JPH0428850A - Heat-resistant ferrous sintered alloy for sliding - Google Patents
Heat-resistant ferrous sintered alloy for slidingInfo
- Publication number
- JPH0428850A JPH0428850A JP13601590A JP13601590A JPH0428850A JP H0428850 A JPH0428850 A JP H0428850A JP 13601590 A JP13601590 A JP 13601590A JP 13601590 A JP13601590 A JP 13601590A JP H0428850 A JPH0428850 A JP H0428850A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- stainless steel
- alloy
- sintered alloy
- heat
- 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.)
- Pending
Links
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 28
- 239000000956 alloy Substances 0.000 title claims abstract description 28
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 title abstract 3
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 16
- 239000010935 stainless steel Substances 0.000 claims abstract description 16
- 229910000531 Co alloy Inorganic materials 0.000 claims abstract description 13
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 13
- 229910052796 boron Inorganic materials 0.000 claims abstract description 10
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 8
- 229910052715 tantalum Inorganic materials 0.000 claims abstract description 7
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 6
- 229910018487 Ni—Cr Inorganic materials 0.000 claims abstract description 5
- 229910052735 hafnium Inorganic materials 0.000 claims abstract description 5
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 5
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 5
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 21
- 239000000203 mixture Substances 0.000 claims description 17
- 229910052742 iron Inorganic materials 0.000 claims description 12
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 230000001747 exhibiting effect Effects 0.000 claims description 4
- 239000000843 powder Substances 0.000 abstract description 27
- 239000011159 matrix material Substances 0.000 abstract description 16
- 230000003647 oxidation Effects 0.000 abstract description 16
- 238000007254 oxidation reaction Methods 0.000 abstract description 16
- 229910000963 austenitic stainless steel Inorganic materials 0.000 abstract description 8
- 239000011812 mixed powder Substances 0.000 abstract description 4
- 238000005245 sintering Methods 0.000 abstract description 3
- 230000000694 effects Effects 0.000 description 11
- 239000000463 material Substances 0.000 description 11
- 239000011651 chromium Substances 0.000 description 8
- 230000013011 mating Effects 0.000 description 7
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 238000005260 corrosion Methods 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 5
- 239000012071 phase Substances 0.000 description 5
- 230000004584 weight gain Effects 0.000 description 3
- 235000019786 weight gain Nutrition 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 229910000765 intermetallic Inorganic materials 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910000905 alloy phase Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- VNNRSPGTAMTISX-UHFFFAOYSA-N chromium nickel Chemical compound [Cr].[Ni] VNNRSPGTAMTISX-UHFFFAOYSA-N 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000005496 eutectics Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 230000000116 mitigating effect Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910001120 nichrome Inorganic materials 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
Abstract
Description
（産業上の利用分野）
本発明は、高温環境で使用される軸受に利用するのに好
適な耐酸化性および耐摩耗性に優れた摺動用鉄系焼結合
金に関するものである。
（従来の技術）
内燃機関のターボチャージャに設けられる排気制御弁の
軸受のように、高温にさらされる摺動部品においては、
油潤滑を行うことができないので、耐摩耗性のある材料
が要求されると共に、排出ガスに対する耐腐蝕性や高温
耐酸化性も求められる。
従来、このような軸受材料としては、ステンレス鋼を使
用していた。
（発明が解決しようとする課題）
しかしながら、従来の軸受材料では、摩耗が著しく多く
、相手軸にあそびを生じたり、相手軸に焼き付いて異常
音を発生したりすることがあるなど、満足すべき耐久性
能を得ることはできないという問題点があり、このよう
な問題点を解決することが課題となっていた。
（発明の目的）
本発明は、このような従来の課題にかんがみてなされた
もので、密度比が高く、８００℃以上の高温でも酸化が
少なく、軸受自身および相手軸とも摩耗が少ない耐熱摺
動用焼結合金を提供することを目的としている。(Industrial Application Field) The present invention relates to a sliding iron-based sintered alloy having excellent oxidation resistance and wear resistance and suitable for use in bearings used in high-temperature environments. (Prior Art) In sliding parts that are exposed to high temperatures, such as bearings for exhaust control valves installed in turbochargers of internal combustion engines,
Since oil lubrication is not possible, materials with wear resistance are required, as well as corrosion resistance against exhaust gas and high temperature oxidation resistance. Conventionally, stainless steel has been used as the material for such bearings. (Problems to be Solved by the Invention) However, with conventional bearing materials, there is a significant amount of wear, which may cause play in the mating shaft, or may seize on the mating shaft and generate abnormal noise. There is a problem in that it is not possible to obtain durable performance, and it has been a challenge to solve this problem. (Object of the Invention) The present invention has been made in view of these conventional problems, and is a heat-resistant sliding bearing with a high density ratio, less oxidation even at high temperatures of 800°C or more, and less wear on both the bearing itself and the mating shaft. The purpose is to provide sintered alloys.
