JPS5947346A - Production of high alloy powder and sintered alloy and sintered alloy - Google Patents

Abstract

PURPOSE:To obtain a sintered alloy in which carbides are finely dispersed and which has improved strength and resistance to abrasion and heat, by compacting the high alloy steel powder contg. Cr, C, Mo and having fine crystalline texture and sintering the same at an adequate temp. CONSTITUTION:The high alloy powder which consists of at least 1 kind among 20-50wt% Cr, 3.0-3.6% C, 5-20% Mo and 15-40% W and the balance Fe and has the fine crystal grain texture exhibiting a non-equil. single phase are prepd. by an ultraquick cooling and solidifying method or the like. Such high alloy powder is used as a raw material and compacted. The resulting green compact is sintered by heating to the temp. at which a part of the non-equil. single phase changes to an equil. carbide phase. The sintered alloy wherein the precipitated carbides are finely dispersed by the migration of the atoms of the high alloy powder arising in the stage of the change to the equil. carbide phase and which is homogeneous and is highly resistant to abrasion is thus obtd.

Description

[Detailed description of the invention]

The present invention relates to a sintering method for powder metallurgy products using this powder, and a sintered crystal. Conventionally, metal powder for powder metallurgy has been produced by the crushing method and the water spray method using the main method.
, brittle metals such as manganese, chromium, anotemon, bismuth, cobalt, etc. Brittle alloys (Fe containing intermetallic compounds)
4. t. Fe-At-Ti, Ni-Al, Ni-Ti, F
This has been done for e-Cr, Fe-8, etc. fj4). 1 g water 1 f! χ Ri method 1: The molten metal of metal or alloy is heated with water (4-mechanical method of turning the metal into a molten metal, and is widely applied to materials other than gold tags and base metals, which are extremely oxidized.) 1. The phase of the powder prepared by the method of et al. is an equilibrium phase. That is, for example, 11r, L, α for Fe-Cr-Mo powder
-1'e phase, carbide phases such as P, 123C, etc., and the other four phases are phases that are generated in four states. Powder made from Powder Anti-Hiko J'L manufactured by conventional method Vhi as raw material.

