JP3114641B2 - Brake disc material for high-speed railway vehicles - Google Patents
Brake disc material for high-speed railway vehiclesInfo
- Publication number
- JP3114641B2 JP3114641B2 JP09032625A JP3262597A JP3114641B2 JP 3114641 B2 JP3114641 B2 JP 3114641B2 JP 09032625 A JP09032625 A JP 09032625A JP 3262597 A JP3262597 A JP 3262597A JP 3114641 B2 JP3114641 B2 JP 3114641B2
- Authority
- JP
- Japan
- Prior art keywords
- cast iron
- brake disc
- value
- brake
- weight
- 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 - Fee Related
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D65/00—Parts or details
- F16D65/02—Braking members; Mounting thereof
- F16D65/12—Discs; Drums for disc brakes
- F16D65/125—Discs; Drums for disc brakes characterised by the material used for the disc body
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Braking Arrangements (AREA)
Description
【0001】[0001]
【発明の属する技術分野】本発明は鉄道車両用などとし
て適用され、特に疲労強度のレベルアップが求められる
ブレーキディスク材に係る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake disc material which is applied to railway vehicles and the like, and particularly requires a higher level of fatigue strength.
【0002】[0002]
【従来の技術】鉄道車両用などのディスクブレーキ方式
に適用されるブレーキディスク材としては、瞬間的に相
手材であるブレーキシュー(たとえばCu系焼結合金材
或はレジン系ライニング材)との高圧下の摺動作用によ
って急熱急冷を繰り返すというきわめて異常な使用条件
に耐え得ることが最も重要な要件であり、繰り返し熱負
荷を受けることによって摺動面の材質的な耐性を超えて
微細な熱亀裂が発生する。この熱亀裂は通常、ブレーキ
ディスク材が円板状に成形されていることから、車軸が
挿通する中央を中心とした円周方向に対して放射状に漸
次伸張していくのが一般的な傾向であり、亀裂の長さと
深さが限度を越せばブレーキディスク自体を分断する虞
れが否定できないから、定期的な検査において亀裂の深
さと長さと本数とを測定し、あらかじめ設定された検査
基準値に達すると廃棄処分にして新品と交換するように
定めている。2. Description of the Related Art As a brake disk material applied to a disk brake system for a railway vehicle or the like, a high-pressure brake shoe (for example, a Cu-based sintered alloy material or a resin-based lining material) instantaneously engages with a brake shoe. The most important requirement is to be able to withstand extremely unusual operating conditions of repeated rapid heating and quenching due to the sliding action below. Cracks occur. Generally, since the thermal cracks are formed in a disk shape, the general tendency is that the thermal cracks gradually expand radially in the circumferential direction centered on the center where the axle is inserted. There is no undeniable possibility that the brake disc itself will be broken if the length and depth of the cracks exceed the limits.Therefore, the depth, length and number of cracks are measured in regular inspections, and the inspection reference values set in advance It is stipulated that when it reaches, it should be disposed of and replaced with a new one.
【0003】一方ブレーキディスク材は実車の各車輪を
両側から挾圧する形で装着されているから、ブレーキ操
作を行なう度に繰り返し熱応力が集中する箇所が特定す
るという形状的な特徴もある。この場合、たとえばボル
ト締結部などの固定部分に応力が集中することは物理的
に避けられず、熱応力の集中が繰り返されるとその部分
を中心とした金属疲労が蓄積して疲労割れなどの欠陥と
して顕われることも金属学の原則として常に警告される
ケースに相当する。[0003] On the other hand, since the brake disk material is mounted so as to clamp each wheel of the actual vehicle from both sides, there is also a characteristic feature that a location where thermal stress is repeatedly concentrated is specified each time a brake operation is performed. In this case, for example, it is physically unavoidable that stress concentrates on a fixed portion such as a bolted portion. When thermal stress is repeatedly concentrated, metal fatigue mainly accumulates at that portion, and defects such as fatigue cracks occur. Is also a case always warned as a rule of metallurgy.
【0004】一方、ブレーキディスク材としては、耐熱
歪み性も具えていることも必要条件の一つであり、繰り
返し急熱、急冷によって永久変形が現われ本来平滑な円
盤状に加工した摺動面に反りが生じると、均一な面接触
を妨げブレーキ特性に著しい低下が始まるから、この点
もまたブレーキディスク材として選択の条件を限定する
一つの要素に挙げられる。ブレーキディスク材として要
求される性質はこのように複雑に関連し合っているか
ら、単一の条件で整理することは難しいが、これらの要
素を中軸に据えて最良のブレーキディスク材を模索すれ
ば、結局、現在実用化されているブレーキディスク材と
して鋳鉄材を主体に採用され、その鋳鉄材をベースとし
て短所を矯め、長所を伸すために数々の開発と実験が繰
り返し継続されてきた経緯が窺える。[0004] On the other hand, one of the necessary conditions is that the brake disk material also has heat distortion resistance, and permanent deformation appears due to repeated rapid heating and rapid cooling, and the sliding surface is originally processed into a smooth disk shape. This is one of the factors that limit the selection conditions for the brake disc material, since the warpage prevents uniform surface contact and causes a significant decrease in braking characteristics. The properties required for a brake disc material are intricately related in this way, so it is difficult to organize them under a single condition, but if these elements are set on the center axis and the best brake disc material is searched for In the end, cast iron was mainly used as a brake disc material that is currently in practical use, and many developments and experiments were repeatedly continued to correct disadvantages and extend advantages based on that cast iron material. I can see.
【0005】最も代表的なブレーキディスク材として旧
国鉄の在来線および新幹線の車両に適用されてきた材質
は、旧国鉄規格・JRS番号12209号−1に基づく
普通鋳鉄(以下「FC280」という)と、同・JRS
番号12209−2に基づくNi,Cr,Moを適量添
加した低合金鋳鉄(以下「NCM鋳鉄」という)とが挙
げられる。何れも片状黒鉛系鋳鉄に分類され、制動時に
適切、かつ、安定した摩擦係数と低摩耗特性を示し、鋳
鉄系であるから経済的にも有利であり、主としてFC2
80は在来線に、また、NCM鋳鉄は新幹線の開通当初
から独占的に適用され材質的な要因に基づく事故を招く
ことなく高い信頼性の元に長期間専用的に使用されてき
た。[0005] The most typical brake disc material that has been applied to vehicles of the former JNR conventional lines and Shinkansen is ordinary cast iron (hereinafter referred to as "FC280") based on the former JNR standard, JRS No. 12209-1. And the JRS
Low-alloy cast iron (hereinafter referred to as “NCM cast iron”) to which an appropriate amount of Ni, Cr and Mo is added based on No. 12209-2. All are classified as flake graphite cast iron, exhibit an appropriate and stable coefficient of friction and low wear characteristics during braking, and are economically advantageous because they are cast iron.