【発明の構成】
（課題を解決するための手段）
本発明に係わる耐熱摺動用鉄系焼結合金は、全体組成が
、重量比で、
Ｓｉ： ０．１〜３．７％
Ｃｒ：１１ 〜２４％
Ｎｉ： ４ 〜２０％
ＭＯ： １ 〜１０％
ＣＯ： ３ 〜１９％
Ｂ ： １ 〜３％
ならびにＦｅおよび不純物：残部からなり、且つ金属硼
化物が分散したＮｉ−Ｃｒ系ステンレス鋼基地中に、Ｓ
ｉ 、ＣｒおよびＭＯを含有するコバルト合金相：５〜
３０重量％が粒状に点在した組織を呈する構成としたこ
とを特徴としており、さらに上記の組成に加え、Ｎｂ、
Ｔａ、Ｈｆ。
Ｔｉ、Ｚｒｃ７）うち少なくとも１種：０．１−１％を
含み、上記組織を呈する構成としたことを特徴としてお
り、これらの耐熱摺動用鉄系焼結合金の構成を前述した
従来の課題を解決するための手段としている。
次に、本発明に係わる耐熱摺動用鉄系焼結合金のマトリ
ックス（基地）、コバルト合金相等の限定理由について
説明する。
マトリックス（基地）について：
マトリックスを形成するオーステナイト系ステンレス鋼
は、ＪＩＳで制定されている組成範囲、すなわちＮｉ：
８〜２２％およびＣｒ：１６〜２６％の組成範囲のもの
となるようにするのが好適である。
すなわち、ステンレス鋼中のＮｉおよびＣｒは鉄基地に
固溶しており、耐蝕性および耐熱性を向上する元素であ
る。この組成範囲は、例えば、原著者ソッフィーの「ス
テンレス鋼入門」 （特殊鋼倶楽部、昭和４８年発行）
に記載されているなど、−船釣に言われているように、
各々下限値より少ない場合にはその特性が不十分であり
。
上限値より多くしてもそれ以上の効果を生じない。
さらに、前記オーステナイト系ステンレス鋼は、Ｍｏを
２〜３％含むもの、および／またはＳｉを最大４％含む
ものであってもよい。
この場合、Ｍｏは耐蝕性を向上する元素であるので２％
以上含むものとすることも必要に応じて望ましいが、９
００℃を超える高温では、むしろＭ蝕を併進する作用が
ある。また、Ｍｏを多く含むステンレス鋼種は、硬度が
高く粉末の圧縮性が悪いことにより、３％以下が望まし
い。
また、Ｓｔは粉末を製造する際に溶湯の流れをよくし、
焼結体の耐酸化性を向上させる元素であるが、４％より
多く含有すると、硬度が高くなり、粉末の圧縮性が悪く
なるので好ましくない。
上述のオーステナイト系ステンレス鋼にＮｂ、Ｔａ、Ｈ
ｆ、Ｔｉ 、Ｚｒのうち少なくとも１種を添加すると、
鋼中に含まれる微量の炭素と炭化物を作り、マトリック
スの耐蝕性および高温での機械強度を向上させる。その
効果は銅粉中に０．１％以上で認められるが、１．５％
より多いと結晶粒界に析出物が目立つようになり靭性が
低下する傾向を示すので、上限は１．３％程度にとどめ
る必要がある。これは全体組成で０．１〜１％に相当す
る。
マトリックス中の金属硼化物は、フェロポロン粉の形で
添加された硼素と、ステンレス鋼粉中の主にクロムとが
反応して生成され、顕微鏡組織ではマトリックスのほぼ
全域に点在している。
硼素はマトリックスの成分と共晶液相を生成し、焼結体
の密度比を上昇させる。添加しない場合より密度は０
、２〜０ 、５ ｇ／ ｃｍｊ高くなる。このため、材
料の内部酸化を少なくする効果がある。また、硼化物を
マトリックス中に析出させて耐摩耗性を向上させる作用
がある。
硼素の含有量は、全体組成で１％より少ないと密度の上
昇および基地の強化が不十分であり、方、３％より多く
ｇｉ加すると粉末圧縮性が悪くなり、硼化物が多く析出
するために焼結体が硬くなって相手軸を摩耗させる。
コバルト合金相について：
次に、分散させる金属間化合物は、Ｓｉ：２．２〜２．
６％、Ｃｒニア、’５〜８．６％、Ｍｏ：２７〜２９％
およびｃｏ＝残部の組成を有する市販の合金粉などが好
適である。
この合金は、粉末が球状に近い形をしていて、マイクロ
ビッカース硬さで約７００程度であり、耐熱性を有する
と共に、比較的柔らかい基地に分散させると特に１３２
Ｍ摩耗を緩和させる作用があるという、多くの実験によ
