JPS63134632A - Heat treatment of rail - Google Patents
Heat treatment of railInfo
- Publication number
- JPS63134632A JPS63134632A JP28001186A JP28001186A JPS63134632A JP S63134632 A JPS63134632 A JP S63134632A JP 28001186 A JP28001186 A JP 28001186A JP 28001186 A JP28001186 A JP 28001186A JP S63134632 A JPS63134632 A JP S63134632A
- Authority
- JP
- Japan
- Prior art keywords
- rail
- cooled
- cooling
- heat treatment
- temp
- 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
- 238000010438 heat treatment Methods 0.000 title claims abstract description 13
- 238000001816 cooling Methods 0.000 claims abstract description 34
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 12
- 230000009466 transformation Effects 0.000 claims abstract description 10
- 229910001562 pearlite Inorganic materials 0.000 claims abstract description 7
- 238000005098 hot rolling Methods 0.000 claims abstract description 4
- 239000007921 spray Substances 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 5
- 238000002347 injection Methods 0.000 claims description 3
- 239000007924 injection Substances 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 229910000831 Steel Inorganic materials 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 229910052748 manganese Inorganic materials 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 229910001563 bainite Inorganic materials 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000012733 comparative method Methods 0.000 description 2
- 239000002826 coolant Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 241000270666 Testudines Species 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 230000029052 metamorphosis Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000003507 refrigerant Substances 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Landscapes
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、レール頭部断面が均質な微細パーライト組織
を有する高強度レールを製造する熱処理方法に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat treatment method for manufacturing a high-strength rail having a homogeneous fine pearlite structure in cross section of the rail head.
（従来の技術）
近年、鉄道輸送は高軸荷重化、高速化を指向し、それに
ともなってレール頭部の摩耗や疲労が激しく、レールに
要求される特性も一層厳しさを増し、耐摩耗性や耐損傷
性などのよシ優れた高強度レベルのレールが要求される
ようになってきた。(Conventional technology) In recent years, rail transportation has become more oriented toward higher axle loads and higher speeds, which has led to severe wear and fatigue on the rail heads, and the characteristics required for rails have become even more stringent. There is a growing demand for high-strength rails with superior properties such as durability and damage resistance.
とのような要求を満足し得るレールは、これまでの報告
から、微細なパーライト組織を有する鋼レールであって
、かかるレールは耐摩耗性や耐損傷性などの点でも優れ
た特性を示すことが知られている。According to previous reports, the rail that can satisfy these requirements is a steel rail with a fine pearlite structure, and such a rail exhibits excellent properties such as wear resistance and damage resistance. It has been known.
このような鋼レールには、
（、） 特開昭５０−１４０３１６号公報に開示され
ているような、炭素鋼Ｋ ８１ 、 Ｍｎ 、 Ｎｉ
、 Ｃｒ 。Such steel rails include carbon steel K81, Mn, Ni, as disclosed in Japanese Patent Application Laid-Open No. 50-140316.
, Cr.
Ｍｏ 、 Ｔｉなどの元素を添加した成分系の圧延まま
の合金鋼レール、
（ｂ） 特開昭５９−７４２２７号公報に開示される
特殊の合金成分を添加することなく、オーステナイト温
度域からある温度域まで噴霧水冷却と自然冷却のくシ返
し冷却によシ製造した熱処理レール、
（ｃ） 特開昭５８−２２１２２９号公報に開示され
る合成冷却剤添加量、冷却液の温度と炭素およびマンガ
ン含量を制御して製造した熱処理レールなどがある。As-rolled alloy steel rail with a component system containing elements such as Mo and Ti; (b) A certain temperature range from the austenite temperature range without adding special alloy components disclosed in JP-A-59-74227. (c) Amount of synthetic coolant added, temperature of coolant, and carbon and manganese disclosed in JP-A-58-221229. There are heat-treated rails manufactured by controlling the content.
（発明が解決しようとする問題点）
しかしながら、上記した従来の何れのレールも以下に述
べる如き問題がある。(Problems to be Solved by the Invention) However, all of the conventional rails described above have the following problems.