80 is used for conventional lines, and NCM cast iron is exclusively used from the beginning of the Shinkansen, and has been used exclusively for a long time with high reliability without causing an accident due to material factors.
【0006】ブレーキディスクとして実用化されている
片状黒鉛系鋳鉄の中でも現時点において最も評価の高い
ブレーキ特性を具えているのがNCM鋳鉄である。NC
M鋳鉄の材料的な特徴から優れたブレーキ特性を関連付
けてみると、この材料の組織中の片状黒鉛の形状は意図
的に大きく成長させているので、制動時の熱応力を吸収
しまたは緩衝する作用が優れ、一方、黒鉛成長に伴う機
械的性質の低下をNi,Cr,Moの添加によって強化
させ、耐熱亀裂性と機械的性質の両機能を他の片状黒鉛
系鋳鉄よりも優越させて、従来の在来線がFC280材
を主体としていた実態から一歩進めて、車両高速化に伴
うブレーキディスク材として相応しい材質に改変した点
に画期的な進展があったと認められる。[0006] Among flaky graphite cast irons practically used as brake discs, NCM cast iron has the most highly evaluated braking characteristics at present. NC
When relating excellent braking characteristics to the material characteristics of M cast iron, the shape of flake graphite in the structure of this material is intentionally grown large, so that thermal stress during braking is absorbed or buffered. On the other hand, the addition of Ni, Cr and Mo enhances the deterioration of mechanical properties due to graphite growth, and makes both functions of heat crack resistance and mechanical properties superior to other flake graphite cast irons. Thus, it is recognized that there has been a breakthrough development in that the conventional line has progressed one step further from the fact that it was mainly made of FC280 material, and has been changed to a material suitable as a brake disk material with the increase in vehicle speed.
【0007】[0007]
【発明が解決しようとする課題】今日の鉄道事業の趨勢
を見ると明らかに長距離の列車運行については航空機と
の激しい競合に曝され、一層の高速化、一層の快適性、
一層の安全性が生残るための唯一の手段となり、さらに
車両各部材の消耗更新に伴う運転経費の優劣もJR民営
化への移行と共に重要なキーポイントとなっている。ブ
レーキ操作についても非常停止ブレーキ速度の高速化、
走行性安定化のためのブレーキ操作の多用が進むから使
用条件が苛酷となる上、経済性を重視して取り替え期間
の延長が求められて、苛酷な条件下における耐用期間の
延長という二重の技術的課題に直面した状態にある。According to the trend of the railway business today, it is clear that long-distance train operation is exposed to intense competition with aircraft, which results in higher speed, more comfort,
It is the only means to survive further safety, and the superiority of operating costs due to the renewal of wear and tear of vehicle components is also an important key point along with the shift to JR privatization. Emergency stop brake speed has been increased for brake operation,
The use of brakes to stabilize driving performance is increasing, so the operating conditions are severe.In addition, the replacement period is required to be extended with emphasis on economy, and the service life is extended under severe conditions. You are facing a technical challenge.
【0008】このようなブレーキ操作はブレーキディス
ク材を直撃する熱負荷を増大して摺動面に発生する熱亀
裂の増加に拍車をかけると共に、ブレーキディスクの形
状因子から熱応力が繰り返し集中する部位、すなわち、
取り付け箇所であるボルト締結部などの疲労割れも問題
視されるようになった。このようにブレーキディスク材
のブレーキディスク特性の向上、具体的にはより苛酷な
条件に曝されたブレーキディスクの耐熱亀裂性を向上
し、疲労破壊を抑止して経済的にも競合に耐え得る材質
の開発が急務とされ、既に以前から試みられたNCM鋳
鉄をベースとしてさらに向上したブレーキディスク材の
開発を目的とした従来技術も含めると、かなりの改善策
が提示され公開されているのは事実である。[0008] Such a brake operation increases the thermal load directly hitting the brake disc material, thereby increasing the thermal cracks generated on the sliding surface, and at the site where thermal stress is repeatedly concentrated due to the form factor of the brake disc. That is,
Fatigue cracking of bolted joints, which are attachment points, has also become a problem. In this way, the brake disk material has improved brake disk characteristics, specifically, a material that can improve the heat crack resistance of brake disks exposed to more severe conditions, suppress fatigue fracture, and withstand economic competition. It is an urgent need to develop a new technology, and it is a fact that considerable improvements have been proposed and disclosed, including the prior art for the development of improved brake disc materials based on NCM cast iron, which had already been tried before. It is.
【0009】片状黒鉛系鋳鉄材に属するブレーキディス
ク材のブレーキ特性の向上としては、基地の強化と黒鉛
形状の変更の二つの流れが従来技術の主体となっている
ように解釈される。たとえば特公昭47−1872号公
報はNCM鋳鉄と総称される低合金鋳鉄の先鞭を付けた
原点となる公開技術と解されるが、片状黒鉛鋳鉄材とし
ての成分範囲へ重量%にしてNi:1.0〜2.0,C
r:0.3〜0.6,Mo:0.3〜0.5を添加し、
溶湯を1500〜1600℃まで昇温して黒鉛核をほぼ
消失した白銑状とした上で、出湯時にCa−Si,Fe
−Siを溶湯に添加(接種)して擬片状黒鉛組織とする
ことを示している。しかし、ブレーキディスク材の耐熱
亀裂性として擬片状黒鉛形状、たとえば芋虫状のバーミ
キュラー鋳鉄が片状黒鉛よりも優れているという見解に
対しては最近の研究や実績から見ても必ずしも同意でき
ない。Regarding the improvement of the braking characteristics of the brake disc material belonging to the flaky graphite cast iron material, two flows, that is, the reinforcement of the base and the change of the graphite shape, are interpreted as being the main bodies of the prior art. For example, Japanese Patent Publication No. 47-1872 is understood to be an open technology which is a starting point of a low alloy cast iron which is collectively referred to as NCM cast iron. 1.0-2.0, C
r: 0.3-0.6, Mo: 0.3-0.5,
The temperature of the molten metal was raised to 1500 to 1600 ° C. to obtain a white pig iron shape in which graphite nuclei had almost disappeared.
This shows that -Si is added (inoculated) to the molten metal to give a pseudo-flake graphite structure. However, recent studies and achievements do not necessarily agree with the view that the pseudo-flaky graphite shape, for example, vermiculite-like vermicular cast iron, is superior to the flaky graphite in terms of heat crack resistance of the brake disc material.