って得た知見に基づいて添加したものである。
コバルト合金粉の添加量は５〜３０％の範囲が好適であ
る。すなわち、５％より少ないと上記の効果が少なく、
３０％を超えると混合粉の圧縮性が悪くなり、焼結体に
度が低く十分な強度かえられないと共に硬い相が多いた
めに相手材料を摩耗させ易くなるためである。
製造方法について：
このように本発明の焼結合金は、オーステナイト系ステ
ンレス鋼粉、フェロポロン粉およびコノヘルド系合金粉
との混合粉を圧縮成形および焼結して作られる。
焼結は、オーステナイト系ステンレス鋼の基地に硼化物
が生成し、且つコノヘルド系合金が拡散しない温度であ
る１１８０〜１２３０℃で行われる。
得られる焼結合金の全体組成は、重量比で、Ｓｉ：０．
１〜３．７％、Ｃｒ：１１〜２４％、Ｎｉ：４〜２０％
、Ｍｏ：１〜１０％、ＣＯ：３〜１９％、Ｂ：１〜３％
、ならびにＦｅおよび不純物：残部、または、この組成
にＮｂ、Ｔａ。
Ｈｆ、Ｔｉ、Ｚｒのうち少なくとも１種二０．１〜１％
が添加された組成に相当する。
（発明の作用）
本発明に係わる耐熱摺動用鉄系焼結合金は、上記した合
金設計により開発されたものであってマトリックスをオ
ーステナイト系ステンレス鋼とし、そのマトリックスに
硼素を添加して焼結密度を高くすることにより高温耐酸
化性が向上したものになると共に、金属硼化物を分散さ
せることにより基地の強化が図られたものになり、さら
に前記マトリックス中に硬質のコバルト系金属間化合物
粒子を分散させることにより＃凝着摩耗性および耐焼付
き性が向上したものになる。
（実施例）
以下、耐摩耗性および耐酸化性を比較した実施例により
説明する。
原料粉として、粒度が１００メツシユ以下で第２表に示
す各種組成のオーステナイト系ステンレス鋼粉と、組成
がＳｉ ：２．５％、Ｃｒ：８．１％、Ｍ ｏ ： ２
７ 、８％、ｃｏ＝残部で、粒度が１００メツシユ以下
のコバルト合金粉と、組成がＢ、１４％、Ｆｅ：残部で
、粒度が２５０メツシユ以下のフェロポロン粉を準備し
た。
これらの粉末を第１表に示す割合で配合および混合した
。成形潤滑剤は１％添加した。
各々の混合粉を所定の形状に圧縮し、その成形体を真空
中で、温度１２００℃で焼結した。
また、比較する従来材として、５ＵＳ３１ＯＳ溶製ステ
ンレス鋼材を、同様の寸法に加工した試料を準備した。
各試料について、密度比、酸化重量増加量ＣＦ！！！化
増量）および摩擦摩耗量を測定した結果を同じく第１表
に示す。
密度比は、密度７．８５ｇ／ｃｍ３を１００％として計
算した。
酸化増量の測定は、直径１３ｍｍ、高さ１５ｍｍの柱体
試料を温度９５０℃で２００時間、大気中で加熱した後
の重量増加で表わした。
摩耗試験は、内径８．１ｍｍ、外径１２．７ｍｍ、高さ
３５ｍｍの軸受材料に、ニッケル基耐熱合金で作られた
軸を嵌合し、その軸に１ｋｇの荷重を加え、温度６００
℃に加熱した状態で、軸をストローク１０ｍｍで軸方向
に毎分６００回往復動させ、３０時間経過した後の軸お
よび軸受摩耗量を測定した。
第
表
第１表において、試料番号１〜５は、原料として用いた
ステンレス鋼粉の種類（Ａ−Ｅ）を比較したものである
。
試料１はＳＵＳ ３０２、試料２は５ＵＳ３０４Ｌ、試
料３は５ＵＳ３１０Ｓ、試料４は５ＵＳ３１６Ｌに相当
するもので、試料５は試料４のＭｏをＳｉに置換した組
成である。
第１表の試料１〜５では、いずれも、軸受試料および軸
の摩耗量、酸化増量が少ない。但し、試料４の酸化増量
が他の試料に比べて大きい値を示しているが、試料１６
と比べると半分以下であり、コバルト合金相および硼素
添加の効果が認められる。
試料６から１０および試料３は、同じステンレス鋼粉Ｃ
を用い、コバルト合金粉およびフェロポロン合金粉の添
加量について比較したものである。
コバルト合金粉の添加による効果は、軸受の耐摩耗性を
向上させるが、相手軸を摩耗させ易くする。また、表記
を省いたが焼結体硬さを高くする。さらに、硼素の添加
