JPS61117202A - Low alloy iron powder for sintering - Google Patents

Abstract

PURPOSE:To obtain low alloy iron powder for sintering having superior hardenability and compactibility at a reduced cost of starting materials by specifying a composition consisting of Mo, C, O, Si, Cr, Cu, Ni and Fe. CONSTITUTION:This low alloy iron powder for sintering consists of, by weight, 0.2-2.0% Mo, <=0.05% C, <=0.2% O, <=0.2% in total of Si, Cr, Cu and Ni, and the balance Fe with inevitable impurities, and it is simply obtd. by a water spraying method by which water is sprayed under high pressure on a molten alloy having said composition allowed to flow out of a tundish. The powder has superior hardenability and compactibility and is suitable for use as a material for a high density and high strength sintered material for structural machine parts.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は構造用機械部品等に適用する高密度高強度焼結
材料である焼結用低合金鉄粉末に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a low-alloy iron powder for sintering, which is a high-density, high-strength sintered material that is applied to structural machine parts and the like.

（従来の技術） 一般に、機械構成材料として多用されている鉄系焼結材
料の高強度化が要望され、これに対して合金化、高密度
化及び均質化等の種々の強化方法により強度的に優れた
焼結材料の開発が行なわれている。(Prior art) In general, there is a desire to increase the strength of iron-based sintered materials, which are often used as machine component materials. Sintered materials with excellent properties are being developed.

例えば合金化によシ材料の高強度化を達成する方法（以
下合金化強化方法という）としては、銅（Ｃｕ）　、　
ニッケル（Ｎ１）　、　−？　ンガｙ　（Ｍｎ）及びク
ロム（Ｃｒ）等の合金元素粉末を個々に鉄粉末に混合ｆ
ｕｎ法’ｐ、前記強化元素（Ｃｕ、　Ｎｉ　、　Ｍｎ、
　Ｃｒ等）を予め合金化したプレアロイ粉末を用いる予
備合金化法等が用いられている。For example, as a method for achieving high strength of materials by alloying (hereinafter referred to as alloying strengthening method), copper (Cu),
Nickel (N1), -? Alloying element powders such as Mn (Mn) and chromium (Cr) are individually mixed with iron powder.
un method'p, the strengthening elements (Cu, Ni, Mn,
A pre-alloying method using a pre-alloyed powder that is pre-alloyed with Cr, etc.) is used.

また、高密度化強化方法としては、２９ｒｅｓｓ−２５
ｉｎｔｅｒ法や焼結鍛造法（Ｐ／１’　）等が行なわれ
ている。In addition, as a densification strengthening method, 29ress-25
The inter method, sinter forging method (P/1'), etc. are used.

さらに、均質化強化方法としては焼結材料を焼結する際
に高温焼結を行なう均質化法が行なわれている。Furthermore, as a homogenization strengthening method, a homogenization method is used in which high temperature sintering is performed when sintering a sintered material.

上記以外のものでは構造用機械部品の空孔を球状化する
球状化法等の強化策が知られている。In addition to the above, strengthening measures such as the spheroidization method, which spheroidizes the pores of structural mechanical parts, are known.

しかしながら上記各種の強化法はいずれも焼結材料の強
化に効果をもたらしているものの、いずれの方法も何ら
かの問題点を含んでいる。However, although all of the above-mentioned various strengthening methods are effective in strengthening the sintered material, each method includes some problems.

すなわち、高密度化強化法としての２　ｐｒｅｓｓ　−
２５ｉｎｔｅｒ法や焼結鍛造法（Ｐ／Ｆ）等においては
、製造工程を変更したり追加したりして圧縮等の強加工
を施すことにより構造用機械部品等の高密度化を達成し
、ているので、強加工を行なう際の雰囲気管理、温度設
定等の管理的工程が増加して製造工程が繁雑となり、こ
のため製造コストが大幅に上昇するという問題を有して
いた。That is, 2 press − as a densification strengthening method
In the 25inter method, sinter forging method (P/F), etc., high densification of structural mechanical parts etc. is achieved by changing or adding manufacturing processes and applying strong processing such as compression. As a result, the number of administrative steps such as atmosphere control and temperature setting during heavy processing increases, making the manufacturing process complicated, which poses the problem of significantly increasing manufacturing costs.

