JPH0222121B2 - - Google Patents
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- Publication number
- JPH0222121B2 JPH0222121B2 JP60260173A JP26017385A JPH0222121B2 JP H0222121 B2 JPH0222121 B2 JP H0222121B2 JP 60260173 A JP60260173 A JP 60260173A JP 26017385 A JP26017385 A JP 26017385A JP H0222121 B2 JPH0222121 B2 JP H0222121B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- less
- particle size
- average particle
- sintering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000843 powder Substances 0.000 claims description 49
- 239000002245 particle Substances 0.000 claims description 24
- 238000005245 sintering Methods 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 229910001315 Tool steel Inorganic materials 0.000 claims description 6
- 239000012535 impurity Substances 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 239000000956 alloy Substances 0.000 claims description 3
- 238000009692 water atomization Methods 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 claims description 2
- 229910052804 chromium Inorganic materials 0.000 claims description 2
- 229910052750 molybdenum Inorganic materials 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims 2
- 229910052721 tungsten Inorganic materials 0.000 claims 2
- 229910052748 manganese Inorganic materials 0.000 claims 1
- 239000002994 raw material Substances 0.000 claims 1
- 229910052710 silicon Inorganic materials 0.000 claims 1
- 229910052720 vanadium Inorganic materials 0.000 claims 1
- 239000000463 material Substances 0.000 description 28
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 14
- 238000005452 bending Methods 0.000 description 10
- 238000000137 annealing Methods 0.000 description 8
- 238000012360 testing method Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 238000000465 moulding Methods 0.000 description 6
- 238000005496 tempering Methods 0.000 description 6
- 230000005496 eutectics Effects 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 238000010298 pulverizing process Methods 0.000 description 5
- 238000009694 cold isostatic pressing Methods 0.000 description 4
- 238000001000 micrograph Methods 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 3
- 229910001566 austenite Inorganic materials 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 239000012768 molten material Substances 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 238000001291 vacuum drying Methods 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910000822 Cold-work tool steel Inorganic materials 0.000 description 1
- 229910000997 High-speed steel Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000009837 dry grinding Methods 0.000 description 1
- 235000019441 ethanol Nutrition 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000010297 mechanical methods and process Methods 0.000 description 1
- 238000010299 mechanically pulverizing process Methods 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 229920000609 methyl cellulose Polymers 0.000 description 1
- 239000001923 methylcellulose Substances 0.000 description 1
