JPS61235537A - Nonmagnetic and amorphous high-carbon iron alloy - Google Patents

Abstract

PURPOSE:To easily manufacture the titled iron alloy having high heat resistance, strength and hardness at a low cost by limiting a composition consisting of Fe, Cr, Mo, W and C. CONSTITUTION:This nonmagnetic and amorphous high-carbon iron alloy has a composition represented by a formula FeaCrbMcQd [where M is one or more among Cr, Mo and W, Q is C, a=28-76 atomic%, b<=20% (not including 0%), c=12-26%, d=12-26%, a+b+c+d 100%, and when M is W, b=4-20%]. The alloy has superior heat resistance, high strength and hardness. In the composition, <=4% N may be substituted for part of C, the amount of Cr may be 0%, and <=about 10% one or more among Ta, Mn and V or <=about 5% one or more among Nb, Ti and Zr may be substituted for part of M.

Description

[Detailed description of the invention] It is something.

Normally, solid metals and alloys are in a crystalline state, but they are cooled much more rapidly than liquids (the cooling rate depends on the composition of the alloy, but approximately 1
04-b A solid with an amorphous structure that does not have a periodic atomic arrangement similar to a liquid is obtained. Such metals are called amorphous metals. In general, this type of metal is an alloy of two or more elements, usually a combination of both transition metal elements and non-metallic elements, with a metalloid content of about 15
It is about 30 atomic %.

The present invention provides heat resistance,
The object of the present invention is to provide a carbon-based nonmagnetic amorphous iron alloy that has high strength and hardness, is easy to manufacture, and is inexpensive. That is, the present invention is a carbon-based nonmagnetic amorphous iron alloy characterized by having a composition substantially represented by the following formula.

1, FeaCrbMcQd (in the formula, Fe is a atomic % of Fe, Crb is Cr is b atomic %, Ko is one or more selected from cr, Mc, and W is C atomic %, and C is C indicates a high content of d atoms, a is 28 to 76, b is 2
0 or less (not including zero), C is 12 to 26, d is 12
~26, and the sum of a, b, c and d is substantially 100. However, when M consists only of W, b
is within the range of 4-20. ) 2, FeaO rbMC QdC formula
, Fe is a atomic %, crb is (Hr is b atomic %, Mc is Cr l Mc , any one or more selected from W is C atomic %, Qd is C containing a large amount of d atoms) a is 28 to 76, b is 20 or less (
However, zero is not included), C is in the range of 12 to 26, d is in the range of 12 to 26, and the sum of a, b, c and d is substantially 100
and a portion of C constituting Q is substituted with 4 atomic % or less of N. However, when M consists only of W, b is within the range of 4 to 20. ) 3, FeaMcQd (In the formula, Fea is Fe selected from a atomic %, Mo is selected from Mc, W, one or both of which are C atomic %,
Qd indicates that C contains many d atoms, and a is 2
8-76, C is in the range of 12-26, d is in the range of 12-26, a.

The sum of C and d is substantially 100. However, M does not consist only of W. ) 4, FeaMcQd (In the formula, Fe means that Fe is a atomic %, Mc is one or two selected from Mc and W that is C atomic %, and Qd is C that contains a large amount of d atoms. and a is 28 to 7
6, C is in the range of 12 to 26, d is in the range of 12 to 26,
a.

The sum of C and d is substantially 100, and a portion of C constituting Q is substituted with 4 atomic % or less of N. However, M does not consist only of W. ) The present inventors have discovered that iron alloys containing carbon as a nonmetallic element (or a portion of it replaced with nitrogen) easily become amorphous over a wide composition range, and that they have excellent strength, hardness, corrosion resistance, and heat resistance. The present invention was completed based on the new finding that it has excellent properties and is non-magnetic.

Next, the present invention will be explained in detail.

Among the well-known amorphous alloys, inexpensive ones are mainly iron-based, such as Fe80P20.
1 F8soBzo + Fe5o PxgBs -F
'e75s115B10F'e75si15plO+
Iron and pp metal element P such as ye80p18c7
, B, Si, and C. However, the present inventors have discovered that each of these metalloid elements, which are necessary additives for amorphousization, has advantages and disadvantages. The effects are summarized in Table 1. In the same table, the characteristics are evaluated by ◎ (excellent), ○ (good), and × (fair).