【0010】一方、鋳鉄基地の強度や靱性を高めて耐熱
亀裂性の向上に結び付けようとする開発はブレーキディ
スク材改善の主流を占め、前記のNCM鋳鉄をベースと
した多数の手段が開示されている。たとえば、特開平7
−127675号公報の従来技術では、Ni:1.50
〜3.00,Mo:1.0〜2.5,Ce:0.01〜
0.03,V:0.2〜0.30(各重量%)の成分に
よってベイナイト基地に多量の片状黒鉛を析出したブレ
ーキディスク材を提案し、高強度の基地と片状黒鉛の析
出によって耐熱亀裂性を向上したと謳っている。On the other hand, the development of increasing the strength and toughness of a cast iron base to improve the heat crack resistance occupies the mainstream of improving brake disc materials, and a number of means based on the NCM cast iron have been disclosed. I have. For example, Japanese Unexamined Patent Publication
In the prior art of JP-A-127675, Ni: 1.50
3.00, Mo: 1.0-2.5, Ce: 0.01-
We propose a brake disc material in which a large amount of flaky graphite is precipitated on a bainite matrix by a component of 0.03, V: 0.2 to 0.30 (each weight%). It claims to have improved heat crack resistance.
【0011】一方、特開昭59−133347号公報で
はNi:2.0〜4.0,Mo:1.0〜3.0,V:
0.35以下,Ce:0.04以下(各重量%)の成分
によって基地組織の微細化などの強化を図り耐熱亀裂性
の向上を図ったとある。その他、片状黒鉛鋳鉄にNi,
Moを添加し冷却能の高い鋳型に注湯しさらに高温で型
ばらしをするか、冷却能の低いの鋳型に注湯して常温で
型ばらしをするなど鋳込みや型ばらしの条件を変えて基
地組織を自由に制御しようとする特開平6−65673
号公報、早ばらしによるマルテンサイト+ベイナイト組
織の基地とする特公昭59−22780号公報、または
オーステナイト+ベイナイト組織とする特開昭60−1
57528号公報、オーステンパー処理によってベイナ
イト組織とする特開昭64−62412号公報など多岐
に亘る。On the other hand, in JP-A-59-133347, Ni: 2.0-4.0, Mo: 1.0-3.0, V:
It is stated that the component of 0.35 or less and Ce: 0.04 or less (each weight%) strengthened the microstructure of the matrix and improved the heat crack resistance. In addition, Ni,
Add Mo and pour into a mold with high cooling capacity and separate the mold at a higher temperature, or pour into a mold with a low cooling capacity and separate at normal temperature to change the casting and mold release conditions. Japanese Patent Application Laid-Open No. 6-65673 for controlling the organization freely
JP-B-59-22780, which is a base of a martensite + bainite structure by early breaking, or JP-A-60-1 having an austenite + bainite structure.
57528, and JP-A-64-62412 in which a bainite structure is formed by austempering.
【0012】しかしながら、このように単に鋳鉄基地の
強度の向上によって結果的に耐熱亀裂性に直接結び付く
のであれば、基地の強化に焦点を絞ってより有効な技術
的手段を試みればよい筈であるが、事実は必ずしもその
ような短絡的な関係になく、基地強化によって、確実に
耐熱亀裂性の向上に直結するという保証はない。前記の
従来技術の一部には、材料の疲労限の向上が耐熱亀裂性
の向上と完全に整合するという前提に立って実験を進め
た例もあるが、鋳鉄材は一方で熱衝撃を吸収する片状黒
鉛の存在が不可欠であり、他方で黒鉛が一種の減摩材の
働きを果たして耐摩耗性も優れ、その代りに基地を強化
するほど高硬度となって耐衝撃性が劣化して脆性が増大
し亀裂の進行を促進するという背反する両面を併せ具え
ているから、単なる基地の強化が直ちに耐熱亀裂性の向
上に直結するとは限らない。より慎重に第三の変数を媒
体としてその引張り強さ、引張り・圧縮疲労限および耐
熱亀裂性間の複雑な規範を律することが課題解決の要件
となる。[0012] However, if the improvement of the strength of the cast iron base is directly linked to the heat crack resistance as a result, the more effective technical means should be focused on the strengthening of the base. However, the fact is not always such a short-circuited relationship, and there is no guarantee that strengthening the base will certainly lead to improved thermal crack resistance. Some of the above-mentioned prior arts have conducted experiments on the assumption that the improvement in the fatigue limit of the material is perfectly matched with the improvement in the thermal crack resistance, but the cast iron material absorbs thermal shock on the other hand. The presence of flaky graphite is indispensable, and on the other hand, graphite acts as a kind of antifriction material and has excellent wear resistance.Instead, the stronger the matrix, the higher the hardness and the lower the impact resistance. Since both sides have the opposite sides of increasing brittleness and accelerating the progress of cracks, mere strengthening of the matrix does not always directly lead to improvement of heat crack resistance. The task of solving the problem is to more carefully determine the complex parameters between tensile strength, tensile / compression fatigue limit, and thermal crack resistance using the third variable as a medium.
【0013】材力の強化だけで課題が解決するのであれ
ば、近年試行されている鍛鋼製のブレーキディスクが最
も他に優越するという推理も成り立つ。しかしながら、
この場合には疲労強度と耐熱亀裂性については明らかに
鋳鉄系よりも優位に立つことが予想できる反面、ブレー
キ作用中の摩擦係数の不安定さや使用の繰り返しと共に
顕著な累積永久変形が避けられないことも容易に推定で
きるから、ますます高速化する車両のブレーキディスク
として一概に高い評価は下し難く、片状黒鉛の存在が熱
衝撃を緩衝し、一種の減摩材の働きも具える特性を根拠
とする原理原則から照合すれば、俄かには推奨し難い重
要な難点を潜在する可能性も払拭し切れない。If the problem can be solved only by strengthening the material strength, it can be reasoned that a forged steel brake disk which has been tried in recent years is the most superior. However,
In this case, fatigue strength and heat crack resistance can be clearly expected to be superior to cast iron, but instability of the friction coefficient during braking and remarkable cumulative permanent deformation are inevitable with repeated use. It can be easily estimated, so it is hard to give a high evaluation as a brake disc for vehicles that are getting faster and faster, and the presence of flaky graphite buffers thermal shock and also has the function of a kind of anti-friction material If we collate based on the principles based on, we cannot completely eliminate the potential for important difficulties that are not immediately recommended.
【0014】本発明は以上の観点に立ったブレーキディ
スク材の開発の歴史から、従来技術として最も安定した
評価を得ているNCM鋳鉄を原点におき、すべての従来
技術とは異なる媒体を介して複雑な相関を平衡させた理
想的な材料成分の誘導によって課題を解決する新規なブ
レーキディスク材の提供を目的とする。The present invention is based on the history of the development of brake disc materials from the above-mentioned viewpoints, and puts NCM cast iron, which has the most stable evaluation as the prior art, as a starting point, through all media different from the prior art. It is an object of the present invention to provide a new brake disc material that solves the problem by deriving an ideal material component in which a complicated correlation is balanced.
【0015】[0015]
【課題を解決するための手段】本発明に係る高速鉄道車
両用ブレーキディスク材は、重量%にしてC:3.10
〜3.45,Si:1.10〜1.50,Mn:0.6
0〜1.00,Ni:1.00〜2.00,Cr:0.
30〜0.60,Mo:0.30〜0.50,P:0.