- 235000010981 methylcellulose Nutrition 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 238000007569 slipcasting Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Description
〔産業上の利用分野〕
本発明は工具鋼焼結部材の製造法に関する。
〔従来の技術〕
JISでSKH、SKDと称される一群の工具鋼の
部材を粉末治金法で製造することは公知である。
なかでも水アトマイズ法によつて作られた不規則
形状の予備合金粉末を焼なまし還元後、プレス、
CIP等で冷間成形して、所望する最終製品と相似
形の形状に成形後、真空又は還元性雰囲気で焼結
する方法は、工具鋼焼結部材の製造法として注目
されている。より具体的に表現すると該製造法は
通常O2含有量5000ppm以下の水アトマイズ不規
則形状粉末を−100meshで分級し、平均粒径50μ
前後とした後、真空中で還元し15000ppm以下の
O2量とし、かつ同処理において焼なまし軟化処
理を行ない、粉末を軟化させ、成形性を向上後、
粉末外皮の酸化物を還元するのに必要な化学量論
値に相応するＣを添加混合後、冷間成形し、以後
焼結する方法である。該方法は添加したＣ、又は
予備合金元素としてあらかじめ粉末中に添加され
たＣから発生するCOガスで粉末の表面酸化物を
還元すること、組成的に焼結時の昇温又は保持段
階で生成する共晶炭化物の部分液相を利用した一
種の液相焼結の２つの作用を利用することによ
り、低酸素で真密度に近い工具鋼焼結部材を製造
することが可能である。
〔発明が解決しようとする問題点〕
然るに前記製造方法において、現状の−
100meshで平均粒径50μ前後の水アトマイズ粉末
を使用した場合、焼結時の共晶炭化物の粗大化と
オーステナイト結晶粒の粗大化が避け難く、金属
組織的に同一材質の溶製法で作つたものより、機
械的性質が劣化する欠点がある。かつ局部的に巨
大な残留空孔が発生する場合があり、信頼性の点
でも溶製材対比不安がある。
〔問題点を解決するための手段〕
本願発明は、以上の２つの欠点を解消する方策
を種々検討の結果、水アトマイズままの粉末を湿
式又は乾式で機械的手法により強制粉砕し、その
平均粒径25μ以下で最大粒を−42μ（−350mesh）
に限定することにより解決できることを見出した
ものである。水アトマイズままで例えば高圧水を
噴射し、本願発明の機械粉砕粉と同等の平均粒
径、並びに最大粒径を限定したものを製造できる
が、この手法では、同様の効果を得ることはでき
ないことも判明した。この理由は定かではない
が、機械粉砕によつて粉末表面に創生面を現出さ
せること、および粉末に歪を付させることが新規
な効果を与える原因と推定される。
また本願発明は機械粉砕をする際、水アトマイ
ズ粉末ままの状態で実施することに特徴がある。
工具鋼粉末の場合、水アトマイズままの急冷凝固
状態において、硬化したマルテンサイト相と残留
オーステナイトとδフエライト、ならびに炭化物
相からなるが、硬化したマルテンサイトの脆性を
利用することで、効果的に粉砕を促進させること
ができる利点がある。
水アトマイズ粉末を焼なましした場合は、マト
リツクスがフエライトとなり、粉砕時にその塑性
変形によつてフレーク化し、後続する冷間成形時
の成形性を著しく減ずる欠点がある。
水アトマイズ粉末ままから機械粉砕後、プレス
成形やCIP（冷間静水圧プレス）成形のように実
質的に粘着剤（バインダー）を必要としない場合
には、粉末が軟らかい必要があり、焼なましを施
して冷間成形を実施するが、押出成形や射出成
形、スリツプキヤストのようにバインダーを使用
する場合は、粉砕後、焼なましを実施せずに冷間
成形を行つても良い。
粉砕後の平均粒径は25μ以下であることが必要
でこれ以上の平均粒径では焼結時の共晶炭化物の
微細化効果が十分でなく、最大粒径が350mesh
（42μ）以上だと、偶発的残留空孔の消失効果が
不十分となる。この際粉砕前の水アトマイズ粉末
の粒径はあまり大きいと、経済的範囲内では粉砕
が困難となる。通常使用される−100meshの粉末
を使用することが望ましい。
〔実施例〕
以下本発明を実施例に基づき説明する。
実施例 １
重量比でC1.51％、Si0.35％、Mn0.29％、Cr4.2
％、W11.2％、Mo0.5％、V5.1％、Co5.3％、残
部鉄および不可避的不純物からなるAISIT15相
当の高速度鋼水アトマイズ粉末を作成した。この
粉末を−100meshで分級し、O2含有量を測定し
たところ、1900ppmであつた。この粉末から更に
−200mesh、−350meshの２種類の分級粉末を得
た。これら３種類のそれぞれの平均粒径は57、
39、20μであつた。これらの３種類の粉末を900
℃×3hr真空焼なましを実施後、O2含有量は
900ppmに低下した。この後、Ｃ粉末を重量比で
0.12％添加混合した。
またこの他に水アトマイズままの−100meshの
水アトマイズ粉末を乾燥後、アトリツター
（atrittor）で300rpmで3hrの機械粉砕をArガス
雰囲気下で行ない、−350meshで分級した。この
時最大粒径は42μで平均粒径は17μでO2含有量
3800ppmであつた。この機械粉砕粉末にＣ粉末を
0.3％添加後、900℃で3hrの真空焼なましを行つ
た。O2量は1600ppmに低下した。
以上４種類の粉末を6ton／cm2の成形圧で8w×
6t×50にプレス成形後、10-2Torrの真空中で
1235、1245、1255℃の３種類の温度で1hr保持後
炉中放冷した。
焼結後の試験片は860℃×3hrの焼なまし後、
6.5w×5t×50の抗析試験片を削出後、T15の標
準熱処理（1240℃焼入、570℃×1hr×３回焼戻）
を施し、抗折試験を実施した。
さらに水中法で密度を測定した。この結果を第
１表に示す。なお、同表中に30φ溶製材の同一熱
処理条件下の特性測定結果を示した。
平均粒径57μの試料Ａは焼結温度の上昇と共
に、焼結密度は増加し、ともなつて抗折強度と熱
処理硬さが上昇する。しかし、溶製材と対比する
と、最高特性が得られる1255℃焼結でも抗折強度
は、205Kg／mm2で溶製材の63％であり、かつ得ら
れる焼戻硬さもHRC65.8と低い。これは第２図
に示すように共晶炭化物が粗大化し、形状も角形
化すること、あわせてオーステナイト結晶粒度も
粗大化することによる。
このように、従来技術では焼結材は溶製材より
特性的に低いものしか得ることができない。
[Industrial Field of Application] The present invention relates to a method for manufacturing a sintered tool steel member. [Prior Art] It is known to manufacture members of a group of tool steels called SKH and SKD in JIS by powder metallurgy.
