JP2011046993A - Coated and heat-treated steel and method for manufacturing the same - Google Patents

Coated and heat-treated steel and method for manufacturing the same Download PDF

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JP2011046993A
JP2011046993A JP2009195487A JP2009195487A JP2011046993A JP 2011046993 A JP2011046993 A JP 2011046993A JP 2009195487 A JP2009195487 A JP 2009195487A JP 2009195487 A JP2009195487 A JP 2009195487A JP 2011046993 A JP2011046993 A JP 2011046993A
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steel material
plating film
heat
coated
film
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Toyomitsu Nakamura
登代充 中村
Tamotsu Toki
保 土岐
Atsushi Tomizawa
淳 富澤
Kazuhito Imai
和仁 今井
Naoaki Shimada
直明 嶋田
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Nippon Steel Corp
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Sumitomo Metal Industries Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a coated and heat-treated steel which has appropriate corrosion resistance after having been painted as an automotive member, with which production of scale due to heat treatment is suppressed, and further which is excellent in weldability and decorativeness, even when having been subjected to the heat treatment of heating at least a part of a steel having a plated film on at least one side to a quenchable temperature range and subsequently cooling it. <P>SOLUTION: The coated and heat-treated steel is obtained by conducting the heat treatment of heating at least a part of the steel that has the alloy plated film including a total of ≥50% of two or more selected from a group of a Ni plated film, a Cr plated film, a Cu plated film, and a Co plated film, or, Ni, Cr, Cu or Co coated on at least one side and has been subjected to an alloying treatment at a temperature of the Ac<SB>3</SB>point or lower, to the quenchable temperature range, and has a film in which a combination of one or two or more selected from a group of iron-Ni, Cr, Cu or Co are alloyed on the surface of at least one part of a portion that has been heat treated. The film has corrosion resistance and also can secure a lubricating function at a high temperature, and further is excellent in weldability and decorativeness. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、被覆熱処理鋼材およびその製造方法に関し、さらに詳しくは、耐食性を有するとともに高温で潤滑機能を確保することができ、かつ、溶接性および装飾性が良好であることから、例えば自動車用部材等に好適に用いることができる被覆熱処理鋼材およびその製造方法に関する。   The present invention relates to a coated heat-treated steel material and a method for producing the same, and more specifically, has corrosion resistance, can ensure a lubricating function at high temperatures, and has good weldability and decorative properties. The present invention relates to a coated heat-treated steel material that can be suitably used for, for example, a manufacturing method thereof.

自動車用部材には、溶融亜鉛めっき鋼板、合金化溶融亜鉛めっき鋼板または電気亜鉛めっき鋼板等の亜鉛系めっき鋼材が、使用環境における耐食性が必要十分であるとともにコスト面で優れることから、広く用いられる。合金化溶融亜鉛めっき鋼板は、鋼板を連続的に溶融亜鉛めっきした後に470〜550℃程度の温度で熱処理してめっき層全体をFe−Znの金属間化合物層に変化させたものである。このため、合金化溶融亜鉛めっき鋼板は、溶融亜鉛めっき鋼板や電気亜鉛めっき鋼板に比較するとめっき層が電気化学的に幾分貴となって犠牲防食能は僅かに低下するものの、めっき層の塗装膜との密着性が向上することから、化成処理および電着塗装を行われることを前提とする自動車用部材として多用される。   For automotive parts, galvanized steel materials such as hot-dip galvanized steel sheets, alloyed hot-dip galvanized steel sheets or electrogalvanized steel sheets are widely used because they have sufficient corrosion resistance in the usage environment and are excellent in cost. . The alloyed hot-dip galvanized steel sheet is obtained by continuously hot-dip galvanizing a steel sheet and then heat-treating it at a temperature of about 470 to 550 ° C. to change the entire plated layer into an intermetallic compound layer of Fe—Zn. Therefore, the alloyed hot-dip galvanized steel sheet has a slightly lower sacrificial anticorrosive ability than the hot-dip galvanized steel sheet or electrogalvanized steel sheet, but the coating layer is coated. Since adhesion to the film is improved, it is frequently used as a member for automobiles on the premise that chemical conversion treatment and electrodeposition coating are performed.

