵ to ^{10 6} ° C./sec. In addition, the present inventors have recently invented a method and apparatus for directly manufacturing wide strips from molten metal (Japanese Patent Laid-Open No. 53-125228
No. 53-125229) can be used. The amorphous iron alloy of the present invention can also be obtained by rapid cooling from a liquid state, and the amorphous alloy of the present invention in the form of a wire or plate can be produced by the above-mentioned methods. Can be done. In addition, the liquid metal is blown off with high pressure gas (nitrogen, argon gas, etc.) and rapidly solidified into a fine powder on an opposing copper plate for several μm using an atomizer.
It is possible to produce amorphous alloy powder with a size of ~ several tens of micrometers, and this alloy consists only of C as a semimetal, so it is not only cheaper but also easier to produce than conventional amorphous alloys. Therefore, it is extremely advantageous in that powders, wires, or plates made of the carbon-based amorphous iron alloy of the present invention can be manufactured on an industrial scale. In the case of the alloy of the present invention, the purpose of the present invention can be achieved even if small amounts of impurities such as P, Si, As, S, Sb, Zn, Cu, Al, etc., which are present in ordinary industrial materials, are contained. can do. The amorphous iron alloy of the present invention can be roughly classified into the following groups based on its composition. (a) Fe—Mo—C (b) Fe—Mo—W—C Next, the reason for limiting the component composition in the present invention will be explained. If Fe is less than 48 atomic % or more than 82 atomic %, it is difficult to easily obtain an amorphous alloy, so Fe needs to be in the range of 48 to 82 atomic %. If the C content of Q is less than 15 atom % or more than 26 atom %, it is difficult to easily obtain an amorphous alloy, so the C content of Q must be within the range of 15 to 26 atom %. Since it is difficult to obtain an amorphous alloy when the c of M _c is outside the range of 4 to 26, the c of M _c needs to be within the range of 4 to 26. In addition, when replacing a part of C in Q with N, if the N content exceeds 4 at %, N will precipitate as bubbles in the alloy structure during rapid solidification, deteriorating the shape of the alloy and reducing mechanical strength. It is necessary to keep it below 4 atomic %. Next, we will discuss the composition, crystallization temperature Tx (℃), hardness Hv (DPN), and fracture strength σ _f of the amorphous iron alloy of the present invention.
(Kg/mm ² ) are shown in Table 2. The sample amorphous alloy was rolled to a thickness of 0.05 mm by the single roll method shown in Figure 1a.
mm, in the form of a ribbon with a width of 2 mm. However, the crystallization temperature Tx is the temperature at which the first exothermic peak starts in the differential calorific value curve heated at 5°C/min, and Hv
The values in the table are measured using a micro-Vickers hardness meter with a load of 50 g.The values in the table have not been measured.

[Table] In general, amorphous alloys crystallize when heated and lose their characteristic ductility and toughness, as well as deteriorating their other excellent properties.
It is practically advantageous to use an alloy with a high Tx.
As shown in Table 2, the Tx of the amorphous alloy of the present invention is mostly within the range of approximately 350 to 650°C, and Mo, W,
It can be seen that Tx tends to increase as the content of .sub.2 increases. Therefore, it can be seen that the alloy of the present invention has a high Tx and is a stable alloy against heat. In addition, the hardness (Hv) and fracture strength (σ _f ) are 800 to 1100 DPN and 280 to 400 Kg/mm ² , respectively, and these values, which increase with increasing Mo and W contents, are conventionally known. Highest value (Fe-
For B alloy, Hv = 1100DPN, σ _f = 330Kg/mm ² )
It is found that it has excellent hardness and strength. In other words, (a) Fe in Table 2
In Mo-c system, the hardness is over 1000DPN, the crystallization temperature is over 600℃, and the breaking strength is 400℃.
Some reach Kg/ ^mm2 . Furthermore, it is generally known that amorphous iron alloys have the drawback of becoming brittle even at temperatures lower than the crystallization temperature. According to research conducted by the present inventors, it has been found that the reduction in embrittlement of the amorphous iron alloy greatly depends on the content and type of metalloid elements contained in the alloy. Table 3 shows the results of comparing the embrittlement temperatures of amorphous iron alloys containing various metalloid elements and the C-containing amorphous iron alloy of the present invention.