In particular, after annealing and reduction of irregularly shaped preliminary alloy powder made by water atomization method, pressing,
A method of cold forming using CIP or the like to form a shape similar to the desired final product and then sintering in a vacuum or reducing atmosphere is attracting attention as a method of manufacturing sintered tool steel members. To express it more specifically, this production method usually involves classifying water atomized irregularly shaped powder with an O 2 content of 5000 ppm or less using -100 mesh, and dividing it into particles with an average particle size of 50 μm.
After mixing, it is reduced in a vacuum to less than 15,000ppm.
After reducing the amount of O 2 and performing annealing and softening treatment in the same treatment to soften the powder and improve moldability,
This is a method in which C is added and mixed in an amount corresponding to the stoichiometric value necessary to reduce the oxides in the powder coat, followed by cold forming and subsequent sintering. This method involves reducing surface oxides on the powder with CO gas generated from added C or C added in advance to the powder as a pre-alloying element. By utilizing the two effects of a type of liquid phase sintering that utilizes the partial liquid phase of eutectic carbide, it is possible to produce a tool steel sintered member with low oxygen and close to true density. [Problems to be solved by the invention] However, in the above manufacturing method, the current -
When using water atomized powder with a 100mesh and average particle size of around 50μ, it is difficult to avoid coarsening of eutectic carbides and coarsening of austenite crystal grains during sintering. This has the disadvantage that mechanical properties deteriorate. In addition, large residual pores may be generated locally, and there are concerns about reliability compared to melt-molded materials. [Means for Solving the Problems] As a result of various studies on ways to solve the above two drawbacks, the present invention has been developed by forcibly crushing water-atomized powder using a wet or dry mechanical method to reduce the average particle size of the powder. -42μ (-350mesh) for maximum grain size of 25μ or less in diameter
It was discovered that the problem can be solved by limiting the problem to . Although it is possible to produce powder with a limited average particle size and maximum particle size equivalent to the mechanically pulverized powder of the present invention by, for example, spraying high-pressure water while water is atomized, it is not possible to obtain the same effect with this method. It was also revealed. Although the reason for this is not clear, it is presumed that the mechanical grinding causes a generated surface to appear on the surface of the powder and the fact that the powder is distorted is the cause of the novel effect. Furthermore, the present invention is characterized in that mechanical pulverization is carried out in the state of water atomized powder.
In the case of tool steel powder, it consists of a hardened martensite phase, residual austenite, δ ferrite, and a carbide phase in the rapidly solidified state of water atomization, but by utilizing the brittleness of hardened martensite, it can be effectively pulverized. It has the advantage of being able to promote When water atomized powder is annealed, the matrix becomes ferrite, which is plastically deformed during pulverization to form flakes, which significantly reduces formability during subsequent cold forming. After mechanically pulverizing the water atomized powder, the powder must be soft and annealing is required in cases where virtually no adhesive (binder) is required, such as press molding or CIP (cold isostatic pressing) molding. However, when a binder is used in extrusion molding, injection molding, or slip casting, cold forming may be performed without annealing after pulverization. The average particle size after crushing must be 25μ or less; if the average particle size is larger than this, the effect of refining the eutectic carbide during sintering will not be sufficient, and the maximum particle size will be 350mesh.