即ち、（＆）の合金元素を添加し、成分系を制御した圧
延ままのレールは、高価な合金元素を多量に使用するた
め、コスト高となる。（ｂ）のレールの場合は、・母−
ライト変態時での冷却停止（自然空冷ゾーン）は変態発
熱による復熱のため変態温度の上昇が生じ、強度を低下
する不都合がある。（ｃ）のレールの場合は冷却浴の温
度管理、合成剤添加量と炭素およびマンガン含量の制御
など各要因の適正管理が必要とされる。特に生産現場に
おいて浴温度と合成剤添加量の可変制御が敏速に対応で
きないため各種強度のレール製造には不都合である。That is, the as-rolled rail in which the alloying elements (&) are added and the composition system is controlled uses a large amount of expensive alloying elements, resulting in high costs. In the case of rail (b), ・mother −
Stopping cooling (natural air cooling zone) during light transformation causes the transformation temperature to rise due to recuperation due to transformation heat generation, which is disadvantageous in that strength decreases. In the case of the rail (c), appropriate management of various factors is required, such as temperature control of the cooling bath, control of the amount of synthetic agent added, and control of the carbon and manganese contents. In particular, it is inconvenient for manufacturing rails of various strengths because variable control of the bath temperature and the amount of synthetic agent added cannot be quickly performed at the production site.
本発明は、高強度という特性のみならず、耐摩耗性、耐
損傷性などの緒特性を併せ有する、よシ優れた高強度レ
ールを安定して製造するととができる熱処理方法を提供
することを目的としたものである。The present invention aims to provide a heat treatment method that can stably produce an excellent high-strength rail that has not only high strength but also other properties such as wear resistance and damage resistance. This is the purpose.
（問題点を解決するための手段）
本発明の要旨は熱間圧延を終えあるいは熱処理する目的
で加熱された温度７００’Ｃ以上の熱を保有する高温照
レール頭部を、空気噴射冷却法と噴霧水冷却法とで交互
に冷却しながら、ノ４−ライト変態を完了させた後、任
意の冷却速度、冷媒で低温度まで冷却するレールの冷却
方法である。(Means for Solving the Problems) The gist of the present invention is to use an air injection cooling method to cool the head of a high-temperature rail that is heated to a temperature of 700'C or more for the purpose of finishing hot rolling or for heat treatment. This is a rail cooling method in which the rail is cooled to a low temperature using a refrigerant at an arbitrary cooling rate after completing the 4-lite transformation while cooling the rail alternately with a spray water cooling method.
以下、本発明について詳細に説明する。The present invention will be explained in detail below.
本発明は、熱間圧延を終えあるいは熱処理する目的で加
熱された温度７００ ’Ｃ以上の熱を保有する高温レー
ルの頭部を上述の条件に従って冷却する。The present invention cools the head of a high-temperature rail, which is heated to a temperature of 700'C or more for the purpose of finishing hot rolling or for heat treatment, according to the above-mentioned conditions.
ここで冷却開始温度を７００℃以上とした理由は、気体
に比較し冷却能力の大きい噴霧水によって、レール頭部
表面下１０１ｉｉＥ以上でも噴霧水使用による冷却効果
が得られ硬質層が得られる必要な温度である。７００℃
以下の温度ではレールの表面近傍のみが冷却され、レー
ル頭部内部まで高硬質（強度）化することが困難である
。The reason why the cooling start temperature was set at 700°C or higher is because spray water has a large cooling capacity compared to gas, and the cooling effect achieved by using spray water can be obtained even below the rail head surface by 101 iiiE or more, which is necessary to obtain a hard layer. It's temperature. 700℃
At temperatures below, only the vicinity of the surface of the rail is cooled, and it is difficult to increase the hardness (strength) to the inside of the rail head.
また、７００℃以上の温度からの冷却は噴霧水と気体を
交互に噴射しなからノ９−ライト変態完了温度まで冷却
する。このようにして得られた鋼組織は微細パーライト
組織を呈して高強度、耐摩耗性などすぐれたレール頭部
が得られる。Further, cooling from a temperature of 700° C. or higher is performed by alternately injecting spray water and gas to the temperature at which the 9-lite transformation is completed. The steel structure obtained in this manner exhibits a fine pearlite structure, and a rail head with excellent high strength and wear resistance can be obtained.