は密度比および耐酸化性を向上することがわかる。
試料１１〜１５は、試料５にＮｂおよびＴａを１種また
は２種添加した例である。試料５に比べて軸受の摩耗量
および耐酸化性が改善されることがわかる。
試料１６はコバルト合金粉およびフェロポロン合金粉を
添加しない焼結ステンレス材料であるが、密度比が低い
ため酸化され易く、摩耗は凝着が認められて軸受試料お
よび相手軸とも大きい。
試料１７の溶製ステンレス鋼材は、酸化は少ないが、摩
耗量が大である。[Structure of the Invention] (Means for Solving the Problems) The heat-resistant sliding iron-based sintered alloy according to the present invention has the following overall composition in terms of weight ratio: Si: 0.1 to 3.7% Cr: 11 to 24% Ni: 4 to 20% MO: 1 to 10% CO: 3 to 19% B: 1 to 3% and Fe and impurities: the balance in a Ni-Cr stainless steel base in which metal borides are dispersed ni, S
i, cobalt alloy phase containing Cr and MO: 5~
It is characterized by having a structure in which 30% by weight exhibits a structure in which granules are scattered, and in addition to the above composition, Nb,
Ta, Hf. It is characterized by containing 0.1-1% of at least one of Ti, Zrc7) and exhibiting the above-mentioned structure. It is used as a means to solve the problem. Next, the reasons for limiting the matrix (base), cobalt alloy phase, etc. of the iron-based sintered alloy for heat-resistant sliding according to the present invention will be explained. Regarding the matrix (base): The austenitic stainless steel that forms the matrix falls within the composition range established by JIS, that is, Ni:
It is preferable that the composition range is 8 to 22% and Cr: 16 to 26%. That is, Ni and Cr in stainless steel are dissolved in the iron base, and are elements that improve corrosion resistance and heat resistance. This composition range can be found, for example, in the original author Sophie's "Introduction to Stainless Steel" (Special Steel Club, published in 1972).