また、合金化強化法のうち混合法においては、添加した
合金元素を鉄（Ｆｅ）中に充分に拡散させるのに長時間
を必要とするという問題があり、まだ活性金属であるク
ロム（Ｃｒ）やマンガｙ（Ｍｎ）等は焼結雰囲気を厳密
にコントロールしないと酸化をおこし、拡散を妨げられ
るという問題があった。In addition, among the alloying strengthening methods, the mixing method has the problem that it takes a long time to sufficiently diffuse the added alloying elements into iron (Fe), and chromium (Cr, which is still an active metal) If the sintering atmosphere is not strictly controlled, oxidation will occur and diffusion will be hindered.

さらに、予備合金化法においても、合金化により粉末の
硬度が増して圧縮成形性が低下し、従って構造用機械部
品の高密度化を阻止していた。Furthermore, even in the prealloying method, alloying increases the hardness of the powder and reduces compression moldability, thus preventing higher density of structural mechanical parts.

ところで、従来前記予備合金化法における圧縮成形性の
低下の問題を解消するだめに種々の提案がなされており
、例えば「低合金粉末鉄の製法」　（特公昭４５−９６
４９号公報）においては、合金元素を特殊還元法によっ
て鉄粉末の表面に付着させて圧縮成形性の改善を図るよ
うにすることが提案されている。By the way, various proposals have been made to solve the problem of deterioration of compression formability in the pre-alloying method, such as the "Production method of low alloy powder iron" (Japanese Patent Publication No. 45-96
No. 49) proposes to improve compression moldability by attaching alloying elements to the surface of iron powder by a special reduction method.

（発明が解決しようとする問題点） しかしながら上記従来の低合金粉末鉄の製法では、圧縮
成形性の向上は達成したものの粉末自体の価格は通常市
販されている低合金鋼粉に比べて相当に割高となってお
り、製造コストに占める原料コスト占有率が高く、構造
用機械部品を焼結材料によって形成する際の大きな障害
となっていた。(Problems to be Solved by the Invention) However, although the above-mentioned conventional method for manufacturing low-alloy powder iron has improved compression formability, the price of the powder itself is considerably higher than that of commercially available low-alloy steel powder. It is relatively expensive, and raw material costs account for a high proportion of manufacturing costs, which has been a major obstacle when forming structural mechanical parts using sintered materials.

（問題点を解決するための手段） 本発明は上記実情に鑑みてその問題点を克服すべくなさ
れたものであり、低価格すなわち原料コストを低くする
と共に焼入性及び圧縮成形性に優れた焼結用低合金鉄粉
末を提供することを目的としている。(Means for Solving the Problems) The present invention has been made in view of the above-mentioned circumstances to overcome the problems. The purpose is to provide low alloy iron powder for sintering.

上記目的を達成するだめの本発明の特徴は、低合金鉄粉
末中に重量百分率でモリブデン（Ｍｏ　）を０．２〜２
．０％、炭素（Ｃ）を０．０５％以下、酸素（Ｏ２）を
０．２％以下夫々含有すると共に珪素（Ｓｉ）、クロる
ことにある。The feature of the present invention for achieving the above object is that molybdenum (Mo) is contained in the low alloy iron powder at a weight percentage of 0.2 to 2.
．． 0%, carbon (C) at 0.05% or less, oxygen (O2) at 0.2% or less, and silicon (Si).

（作　　　用） 上記のように構成した本発明に係る焼結用低合金鉄粉末
において、モリブデン（ＭＯ）を鉄（Ｆｅ）粉末中に含
有せしめたのは、モリブデン（Ｍｏ）は予備合金化する
と圧縮成形性を失わず、また焼入性も充分に確保するこ
とができるからである。(Function) In the low-alloy iron powder for sintering according to the present invention configured as described above, molybdenum (MO) is contained in the iron (Fe) powder because molybdenum (Mo) is pre-alloyed. This is because compression moldability is not lost and hardenability can also be sufficiently ensured.