なお、合金化溶融亜鉛めっき鋼板は、そのめっき層が上述したように金属間化合物で形成されることから、プレス(曲げ、絞り)加工時にめっき皮膜の一部がパウダリングする場合がある。このような場合には、自動車用部材として、かかる問題が少ない溶融亜鉛めっき鋼板や電気亜鉛めっき鋼板が、合金化溶融亜鉛めっき鋼板に代替して、用いられる。   In addition, since the plating layer of an alloyed hot-dip galvanized steel sheet is formed of an intermetallic compound as described above, a part of the plating film may be powdered during press (bending, drawing) processing. In such a case, a hot dip galvanized steel plate or an electrogalvanized steel plate with few such problems is used as a member for automobiles in place of the alloyed hot dip galvanized steel plate.

近年、自動車構造用鋼材には、地球環境への配慮から軽量で高強度の材料が強く要請される。また、衝突時の車体の安全性を高めて安全性の向上の要求の高まりに応えるため、衝突時における自動車用部材のエネルギー吸収特性を高めるための開発も推進されている。例えば、自動車の側面からの衝突に対する安全性を高めるため、ドアーの内部に補強用のビームとして配置される鋼管等の金属管に適当な湾曲形状を付与することによって衝突エネルギーの吸収能を高めている。また、センターピラーの補強材もその形状や曲率の適正化を図ることにより、衝突時のエネルギー吸収能を高めている。このような自動車用部材を提供するために、特に鋼管や鋼板のプレ成形品素材を最適な形状に加工する発明が開示されている。   In recent years, lightweight and high-strength materials have been strongly demanded for automotive structural steel materials in consideration of the global environment. In addition, in order to increase the safety of a vehicle body at the time of a collision and meet the increasing demand for improvement in safety, development for enhancing the energy absorption characteristics of automobile members at the time of a collision is being promoted. For example, in order to increase the safety against a collision from the side of an automobile, the ability to absorb the collision energy is enhanced by giving an appropriate curved shape to a metal pipe such as a steel pipe arranged as a reinforcing beam inside the door. Yes. In addition, the reinforcing material of the center pillar also increases the energy absorption capability at the time of collision by optimizing its shape and curvature. In order to provide such a member for an automobile, an invention for processing a pre-formed material of a steel pipe or a steel plate into an optimum shape has been disclosed.

一方、自動車用部材には、車体の軽量化を図るため、高張力化に対する要請も強い。このような要請に対応するため、従来とは全く異なる強度レベルからなる高張力鋼、例えば、引張強さが780MPa以上、さらに900MPa以上という超高強度の鋼材も広く用いられるようになっている。高張力鋼からなる素材に、冷間で曲げ加工を行うことは困難であり、また熱間で曲げ加工を行う場合にも不均一な歪みの発生による形状のばらつきを防止できず、形状凍結性が不足する。これに加えて、上述の観点から最適な形状に曲げ加工を行うために、例えば曲げ方向が2次元的や3次元的に変化する、多岐にわたる曲げ形状からなる鋼材を高い寸法精度で加工する曲げ加工技術の開発も強く要請される。   On the other hand, in order to reduce the weight of the vehicle body, there is a strong demand for higher tension in automobile members. In order to meet such demands, high-strength steel having a completely different strength level from that of the prior art, for example, ultra-high-strength steel materials having a tensile strength of 780 MPa or more and 900 MPa or more are widely used. It is difficult to bend a material made of high-strength steel cold, and even when hot bending is performed, shape variation due to uneven distortion cannot be prevented and shape freezing Is lacking. In addition to this, in order to bend into an optimal shape from the above viewpoint, for example, bending that processes a steel material having a wide variety of bending shapes with a high dimensional accuracy in which the bending direction changes two-dimensionally or three-dimensionally. Development of processing technology is also strongly requested.