As stated in - As is said in Boat Fishing,
If each value is less than the lower limit, the characteristics are insufficient. Even if the amount is increased more than the upper limit value, no further effect will be produced. Further, the austenitic stainless steel may contain 2 to 3% Mo and/or up to 4% Si. In this case, Mo is an element that improves corrosion resistance, so 2%
It is desirable to include the above as necessary, but 9
At high temperatures exceeding 00°C, there is an effect of accelerating M erosion. Further, stainless steel types containing a large amount of Mo have a high hardness and poor powder compressibility, so it is desirable that the Mo content is 3% or less. In addition, St improves the flow of molten metal when producing powder,
It is an element that improves the oxidation resistance of the sintered body, but if it is contained in an amount exceeding 4%, the hardness increases and the compressibility of the powder deteriorates, which is not preferable. Nb, Ta, and H are added to the austenitic stainless steel mentioned above.
When at least one of f, Ti, and Zr is added,
Creates trace amounts of carbon and carbides contained in steel, improving the corrosion resistance of the matrix and mechanical strength at high temperatures. The effect is recognized at 0.1% or more in copper powder, but at 1.5%
If the content is larger than this, precipitates become noticeable at grain boundaries and the toughness tends to decrease, so the upper limit should be kept at about 1.3%. This corresponds to 0.1 to 1% of the total composition. The metal borides in the matrix are produced by the reaction between boron added in the form of ferroporon powder and mainly chromium in the stainless steel powder, and are scattered throughout almost the entire matrix in the microscopic structure. Boron forms a eutectic liquid phase with the matrix components, increasing the density ratio of the sintered body. The density is 0 compared to when it is not added.
, 2 to 0, 5 g/cmj higher. This has the effect of reducing internal oxidation of the material. It also has the effect of precipitating boride into the matrix to improve wear resistance. If the boron content is less than 1% in the overall composition, the increase in density and the strengthening of the base will be insufficient, while if more than 3% gi is added, the powder compressibility will deteriorate and a large amount of boride will precipitate. The sintered body becomes hard and wears out the mating shaft. Regarding the cobalt alloy phase: Next, the intermetallic compound to be dispersed is Si:2.2-2.
6%, Cr near, '5~8.6%, Mo: 27~29%
A commercially available alloy powder having a composition of and co=remainder is suitable. The powder of this alloy has a nearly spherical shape, has a micro-Vickers hardness of about 700, and is heat resistant, especially when dispersed in a relatively soft base.
M was added based on the knowledge obtained through many experiments that it has the effect of mitigating wear. The amount of cobalt alloy powder added is preferably in the range of 5 to 30%. In other words, if it is less than 5%, the above effect will be small;
This is because if it exceeds 30%, the compressibility of the mixed powder deteriorates, and the sintered body has a low degree of strength and cannot have sufficient strength, and also has many hard phases, making it easy to wear out the mating material. Regarding the manufacturing method: As described above, the sintered alloy of the present invention is made by compression molding and sintering a mixed powder of austenitic stainless steel powder, ferroporon powder, and Conoheld alloy powder. Sintering is carried out at a temperature of 1180 to 1230° C. at which borides are generated in the austenitic stainless steel base and at which the Conoheld alloy does not diffuse. The overall composition of the obtained sintered alloy is Si:0.