[Table] The embrittlement temperatures shown in the table indicate the temperatures at which bending is possible by 180° when heated at each temperature for 30 minutes, and the higher the temperature, the smaller the tendency to embrittle. As shown in the same table, most of the alloys of the present invention have a higher embrittlement temperature than the Fe ₈₀ P ₂₀ alloy and are less likely to become embrittled, and are approximately comparable to the Fe ₈₀ B ₂₀ alloy, which is conventionally known as an alloy that is less likely to become embrittled. have comparable embrittlement temperatures. These properties allow the alloy of the present invention to be used as tool materials such as knives and saws, hard wire materials such as tire cords and wire ropes, composite materials with synthetic resins such as vinyl and rubber, and composite materials with low melting point metals such as aluminum. It is advantageous because it does not become brittle even when subjected to inevitable heat treatment or temperature rise during manufacturing when used in other applications. As mentioned above, the alloy of the present invention is a high-strength material with amazing hardness and strength, and has a hardness of 700~
Even better than 800DPN, breaking strength 250-300Kg/ ^mm2 . In addition, it is generally difficult to make high-strength steel into wire or plate, and the manufacturing process is complicated (melting → casting →
Requires soaking → forging, rolling → heat treatment). The alloy of the present invention has the great advantage that it is possible to manufacture the final product wire or plate directly after melting.
Therefore, the amorphous iron alloy of the present invention can be used in tool materials such as knives and saw teeth, hard wire materials such as tire cords and wire ropes, and composite materials with organic and inorganic materials (vinyl, plastic, rubber, aluminum, concrete). reinforcement materials such as), blended materials (safety work clothing,
Protective tents, ultra-high frequency protective clothing, microwave absorbing plates, shield sheets, conductive tape, surgical gowns,
It has many uses, including antistatic socks, carpets, belts, etc.), and pollution prevention filters and screens. Next, as an example of the use of the amorphous alloy of the present invention, a physical property test will be shown. Example 1 Carbon steel, hard stainless steel, and low-alloy steel are widely used in conventional cutlery, such as razors and paper cutters.The properties suitable for cutlery materials include high hardness, corrosion resistance, and elasticity. high,
Good wear resistance is required. It has been found that the alloy of the present invention fully has the above-mentioned properties and is extremely excellent. Table 4 shows the hardness and the weight loss, i.e., the amount of wear when worn on emery paper (#400) for 10 minutes under a load of 193 g, in comparison with commercially available products. The amount of wear in the table shows the results of two measurements on the same sample.

[Table] From the same table, it can be seen that the amount of wear of this alloy material is approximately 1/100 or less compared to commercially available razor blade materials. Example 2 The properties of the alloy of the present invention (Fe ₆₂ Mo ₁₂ W ₈ C ₁₈ ) as a reinforcing material and the results of its use are shown in Table 5 in comparison with existing reinforcing materials such as piano steel wire, glass fiber, and nylon wire.