但しモリブデン（Ｍｏ）は０．２チ未満では熱処理後の
機械的特性が低下してしまい、また２、０係を超えると
逆に圧縮成形性が低下し、かつ熱処理後の強度もＭＯを
添加した割には向上しないという傾向があるからである
。However, if molybdenum (Mo) is less than 0.2 mm, the mechanical properties after heat treatment will decrease, and if it exceeds 2.0, compression moldability will decrease, and the strength after heat treatment will decrease. This is because there is a tendency that no improvement is achieved.

さらに珪素（Ｓｉ）　、りＣＩ　Ａ　（Ｃｒ）、銅（Ｃ
ｕ）及びニッケル（Ｎ１）の金属元素を総含有量で０．
２％以下に限定したのは、前記各金属元素には夫々圧縮
成形性を低下させる作用があるからである。不可避不純
物としては他にＰ、　Ｓ、　Ｍｎ等がある。Furthermore, silicon (Si), RICI A (Cr), copper (C
u) and nickel (N1) in a total content of 0.
The reason why the content is limited to 2% or less is that each of the metal elements has the effect of reducing compression moldability. Other unavoidable impurities include P, S, Mn, etc.

また、炭素（Ｃ）は０．０５％、酸素は０．２％を夫々
超えると合金の圧縮成形性を著しく悪化させるため夫々
上記重量百分率に抑え、圧縮成形性の向、上のために有
効に作用している。In addition, if carbon (C) exceeds 0.05% and oxygen exceeds 0.2%, the compression formability of the alloy will be significantly deteriorated, so it is effective to limit the weight percentages to the above weight percentages and improve the compression formability. It is acting on

以上のように鉄（Ｆｅ）粉末中に上記重量百分率の金属
元素を含有せしめたので、圧縮成形性を高くすると共に
焼入性にも優れた焼結用低合金粉末を低コストで提供す
ることができる。As described above, since the above weight percentage of metal elements is contained in the iron (Fe) powder, it is possible to provide a low-alloy powder for sintering that has high compression moldability and excellent hardenability at a low cost. I can do it.

（実　施　例） 以下、本発明の実施例を比較例と対比しつつ説明する。(Example) Examples of the present invention will be described below in comparison with comparative examples.

実施例１ 溶解炉にて目標成分に調整した溶湯を作シ、この溶湯を
タンプ年イッシーよシ流出させた後、この流出した溶湯
に高圧水を噴霧して作用させ粉末化する（以下水噴霧法
という）。前記水噴霧法により形成した粉末を分解アン
モニア雰囲気中で９００℃ｘ６０分の還元処理を施した
後粉砕し、その後８０　ｍｅｓｈの篩で分級し、−８０
ｍｅｓｈ粉を得た。この粉末の組成については第１表の
該当欄に示すように、鉄（Ｆｅ）傘半とモリブデン（Ｍ
ｏ）０．３１１Ｊ、酸素（Ｏｚン０．０８％、炭素（Ｃ
）０．０２％、珪素（Ｓｌ）０．０２９４の各重量百分
率となっている。Example 1 A molten metal adjusted to the target composition is produced in a melting furnace, and the molten metal is allowed to flow out from a tamp, and then high-pressure water is applied to the outflowing molten metal to form a powder (hereinafter referred to as water spray). law). The powder formed by the water spray method was subjected to reduction treatment at 900°C for 60 minutes in a decomposed ammonia atmosphere, and then pulverized, and then classified with an 80 mesh sieve to obtain -80
Mesh powder was obtained. The composition of this powder is as shown in the relevant column of Table 1.
o) 0.311J, oxygen (0.08%), carbon (C
) 0.02%, and silicon (Sl) 0.0294.

上記−８０ｍｃｓｈ粉に対し圧縮成形性の数値を得るた
めに試験を行なうこととし、ＪＳＰＭ標準１−６４（金
属粉の圧縮性試験法）に準拠して試験を実施した。成形
を行なう際の成形圧力を１平方センチメートル当り３ｔ
、５１，７ｔとしてこの３水準についての試験を行なっ
た結果、第２表に示すように夫々６．２２匙、！、６．
８７％、１，７．２ｊりｄとなっており、また、７泡の
成形圧力における成形体密度を第１図に示している。A test was conducted to obtain a compression moldability value for the -80mcsh powder, and the test was conducted in accordance with JSPM Standard 1-64 (Metal Powder Compressibility Test Method). The molding pressure during molding is 3 tons per square centimeter.
, 51,7 tons, and the results of the tests for these three levels were 6.22 spoons each, as shown in Table 2. ,6.
87%, 1.7.2j d, and the density of the molded body at the molding pressure of 7 bubbles is shown in FIG.