1-3.7%, Cr: 11-24%, Ni: 4-20%
, Mo: 1-10%, CO: 3-19%, B: 1-3%
, and Fe and impurities: the remainder or Nb, Ta in this composition. At least one of Hf, Ti, and Zr20.1-1%
This corresponds to a composition in which . (Function of the invention) The heat-resistant sliding iron-based sintered alloy according to the present invention was developed based on the alloy design described above, and the matrix is made of austenitic stainless steel, and boron is added to the matrix to improve the sintered density. By increasing the oxidation resistance at high temperatures, the matrix is strengthened by dispersing metal borides, and by adding hard cobalt-based intermetallic compound particles to the matrix. By dispersing it, adhesive wear resistance and seizure resistance are improved. (Example) The following will explain examples comparing wear resistance and oxidation resistance. As raw material powder, austenitic stainless steel powder with a particle size of 100 mesh or less and various compositions shown in Table 2, and a composition of Si: 2.5%, Cr: 8.1%, Mo: 2
A cobalt alloy powder having a composition of 7%, 8%, co=balance and a grain size of 100 mesh or less, and a ferroporon powder having a composition of B, 14%, Fe: the balance and a grain size of 250 mesh or less were prepared. These powders were blended and mixed in the proportions shown in Table 1. Molding lubricant was added at 1%. Each mixed powder was compressed into a predetermined shape, and the compact was sintered at a temperature of 1200° C. in a vacuum. In addition, as a conventional material for comparison, a sample of 5US31OS molten stainless steel material processed into similar dimensions was prepared. For each sample, density ratio, oxidation weight increase CF! ! ! Table 1 also shows the results of measuring the amount of friction and wear. The density ratio was calculated with a density of 7.85 g/cm3 as 100%. Oxidation weight gain was measured by heating a columnar sample with a diameter of 13 mm and a height of 15 mm at a temperature of 950° C. for 200 hours in the atmosphere, and then expressed as the weight increase. In the wear test, a shaft made of nickel-based heat-resistant alloy was fitted to a bearing material with an inner diameter of 8.1 mm, an outer diameter of 12.7 mm, and a height of 35 mm, a load of 1 kg was applied to the shaft, and the temperature was 600 mm.
The shaft was reciprocated 600 times per minute in the axial direction with a stroke of 10 mm in a state heated to .degree. C., and the wear amount of the shaft and bearing was measured after 30 hours had elapsed. In Table 1, sample numbers 1 to 5 compare the types of stainless steel powder (A-E) used as raw materials. Sample 1 corresponds to SUS 302, sample 2 corresponds to 5US304L, sample 3 corresponds to 5US310S, sample 4 corresponds to 5US316L, and sample 5 has a composition in which Mo of sample 4 is replaced with Si. In all of Samples 1 to 5 in Table 1, the wear amount and oxidation weight gain of the bearing sample and shaft were small. However, although the oxidation weight gain of sample 4 is larger than that of other samples, sample 16
This is less than half compared to the above, and the effects of the cobalt alloy phase and boron addition are recognized. Samples 6 to 10 and Sample 3 are the same stainless steel powder C
The amounts of cobalt alloy powder and ferroporon alloy powder added were compared using . The effect of adding cobalt alloy powder is to improve the wear resistance of the bearing, but it also makes the mating shaft more likely to wear out. Also, although not shown, the hardness of the sintered body is increased. Furthermore, it can be seen that the addition of boron improves the density ratio and oxidation resistance. Samples 11 to 15 are examples in which one or two types of Nb and Ta were added to sample 5. It can be seen that the wear amount and oxidation resistance of the bearing are improved compared to Sample 5. Sample 16 is a sintered stainless steel material without the addition of cobalt alloy powder and ferroporon alloy powder, but because of its low density ratio, it is easily oxidized, and wear is large on both the bearing sample and the mating shaft, with adhesion observed. The molten stainless steel material of Sample 17 has little oxidation, but a large amount of wear.
以上説明したように、本発明に係わる耐熱摺動用鉄系焼
結合金は、金属硼化物が分散したＮｉＣｒ系ステンレス
鋼のマトリックスに、００合金相が分散した組織を呈す
る焼結合金、またはこのマトリックスに炭化物生成元素
であるＮｂ。
Ｔａ、Ｈｆ 、Ｔｉ 、Ｚｒ（７）うち１種以上を含有
する上記組織の焼結合金に構成したものであるから、い
ずれも高温環境での耐蝕性および耐摩擦摩耗性に優れて
いることにより、軸受等の摺動部材の耐用寿命を大幅に
延長することかできるようになり、軸受簿の摺動部材の
全体を本発明に係わる焼結合金から形成したり、必要な
摺動部位のみを本発明に係わる焼結合金から形成して必
要に応してバックアツプ材を設けたりするなどして適用
することが可能であるという著大なる効果がもたらされ
る。
特許出願人 日産自動車株式会社As explained above, the heat-resistant sliding iron-based sintered alloy according to the present invention is a sintered alloy exhibiting a structure in which a 00 alloy phase is dispersed in a matrix of NiCr-based stainless steel in which metal borides are dispersed, or this matrix. and Nb, which is a carbide-forming element. Since it is composed of a sintered alloy with the above structure containing one or more of Ta, Hf, Ti, and Zr (7), all of them have excellent corrosion resistance and friction and wear resistance in high-temperature environments. It has become possible to significantly extend the service life of sliding members such as bearings, and it has become possible to form the entire sliding member of a bearing register from the sintered alloy according to the present invention, or to form only the necessary sliding parts. A significant effect is brought about in that it can be formed from the sintered alloy according to the present invention and applied by providing a back-up material if necessary. Patent applicant Nissan Motor Co., Ltd.