[Table] From the same table, the tensile strength required as a reinforcing material is 50 to 100 kg/ ^mm2 higher than that of piano wire, and the high temperature tensile strength and bending fatigue limit are also excellent. Adhesion, which is another important property, was good when used as a reinforcing material for rubber and plastic. Traditionally, steel wire, synthetic fibers, and glass fibers have been used as reinforcement materials for rubber structures, but it is difficult to further increase the fatigue strength currently obtained with steel wires, and synthetic fibers and glass fibers It is well known that it is almost impossible to provide a wire with a fatigue strength higher than that of steel wire. Furthermore, to reinforce synthetic resins, pine-shaped reinforcing materials mainly made of processed glass fibers have been conventionally used, and although this reinforcing material has good corrosion resistance, it is brittle and therefore does not have sufficient bending strength. Concrete structures include PC concrete that uses steel wires or cables as reinforcement materials, and concrete that is randomly mixed with shortened steel wires, but both have shortcomings in terms of corrosion resistance.
However, if the alloy of the present invention is used as a reinforcing material, it can be extremely advantageously used as a reinforcing material for the above-mentioned rubbers, synthetic resins, concrete, etc. A few examples will be explained below. (A) Fe ₆₂ Mo ₂₀ C ₂₈ and Fe ₆₂ Mo ₁₂ W ₈ C ₁₈ amorphous alloys were prepared with a width of 0.06 mm and a thickness using the apparatus shown in Figure 1 a.
A 0.04 mm wire was formed into a steel shape and embedded in a tire rubber material to form a test piece. The mesh spacing is 1 mm, and the specimen size is 3 x 10 x
It was made of 100mm board. When vulcanizing the rubber, the temperature of the specimen was raised to about 150 to 180°C for about 1 hour. Using this specimen, a long-term fatigue test (amplitude elongation of 1 cm) was conducted using a tensile fatigue testing machine. the result,
It did not break even after ¹⁰⁶ cycles, and no peeling between the rubber and the wire was observed. This result is
Fe ₆₂ Mo ₁₂ W ₈ C ₁₈ alloy has a fracture strength (390Kg/mm ² ),
This is because it has excellent crystallization temperature (552°C) and fatigue strength (78Kg/mm ² ). Rubber alloys must also resist corrosion by sulfur. Therefore, the above-mentioned alloy wire was embedded in excessively vulcanized rubber and left at 30°C for about one year, and then the surface and strength of the alloy wire were examined, but there was almost no change. (B) Fe ₆₂ Mo ₂₀ C ₁₈ , Fe ₇₄ Mo ₈ C ₁₈ ,
Three types of amorphous alloys, Fe ₆₂ Mo ₁₂ W ₈ C _18, are made into wires with a diameter of approximately 0.05 mm using the equipment shown in Figure 1a, cut into a certain length, and a certain amount is poured into resin concrete. mixed inside. The specimen shape is 15×15
The specimen was a 52 cm x 52 cm square prism, the specimen support distance was 45 cm, and the load application points were at two locations 15 cm from each fulcrum. The table below shows the results of the bending test.

[Table] As seen in the table, it can be seen that the fiber reinforcement material has a maximum load about 3 to 4 times and a deflection about twice that of the non-reinforced material. In other words, the strength and deflection of fiber-reinforced concrete is expected to be 1.5 to 2.0 times greater than that of ordinary steel-reinforced concrete. As described above, the alloy of the present invention has high hardness and strength,
It has many features such as excellent fatigue limit, excellent corrosion resistance, and is cheaper and easier to manufacture than conventional amorphous alloys, so it is expected to be used in many fields. The alloy of the present invention can be manufactured into powder, wire or plate depending on the purpose.

[Brief explanation of the drawing]

FIGS. 1a and 1b are diagrams showing the principle of an apparatus for producing an amorphous alloy by rapidly cooling a molten alloy. 1... Molten metal, 2... Rapidly solidified amorphous alloy wire or plate, 3... Cooling disk, 4... Roll.

Claims (1)

[Scope of Claims] 1. A carbon-based amorphous iron alloy having high strength, high hardness, high crystallization temperature, and high embrittlement temperature and having a composition represented by the following formula. Fe _a Mc Qd (In the formula, Fe _a means a atomic % of Fe, Mc contains c atomic % of one or two selected from Mo and W, and Qd means d atomic % of C. , a is in the range of 48 to 82, c is in the range of 4 to 26, and d is in the range of 15 to 26, and the sum of a, c, and d is substantially 100.However, if M consists only of W, do not have.)