From the same table, Ge is unfavorable in all respects, and P! 2. Properties such as raw material cost, amorphous formation ability, and corrosion resistance are good), but other properties are not desirable. In particular, it is a problematic element because it generates harmful gases during melting and promotes brittleness of the material during heating. In the same table, Si and B are undesirable because they have the effect of lowering corrosion resistance, and B has the disadvantage of high raw material cost. It was found from the same table that C is an element having preferable properties in all respects as shown in the table above.

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 applied on the outer circumferential surface of one disc rotating at high speed (Fig. 1 (a)) or between two rolls rotating in opposite directions at high speed (Fig. 1 (b)). 105 ~ on the surface of a rotating disk or twin rolls by squirting
A method of rapid solidification at a rate of about 0.6°C/sec is known.

In addition, the present inventors have recently invented a method for directly manufacturing a wide thin plate from molten metal, and an apparatus for manufacturing the same (Japanese Patent Laid-Open No. 53
-125228, 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. 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 cooling steel plate. For example, an amorphous alloy powder with a size of several μm to several tens of μm is produced using an atomizer or the like. This alloy can also be substituted with C as a semimetal, or with up to 4 atomic percent N as a partial replacement for C, and is therefore not only cheaper than conventional amorphous alloys, but also Since it is easy to manufacture, 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. The alloy of the present invention does not contain impurities present in ordinary industrial materials, such as P, Si + As, S,
Even if a small amount of Sb + Zn + Cu, Aj, etc. is used, the object of the present invention can be achieved. Further, a part of M is 10 atomic % or less of V, Ta, In, or 5 atomic % or less of Wb.

Even if Ti and Zr are included, the object of the present invention can be achieved.

The amorphous iron alloy of the present invention can be roughly classified into the following groups based on its composition.

(a) Fe -0r-C(N) (b) Fe -Mc-0(N) (c) Fe -Cr -No -C(N) (d)
Fe −Cr −W −C(N)(e) Fe −
No −W −C(N)(f) Fe −Cr −M
c-W-C(N) Next, the reason for limiting the component composition in the present invention will be explained.

If Fe is less than 28 atom %, it is difficult to obtain an amorphous alloy, and if it is more than 76 atom %, it is no longer nonmagnetic, so 11 must be within the range of 28 to 76 atom %.

If Q is less than 2 atomic % or more than 26 atomic %, it will be difficult to obtain an amorphous alloy, so Q is 12.
It is necessary to keep it within the range of ~26 at.%.

If b of CrbMc is outside the range of 0 to 20 and C is outside the range of 12 to 26, nonmagnetism is lost and it becomes ferromagnetic, so it is necessary that the values of b and c of CrbMc be within the range of 0 to 20.12 to 26, respectively. be. Furthermore, when K consists only of W, if b is less than 4, the properties will deteriorate, while if it is more than 20, it will be difficult to make it amorphous, so b must be within the range of 4 to 20. be.

Further, when a part of M is replaced with V, Ta, or In, when any one or more of V, Ta, and Kn is more than 10 atomic %, or a part of M is replaced with Nb.

When replacing with Ti, Zr, Nb, Ti, Z
It is difficult to obtain an amorphous alloy when one or more of r is more than 5 atomic %, so V, Ta
.

Mn0 group is 10 atomic % or less, Nb # Ti * zr
It is preferable that the content of each group is 5 atomic % or less.

In addition, when a part of Q is replaced with H, if the N content exceeds 4 atomic %, N will precipitate as bubbles in the alloy structure during rapid solidification.
Since the shape of the alloy deteriorates and the mechanical strength decreases, it is advantageous to reduce the amount of N to less than 1 atomic %.

Next, the composition and crystallization temperature Tx of the amorphous iron alloy of the present invention
(''C), hardness Hv (DPN) and breaking strength (If
(J19/Utai 2) are shown in Table 2. The sample amorphous alloy was rolled to a thickness of 0.0 mm by the single roll method shown in Figure 1(a).
It is in the shape of a ribbon with a length of 0.5 dew and a width of 2 songs. 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 is the value measured by a micro Vickers hardness tester with a load of 50 g. - in the table means not measured.