16以下,S:0.12以下の他、Sn+Sb+Cuの
合計を0.01〜0.50,Al:0.01〜0.10
を含んで残部がFeからなり、かつ、 炭素飽和度(Sc値)=C重量%÷[4.23−(Si
重量%/3.2)] で算出される炭素飽和度が0.82〜0.91の範囲に
限ることにより前記熱亀裂性を少なくとも旧国鉄規格・
JRS番号12209−2に基づく低合金鋳鉄と同等ま
たはそれ以上に維持しつつ疲労強度がこれより優れた片
状黒鉛鋳鉄材で構成することによって前記の課題を解決
した。SUMMARY OF THE INVENTION A high-speed railway car according to the present invention.
The dual-use brake disc material is expressed as C: 3.10 in weight%.
~ 3.45, Si: 1.10 to 1.50, Mn: 0.6
0-1.00, Ni: 1.00-2.00, Cr: 0.
30 to 0.60, Mo: 0.30 to 0.50, P: 0.
16 or less, S: 0.12 or less, the total of Sn + Sb + Cu is 0.01 to 0.50, Al: 0.01 to 0.10
And the balance is Fe, and carbon saturation (Sc value) = C weight% ÷ [4.23- (Si
Weight% / 3.2)] to limit the thermal cracking property to at least the former Japanese National Railways standard by limiting the carbon saturation calculated in the range of 0.82 to 0.91.
The above-mentioned problem has been solved by using a flaky graphite cast iron material having a fatigue strength superior to or lower than that of a low alloy cast iron based on JRS No. 12209-2 .
【0016】前記各構成元素のブレーキディスク材とし
て具備すべき機能との関連から含有量の上限、下限の限
定理由を説明する。 C:3.1重量%以下の場合には黒鉛化促進元素であ
るAlを添加しているもののブレーキディスク材のフィ
ン部(ブレーキディスクは放熱性を高めるために摺動面
の反対側に多数の放射状フィンを設ける)などの薄肉部
がチル化し易く、変形抵抗の低下や耐熱亀裂性が劣化
し、逆に3.45重量%を越えると炭素飽和度(以下単
に「Sc値」という)のバランスが後に具体的に述べる
ように崩れて黒鉛量が過大に失し、材料の引張り強さが
明確に低下して引張り・圧縮疲労限の改善に逆行する原
因を形成する。 Si:Sc値との関連でCと同様の挙動を示し、含有
量が1.0重量%未満のときはチル化し易く、変形抵抗
の低下や耐熱亀裂性の劣化を誘発する。逆に1.50重
量%を越えると、黒鉛量が過大となって引張り強さが低
下して引張り・圧縮疲労限の改善が不可能となる。 Mn:0.60重量%未満のときは溶湯の脱硫、脱酸
が不十分となり、1.00重量%を越えるとチル化の傾
向を示しブレーキディスク材としての耐熱亀裂性、耐熱
歪み性が劣化する。 P:0.16重量%を越えるとリンの共晶物を生成し
て脆化を生じるので同値を上限に定める。 S:0.12重量%を越えると結晶粒界にSが偏析し
て脆化の原因となるので同値を上限に定める。The reasons for limiting the upper and lower limits of the contents will be described in relation to the function of each of the above constituent elements as a brake disk material. C: In the case of not more than 3.1% by weight, although Al which is a graphitization promoting element is added, the fin portion of the brake disk material (the brake disk has a large number of Thin portions such as radial fins are easily chilled, and the deformation resistance and the heat crack resistance deteriorate. On the contrary, when the content exceeds 3.45% by weight, the balance of carbon saturation (hereinafter simply referred to as "Sc value") is balanced. However, as will be described in detail later, the material collapses and the amount of graphite is excessively lost, and the tensile strength of the material is clearly reduced, thereby forming a cause which goes against improvement of the tensile and compression fatigue limit. It exhibits the same behavior as C in relation to the Si: Sc value. When the content is less than 1.0% by weight, it tends to be chilled, which causes a decrease in deformation resistance and a deterioration in heat crack resistance. Conversely, if the content exceeds 1.50% by weight, the amount of graphite becomes excessively large and the tensile strength decreases, making it impossible to improve the limit of tensile and compressive fatigue. When Mn is less than 0.60% by weight, desulfurization and deoxidation of the molten metal become insufficient, and when it exceeds 1.00% by weight, chilling tends to occur and heat cracking resistance and heat distortion resistance as a brake disk material deteriorate. I do. P: If it exceeds 0.16% by weight, a eutectic of phosphorus is formed to cause embrittlement, so the upper limit is set to the same value. S: If it exceeds 0.12% by weight, S segregates at the crystal grain boundary and causes embrittlement. Therefore, the same value is set as the upper limit.
【0017】本発明に係るブレーキディスク材の原点は
NCM鋳鉄を出発点とする。よってNCM鋳鉄と同様の
合金成分の添加は基本的な前提である。 Ni:1.00重量%未満のときは基地組織のパーラ
イトが粗大化して引張り強さの低下を来し、逆に2.0
0重量%を越えると基地組織がマルテンサイトし易くな
りNCM鋳鉄の特徴である耐熱亀裂性に悪影響が及ぶ。 Cr:パーライトを微細化し高温強度の維持に効果が
あるが、炭化物形成能が高いため0.60重量%を越え
ると炭化物が析出して引張り・圧縮疲労限が低下する。 Mo:パーライト組織の微細化による高温強度の向上
の他に、少量添加でも熱伝導性を増大して熱応力抑制に
有効であるが、0.50重量%を越えると黒鉛化を阻害
し、かつ、炭化物を形成して耐熱亀裂性を劣化させる原
因となるので同値を以て上限と定める。The starting point of the brake disk material according to the present invention starts from NCM cast iron. Therefore, the addition of alloy components similar to those of NCM cast iron is a basic premise. When the content of Ni is less than 1.00% by weight, the pearlite of the base structure becomes coarse and the tensile strength is reduced.
If the content exceeds 0% by weight, the base structure is apt to martensite, which adversely affects the heat-resistant cracking characteristic of NCM cast iron. Cr: It is effective in maintaining high-temperature strength by making pearlite finer, but because of its high carbide forming ability, if it exceeds 0.60% by weight, carbide will precipitate to lower the tensile / compression fatigue limit. Mo: In addition to improving high-temperature strength by making the pearlite structure finer, addition of a small amount increases thermal conductivity and is effective in suppressing thermal stress. However, if it exceeds 0.50% by weight, graphitization is inhibited, and , Forming a carbide and deteriorating the heat crack resistance, so the upper limit is set to the same value.