(42μ) or more, the effect of eliminating accidental residual pores will be insufficient. At this time, if the particle size of the water atomized powder before pulverization is too large, pulverization becomes difficult within an economical range. It is desirable to use the commonly used −100 mesh powder. [Examples] The present invention will be described below based on Examples. Example 1 Weight ratio: C1.51%, Si0.35%, Mn0.29%, Cr4.2
%, W11.2%, Mo0.5%, V5.1%, Co5.3%, balance iron and unavoidable impurities.High speed steel water atomized powder equivalent to AISIT15 was created. This powder was classified with -100mesh and the O 2 content was measured and found to be 1900 ppm. Two types of classified powders of -200mesh and -350mesh were further obtained from this powder. The average particle size of each of these three types is 57,
It was 39.20μ. 900 of these three types of powder
After performing vacuum annealing for ℃×3hr, the O 2 content is
It decreased to 900ppm. After this, add C powder in weight ratio.
0.12% was added and mixed. In addition, -100mesh water atomized powder was dried and then mechanically pulverized using an atrittor at 300 rpm for 3 hours in an Ar gas atmosphere, and classified at -350mesh. At this time, the maximum particle size is 42μ, the average particle size is 17μ, and the O 2 content
It was 3800ppm. Add C powder to this machine-pulverized powder.
After adding 0.3%, vacuum annealing was performed at 900°C for 3 hours. O2 amount decreased to 1600ppm. The above four types of powders were mixed at a molding pressure of 6 tons/cm 2 for 8w
After press forming into 6t×50, in vacuum at 10 -2 Torr
After being held at three temperatures of 1235, 1245, and 1255°C for 1 hour, it was allowed to cool in the furnace. After sintering, the specimen was annealed at 860°C for 3 hours.
After cutting a 6.5w x 5t x 50 anti-resistance test piece, T15 standard heat treatment (quenching at 1240℃, tempering at 570℃ x 1hr x 3 times)
was applied, and a bending test was conducted. Furthermore, the density was measured using an underwater method. The results are shown in Table 1. In addition, the same table shows the results of measuring the characteristics of the 30φ melted material under the same heat treatment conditions. For sample A with an average grain size of 57 μm, as the sintering temperature increases, the sintered density increases, and the bending strength and heat treatment hardness increase accordingly. However, when compared with ingot material, even when sintered at 1255°C, where the best properties can be obtained, the bending strength is 205Kg/mm 2 , 63% of that of ingot material, and the obtained tempering hardness is also low, at HRC65.8. This is because, as shown in FIG. 2, the eutectic carbide becomes coarse and square in shape, and the austenite crystal grain size also becomes coarse. As described above, with the prior art, it is only possible to obtain sintered materials that have lower properties than molten materials.