Table 2 In general, amorphous alloys crystallize when heated and lose their characteristic ductility and toughness, as well as deteriorating other excellent properties, so their crystallization temperature (TX) is high. It is practically advantageous to use an alloy. As shown in Table 2, the TX of the amorphous base metal of the present invention is approximately 450~
Within the range of 650°C, Cr, No, W
, Tx with increasing content of V, Ta, Mn
It can be seen that there is a tendency to increase, and 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 breaking strength (af) are 900~1100DPN and aoo~400DPN, respectively.
A9/Parrot 2, Cr, Mo + W + V
* Both of Ta and Mn increase as the content increases. These values are the highest values conventionally known (for Fe-B alloys, HV-1100DPN, af-3a O
ki/Mm"), which indicates that it has excellent hardness and strength. In other words, in Table 2, (c
) Hardness is 10000 in Fe-Mo-0 system
There are some that are PN or higher, have a crystallization temperature of over 600°C, and have a breaking strength of 4ookg/l1l12.

In addition, a part of M in the above alloy composition is 10 atomic % or less of Ta.
, In, and any one or more elements selected from the group consisting of V, or 5 atomic % or less of Nb
An alloy containing one or more elements selected from the group consisting of , Ti, and Zr, or a combination with at least one element from each of the above two groups also has high strength and high It was found that it has hardness and high crystallization temperature.

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 embrittlement phenomenon 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.

The embrittlement temperature shown in the same table is 1 when heated for 30 minutes at each temperature.
It indicates the temperature at which 80° bending is possible, and the higher the temperature, the smaller the tendency to embrittle. As shown in the table, most of the alloys of the present invention have a higher embrittlement temperature than the Fe80P20 alloy, and are less likely to become brittle, and have an embrittlement temperature almost comparable to the Fe80B20 alloy, which is conventionally known as an alloy that does not easily become brittle. have Such properties are advantageous because they do not easily become brittle even when subjected to heat treatment or temperature elevation during manufacturing.

The present inventors believe that N (nitrogen) has almost the same effect as C in terms of the ability to amorphize an amorphous alloy and the alloy properties, and that a part of C in the alloy composition of the present invention is replaced with N. I found out what I can do. That is, a part of C constituting Q of the alloy of the present invention can be replaced with N of 4 atomic % or less. However, since N is a gas element, if it is added in excess of the equilibrium absorption amount of the molten alloy, it will precipitate as bubbles in the alloy structure during rapid solidification, deteriorating the shape of the alloy and reducing its mechanical strength. It is disadvantageous to add more than atomic percent. Table 4 shows the composition and properties of nitrogen-containing amorphous alloys.It has also been newly discovered that the amorphous alloy of the present invention has particularly excellent corrosion resistance. Table 5 shows the thickness Q made by the twin roll method in Figure 1(b).
, Q511111, width 211247)! J Hong-like alloy INH2So, , INHC/.

These are the results of a one-week immersion corrosion test in a 30°C aqueous solution of INNaO7.

Table 5 Commercially available 13% Cr steel, 18-8 stainless steel (Al5I s O4!l), 17-14-2.5M for comparison of corrosion test results
A similar test was also conducted on C stainless steel w1 (A engineering s engineering 316Lwl).

As shown in the table, the amorphous iron alloy of the present invention exhibits superior corrosion resistance to commercially available materials in all solutions.

As can be seen from the above results, the amorphous alloy of the present invention is a revolutionary highly corrosion-resistant material with corrosion resistance 103 to 5 times better than commercially available high-grade stainless steel, and can be used in severe corrosive atmospheres. It can be used for wires and plate parts.

On the other hand, conventional crystalline alloys having the same composition range as the alloy composition range have ferromagnetism. Despite having the same composition, amorphous alloys are non-magnetic, while crystalline alloys are ferromagnetic.The reason for this is that the Curie temperature of amorphous alloys is below room temperature. The present inventors have newly discovered that. Therefore, this alloy is suitable as a component material that is not affected by magnetic fields, such as a component material for watches, precision measuring instruments, etc.

Next, an example of physical property testing for an application example of the amorphous alloy of the present invention will be shown.