しかしながら、この間噴霧水冷却法だけの場合は、過冷
却になシやすく、またレール表面のスケール有無によシ
冷却速度が大幅に違いベーナイトやマルテンサイト等の
組織を生成してしまう。したがってよシ安定した熱処理
を行うため、冷却速度の遅い気体冷却とを交互に行い冷
却する必要がある。一方、気体噴射のみの場合は、噴霧
水に比べ冷却速度がきわめて遅く、粗大化したパーライ
ト組織を呈し、レールに必要な諸性質を得ることができ
ない。このようにして冷却されパーライト変態を完了し
たレールは、さらに任意の冷却速度で低温度に冷却され
る。However, if only the spray water cooling method is used during this time, overcooling is likely to occur, and the cooling rate varies greatly depending on the presence or absence of scale on the rail surface, resulting in the formation of structures such as bainite and martensite. Therefore, in order to perform stable heat treatment, it is necessary to perform cooling alternately with gas cooling, which has a slow cooling rate. On the other hand, in the case of only gas injection, the cooling rate is extremely slow compared to sprayed water, and a coarse pearlite structure is formed, making it impossible to obtain the properties necessary for the rail. The rail that has been cooled in this manner and has undergone pearlite transformation is further cooled to a low temperature at an arbitrary cooling rate.
上記のような本発明の熱処理方法によシ製造されたレー
ルは、頭部が微細ノ々−ライト組織を呈して高硬質（高
強度）化し、耐摩耗性などにすぐれたものが得られる。The rail manufactured by the heat treatment method of the present invention as described above has a fine nonorite structure at the head, is highly hard (high strength), and has excellent wear resistance.
（実施例） 次に本発明を実施例に基づいて説明する。(Example) Next, the present invention will be explained based on examples.
第１表に示す化学成分を含有した１３２ポンド／ヤード
のレールを本発明に従い温度８５０℃からノ母−ライト
変態完了まで噴霧水と空気による交互冷却を行い、続い
て放冷するレールの熱処理を施した。According to the present invention, a 132 lb/yard rail containing the chemical components shown in Table 1 was cooled alternately with spray water and air from a temperature of 850°C until the completion of the mother-lite transformation, and then the rail was heat-treated to allow it to cool. provided.
得られたレール頭部断面硬度分布例を第１図のＡで示す
。熱処理中の冷却曲線例を第２図のＡに示す。An example of the cross-sectional hardness distribution of the rail head obtained is shown by A in FIG. An example of a cooling curve during heat treatment is shown in A of FIG.
本発明の比較として、第１図Ｂに３５秒間連続噴霧水冷
却後、自然冷却をした場合のレール頭部断面硬度分布を
示すが、ＢはＡに比較して約５０の硬度差が生じ、変態
時の抜熱の重要性を示している。As a comparison of the present invention, Fig. 1B shows the cross-sectional hardness distribution of the rail head when natural cooling was performed after continuous spray water cooling for 35 seconds. This shows the importance of heat removal during metamorphosis.
第２図のＢに第１図のＢの熱処理中の冷却曲線を示す。FIG. 2B shows a cooling curve during the heat treatment of FIG. 1B.
第２図のＣは高温度から連続して噴霧水冷却を実施した
場合の冷却曲線を示す。この曲線から明らかなように表
面温度が４００〜５００℃になると沸騰現象の変化によ
る冷却能力の急上昇のため急激な抜熱が行われ、レール
の表面近傍の温度は急降下する。この結果、ベーナイト
やマルテンサイト組織が生成しやすい。したがって噴霧
冷却のみの熱処理法では高強度レールの製造は著しく制
御が困難であることが判る。C in FIG. 2 shows a cooling curve when spray water cooling is performed continuously from a high temperature. As is clear from this curve, when the surface temperature reaches 400 to 500 degrees Celsius, the cooling capacity rapidly increases due to changes in the boiling phenomenon, leading to rapid heat removal and the temperature near the rail surface to drop rapidly. As a result, bainite and martensitic structures are likely to be generated. Therefore, it can be seen that it is extremely difficult to control the production of high-strength rails using a heat treatment method using only spray cooling.
（発明の効果）
本発明によれば、所望の全断面微細／４’−ラ゛イト組
織を有する高強度でかつ耐摩耗性及び耐損傷性に優れた
レールが高能率でしかも安定して得られるので、産業界
に稗益するところが極めて大である。(Effects of the Invention) According to the present invention, a rail having a desired overall cross-sectional fine/4'-light structure, high strength, and excellent wear resistance and damage resistance can be obtained with high efficiency and stability. Therefore, the benefits to industry are extremely large.