【表】
試料Ｂ、Ｃは分級によつて粉末の細粒径材につ
いて同様の実験を行つたものである。
未粉砕粉末では粒径が微細になると真密度化す
る焼結温度が低下し、抗折強度もわずかに改善さ
れるが、溶製材と比較すると、抗折強度ならびに
熱処理硬さも低い。
これに対し、本願発明材は、1235℃の温度で真
密度化し、抗折強度も380Kg／mm2と溶製材の約1.2
倍の値を示す。焼戻硬さも溶製材と同等以上であ
る。焼結温度が1245、1255℃と漸次高くなると、
抗折強度は低下するが、これは溶製材でも認めら
れるオーバーヒート現象で、実用的には焼結温度
を下げることで解決できるので問題とならない。
第１図に本発明材のミクロ組織を示す。第３図
に溶製材のミクロ組織も示したが、本発明材は第
２図に示す試料Ａは勿論、溶製材より共晶炭化物
のサイズがきわめて微細であり、均一に分散して
いることが明らかである。
実施例 ２
重量比で、C1.51％、Si0.92％、Mn0.42％、
Cr13.12％、Mo0.91％、V0・94％、残部鉄およ
び不可避的不純物よりなるJISS KD11相当の冷
間工具鋼の水アトマイズ粉末を作成した。平均粒
径は、48μで真空乾操後のO2含有量は820ppmで
あつた。この粉末を乾式アトライターでエチルア
ルコール中で250rpmで4hrの粉砕を行つた。粉砕
後の平均粒径は13μで真空乾燥後のO2含有量は、
1400ppmであつた。この２種類の粉末にＣ粉末を
0.15％添加混合後、880℃×3hrの真空焼なましを
行つた後、6ton／cm2の成形圧で8φ×120のCIP
成形を行つた。このグリーンを1160、1180、1200
℃の３種類の温度条件下で1hr真空焼結を行なつ
た。これらの焼結体から5φ×70の抗折試験片
を削出後、860℃×3hrの大気焼なましを行ない、
1050℃で20分保持後空冷の焼入処理と200℃×1hr
×２回の焼戻処理を行ない、抗折テストを実施し
た。また、比較としては30φの溶製材から削出し
た同一熱処理条件の試験片とした。これらの結果
を第２表に示す。[Table] Samples B and C were obtained by conducting similar experiments on fine-grained powder materials by classification. In the case of unpulverized powder, when the particle size becomes finer, the sintering temperature at which true density is achieved is lowered, and the flexural strength is slightly improved, but the flexural strength and heat treatment hardness are also lower compared to molten material. On the other hand, the material of the present invention attains true density at a temperature of 1235°C and has a bending strength of 380 Kg/mm 2 , which is about 1.2 that of melted material.
Indicates the double value. The tempering hardness is also equal to or higher than that of ingot material. As the sintering temperature gradually increases to 1245 and 1255℃,
Although the bending strength decreases, this is an overheating phenomenon that is also observed in melted materials, and is not a problem because it can be solved practically by lowering the sintering temperature. FIG. 1 shows the microstructure of the material of the present invention. Figure 3 also shows the microstructure of the melt-sawn material, and it can be seen that the eutectic carbide size of the inventive material is extremely finer than that of the melt-sawn material, as well as sample A shown in Figure 2, and that it is uniformly dispersed. it is obvious. Example 2 Weight ratio: C1.51%, Si0.92%, Mn0.42%,
A water atomized powder of cold work tool steel equivalent to JISS KD11 was created, consisting of 13.12% Cr, 0.91% Mo, 94% V0, the balance iron and unavoidable impurities. The average particle size was 48μ, and the O 2 content after vacuum drying was 820ppm. This powder was ground in ethyl alcohol using a dry attritor at 250 rpm for 4 hours. The average particle size after crushing is 13μ, and the O 2 content after vacuum drying is:
It was 1400ppm. Add C powder to these two types of powder.
After adding 0.15% and mixing, vacuum annealing at 880℃ x 3 hours, and then CIP of 8φ x 120 with a molding pressure of 6ton/cm 2
I did the molding. This green is 1160, 1180, 1200
Vacuum sintering was carried out for 1 hour under three different temperature conditions: ℃. After cutting a 5φ x 70 bending test piece from these sintered bodies, it was annealed at 860℃ x 3 hours in the atmosphere.
After holding at 1050℃ for 20 minutes, air cooling quenching treatment and 200℃×1 hour
Tempering treatment was performed twice, and a bending test was conducted. For comparison, a test piece cut from a 30φ melted material and subjected to the same heat treatment conditions was used. These results are shown in Table 2.