[1'Bali-'j4 products of the present invention;
'i &, 4. From the following viewpoints 71S et al. :Futei 4
He carried out seven raids. (b) Conventional (powder manufacturing kettle by wave crushing, ease of use: In the conventional method, powdered iron and electric iron, which are fragile metals, are made into powder by 11 small pieces); What is the cause of the rise in the cost of products? In addition, there is a risk of unmetallurgical metal production in this alloy due to artificial production. 14 out of 3 degrees and 6 results. - Select 4 and 22 to eliminate this vulnerability. (B) 71 min.
The I3,4 minute J'J- conversion occurs, which is at the same time as the equilibrium phase develops. Here, the equilibrium phase is, for example, Ii"e-er-i ~
The degree of component homogenization is determined by how uniformly dispersed the carbide 1 is, but since the carbide is already dispersed in the matrix, the component homogeneity is There is a ljl field which is said to be caused by the hev method/-)0.
<? When ultra-quenched from the molten state, the non-equilibrium phase is called the 171 solid solution, the non-equilibrium crystalline R phase, or the amorphous phase. is known to be formed. The present invention-8 is ``Knowing the 7 points of ``double points (a)'' and ``ri points, I was conducting research on ultra-Ω, cold alloys: about 111M, 20 to 50% 117) Cr and , 3.0-3.fi
'% C, at least one glaze of 5 to 20 MO and 15 to 40 W (white fraction is by weight unless otherwise specified)
, the balance being Fe, exhibits a non-flat h+ single-phase and solves the problems of conventional powder metallurgy raw materials and products, and has accomplished the present invention. That is, the present invention provides 20 to 50% Cr, 3.0 to 3.6% C, and 5 to 20 ol) M
. and 15 to 40% of at least one kind of W, and the balance is Fe, and exhibits a non-equilibrium single phase.4. We would like to introduce the present invention to fish) with a ratio of 20 to 50 Cr.
, C of Articles 30 to 3.6, Mo of Sections 5 to 20, and 15
A raw material powder for sintering a crystalline alloy powder that has a composition consisting of at least one group of W in ~4 () and the balance Fe, and has a fine crystal grain structure exhibiting a non-equilibrium single phase. This raw material powder is pressed into powder, and the compact is heated to 1/C at a temperature at which a part of the non-equilibrium single phase changes to an equilibrium carbide phase, and the compact is sintered. 4), which provides a method for producing a homogeneous sintered alloy by the atomic transfer of the heavy alloy powder during transformation (IQ); Furthermore, the present invention contains 20 to 50% of Cr, 3.0 to 3.6% of C, 5 to 20% of Mo, and a small amount of 15 to 40% of W. Tomo 1 zhong and rest Fe and 〃
・Narai) Composition; 1. First, the high-grade meeting according to the present invention is carried out to provide 4H4 sintered alloy.
) i-Ct;'1', clear. In this high alloy powder, Cr2O~50g, C3,0~3.6%, M
O5 to 20% and/or W15 to 40%, balance Fe and 17%, Si, Cr. This is because when Mo, W and C are outside this range, no single phase is formed. This non-flat street! I Sea 11
Ratio 1: Rif alloy alloy or ultra-quenched J- at a cooling rate of N+'I(/(8) or more) using the Q method described below.
In addition, the non-flat 0.S single phase in the present invention and the Fe-Cr-Ivlo (:vV)-C alloy by the usual RJ preparation method are To explain this in comparison, in this alloy:
7. +Jσ, 11] etc. are formed as a fraction -C: 1L% In this structure, )K, l, 7 phases are formed even in the normal {iν\i state, δA1, /b is also Q), However, in the case of the uninvented high alloy powder, the non-inventive high alloy powder has a single phase, and this phase is a phase that cannot exist in the flat state. When they were added together by XfDA diffraction, it became almost certain that it was an α-M milk-type lateral structure compound.F"e -Cr-Mo or W or Fe
-Cr -rs'Io -W ternary or quaternary 1 (e child,
7Js has never before been found in gold. The industrial significance of the non-equilibrium single phase described above is that phases of different orders of composition are Fe-Ur-M
o Fe-Cr-Mo that is not present in the (W)-C alloy and therefore has homogeneity at the level of microscopic composition.
When the (W)-C alloy is finely divided into 9 powders, the distribution of components is uniform both between and within the powder particles.
The homogeneity of powder metallurgy products is greatly enhanced. Furthermore, Shimadai gold powder consisting of a non-equilibrium single phase is extremely brittle6.
It was found that it easily turned into powder. Therefore, the high alloy powder of the present invention is different from the conventional Fe-Cr-8io(W)-C
It has lI/'1 characteristics, which can never be obtained with @gold, and it greatly contributes to powder metallurgy. υ, the sintering method will be explained 2). The high-alloy powder of the present invention is extremely sensitive to heat, and the sintering
．． 1 The non-equilibrium single phase decomposes, producing a carbide decomposition reaction such as αF'e + M7C3 or αFe + M2s Ca. Compare this reaction with the reaction during sintering of a conventional li'e -Cr -Mo -C alloy. Then, in this alloy (-↓change in carbide reaction or solid solubility, 1 - change in deafness, ■(・
-, atoms move, but A of this alloy: 't
b. Because the phase is the Ml phase, the movement of atoms is slower than in the case of the present invention.On the other hand, in the case of the present invention, the ash decomposition reaction Therefore, the atomic transfer fi11 accompanying this reaction is promoted by sintering C
(The inventor A'j' noticed that when used, the sintering reaction between raw material powders is accelerated. Alignment is performed between single metals (alloys), but 1iiJ ,, r
l-Koha (1, 1; Due to this problem, there are restrictions on the type of raw material powder Z). In the latter case, the sinterability is not good even in the case of the liquid phase HA'lI''l'J.On the other hand, in the case of the present invention, the sinterability is improved by iB,'', which promotes the sintering reaction. Improvements may ease sintering limitations or provide sintered joints with superior performance. In the name l-), based on the above carbide decomposition reaction, 81
Form stable carbides such as C3゜M23C6, j, 'x
Rotated Cr, ~1o. W diffuses into the base and strengthens the base, improving the strength, wear resistance, and heat resistance of the sintered product. The raw material powder may be the high alloy powder of the present invention alone, Fe-based, Co-based, Ni-based pure gold, alloy, carbide, etc.