次に、熱処理後め引張り強さを測定するためにＪＳＰＭ
２−６４の金属焼結体の引張試験片を用い引張試験を行
なった。この引張試験片は、第１表に示す粉末に対し黒
鉛粉０．５チ及び潤滑剤ａ、Ｓチを加えて混合した後、
約７．０〜の成形体密度となるよう成形した後、分解ア
ンモニア雰囲気中で１２００℃×４０分の焼結を行ない
、この焼結体に対し８７０℃ｘ５０分の熱処理を施し、
焼割れ及び熱ひずみを防止するため油による焼入液に浸
潤させて冷却し、１７０℃×９０分の焼戻しを行なった
ものである。尚引張試験は２５品。のクロスヘッドスピ
ードで実施した。この結果が、第７図に示してあり、本
実施例においては９７Ｋｇ％−の強度が得られた。Next, JSPM was used to measure the tensile strength after heat treatment.
A tensile test was conducted using a tensile test piece of the metal sintered body No. 2-64. This tensile test piece was prepared by adding and mixing 0.5 g of graphite powder and lubricants a and S to the powder shown in Table 1.
After molding to a compact density of about 7.0~, sintering is performed at 1200°C for 40 minutes in a decomposed ammonia atmosphere, and the sintered body is heat treated at 870°C for 50 minutes.
In order to prevent quench cracking and thermal distortion, the material was soaked in a quenching fluid containing oil, cooled, and then tempered at 170° C. for 90 minutes. In addition, 25 items were tested in the tensile test. The test was carried out at a crosshead speed of The results are shown in FIG. 7, and in this example a strength of 97 kg% was obtained.

冑、第１表は実施例２乃至４及び比較□例１乃至４の粉
末の組成をも併せて示しており、第２表には各条件にお
ける成形圧力に対する上記各側の成形体密度をも示して
いる。また、第１図は実施例１ばかシでなく上記各側の
成形圧カフｔイシにおける成形体密度の特性をグラフに
より示すこととし、第２図には熱処理後の各側の引張強
さを比較したグラフも併せて示すこととする。Table 1 also shows the compositions of the powders of Examples 2 to 4 and Comparative Examples 1 to 4, and Table 2 also shows the density of the compacts on each side with respect to the molding pressure under each condition. It shows. In addition, Fig. 1 shows the characteristics of the compact density at the molding pressure cuffs on each side as a graph instead of those in Example 1, and Fig. 2 shows the tensile strength on each side after heat treatment. A comparison graph is also shown.

実施例２ 水噴霧法によシ形成した粉末を前記実施例１第２表 と同様に環元処理及び分級処理して、重量百分率でモリ
プデ７　（Ｍｏ）を０．６％、酸素（Ｏ２）　ｔ−０，
０８％。Example 2 Powder formed by the water spray method was subjected to the ring treatment and classification treatment in the same manner as in Table 2 of Example 1 to obtain 0.6% molypde 7 (Mo) and oxygen (O2) by weight percentage. t-0,
08%.

炭素（Ｃ）を０．０２％、珪素（Ｓｉ）を０．０１％夫
々含有する低合金鉄粉末を得だ。前記組成の低合金鉄粉
末に対し圧縮成形性及び引張強さの試験を行なった。そ
の結果は圧縮成形性が第２表に示すように”１ｃｒｌ、
５”ｃｒｌ　、７”ｃｒｉｌの成形圧力において夫々６
．２０／、、　６．８５地、Ｚ１９イ、の成形体密度で
あり、熱処理後の試験片の引張強さは第２図゛に示すよ
うに１ｏ　５　Ｋｐｆ／、７であった。A low alloy iron powder containing 0.02% carbon (C) and 0.01% silicon (Si) was obtained. Compression formability and tensile strength tests were conducted on the low alloy iron powder having the above composition. The results showed that the compression moldability was 1 crl, as shown in Table 2.
6 at molding pressures of 5"crl and 7"cril, respectively.
．． The density of the compact was 20/, 6.85, Z19, and the tensile strength of the test piece after heat treatment was 10 5 Kpf/, 7, as shown in FIG.