第１図は本発明及び比較法により得られたレール頭部断
面硬度分布を示す、図、第２図は本発明及び比較法によ
るレール頭部熱処理中の冷却曲線を示す図である。
１・−
一°コ
本多小平 、１
１１．二
岸田正行１．ｃ′
ｊ邦山３
、・１−Ｔ′ｌ
新部興治１
１’、”−１−、ｉ、１
第１図
表面ハ゛らのｉ巨負亀ｍｍ
ｉ襄（０Ｃ）FIG. 1 is a diagram showing the cross-sectional hardness distribution of the rail head obtained by the present invention and the comparative method, and FIG. 2 is a diagram showing the cooling curve during heat treatment of the rail head by the present invention and the comparative method. 1・- 1° Kodaira Honda, 1 11. Masayuki Nikishida 1. c' j Kuniyama 3, 1-T'l Shinbu Koji 1 1', "-1-, i, 1 Figure 1 surface of these i giant turtle mm i 襄 (0C)
Claims (1)
温度７００℃以上の熱を保有する高温度レールの頭部を
噴霧水冷却法と気体噴射冷却法とで交互に冷却しながら
パーライト変態を完了させた後、任意の冷却速度で低温
度まで冷却することを特徴とするレールの熱処理方法。The head of a high-temperature rail that has been heated to a temperature of 700°C or higher after hot rolling or for the purpose of heat treatment is cooled alternately using spray water cooling method and gas injection cooling method to complete pearlite transformation. A method for heat treating rails, which comprises cooling the rails to a low temperature at an arbitrary cooling rate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28001186A JPS63134632A (en) | 1986-11-25 | 1986-11-25 | Heat treatment of rail |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28001186A JPS63134632A (en) | 1986-11-25 | 1986-11-25 | Heat treatment of rail |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63134632A true JPS63134632A (en) | 1988-06-07 |
Family
ID=17619058
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28001186A Pending JPS63134632A (en) | 1986-11-25 | 1986-11-25 | Heat treatment of rail |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63134632A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03166318A (en) * | 1989-11-27 | 1991-07-18 | Nippon Steel Corp | Method for heat-treating rail |
| JP2011504967A (en) * | 2007-11-28 | 2011-02-17 | ダニエリ アンド シー．オフィチネ メッカニチェ ソシエタ ペル アチオニ | Method and apparatus for heat treating rails |
| WO2014157198A1 (en) * | 2013-03-28 | 2014-10-02 | Ｊｆｅスチール株式会社 | Rail manufacturing method and manufacturing equipment |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6289818A (en) * | 1985-10-14 | 1987-04-24 | Nippon Kokan Kk <Nkk> | Heat treatment of rail |
-
1986
- 1986-11-25 JP JP28001186A patent/JPS63134632A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6289818A (en) * | 1985-10-14 | 1987-04-24 | Nippon Kokan Kk <Nkk> | Heat treatment of rail |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03166318A (en) * | 1989-11-27 | 1991-07-18 | Nippon Steel Corp | Method for heat-treating rail |
| JP2011504967A (en) * | 2007-11-28 | 2011-02-17 | ダニエリ アンド シー．オフィチネ メッカニチェ ソシエタ ペル アチオニ | Method and apparatus for heat treating rails |
| WO2014157198A1 (en) * | 2013-03-28 | 2014-10-02 | Ｊｆｅスチール株式会社 | Rail manufacturing method and manufacturing equipment |
| JP5686231B1 (en) * | 2013-03-28 | 2015-03-18 | Ｊｆｅスチール株式会社 | Rail manufacturing method and manufacturing apparatus |
| AU2014245505B2 (en) * | 2013-03-28 | 2016-09-15 | Jfe Steel Corporation | Rail manufacturing method and manufacturing equipment |
| US10214795B2 (en) | 2013-03-28 | 2019-02-26 | Jfe Steel Corporation | Rail manufacturing method and manufacturing equipment |
| US10563278B2 (en) | 2013-03-28 | 2020-02-18 | Jfe Steel Corporation | Rail manufacturing method and manufacturing equipment |
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