【0018】本発明の技術的特徴の一つは従来技術のブ
レーキディスク材のレベルを凌駕するブレーキ特性を得
る点にあり、具体的には少なくとも従来のNCM鋳鉄の
保有する卓抜した耐熱亀裂性は維持したままでさらに引
張り強さと引張り・圧縮疲労限とがバランスよく向上し
て鉄道車両の高速化とブレーキディスク制動の頻発化に
対応しようとする点にある。そのために従来技術には認
められない新しい添加成分と、新しい指標による要素間
の相対的な管理手法を導入したことを特徴とするが、ま
ず、添加成分から説明する。 Sn,Sb,Cuの中から選ばれた1種または2種以
上の成分であって、その合計量が0.01から0.50
重量%を含むことを特徴とする。Sb,Snは0.01
%程度の単独添加でも微細層状パーライトの安定化に著
しい効果を示すことが既に知られている。また、Cuは
黒鉛化促進元素であることはよく知られているが、さら
にMnと共存させた場合には、パーライトの安定化元素
として作用することも知られている。しかし、これらの
成分を多量に添加したときには、脆性のある化合物が形
成され、衝撃値など靱性の低下を来すので複合添加の上
限を0.50重量%に限定した。 Al:この元素は黒鉛化促進元素として顕著な作用を
示すことが周知であるが、他の成分、とくにC,Siお
よびその含有量によって決定されるSc値との関連性を
十分に考慮しなければならない。すなわち、比較的Sc
値を低いレベルに抑制した上でなお、所望の片状黒鉛の
形状を維持するためには0.01%以上の添加を要件と
するが、多量の添加は脆化の原因となるので0.10%
を上限に定めた。One of the technical features of the present invention is to obtain braking characteristics exceeding the level of the conventional brake disc material. Specifically, at least, the outstanding heat crack resistance of the conventional NCM cast iron is at least as high as that of the prior art. The point is that the tensile strength and the tensile / compression fatigue limit are further improved in a well-balanced manner while maintaining the same, so as to cope with speeding up of railway vehicles and frequent brake disc braking. For this purpose, a new additive component that is not recognized in the prior art and a relative management method between elements using a new index are introduced. First, the additive component will be described. One or more components selected from Sn, Sb, and Cu, the total amount of which is 0.01 to 0.50
% By weight. Sb and Sn are 0.01
It has been already known that even a single addition of about% by weight shows a remarkable effect on stabilization of fine layered pearlite. It is well known that Cu is a graphitization promoting element, but it is also known that when coexisting with Mn, it acts as a pearlite stabilizing element. However, when a large amount of these components is added, a brittle compound is formed and the toughness such as an impact value is reduced. Therefore, the upper limit of the composite addition is limited to 0.50% by weight. Al: It is well known that this element has a remarkable effect as a graphitization promoting element, but its relationship with other components, especially C and Si and the Sc value determined by its content must be sufficiently considered. Must. That is, relatively Sc
In order to maintain the desired shape of flaky graphite after controlling the value to a low level, addition of 0.01% or more is required. However, addition of a large amount causes embrittlement, so that 0.1% or more is required. 10%
Was set as the upper limit.
【0019】既に述べたように高速車両に使用するブレ
ーキディスク材のブレーキ特性の開発は、単に各成分元
素の上限、下限を提示しただけで決められるものではな
い。ブレーキ特性は引張り強さと引張り・圧縮疲労限と
耐熱亀裂性との複雑な相関性から誘導すべきであり、単
純な成分限定と、単純な物理的試験によってだけ評価す
ると、必ず実車に使用したテストとの乖離に苦しむこと
は必定である。出願人は豊富なブレーキディスク材の開
発と実地テストとの関連性を知り尽くした長い経験を活
かして、第三の指標として鋳物材の原点にあるSc値に
着目し、後述する多くの模擬的な確性テストを繰り返し
た後、驚くべき傾向を見出したが、この認識は未だかっ
て何人によっても予想されなかった全く新規な技術的所
見である。課題解決の手段としてきわめて独創的な試験
結果を纏めた原則は次の通りである。なお、かかる原則
に到達する根拠となったデータは、次項の実施形態にお
いて明示する。As described above, the development of the brake characteristics of the brake disc material used for a high-speed vehicle cannot be determined merely by presenting the upper and lower limits of each component element. Brake characteristics should be derived from the complex correlation between tensile strength, tensile / compression fatigue limit, and thermal crack resistance. It is indispensable to suffer from the deviation. The applicant has taken advantage of the long experience of knowing the relationship between the development of abundant brake disc materials and the field tests, focusing on the Sc value at the origin of the casting material as a third index, and many simulations described later. After repeated rigorous tests, we have come up with a surprising trend, but this perception is a completely new technical finding that has never been anticipated by anyone. Principles that summarize test results that are extremely original as a means of solving the problem are as follows. In addition, the data on which this principle is reached will be specified in the following embodiment.
【0020】本発明の基本的な目標はあくまで従来技術
として最も安定した評価のあるNCM鋳鉄を上回るブレ
ーキ特性を具えた新材質の開発である。すなわち、新材
質の評価はすべてSc値との比較に基づいて行なうこと
を基準とする。図2は横軸にSc値、縦軸に引張り強さ
をプロットした関係図であり、本発明材は何れのSc値
においても従来技術の代表であるNCM鋳鉄を凌駕する
こと、並びにその中でもSc値の増加と共にほぼ直線的
に比例して引張り強さが低下し続けることが確認され
る。The basic goal of the present invention is to develop a new material having a braking characteristic exceeding that of the most stable and evaluated NCM cast iron as the prior art. That is, the evaluation of the new material is based on comparison with the Sc value. FIG. 2 is a relationship diagram in which the Sc value is plotted on the horizontal axis and the tensile strength is plotted on the vertical axis, and the material of the present invention surpasses NCM cast iron, which is a representative of the prior art, at any Sc value. It is confirmed that the tensile strength continues to decrease almost linearly in proportion to the increase in the value.
【0021】図1では横軸に引張り強さ、縦軸に引張り
・圧縮疲労限をプロットした関係図であり、本発明は何
れの引張り強さにおいてもNCM鋳鉄を凌駕し、同一値
の引張り強さであっても引張り・圧縮疲労限が優れてい
ることを明示している。このことから三段論法的に言え
ば本発明品は限定成分の範囲内であれば必ずNCM鋳鉄
を凌ぐが、その中にあっても特にSc値が低いほど引張
り・圧縮疲労限が向上するという相関を誘導することが
できる。FIG. 1 is a relationship diagram in which the horizontal axis plots the tensile strength and the vertical axis plots the tensile / compression fatigue limit. In any of the tensile strengths, the present invention surpasses NCM cast iron and has the same value of tensile strength. Even so, it clearly shows that the tensile / compression fatigue limit is excellent. From this point of view, from a theoretical point of view, the product of the present invention always surpasses NCM cast iron as long as it is within the range of limited components, but even among them, the lower the Sc value, the higher the tensile / compression fatigue limit is. Can be induced.