実施例３ 上記２例と同様に水噴霧法により形成した粉末に環元処
理及び分級処理を施し、鉄（Ｆ’ｅ）＄＃＃中重量百分
率でモリプデ／（Ｍｏ）を１．０％、酸素（Ｏｚ）ヲｏ
、ｏ　７　％、　炭ｉ　（Ｃ）を（ＬＯ１％、珪素（Ｓ
ｌ）を０．０２％夫々含有する低合金鉄粉末を得た。こ
の低合金鉄粉末に対し圧縮成形性及び引張強さを調べる
ため実施例１．２と同−条件及び同一方法で試験を行な
った。その結果７癩のとき７．１７ターの成形体密度と
１１０Ｋｆｆ／ｌｌの引張り強さを示した。Example 3 Powder formed by the water spray method in the same manner as in the above two examples was subjected to a ring treatment and a classification treatment, and 1.0% of molybdenum/(Mo) was added to the iron (F'e) $## medium weight percentage. Oxygen (Oz)
, o 7%, carbon i (C) (LO1%, silicon (S
A low alloy iron powder containing 0.02% of each of l) was obtained. In order to examine the compression moldability and tensile strength of this low alloy iron powder, tests were conducted under the same conditions and in the same manner as in Example 1.2. As a result, the molded product density was 7.17 ter and the tensile strength was 110 Kff/ll at 7 leprosy.

実施例４ 前記実施例１乃至３と同様に水噴霧法により形成した粉
末に環元処理及び分級処理を施し、鉄（Ｆｅ）呑半中に
重量百分率でモリブデン（Ｍｏ）を１．５％、酸素（Ｏ
→を０，０８％、炭素（Ｃ）を０．０２％、珪素同様に
圧縮成形性と引張り強さの試験を行ない、夫々７，４ｉ
において７．１４　’／、４の成形体密度と１１２Ｋｇ
ｆ７．の引張′り強さの値を得た。Example 4 Powder formed by the water spray method in the same manner as in Examples 1 to 3 was subjected to a ring treatment and a classification treatment, and 1.5% by weight of molybdenum (Mo) was added to an iron (Fe) cup. Oxygen (O
→ 0.08%, carbon (C) 0.02%, compression moldability and tensile strength tests were conducted in the same way as silicon, and 7 and 4i, respectively.
With a compact density of 7.14'/, 4 and 112Kg
f7. The tensile strength value was obtained.

ｍ１ 比較例１　　′ 比較例１は代表的な市販の低合金鉄粉末であり、油噴霧
法により製造されたものである二油噴霧法は、噴霧媒と
して油を用いるため、粉化時の酸化が抑制でき、酸素＜
０２＞　、炭素（Ｃ）の低い粉末が生成されるので圧縮
性に優れるが、粉末からの油分の除去にコストがかかる
。この粉末を化学分析したところ、鉄（Ｆｅ）参半中に
重量百分率でモリブデン（Ｍｏ）を０．２３％、クロム
（Ｃｒ）をα９５％、マンガｙ　（Ｍｎ）を０．７６％
含有していることが分った。この比較例１について前記
各実施例と同様の条件で試験を行なった結果、圧縮成を 形性では７　／ｃａにおいて７．１５　’／イを示すも
、熱処理後の試験片の引張り強さでは各実施例の何れに
も及ばなかった。m1 Comparative Example 1 ' Comparative Example 1 is a typical commercially available low-alloy iron powder, which was produced by an oil spray method.Since oil is used as a spray medium in the two-oil spray method, oxidation during powdering is can be suppressed, oxygen <
02>, a powder with a low carbon (C) content is produced, so it has excellent compressibility, but it is costly to remove oil from the powder. Chemical analysis of this powder revealed that molybdenum (Mo) was 0.23% by weight, chromium (Cr) was α95%, and mangay (Mn) was 0.76% by weight.
It was found that it contained As a result of testing Comparative Example 1 under the same conditions as in each of the above-mentioned Examples, the formability of compression molding was 7.15'/I at 7/ca, but the tensile strength of the test piece after heat treatment was 7.15'/I. It was not as good as any of the examples.