In either case, the above-mentioned iJ point can be obtained. In K No. 5, the sintered alloy of the present invention will be explained in comparison with the conventional one.The structure of the conventional sintered alloy is formed by changing one equilibrium phase to another equilibrium phase during sintering. However, the structure of the present invention can be distinguished from the conventional one by the stable dispersed phase of carbides precipitated from the non-equilibrium single phase.This dispersed phase of carbides is extremely finely dispersed and has excellent wear resistance. In contrast, the carbide particle size of conventional sintered alloys can be reduced to a minimum of 10 microns by water spraying and using alloy steel powder. It can only be granulated. In view of these points, the γ magnetism resistance of the sintered alloy of the present invention is significantly improved over that of the conventional one. The canine embodiment of the present invention will be described below. An alloy obtained by ultra-quenching rI 4'j of a predetermined composition is 125
The high alloy powder of the present invention is obtained by mechanically or by the water jet method to obtain a high alloy powder of the present invention. This lj'jl 4J gold powder is mixed with lead powder, Fe, co, Ni, if necessary.
l? : Mix with single powder or alloy powder for about 30 minutes using a V-type mixer, etc. In this case, zinc stearate with a 0.5 to 1.2 double base ratio, which is known as F1 agent, is also simultaneously mixed with Q.4. It is preferable. Next, the mixed powder is compression-molded at a pressure of 4 to 12 tons/crA, and the obtained compact is ? Sinter in deep heat or in a reducing atmosphere. Sintering vortex 1 people) 1j1
It may be at normal temperature. Preferred implementation of the present invention Ω((samayo 2) and j!:i
The sintering temperature is 10 to 100K lower than the usual sintering temperature. This is because the solidus line of the quasi-equilibrium phase diagram of the non-equilibrium phase is lower than that of the equilibrium phase diagram V). It is preferable that the present invention be more than 100%.
. Example 1 Metallic chromium, metallic molybdenum, pig iron (4.4% C) and activated carbon were charged into a Litanmann tube with an inner diameter of 30 mm and a depth of 5120 mm, and the activated carbon, metallic chromium, metallic molybdenum and pig iron were charged in that order from the bottom and heated at high frequency. Dissolved. After melting, 17
The molten metal of 00 was sucked up with a #4 opaque quartz tube and solidified.
After cooling, the quartz tube [Fe-Cr-Mo-C
I took out the motherboard dangerously. Its A11 composition is 25.82% C
r, 3.34% C, 7,94%△'Jo, a?
It was fBFe. Next, ultra-rapid cooling is performed using the rapid solidification equipment shown in Figure 1.
J-, :' fc n 1st and 1st J? 1 is a heater, 2 is a bottom diameter Q, an Akari quartz tube with a 4 mm hole, 3 is an archon sword v1 included ['i, 4 is a cooling roll, 5t is a rotating part of the cooling roll 4. ΦIJ is a b motor. Mother B' alloy 2! 4”r, p+j shi, 1
600 r< 0iff degree bottom position of transparent quartz mark 2, b
The alloy is collected from the hole and blown onto the cooling roll 4 rotating at 6000 rpm, and is ultra-cooled at a speed of about 1 K/s to form the structure of the alloy shown in FIG. As shown, it has a single-phase structure with crystal grains of less than 1 micron. The plot contrast is due to casting defects. The alloy was very hard and very brittle. This alloy was ground in a mortar to create a high alloy powder of 1250 mesh/ζ. , Example 2 Actual power Example 1-1 (single alloy powder was used as raw material and 7"C
Adjust the sintered alloy. Raw material C Majino and 9jl l'
1. '+combination/(-8 high alloy powder(-25(lmenon,
) 23:! Water fountain 6 iron powder (-1(n0 horn/
-L) 757・me graphite powder (1μ7n or more F)
0.2 stearic acid (commercially available)
08 type sintering member - The case is the same Δ-0 Molding pressure 61.7/cnI sintering temperature
】、14ri8■～Atmosphere
] (1"'I'orr (-+, - air) Hardness of the obtained sintered alloy it II R1 (90-1 (
It was 10. Sintered metallurgy optical microscope λ'1 Orikane 1113 Figure 6 shows. In I゛〕1, C is a sintered matrix of the heavy alloy powder of the present invention, and D is this matrix for the pearlite group. −
(: r-f+4o's 4i<r-J#j is formed.In addition, non-31'-+shi I-II+-, 11J/)・
The carbides on Id and q.1' cannot be clearly detected at 700x magnification. Such fine carbides are heated to 1000℃
It was generated by heat treatment for x1 hour and detected at 40,000 times magnification. As a result, it was confirmed that fine +1'lll carbides were uniformly dispersed. Actual power (μ Example 3 (Special I shark example) Conventional crushed iron powder was used in place of the high alloy powder according to the present invention once a month to prepare IJg and material with the following composition. Iron powder (-10 (+ mesh) 9
52-line graphite powder (1 μm or less) 10≠Chromium powder (-250 meso,,)
3. (1” zinc stearate
(), 8 degrees or 1-conditions were the following and 99. Molding pressure 6 tons/crl Showing temperature
] 473 atmosphere
min J'/N7n7nia gas type abrasion test I
Figure 4 shows the results of the t-fu and (, X-mill tests). It is clear that the material sinks in all thick part speed ranges compared to that of the comparative example, and that it changes to 21γi'l';l''L. Example 4 20.5% Cr, 7.5% hlo, 28+317
A + V, :2.7 ・Complete bC. It has a 1f11 configuration with the remainder 11゛e and is a non-equilibrium single phase.
1-Ru-250 Methy High Alloy Powder IXl]
and l"l 4.in method, -100 menosier's powder 20' adhesion, :, eyes,) powder 1.0 part and mol I/'- mixed, '4r) [tsu i L fC mixed r
Thing k 7 door / cr & ) Ka J upper blade Naoko, I O
+px, jj; l Shaped into a 7 mm disk and heated in vacuo at 10'f'orr, l 4G3K. Sintered/coated for 30 minutes. M23C6 carbide in the matrix of Pern-11-structure 1r'i', i l
il uniform-VC no J・fft l-ta, hardness Hvfi70
'g,'s A:;jj, /:, yruaga::I et al.
did. ', -A box example 5 23.51 "Iy Cr, ] 6.675b W
, ';i, Oi+% C, remainder': rll
t'5 alloy powder was prepared by the same method as in Example 1, and then sintered by the method of Example 4.
I paid 1 paddy. As a result, M23C is added to the pearlite organized matrix.
A self-bonding gold with a hardness of 11v (4 old) and 7 J was obtained in which the θ carbide phase was dispersed. In addition, as a comparative example, 15% of crushed powder of ordinary Fe-20φCr alloy (-100 Metsushi) and iron powder (822
The other ingredients were the same as the above-mentioned raw materials 1. The results of a 4-p wear test conducted in the same manner as in Example 3 are shown in FIG. In the figure -・0-ke Example 5. ...×...V doesn't mean a comparative example. From FIG. 5, the sintered alloy r/ of the present invention
It is important to remove the wear resistance that has deteriorated. Example 6 25.82φCr was prepared in the same manner as in Example 1. A 1.6 alloy powder having a composition of 3.34% C, 7.94% Mo, and the balance Fe and having a single-phase structure was produced. A sintered base metal was prepared using this high alloy powder as one of the raw materials. The raw materials were mixed with the following: i? ? i Kaikin Powder (-250 mesh)
23.3' Spear iron powder (-100 Mesosi illusion
75.7%L! -++Lead powder<3ttmF)
0.2% zinc stearate
The 0.8 inch sintering conditions were as follows. Molding pressure 6tono/c4 Sintering temperature 438mm atmosphere
water record/cass time
As a result of this for 30 minutes, martensitic phase, (-r, α-Fe phase with Mo solid solution and M2
3C6 carbide 11] is dispersed, and the hardness is HB
93. (l),")'bM-"BKinka lJu! +
is.