本発明者らは、特許文献1により、鋼材の曲げ方向が3次元的に変化する連続曲げの場合であっても、多次元に移動自在に配置されたローラダイスを用いて効率的に、曲げ加工、さらには曲げ加工と同時に鋼材の焼入れを行うための曲げ加工方法および曲げ加工装置に係る発明を開示した。特許文献1により開示された発明では、高周波加熱コイルにより被加工材である鋼材を、部分的かつ連続的に鋼材の焼入れ可能な温度以上であってかつ組織が粗粒化しない温度まで急速に加熱し、加熱された部分的な領域を、可動ローラダイスを用いて塑性変形させ、その直後に急冷するものである。   According to Patent Document 1, the present inventors can efficiently perform bending using a roller die arranged in a multi-dimensional manner, even in the case of continuous bending in which the bending direction of the steel material changes three-dimensionally. An invention relating to a bending method and a bending apparatus for quenching a steel material at the same time as the bending process is disclosed. In the invention disclosed in Patent Document 1, a steel material that is a workpiece is rapidly heated to a temperature at which the steel material is partially and continuously at or above the temperature at which the steel material can be quenched and the structure is not coarsened. Then, the heated partial region is plastically deformed using a movable roller die, and immediately cooled immediately thereafter.

特許文献1により開示された発明により自動車用部材を現実に量産するには、製造コストの上昇を抑制するために、被加工材を大気中で加熱することが常識的である。前述の通り、自動車用部材に用いられる鋼材には、基本的に化成処理や電着塗装が施されるが、耐食性を強化する観点から、亜鉛系めっき鋼材が多用されている。したがって、特許文献1により開示した加工方法等において被加工材として亜鉛系めっき鋼材を用いることが可能であれば、被加工材の加熱による酸化を防止できるとともに耐食性を有する曲げ加工部材や焼入部材を製造することができるため、自動車用用途への適用範囲を大幅に拡大することができるようになる。   In order to actually mass-produce automobile members according to the invention disclosed in Patent Document 1, it is common sense to heat a workpiece in the air in order to suppress an increase in manufacturing cost. As described above, chemical conversion treatment and electrodeposition coating are basically performed on steel materials used for automobile members, but zinc-based plated steel materials are frequently used from the viewpoint of enhancing corrosion resistance. Therefore, if it is possible to use a zinc-based plated steel material as a workpiece in the processing method disclosed in Patent Document 1, a bending member and a quenching member that can prevent oxidation due to heating of the workpiece and have corrosion resistance Therefore, the range of application to automotive applications can be greatly expanded.

しかしながら、亜鉛めっき鋼材をそのAc変態点、さらにはAc変態点以上に加熱した場合、めっき層としての機能が喪失されるおそれがある。その理由は、第1に、亜鉛の蒸気圧が例えば200mmHg:788℃、400mmHg:844℃と温度の上昇とともに急増するために急速加熱過程で気化する可能性があること、第2に、大気中での加熱に伴い亜鉛の酸化が生じること、そして第3に、亜鉛めっき鋼材が600℃以上、特にΓ相(FeZn10)が分解する660℃を超える温度に加熱されると、鋼素地のフェライト中へのZnの固溶現象が顕著になり、めっき層が失われる可能性があるからである。 However, when the galvanized steel material is heated to its Ac 1 transformation point, and further to the Ac 3 transformation point or higher, the function as a plating layer may be lost. The reason for this is that, firstly, the vapor pressure of zinc increases with increasing temperature, for example, 200 mmHg: 788 ° C. and 400 mmHg: 844 ° C .; When zinc is oxidized with heating in the steel, and thirdly, when the galvanized steel is heated to a temperature of 600 ° C. or higher, particularly over 660 ° C. at which the Γ phase (Fe 3 Zn 10 ) decomposes, the steel substrate This is because the solid solution phenomenon of Zn in the ferrite becomes prominent and the plating layer may be lost.