比較例２ 比較例２は水噴霧法により形成された市販の低合金粉末
であり、その組成は第１表に示すように重量百分率でモ
リブデン（Ｍｏ）を０．５２％、マンガｙ　（Ｍｎ）．
１６％、ニッケル（Ｎｉ）をｔ　７９％夫々含有してい
る。強化元素であるニッケル（Ｎｉ）及びマンガン（Ｍ
ｎ　）の総量が１．９５％と各例中で最も多いため圧縮
成形性を示す成形体密度ではさ程高い数値を示していな
いが、熱処理品の引張り強さでは１０５ＫＦ〜と比較例
中量も引張り強くなっている。Comparative Example 2 Comparative Example 2 is a commercially available low-alloy powder formed by a water spray method, and its composition is as shown in Table 1, with a weight percentage of 0.52% molybdenum (Mo) and 0.52% mangay (Mn). ．．
It contains 16% of nickel (Ni) and 79% of nickel (Ni). Nickel (Ni) and manganese (M
The total amount of n) is 1.95%, which is the highest in each example, so the density of the compact, which indicates compression moldability, does not show a very high value, but the tensile strength of the heat-treated product is 105KF ~, which is the middle of the comparison example. It is also tensile and strong.

比較例５ 本例は、モリブデン（ＭＯ）と銅（Ｃｕ）とを予備合金
化した合金鉄粉末を用いており、鉄（Ｆｅ）呑未に対す
る割合は重量百分率でモリブデン（Ｍｏ　）を。Comparative Example 5 This example uses a ferroalloy powder prepared by pre-alloying molybdenum (MO) and copper (Cu), and the ratio of molybdenum (Mo) to iron (Fe) is expressed as a weight percentage.

０．６％、銅（Ｃｕ）を０．４　％　、珪素（Ｓｉ）を
α０１％、炭素０を０．０１％、酸素（Ｏ２）を０．０
８チ夫々含有した低合金鉄粉末である。この低合金鉄粉
末を用い、上記各側と同様、圧縮成形性及び引張り強度
の試験を行なったところ、銅（Ｃｕ）の添加によシ圧縮
成形性の著しい低下を示した。また、引張り強さでも何
れの実施例にも及ばないことが分った。0.6%, copper (Cu) 0.4%, silicon (Si) α01%, carbon 0 0.01%, oxygen (O2) 0.0
It is a low-alloy iron powder containing 80% of each. Using this low-alloy iron powder, compression moldability and tensile strength tests were conducted in the same way as for each side above, and it was found that the addition of copper (Cu) significantly reduced the compression moldability. It was also found that the tensile strength was not as good as any of the examples.

比較例４ 比較例４は低合金鉄粉末の組成を鉄（Ｆｅ）に対し重量
百分率で、モリブデン（Ｍｏ）を０．６％、クロム（Ｃ
ｒ）を０．５％、マンガン（Ｍｎ）を０．１３％、酸素
（Ｏρを０．１２％、炭素（Ｃ）を０．０１％含有した
ものを用いている。この低合金鉄粉末を圧縮成形性及び
引張り強度試験に供したところ、モリプデ／（Ｍｏ）と
クロム（Ｃｒ）を加えたので比較例５と同様に引張シ強
さでは第２図に示すように比較例２及び各実施例に近い
数値を示したが、圧縮成形性を示す成形体密度において
は第２表及び第１図に示すように余り高い数値を示さず
、圧縮成形性が著しく低いことが分った。Comparative Example 4 In Comparative Example 4, the composition of the low alloy iron powder was 0.6% molybdenum (Mo) and chromium (C) in weight percentage relative to iron (Fe).
This low alloy iron powder contains 0.5% of r), 0.13% of manganese (Mn), 0.12% of oxygen (Oρ), and 0.01% of carbon (C). When subjected to compression moldability and tensile strength tests, as shown in Figure 2, the tensile strength was the same as in Comparative Example 5, since Molypide/(Mo) and chromium (Cr) were added. Although the value was close to that of the example, the density of the compact, which indicates compression moldability, did not show a very high value as shown in Table 2 and FIG. 1, indicating that the compression moldability was extremely low.