[Brief explanation of the drawing]

J I W V-J', Mr A'E GiJ Sop
'f(1)i1('L's image, Figure 2 is 25.82%Cr
, 3: (4%C, 7,94AMo, balance l;"
e,! , Rinari, non-1' equilibrium tp, -J1]k Yesj
- Metal microscopic photograph of the alloy (magnification 30. (1 (10x), Figure 3)
37+i If true (magnification: 700 times), Figures 4 and 5 are graphs of 7J'<'. 1-Heater, 2-Transparent A'eye, 4-T'+
5 no; 1j roll. C-high alloy steel r-1D-matrix. Tei 11. “・“1 Btq, 2℃4 3rd 4th 1! l rubbing speed

Claims (1)

[Claims] A composition consisting of 20 to 50% Cr, 30 to 36 φ C, 5 to 20% Mo and at least one of 15 to 40 φ W, and the balance Fe at a weight ratio of 10. A high alloy powder having a fine grain structure exhibiting a non-equilibrium single phase. 2. Composition consisting of 20 to 50% Cr by weight, 3.0 to 3.6% C, 5 to 20% Mo, and at least one of 15 to 40% W, and the balance Fe. and one non-equilibrium single phase? A high alloy powder having a fine grain structure exhibiting the following properties is used as a raw material powder for sintering, and the τ material powder is compacted to a temperature at which a part of the non-equilibrium single phase changes to an equilibrium carbide phase. The body is heated and sintered, and the change to the equilibrium carbide phase occurs at 1:J and Q's movement of the heavy alloy powder (f rises, average f'1, 1, □-7). ω method of manufacturing. 3. jfi amount ratio of 20 to 50% Cr; 3.
C of 0 to 3.6 yen, 8 1o of 5 to 20 chi and 15 to 4
()ze, at least one type of thing W, and the remainder [・'e do force・(,, +, precipitated from a non-equilibrium single phase,
'、H! 13] A sintered alloy containing high alloy particles dispersed in vl and lll and having excellent wear resistance. .