このような問題に対応するため、特許文献2には、亜鉛めっきされた高周波焼入用鋼板をAr点以上1000℃以下の焼入温度で、かつ加熱開始から350℃に冷却されるまでのヒートサイクルタイムを60秒間以内に制限して加熱および冷却する高周波焼入による強化部材の製造方法に係る発明が開示されている。この発明によれば、高周波焼入強化部材として、焼入用鋼板を素板とする溶融亜鉛めっき鋼板を用いて強度を向上させる部位に高周波焼入を施しても、焼入部にめっき層を残存させることができ、しかも、めっき層中のFe濃度が35%以下(本明細書では特に断りがない限り「%」は「質量%」を意味する)に制御され、塗装性および耐食性にも優れる自動車用部材を提供できるとしている。 In order to cope with such a problem, Patent Document 2 describes that a steel plate for induction hardening that has been galvanized has a quenching temperature of Ar 3 or higher and 1000 ° C. or lower and is cooled to 350 ° C. from the start of heating. An invention relating to a method for manufacturing a reinforcing member by induction hardening in which the heat cycle time is limited to 60 seconds or less and heated and cooled is disclosed. According to this invention, even if induction hardening is performed on a portion whose strength is improved by using a hot dip galvanized steel plate made of a hardened steel plate as the induction hardening reinforcing member, the plating layer remains in the hardened portion. Moreover, the Fe concentration in the plating layer is controlled to 35% or less (in this specification, “%” means “mass%” unless otherwise specified), and is excellent in paintability and corrosion resistance. The company says it can provide automotive parts.

国際公開第2006/093006号パンフレットInternational Publication No. 2006/093006 Pamphlet 特開2000−248338号公報JP 2000-248338 A

本発明者らは、特許文献2により提案された焼入用鋼板に形成される亜鉛めっき層の挙動を明らかにするため、亜鉛系めっき鋼材を用いて高周波加熱による加熱・冷却実験を行った。   In order to clarify the behavior of the galvanized layer formed on the steel sheet for quenching proposed by Patent Document 2, the present inventors conducted a heating / cooling experiment by high-frequency heating using a zinc-based plated steel material.

通常のめっき付着量レベルである60g/m(片面当たり)の亜鉛系めっき鋼材を900℃程度に加熱してから急冷した場合に、めっき層は15%以上のFeを含有する組成となるが、めっき層中にはη相(化学式:Zn)が存在する。供試材に合金化溶融亜鉛めっき鋼材を用いた場合にもめっき層中にη相が存在する。 When a zinc-plated steel material of 60 g / m 2 (per one side), which is a normal plating adhesion level, is rapidly cooled after being heated to about 900 ° C., the plating layer has a composition containing 15% or more of Fe. The η phase (chemical formula: Zn) is present in the plating layer. Even when an alloyed hot-dip galvanized steel material is used as the test material, the η phase is present in the plating layer.

これは、合金化溶融亜鉛めっき鋼材を用いる場合を例として考察すれば、高周波加熱および冷却の過程で金属間化合物が一旦分解して再構成されることによる。すなわち、900℃の加熱温度は、Fe−Zn系の金属間化合物であるζ相(化学式:FeZn13)、δ相(同:FeZn)、Γ相(同:FeZn21)およびΓ相(同:FeZn10)のいずれの融点または分解温度より高いため、加熱過程におけるめっき層には高濃度のFeを含有するZnの液相のみが存在し、冷却過程で金属間化合物を析出しつつ、一部に液相Znを残存させたまま凝固するものと考えられる。 Considering the case of using an alloyed hot-dip galvanized steel as an example, this is because the intermetallic compound is once decomposed and reconfigured in the process of high-frequency heating and cooling. That is, the heating temperature of 900 ° C. is a ζ phase (chemical formula: FeZn 13 ), a δ 1 phase (same: FeZn 7 ), a Γ 1 phase (same: Fe 5 Zn 21 ), which are Fe—Zn-based intermetallic compounds. Since the melting point or decomposition temperature of the Γ phase (same as Fe 3 Zn 10 ) is higher, only a Zn liquid phase containing a high concentration of Fe exists in the plating layer in the heating process, and an intermetallic compound is present in the cooling process. It is considered that the liquid phase Zn remains in a part and solidifies while precipitating.

このような加熱および冷却条件で得られためっき層は、その表面粗度は非常に粗いものになる。このように、加熱および冷却によりめっき層の表面性状が劣化した熱処理鋼材は、その後に行われる化成処理および電着塗装により形成される電着塗膜の膜厚の不均一を生じ、耐食性の著しい低下を誘発することとなる。   The plating layer obtained under such heating and cooling conditions has a very rough surface. Thus, the heat-treated steel material whose surface properties of the plating layer have deteriorated by heating and cooling causes unevenness of the film thickness of the electrodeposition coating film formed by chemical conversion treatment and electrodeposition coating performed thereafter, and has remarkable corrosion resistance. It will induce a decline.