【0022】一方図3は横軸に熱衝撃繰り返し数、縦軸
に熱亀裂長さをプロットした関係図であり、耐熱亀裂性
をSc値の範囲との関連において示したものである。こ
の図によれば本発明品はNCM鋳鉄と耐熱亀裂性そのも
のについてはほとんど変りなく、しかもその間において
さらに詳細に分析すれば、Sc値の高いほど耐熱亀裂性
に優れて従来技術のNCM鋳鉄を凌ぐ試料も認められる
が、Sc値の低下と共にこの優位性が失われ、ある範囲
を越えると優劣が逆転することが把握された。On the other hand, FIG. 3 is a relational plot in which the number of thermal shock repetitions is plotted on the abscissa and the length of the thermal crack is plotted on the ordinate, and shows the thermal crack resistance in relation to the range of the Sc value. According to this figure, the product of the present invention is almost the same as the NCM cast iron with respect to the heat crack resistance itself, and when analyzed in more detail between them, the higher the Sc value, the better the heat crack resistance and the superiority of the prior art NCM cast iron. Although a sample was observed, it was found that this superiority was lost as the Sc value decreased, and that the superiority was reversed when the value exceeded a certain range.
【0023】すなわち、前記の限定成分の範疇に属して
も、Sc値が大きいほど、換言すればC,Siが高いほ
ど引張り強さは低下するが、絶対値においてNCM鋳鉄
を大きく凌駕し低下する勾配もNCM鋳鉄のそれよりも
大きい。一方、引張り強さの高いほど引張り・圧縮疲労
限が高く、これも絶対値においてNCM鋳鉄を凌駕す
る。ところが耐熱亀裂性については逆にSc値の高いほ
ど耐性が高く、Sc値の低いある限度においてはNCM
鋳鉄が逆転する。このことは耐熱亀裂性はブレーキディ
スクの摺動面全面にほぼ均一に分散して負荷する熱応力
によって支配され漸次進行していくのに対し、引張り・
圧縮疲労限は耐熱亀裂性の原因の一部にはなり得るにし
ても、むしろブレーキディスクの取り付け部など熱衝撃
の繰り返し集中する箇所に蓄積して遂に破断など視認で
きる現象となって初めて顕われると見るのが妥当ではな
いかと解される。したがって引張り・圧縮疲労限と耐熱
亀裂性、または引張り強さと耐熱亀裂性とを単純に短絡
して取り合せ改良する従来の手法には、実車の運転時に
作用する外力を分析する上でなお、不十分であったので
はないかと言わざるを得ない。この因果関係を整理した
結果、本発明ではSc値の範囲を 耐熱亀裂性において少なくともNCM鋳鉄の水準また
はそれ以上を維持できる範囲であること。 引張り・圧縮疲労限においてNCM鋳鉄を凌駕できる
範囲であること。 の2点から0.82〜0.91に限定したが、その根拠
は次項で述べる。That is, even within the category of the above-mentioned limited components, as the Sc value increases, in other words, as C and Si increase, the tensile strength decreases, but the absolute value greatly exceeds that of NCM cast iron. The slope is also greater than that of NCM cast iron. On the other hand, the higher the tensile strength, the higher the tensile / compression fatigue limit, which also exceeds the NCM cast iron in absolute value. On the other hand, as for the heat crack resistance, the higher the Sc value, the higher the resistance.
The cast iron reverses. This means that the heat-resistant cracking property is governed by the thermal stress that is distributed and applied almost uniformly over the entire sliding surface of the brake disc, and progresses gradually,
Although the compression fatigue limit can be a part of the cause of heat cracking, it only appears at the point where thermal shock is repeatedly concentrated, such as the mounting part of the brake disk, and finally becomes a visible phenomenon such as breakage. It is understood that it is not appropriate to see. Therefore, the conventional method of simply short-circuiting the tensile / compression fatigue limit and heat-resistant cracking, or the tensile strength and heat-resistant cracking by simply short-circuiting them, is still insufficient for analyzing the external force acting during actual vehicle operation. I have to say that it was. As a result of arranging this causal relationship, in the present invention, the range of the Sc value should be a range that can maintain at least the level of NCM cast iron in heat crack resistance or higher. The tensile / compression fatigue limit must be within the range that can surpass NCM cast iron. From the two points described above, the ratio was limited to 0.82 to 0.91, but the basis is described in the next section.
【0024】[0024]
【発明の実施の形態】表1は本発明の実施形態と比較の
ために数値限界の根拠とした比較例の成分およびSc値
の一覧表である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Table 1 is a list of components and Sc values of a comparative example used as a basis for a numerical limit for comparison with the embodiment of the present invention.
【0025】[0025]
【表1】 [Table 1]
【0026】表1において比較材1はSc値が0.79
8であり、図3で示すように従来技術のNCM鋳鉄材よ
り若干低い。従来材と少なくとも同等またはそれ以上を
維持するにはSc値が0.82以上を要しこの値がSc
値の下限となる。一方、比較材2はSc値が0.917
であり、Sc値を高めると耐熱亀裂性は向上するが疲労
強度に係わる引張り強さは、図2で示すようにJRS番
号12209−1で要求される引張り強さ28Kgf/
mm2≒275N/mm2以上を満足しなくなるため上限値を
0.91とし、結局Sc値の範囲を0.82≦Sc値≦
0.91に限定することとした。In Table 1, Comparative Material 1 had an Sc value of 0.79.
8, which is slightly lower than that of the prior art NCM cast iron as shown in FIG. In order to maintain at least the same as or higher than the conventional material, the Sc value needs to be 0.82 or more.
This is the lower limit of the value. On the other hand, the comparative material 2 had an Sc value of 0.917.
When the Sc value is increased, the thermal crack resistance is improved, but the tensile strength related to the fatigue strength is, as shown in FIG. 2, a tensile strength of 28 kgf / required by JRS No. 12209-1.
Since mm 2 ≒ 275 N / mm 2 or more is no longer satisfied, the upper limit value is set to 0.91, and eventually the range of the Sc value is set to 0.82 ≦ Sc value ≦
It was decided to be limited to 0.91.
【0027】従来技術の典型であるNCM鋳鉄や、既に
述べた主な公開技術と本発明材との主要な成分範囲に限
った比較を纏めたものが図4および図5である。図にお
いては特公昭47−1872号公報に係るNCM鋳鉄
の原形となる従来技術であり、は特開平6−6567
3号公報、は特開平7−127675号公報、は特
開昭59−133347号公報をそれぞれ示し、本発明
の限定成分と共に各成分毎に列挙した。FIG. 4 and FIG. 5 show a comparison of NCM cast iron, which is a typical example of the prior art, and a comparison between the main disclosed technologies described above and the main component range of the present invention. FIG. 1 shows a prior art which is the original form of NCM cast iron according to Japanese Patent Publication No. 47-1872.
No. 3, JP-A-7-127675 and JP-A-59-133347, which are listed for each component together with the limiting components of the present invention.