Example 1 Currently, there are almost no alloys available on the market that are non-magnetic and have high strength and left-ductility. For example, a ferromagnetic steel material can be made non-magnetic by alloying it with a large amount of chromium, or by alloying it with nickel or manganese to form an austenitic phase. Currently, a useful non-magnetic alloy is an Fe-Ni alloy containing about 30% or more nickel, but the strength of this alloy is at most 80 kg/
In contrast, the alloy of the present invention has a diameter of about 3 mm.
It is a non-magnetic material that has both fracture strength and toughness of 97 m'' at 0o~400, and can be used as a material for articles suitable for this performance.For example, apertures and shutter materials for cameras are non-magnetic and Currently, aluminum alloys and the like are used, which must have wear resistance.For this purpose, the Fe72Cr1gCI6 alloy split roll method of the present invention is used to produce efJs''s thickness of 0.05.
Use the SAA plate material and punch out the aperture blades.
As a result of its application, there were no problems caused by external magnetic fields, and the wear resistance was approximately 1,000 times higher than that of conventional Al alloy blades, significantly increasing the lifespan of the aperture blades.

1 In addition, dFe7 is available as a relay line material for special purposes.
As a result of measuring ultrasonic attenuation using zCr and C06 alloy wires, the dB/cm was approximately O.
It has the same characteristics as glass, and is not as brittle as glass. On the other hand, Fe-Ni thread Elinvar alloy is often used as a conventional metal material for relay lines, but its dB/cm is as high as about 10.

Therefore, the alloy of the present invention can be advantageously used as a material for relay lines.

As described above, the alloy of the present invention has high hardness and strength, excellent fatigue limit, excellent corrosion resistance, can be made non-magnetic, and is also cheaper and easier to manufacture than conventional amorphous alloys. It has a number of features such as, and 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 drawings]

FIGS. 1(a) and 1(b) are diagrams showing the principle of an apparatus for producing an amorphous alloy by rapidly cooling a molten alloy. ]... Molten metal 2... Rapidly cooled U solidified amorphous alloy or plate 3...
・Cooling disk 4...Roll Patent applicant: Tohoku University Research Institute for Metals and Materials Research Director No. 1 (a) ζb)

Claims (1)

[Claims] 1. A carbon-based non-magnetic amorphous iron alloy having a composition represented by the following formula. Fe_aCr_bM_cQ_d (In the formula, Fe_a is Fe at a atomic %, Cr_b is Cr at b
atomic %, M_c indicates that one or more selected from Cr, Mo, and W are contained in c atomic %, Q_d indicates that C is contained in d atomic %, a is 28 to 76, b is 20 or less (not including zero), c is 12-26, d is 1
2 to 26, and the sum of a, b, c and d is substantially 100. However, when M consists only of W, b
is within the range of 4-20. 2. A carbon-based non-magnetic amorphous iron alloy having a composition represented by the following formula. Fe_aCr_bM_cQ_d (In the formula, Fe_a is Fe at a atomic %, Cr_b is Cr at b
atomic %, M_c indicates that one or more selected from Cr, Mo, and W are contained in c atomic %, Q_d indicates that C is contained in d atomic %, a is 28 to 76, b is 20 or less (not including zero), c is 12-26, d is 1
2 to 26, the sum of a, b, c and d is substantially 100, and a portion of C constituting Q is substituted with 4 atomic % or less of N. However, when M consists only of W, b is within the range of 4 to 20. ) 3. A carbon-based non-magnetic amorphous iron alloy having a composition represented by the following formula. Fe_aM_cQ_d (In the formula, Fe is a atomic % of Fe, M_c is c atomic % of one or two selected from Mo and W, and Q_
d indicates that C is contained in d atomic percent, and a is 28
~76, c is in the range 12-26, d is in the range 12-26, and the sum of a, c and d is substantially 100. However, K
cannot consist only of W. ) 4. A carbon-based non-magnetic amorphous iron alloy having a composition represented by the following formula. Fe_aM_cQ_d (In the formula, Fe_a is Fe in a atomic %, M_c is one or two selected from Mo and W in c atomic %, Q
_d indicates that C is contained in d atomic percent, and a is 2
8 to 76, c is in the range of 12 to 26, d is in the range of 12 to 26, the sum of a, c and d is substantially 100, and a part of C constituting Q is 4 atomic % Substituted with the following N. However, M does not consist only of W. )