換言すると、亜鉛系めっき鋼材に600℃以上の温度域、特にAc点以上1000℃以下のような高温域に加熱し、冷却するプロセスを施すと、めっき層が鋼素地へ拡散し、または酸化若しくは蒸発により消失する現象を示すものの、何らかの耐食性が期待できる程度に加熱された部分にめっき層を残存させることは特許文献2により開示されるように可能であるものの、残存するめっき層の表面状態が粗いために、その後に自動車用部材として十分な表面処理を施すことが困難である。 In other words, when the zinc-based plated steel material is heated to a temperature range of 600 ° C. or higher, particularly in a high temperature range such as Ac 1 point or higher and 1000 ° C. or lower, the plating layer diffuses into the steel base or is oxidized. Alternatively, although the phenomenon disappears by evaporation, it is possible to leave the plating layer in a portion heated to such an extent that some corrosion resistance can be expected, as disclosed in Patent Document 2, but the surface state of the remaining plating layer Since it is rough, it is difficult to perform sufficient surface treatment as a member for automobiles thereafter.

本発明は、このような課題に鑑みてなされたものであり、少なくとも片面にめっき皮膜を有する鋼材の少なくとも一部を焼入れ可能温度域に加熱した後に冷却する熱処理を行っても、自動車用部材としての塗装後の適正な耐食性を有するとともに、熱処理に伴うスケールの発生を抑制でき、さらにはスケールの発生を抑制できるとともに硬質であることから高温での加工時にも優れた潤滑性を示し、さらに、溶接性および装飾性が良好な被覆熱処理鋼材およびその製造方法を提供することを目的とする。   The present invention has been made in view of such a problem, and even if a heat treatment is performed by cooling at least a part of a steel material having a plating film on at least one surface to a quenchable temperature range, it can be used as an automobile member. In addition to having the appropriate corrosion resistance after coating, it can suppress the generation of scales due to heat treatment, and can also suppress the generation of scales and is hard and exhibits excellent lubricity even during processing at high temperatures. An object of the present invention is to provide a coated heat-treated steel material having good weldability and decorativeness and a method for producing the same.

本発明は、高融点めっき皮膜形成元素系めっき皮膜を備える鋼材をAc点以下の温度で合金化処理された鋼材を焼入れ可能温度域に加熱する熱処理を行うと、この熱処理を行われた部分の少なくとも一部の表面に鉄−高融点めっき皮膜形成元素が合金化された高融点めっき皮膜を有し、この高融点めっき皮膜が、耐食性を有するとともに高温で潤滑機能を確保することができ、さらに、溶接性および装飾性が良好な皮膜であることから、自動車用部材として好適な被覆熱処理鋼材を得られるという知見に基づく。 In the present invention, when a steel material provided with a high melting point plating film-forming element-based plating film is subjected to a heat treatment to heat the steel material alloyed at a temperature of Ac 3 points or less to a quenchable temperature range, the heat-treated portion Having a high melting point plating film in which an iron-high melting point plating film forming element is alloyed on at least a part of the surface, and this high melting point plating film has corrosion resistance and can ensure a lubricating function at a high temperature, Furthermore, since it is a film having good weldability and decorativeness, it is based on the knowledge that a coated heat-treated steel material suitable as an automobile member can be obtained.

本発明は、少なくとも一つの面に被覆された高融点めっき皮膜形成元素系めっき皮膜を備える鋼材を、Ac点以下の温度で合金化処理された鋼材の少なくとも一部を焼入れ可能温度域に加熱する熱処理を行われてなる被覆熱処理鋼材であって、この熱処理を行われた部分の少なくとも一部の表面に鉄−高融点めっき皮膜形成元素が合金化された高融点めっき皮膜を有し、この高融点めっき皮膜が、耐食性を有するとともに高温で潤滑機能を確保することができ、さらに、溶接性および装飾性が良好な皮膜であることを特徴とする被覆熱処理鋼材である。 The present invention heats at least a part of a steel material that has been alloyed at a temperature of 3 points or less to a quenchable temperature range in a steel material having a high melting point plating film-forming element-based coating film coated on at least one surface. A heat-treated coated steel material having a high-melting-point plating film in which an iron-high-melting-point plating film-forming element is alloyed on at least a part of the surface of the heat-treated part. A high-melting-point plated film is a coated heat-treated steel material that is corrosion-resistant, can ensure a lubricating function at high temperatures, and has good weldability and decorative properties.