【表】
実施例１の場合と同様、SKD11においても、
機械的粉砕粉末を出発原料とした発明Ｆはアトマ
イズまま粒径粉（比較材Ｅ）対比、20℃低い焼結
温度で真密度化し、その場合の抗折強度も溶製材
を上廻る特性を示す。
実施例 ３
重量比で、C2.83％、Si0.47％、Mn0.35％、
Cr4.10％、W11.9％、Mo7.80％、V8.00％、
Co10.02％、残部鉄および不可避的不純物からな
る高合金鋼の水アトマイズ粉末を作成した。平均
粒径は48μ最大粒径は68μでO2含有量は1900ppm
であつた。本粉末をN2雰囲気中で振動ミルで
1500rpm、振幅８mmで5hrの乾式粉砕を行なつた。
この時、平均粒径は22μ最大粒径は23μでO2含有
量は3400ppmであつた。
このアトマイズままと機械粉砕粉の２種類の粉
末にそれぞれＣ粉末を0.15％添加混合後、メチル
セルロース２％（市販品信越化学SM4000）とグ
リセリン１％、水11.5％を添加後、ヘンシエルミ
キサーで混練した。この混練物をインラインスク
リユータイプの射出成形機を用いて、成形圧300
Kg／cm2、金型温度90℃で20φ×150の円柱状に
成形した。この成形体を500℃の真空中で脱バイ
ンダー後、1170、1190℃×1trの真空焼結を実施
した。
この焼結材を900℃×3hrの焼なまし後、5φ×
70の抗折試験片を削出し、1180℃で焼入し、
550℃で1hr×３回の焼戻を実施した。なお比較材
としては、かかる高合金材質では偏析が著しく、
溶製材は製造できなかつたので粉末材のみについ
て、試験を行つた。その結果を第３表に示す。
本発明材は、1190℃×1hrの焼結で実質的に真
密度（光学顕微鏡下で残留空孔が観察できない）
に到達した。他方アトマイズままの48μ平均粒径
材については、1170℃、1190℃の両温度でも多孔
質で、真密度化は不可能と判断される。本発明材
はHRC71.5の焼戻硬さを示し、最高205Kg／mm2の
抗折強度を有した。[Table] As in Example 1, for SKD11,
Invention F, which uses mechanically crushed powder as a starting material, achieves true density at a sintering temperature 20°C lower than the atomized particle size powder (comparative material E), and exhibits the characteristic that the bending strength in this case exceeds that of the melted material. . Example 3 Weight ratio: C2.83%, Si0.47%, Mn0.35%,
Cr4.10%, W11.9%, Mo7.80%, V8.00%,
A water atomized powder of high-alloy steel consisting of 10.02% Co, balance iron and unavoidable impurities was prepared. The average particle size is 48μ, the maximum particle size is 68μ, and the O2 content is 1900ppm
It was hot. The powder was processed in a vibratory mill in an N2 atmosphere.
Dry milling was carried out at 1500 rpm and an amplitude of 8 mm for 5 hours.
At this time, the average particle size was 22μ, the maximum particle size was 23μ, and the O 2 content was 3400ppm. After adding and mixing 0.15% C powder to the two types of powder, the as-atomized powder and the mechanically pulverized powder, 2% methyl cellulose (commercial product Shin-Etsu Chemical SM4000), 1% glycerin, and 11.5% water were added, and then kneaded with a Henschel mixer. did. This kneaded material was molded using an in-line screw type injection molding machine under a molding pressure of 300.
Kg/cm 2 and a mold temperature of 90°C, it was molded into a cylindrical shape of 20φ×150. After removing the binder from this molded body in a vacuum at 500°C, vacuum sintering was performed at 1170 and 1190°C x 1 tr. After annealing this sintered material at 900℃ x 3 hours, 5φ x
70 bending test pieces were cut out, quenched at 1180℃,
Tempering was performed at 550°C for 1 hr x 3 times. As a comparative material, such high alloy materials have significant segregation and
Since ingot lumber could not be manufactured, tests were conducted only on powdered lumber. The results are shown in Table 3. The material of the present invention has substantially true density (residual pores cannot be observed under an optical microscope) after sintering at 1190°C for 1 hour.
reached. On the other hand, the atomized material with an average particle diameter of 48μ remains porous even at both temperatures of 1170°C and 1190°C, and it is judged that true densification is impossible. The material of the present invention exhibited a tempering hardness of HRC71.5 and a maximum bending strength of 205 Kg/mm 2 .