【0028】図からも顕著な傾向として認められるよう
に、C,Siは他の従来技術に比べると低位にあり、S
c値の低下に基づく黒鉛形状の悪化をAlの添加によっ
て補う一方、引張り・圧縮疲労限の向上という本発明の
主目的の達成に有効な成分としている。添加する合金元
素については原形であるNCM鋳鉄の範疇を特に変え
ず、過去の卓抜した実績をそのまま踏襲持続する姿勢で
終始しているが、、、で盛んに意図されたVの添
加については全く考慮外としている。本来鋳鉄のように
C量のきわめて高い材質にあっては、強力な炭化物形成
元素であるVの添加は、一般的な耐摩耗性の向上には最
も有効であるが、繰り返し熱衝撃による金属疲労の改善
に対してはきわめて慎重であるべきであり、耐熱亀裂性
の向上についても疑問がないわけではない。As can be seen from the figure as a remarkable tendency, C and Si are lower than other prior arts,
While the addition of Al compensates for the deterioration of the graphite shape due to the decrease in the c value, it is an effective component for achieving the main object of the present invention of improving the limit of tensile and compressive fatigue. Regarding the alloying elements to be added, the category of the original NCM cast iron does not change in particular, and it has continued from the outstanding performance in the past with the attitude that continues as it is. Not considered. For a material with an extremely high C content, such as cast iron, the addition of V, which is a strong carbide-forming element, is most effective for improving general wear resistance. It is necessary to be extremely cautious about the improvement of the thermal cracking, and it is not without doubt that the improvement of the thermal crack resistance is also possible.
【0029】引張り強さやそれに関連する疲労破壊テス
トについて論ずるには、フィールドで実走行しているブ
レーキディスクの実体強度を再現できる試験片によって
効果を確認しなければ意図した材料開発から縁遠いもの
になり兼ねない。通常、鉄道車両に使用するブレーキデ
ィスクは左右両面に相対する約20mm厚さの摺動面地板
部を、構造体としての強度保持および摺動面への冷却効
果を持たせる目的から放射状に並べたフィンを多数凸設
した構造からなる。そこで実体品のモジュラスを算定、
あるいは凝固時近傍の冷却速度を実測し、これら凝固組
織を律則する因子が実体品に類似する供試材の形状を引
張り強さと顕微鏡組織の確認により実験的に求めて供試
材の形状を決定した。In order to discuss the tensile strength and the related fatigue fracture test, it will be far from the intended material development unless the effect is confirmed by a test piece which can reproduce the actual strength of the brake disk actually running in the field. I can't do it. Normally, brake discs used for railway vehicles have a sliding surface base plate of about 20 mm thickness facing the left and right sides arranged radially for the purpose of maintaining strength as a structure and having a cooling effect on the sliding surface. It has a structure in which many fins are protruded. So we calculate the modulus of the entity,
Alternatively, the cooling rate in the vicinity of solidification was measured, and the factors governing these solidification structures were experimentally obtained by confirming the tensile strength and microstructure of the test material to determine the shape of the test material. Were determined.
【0030】供試材の成分は表1に掲げた通りであり、
まず、図2のように引張り強さとSc値との関係をNC
M鋳鉄との比較において確認し、次に図1に結果を示す
ように引張り強さの異なる試料(すなわちSc値の異な
る試料)毎に両振り引張り−圧縮疲労試験を行なった。
試験条件は 試験機 :油圧サーボ疲労試験機 テストピース形状 :10mmφ円柱形試験片 制御方式 :荷重制御−両振引張り・圧縮 繰り返し速度 :20Hz であり引張り強さで整理できる相関が得られ、引張り強
さと同様にNCM鋳鉄に優越する疲労強度の改善された
新素材の確認が実現した。耐熱亀裂性については図3の
ように出願人保有の円柱試験片による繰り返し熱衝撃試
験で熱疲労をシュミレートして評価した。試験条件は テストピース形状 :25φmm×25Hの円柱試験片 熱衝撃方法 :高周波誘導加熱によって最高加熱温度に急熱し、到達 後、直ちに水シャワーで急冷する。昇温15秒、最高 加熱温度780℃、繰り返し数300回。 判定法 :最も急水冷される円柱上面に生じた熱亀裂を集計して (長い亀裂から10本)、発生状況を累積検討。 であり、その結果は既に述べた通り限定した成分範囲の
中の限定したSc値において耐熱亀裂性がNCM鋳鉄と
少なくとも同等または優越し、引張り強さと引張り・圧
縮疲労限において大幅に凌駕することを確定したもので
ある。The components of the test materials are as listed in Table 1.
First, as shown in FIG. 2, the relationship between tensile strength and Sc value was determined by NC.
Confirmation was made in comparison with M cast iron, and then a swing-pull-compression fatigue test was performed for each sample having a different tensile strength (that is, a sample having a different Sc value) as shown in FIG.
Test conditions: Testing machine: Hydraulic servo fatigue testing machine Test piece shape: 10mmφ cylindrical test piece Control method: Load control-bi-axial tension / compression Repetition rate: 20Hz, a correlation that can be arranged by tensile strength is obtained, and tensile strength is obtained. Similarly to the above, a new material with improved fatigue strength superior to NCM cast iron was confirmed. The thermal crack resistance was evaluated by simulating thermal fatigue in a repeated thermal shock test using a cylindrical test piece owned by the applicant as shown in FIG. Test conditions: Test piece shape: 25φmm × 25H cylindrical test piece Thermal shock method: Rapidly heat to the maximum heating temperature by high frequency induction heating, and immediately after cooling, immediately cool with a water shower. Temperature rise 15 seconds, maximum heating temperature 780 ° C, number of repetitions 300 times. Judgment method: Thermal cracks generated on the top surface of the cylinder that is most rapidly cooled are counted (10 from long cracks), and the occurrence status is examined cumulatively. The results show that the heat crack resistance is at least equal to or superior to that of NCM cast iron at a limited Sc value within the limited component range as described above, and significantly exceeds the tensile strength and the tensile / compression fatigue limit. It has been decided.
【0031】実際のブレーキ特性を確認するために重量
%としてC:3.3,Si:1.3,Mn0.6,N
i:1.5,Cr:0.4,Mo:0.4,(Sn+S
b+Cu):0.40の成分で在来線で現に使用されて
いるブレーキディスクを溶製し、実走行を想定した厚肉
(20mm)と限界肉厚(10mm)におけるベンチテスト
(17回ランダム試験、試験最高初速度135km/h
r)を実施してブレーキ特性の変化を確認した。その結
果、現用ノンアスベスト系ライニング材2種に対し、平
均摩擦係数fms,fmtの何れも低速から高速まで現
用NCM鋳鉄と同等であり、制動性について変らない保
証を認定された。In order to confirm actual brake characteristics, C: 3.3, Si: 1.3, Mn 0.6, N
i: 1.5, Cr: 0.4, Mo: 0.4, (Sn + S
b + Cu): A component of 0.40 is used to melt the brake disc currently used in conventional lines, and a bench test (17 times random test) is performed on a thick wall (20 mm) and a limit wall thickness (10 mm) assuming actual running. , Test maximum initial speed 135km / h
r) was performed to confirm changes in brake characteristics. As a result, with respect to the two non-asbestos lining materials in use, both average friction coefficients fms and fmt were equivalent to those of the current NCM cast iron from low to high speeds, and the assurance of no change in braking performance was recognized.