Claims (1)
化物が分散したＮｉ−Ｃｒ系ステンレス鋼基地中に、Ｓ
ｉ，ＣｒおよびＭｏを含有するコバルト合金相：５〜３
０重量％が粒状に点在した組織を呈することを特徴とす
る耐熱摺動用鉄系焼結合金。 Ｎｉ：４〜２０％ Ｍｏ：１〜１０％ Ｃｏ：３〜１９％ Ｂ：１〜３％ Ｎｂ，Ｔａ，Ｈｆ，Ｔｉ，Ｚｒのうち少なくとも１種：
０．１〜１％、 ならびにＦｅおよび不純物：残部からなり、且つ金属硼
化物が分散したＮｉ−Ｃｒ系ステンレス鋼基地中に、Ｓ
ｉ，ＣｒおよびＭｏを含有するコバルト合金相：５〜３
０重量％が粒状に点在した組織を呈することを特徴とす
る耐熱摺動用鉄系焼結合金。(1) The overall composition is as follows: Si: 0.1-3.7% Cr: 11-24% Ni: 4-20% Mo: 1-10% Co: 3-19% B: 1-3 % and Fe and impurities: The balance is S in a Ni-Cr stainless steel base in which metal boride is dispersed.
Cobalt alloy phase containing i, Cr and Mo: 5 to 3
A heat-resistant sliding iron-based sintered alloy characterized by exhibiting a structure in which 0% by weight is scattered in a granular manner. Ni: 4-20% Mo: 1-10% Co: 3-19% B: 1-3% At least one of Nb, Ta, Hf, Ti, and Zr:
0.1 to 1%, and Fe and impurities: The balance is S in a Ni-Cr stainless steel base in which metal boride is dispersed.
Cobalt alloy phase containing i, Cr and Mo: 5 to 3
A heat-resistant sliding iron-based sintered alloy characterized by exhibiting a structure in which 0% by weight is scattered in a granular manner.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13601590A JPH0428850A (en) | 1990-05-25 | 1990-05-25 | Heat-resistant ferrous sintered alloy for sliding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13601590A JPH0428850A (en) | 1990-05-25 | 1990-05-25 | Heat-resistant ferrous sintered alloy for sliding |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0428850A true JPH0428850A (en) | 1992-01-31 |
Family
ID=15165192
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13601590A Pending JPH0428850A (en) | 1990-05-25 | 1990-05-25 | Heat-resistant ferrous sintered alloy for sliding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0428850A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104889379A (en) * | 2014-03-04 | 2015-09-09 | 精工爱普生株式会社 | Metal powder for powder metallurgy, compound, granulated powder, and sintered body |
| US9950990B2 (en) | 2006-07-06 | 2018-04-24 | Polnox Corporation | Macromolecular antioxidants comprising differing antioxidant moieties: structures, methods of making and using the same |
-
1990
- 1990-05-25 JP JP13601590A patent/JPH0428850A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9950990B2 (en) | 2006-07-06 | 2018-04-24 | Polnox Corporation | Macromolecular antioxidants comprising differing antioxidant moieties: structures, methods of making and using the same |
| CN104889379A (en) * | 2014-03-04 | 2015-09-09 | 精工爱普生株式会社 | Metal powder for powder metallurgy, compound, granulated powder, and sintered body |
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