かかる如く、本願発明の手法により、溶製材な
らびに従来の水アトマイズ粉末を出発原料とした
場合、高密度化が不可能な材料系においても、工
業性に優れた材料の製造が可能なることを判明し
た。
As described above, it has been found that by using the method of the present invention, it is possible to manufacture materials with excellent industrial efficiency even in material systems that cannot be made highly densified, when melted lumber and conventional water atomized powder are used as starting materials. did.
第１図は、本発明法によるAISI T15相当材の
ミクロ金属組織顕微鏡写真、第２図は、従来法に
よるAISI T15相当材のミクロ金属組織顕微鏡写
真、第３図はAISI T15相当溶製材のミクロ金属
組織顕微鏡写真である。
Figure 1 is a micrometallic micrograph of a material equivalent to AISI T15 produced by the method of the present invention, Figure 2 is a microscopic micrograph of a material equivalent to AISI T15 produced by the conventional method, and Figure 3 is a micrograph of a melted material equivalent to AISI T15. This is a metallographic micrograph.
Claims (1)
Ｖ、Co、Si、Mn、Niの単独又は複数をCr3.0〜
15.0％、Ｗ＋2Mo30.0％以下、V15.0％以下、
Co15.0％以下、Si1.5％以下、Mn1.0％以下、
Ni5.0％、残部鉄および不可避的不純物からなる
工具鋼合金で、水アトマイズ法によつて予備合金
化された−100meshの不規則形状粉末をアトマイ
ズままの状態から湿式又は乾式で機械的に粉砕し
て、平均粒径25μ以下、最大粒径42μ以下の粉末
とし、この粉末を焼結用の原料粉末とすることを
特徴とする工具鋼焼結部材の製造法。1 C0.6-3.0% by weight, and Cr, W, Mo,
V, Co, Si, Mn, Ni or more in Cr3.0~
15.0%, W+2Mo30.0% or less, V15.0% or less,
Co15.0% or less, Si1.5% or less, Mn1.0% or less,
A tool steel alloy consisting of 5.0% Ni, balance iron and unavoidable impurities. -100mesh irregularly shaped powder pre-alloyed by water atomization method is mechanically pulverized in the atomized state using wet or dry methods. A method for producing a sintered tool steel member, characterized in that the powder has an average particle size of 25 μm or less and a maximum particle size of 42 μm or less, and this powder is used as a raw material powder for sintering.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60260173A JPS62120401A (en) | 1985-11-20 | 1985-11-20 | Production of sintered tool steel member |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60260173A JPS62120401A (en) | 1985-11-20 | 1985-11-20 | Production of sintered tool steel member |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62120401A JPS62120401A (en) | 1987-06-01 |
| JPH0222121B2 true JPH0222121B2 (en) | 1990-05-17 |
Family
ID=17344331
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60260173A Granted JPS62120401A (en) | 1985-11-20 | 1985-11-20 | Production of sintered tool steel member |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62120401A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2755974B2 (en) * | 1988-12-06 | 1998-05-25 | 日立金属株式会社 | Powder high speed tool steel |
| JPH02182867A (en) * | 1989-01-06 | 1990-07-17 | Daido Steel Co Ltd | Powdered tool steel |
| JPH02263901A (en) * | 1989-04-04 | 1990-10-26 | Daido Steel Co Ltd | Powder for metal injection-molding and manufacture thereof |
| JPH0759743B2 (en) * | 1989-05-23 | 1995-06-28 | 冨士ダイス株式会社 | High strength and high hardness sintered alloy |
| US20050227772A1 (en) * | 2004-04-13 | 2005-10-13 | Edward Kletecka | Powdered metal multi-lobular tooling and method of fabrication |
| JP6096040B2 (en) * | 2013-04-17 | 2017-03-15 | 山陽特殊製鋼株式会社 | Powdered high-speed tool steel with excellent high-temperature tempering hardness |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5484813A (en) * | 1977-12-20 | 1979-07-06 | Toshiba Corp | Manufacture of sintered high-speed steel |
-
1985
- 1985-11-20 JP JP60260173A patent/JPS62120401A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5484813A (en) * | 1977-12-20 | 1979-07-06 | Toshiba Corp | Manufacture of sintered high-speed steel |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62120401A (en) | 1987-06-01 |
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