【0032】[0032]
【発明の効果】本発明は以上に述べた通り在来線、新幹
線共に航空機などとの競合に対応して一層の高速性、快
適性の向上が生残りの条件として課せられ、結果的にブ
レーキディスク材に従来以上の苛酷な使用条件下で従来
以上の耐用期間を求められる二重の課題を解決する効果
が著しい。その開発の原則は飽くまで従来から定評が固
定し、とくに安全運転の模範的な部材とされてきたNC
M鋳鉄をベースに据え、従来は誰しもが思い至らなかっ
た独創的な添加元素を添加して有効成分を限定すると同
時に、第三の指標としてSc値を管理の媒体に選んで複
雑に錯綜した耐熱亀裂性、引張り強さ、引張り・圧縮疲
労限の各要素間の理想的な平衡関係を確立した点にあ
り、とくに評価の高いNCM鋳鉄の耐熱亀裂性と同等以
上を確保しつつ引張り・圧縮疲労限を大幅に向上して苛
酷化する一方のブレーキディスク材としての資質を実現
した効果が抜群である。As described above, according to the present invention, further improvement in speed and comfort is imposed as a surviving condition for both conventional lines and Shinkansen in response to competition with aircraft and the like. The effect of resolving the double problem of requiring a longer service life than before under severer use conditions than before is remarkable. The principle of its development has been fixed until recently, and has been regarded as a typical example of safe driving.
Based on M cast iron, it limits the effective ingredients by adding original additive elements that no one could have imagined before, and at the same time, selects the Sc value as the third index as the medium of management and complicates the complexities. It has established an ideal equilibrium relationship between each of the following factors: heat crack resistance, tensile strength, and tensile and compressive fatigue limits. The effect of realizing the qualities as a brake disc material while significantly increasing the compression fatigue limit and making it more severe is outstanding.
【図1】本発明と比較材の引張り・圧縮疲労限を示す図
表である。FIG. 1 is a table showing the tensile and compressive fatigue limits of the present invention and comparative materials.
【図2】本発明と比較材の引張り強さを示す図表であ
る。FIG. 2 is a table showing tensile strengths of the present invention and comparative materials.
【図3】本発明と比較材の耐熱亀裂性を示す図表であ
る。FIG. 3 is a table showing the heat crack resistance of the present invention and a comparative material.
【図4】本発明と代表的な従来技術の成分範囲(C,S
i,Mn)の比較図である。FIG. 4 shows the component ranges (C, S) of the present invention and typical prior art.
(i, Mn).
【図5】本発明と代表的な従来技術の成分範囲(Ni,
Mo,Cr,V)の比較図である。FIG. 5 shows a range of components (Ni,
Mo, Cr, V).
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平6−25795(JP,A) 特開 昭59−1655(JP,A) 特開 昭57−171647(JP,A) 特公 昭47−1872(JP,B1) (58)調査した分野(Int.Cl.7,DB名) C22C 37/00 C22C 37/06 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-25795 (JP, A) JP-A-59-1655 (JP, A) JP-A-57-171647 (JP, A) 1872 (JP, B1) (58) Field surveyed (Int. Cl. 7 , DB name) C22C 37/00 C22C 37/06
Claims (1)
5,Si:1.10〜1.50,Mn:0.60〜1.
00,Ni:1.00〜2.00,Cr:0.30〜
0.60,Mo:0.30〜0.50,P:0.16以
下,S:0.12以下の他、Sn+Sb+Cuの合計を
0.01〜0.50,Al:0.01〜0.10を含ん
で残部がFeからなり、かつ、 炭素飽和度(Sc値)=C重量%÷[4.23−(Si
重量%/3.2)] で算出される炭素飽和度が0.82〜0.91の範囲に
限ることにより前記熱亀裂性を少なくとも旧国鉄規格・
JRS番号12209−2に基づく低合金鋳鉄と同等ま
たはそれ以上に維持しつつ疲労強度が該低合金鋳鉄より
優れたことを特徴とする片状黒鉛鋳鉄からなる高速鉄道
車両用ブレーキディスク材。C: 3.10 to 3.4 in terms of% by weight
5, Si: 1.10 to 1.50, Mn: 0.60 to 1.
00, Ni: 1.00 to 2.00, Cr: 0.30
0.60, Mo: 0.30 to 0.50, P: 0.16 or less, S: 0.12 or less, the total of Sn + Sb + Cu is 0.01 to 0.50, Al: 0.01 to 0. 10 and the balance is made of Fe, and carbon saturation (Sc value) = C weight% 4 [4.23- (Si
Weight% / 3.2)] to limit the thermal cracking property to at least the former Japanese National Railways standard by limiting the carbon saturation calculated in the range of 0.82 to 0.91.
The fatigue strength is lower than that of the low alloy cast iron while maintaining the same or higher than that of the low alloy cast iron based on JRS No. 12209-2.
High-speed railway made of flaky graphite cast iron characterized by excellent properties
Brake disc material for vehicles .
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP09032625A JP3114641B2 (en) | 1997-01-30 | 1997-01-30 | Brake disc material for high-speed railway vehicles |
KR1019970038257A KR100269009B1 (en) | 1997-01-30 | 1997-08-12 | Brake disc material having exellent fatigue strength |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP09032625A JP3114641B2 (en) | 1997-01-30 | 1997-01-30 | Brake disc material for high-speed railway vehicles |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH10212545A JPH10212545A (en) | 1998-08-11 |
JP3114641B2 true JP3114641B2 (en) | 2000-12-04 |
Family
ID=12364044
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP09032625A Expired - Fee Related JP3114641B2 (en) | 1997-01-30 | 1997-01-30 | Brake disc material for high-speed railway vehicles |
Country Status (2)
Country | Link |
---|---|
JP (1) | JP3114641B2 (en) |
KR (1) | KR100269009B1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
RU2605008C1 (en) * | 2015-09-21 | 2016-12-20 | Юлия Алексеевна Щепочкина | Cast iron |
IT201900016835A1 (en) * | 2019-09-20 | 2021-03-20 | Cofren Srl | PAIR OF DISC / BRAKE FRICTION FOR RAILWAY VEHICLES |
-
1997
- 1997-01-30 JP JP09032625A patent/JP3114641B2/en not_active Expired - Fee Related
- 1997-08-12 KR KR1019970038257A patent/KR100269009B1/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
KR19980069885A (en) | 1998-10-26 |
KR100269009B1 (en) | 2000-10-16 |
JPH10212545A (en) | 1998-08-11 |
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