以上の結果より、本発明に係る焼結用低合金鉄粉末を用
いて構造的機械部品を形成しても圧縮成形性に優れ、ま
た、機械的特性としての引張シ強さも備えているので、
市販の高価な焼結用低合金鉄粉末を原料として用いたも
のと比べても遜色がないばかりか含有量を好適なものと
することによシ、市販のものより好結果を挙げることか
できることが判明した。From the above results, even when structural mechanical parts are formed using the low alloy iron powder for sintering according to the present invention, it has excellent compression moldability and also has tensile strength as a mechanical property.
Not only is it comparable to products using commercially available expensive low-alloy iron powder for sintering as a raw material, but by adjusting the content to a suitable level, it is possible to achieve better results than commercially available products. There was found.

（発明の効果） 以上詳細に説明したように、本発明に係る焼結用低合金
鉄粉末によれば、以下のような効果を奏する。(Effects of the Invention) As described above in detail, the low alloy iron powder for sintering according to the present invention provides the following effects.

実質的に鉄（Ｆｅ）よりなる粉末中に重量百分率でモリ
ブデｙ　（Ｍｏ）　０．２〜２．０％、炭素（Ｃ）０．
０５％以下、酸素（Ｏ２）　０．２％以下夫々含有する
と共に珪素（Ｓｉ）　、りａ　ム（Ｃｒ）　、銅（Ｃｕ
）及びニア　ケル（Ｎｉ）の総含有量を０．２％以下に
抑えたので、機械構成部品の原材料として用いた場合、
同一成形圧力での圧縮性に極めて優れると共に成形部品
化した場合の強度についても優れた特性を示し、しかも
水噴霧法という低摩な製造方法によシ製造することがで
きるので製造コストにおける原料占有率を少なくするよ
うな安価な焼結用低合金鉄粉末を提供することができる
。Molybdenum (Mo) 0.2 to 2.0% and carbon (C) 0.2% to 2.0% by weight are contained in a powder substantially consisting of iron (Fe).
05% or less, oxygen (O2) 0.2% or less, and silicon (Si), rim (Cr), copper (Cu
) and Ni (Ni) to less than 0.2%, so when used as a raw material for machine components,
It has excellent compressibility at the same molding pressure and excellent strength when molded into parts, and can be manufactured using a low-friction manufacturing method called water spraying, which reduces the raw material share in manufacturing costs. It is possible to provide an inexpensive low-alloy iron powder for sintering that reduces the sintering rate.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図及び第２図は本発明に係る焼結用低合金鉄粉末を
説明するためのもので、第１図は成形圧カフ　ｔ／、Ｈ
における成形体密度、第２図は引張試験片による引張強
さを夫々実施例１乃至４゜比較例１乃至４について測定
した特性図である０特許　出　願人　トヨタ自動車株式
会社第１図 第２図Figures 1 and 2 are for explaining the low alloy iron powder for sintering according to the present invention, and Figure 1 shows the molding pressure cuff t/, H
Fig. 2 is a characteristic diagram of the tensile strength measured using tensile test pieces for Examples 1 to 4 and Comparative Examples 1 to 4, respectively.Patent Applicant Toyota Motor Corporation Fig. 1 Fig. 2 figure

Claims (1)

【特許請求の範囲】[Claims] （１）重量百分率で、モリブデン（Ｍｏ）を０．２〜２
．０％、炭素（Ｃ）を０．０５％以下、酸素（Ｏ＿２）
を０．２％以下夫々含有すると共に珪素（Ｓｉ）、クロ
ム（Ｃｒ）、銅（Ｃｕ）及びニッケル（Ｎｉ）の総含有
量を０．２％以下に抑え、不可避不純物を含む残部が実
質的に鉄（Ｆｅ）よりなることを特徴とする焼結用低合
金鉄粉末。(1) 0.2 to 2 molybdenum (Mo) in weight percentage
．． 0%, carbon (C) 0.05% or less, oxygen (O_2)
The total content of silicon (Si), chromium (Cr), copper (Cu) and nickel (Ni) is suppressed to 0.2% or less, and the remainder containing unavoidable impurities is substantially A low alloy iron powder for sintering, characterized in that it is made of iron (Fe).