別の観点からは、本発明は、少なくとも一つの面に被覆された高融点めっき皮膜形成元素系めっき皮膜を備える鋼材を、Ac点以下の温度で合金化処理された鋼材の少なくとも一部を焼入れ可能温度域に加熱し、加熱された部分の少なくとも一部の表面に液相が存在しないうちに冷却することにより、加熱および冷却を行われた部分の少なくとも一部の表面に、鉄−高融点めっき皮膜形成元素が合金化され、耐食性を有するとともに高温で潤滑機能を確保することができ、さらに、溶接性および装飾性が良好な皮膜を形成することを特徴とする被覆熱処理鋼材の製造方法である。 From another point of view, the present invention relates to a steel material having a high melting point plating film-forming element-based coating film coated on at least one surface, and at least a part of the steel material alloyed at a temperature of Ac 3 points or less. By heating to a quenchable temperature range and cooling before the liquid phase is present on at least part of the surface of the heated part, at least part of the surface of the heated and cooled part A method for producing a coated heat-treated steel material, characterized in that a melting point plating film-forming element is alloyed, has corrosion resistance, can ensure a lubricating function at high temperatures, and further forms a film with good weldability and decorative properties It is.

これらの本発明では、高融点めっき皮膜形成元素が、Ni、Cr、CuまたはCoからなる群から選ばれた一種または二種以上の組み合わせであることが好ましい。
これらの本発明では、高融点めっき皮膜が、Niめっき皮膜、Crめっき皮膜、Cuめっき皮膜、Coめっき皮膜、または、Ni、Cr、CuまたはCoからなる群から選ばれた二種以上を合計で50%以上含有する合金めっき皮膜であることが好ましい。
In these present inventions, the refractory plating film-forming element is preferably one or a combination of two or more selected from the group consisting of Ni, Cr, Cu or Co.
In these present inventions, the high melting point plating film is a total of two or more selected from the group consisting of Ni plating film, Cr plating film, Cu plating film, Co plating film, or Ni, Cr, Cu or Co. An alloy plating film containing 50% or more is preferable.

これらの本発明では、高融点めっき皮膜の付着量が一面当たり、Niめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Crめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Cuめっき皮膜の場合には
0.1g/m以上30g/m以下であることが好ましく、Coめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、さらに、Ni、Cr、CuまたはCoからなる群から選ばれた二種以上を合計で50%以上含有する合金めっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましい。
In these present inventions, the amount of high melting point plating film deposited per surface is preferably 0.1 g / m 2 or more and 30 g / m 2 or less in the case of Ni plating film, and 0 in the case of Cr plating film. preferably .1g / m 2 or more and 30 g / m 2 or less, preferably 0.1 g / m 2 or more 30 g / m 2 or less in the case of Cu plating film, in the case of Co plating film 0 preferably .1g / m 2 or more 30 g / m 2 or less, further, Ni, Cr, in the case of alloy plating film containing 50% or more in total of two or more selected from the group consisting of Cu or Co Is preferably 0.1 g / m 2 or more and 30 g / m 2 or less.

Ni,Cr,Cu,Coは30g/mを超えてめっきさせても良いが、追加的な特性の改善がなく、その一方でめっきコストが過大になるため、30g/mを上限とするのが工業的に好ましい。 Ni, Cr, Cu, and Co may be plated over 30 g / m 2 , but there is no additional improvement in characteristics, while the plating cost becomes excessive, so 30 g / m 2 is the upper limit. Is industrially preferred.

これらの本発明では、このめっき層の表面の、JIS B 0610により規定される中心線平均粗さRa(以下、単に「表面粗さRa」という)は、特に規定しない。
上述した本発明に係る被覆熱処理鋼材の製造方法では、高融点めっき皮膜形成元素系めっき皮膜を備える鋼材をAc点以下の温度で合金化処理された鋼材が、その長手方向へ向けて断続的または連続的に送られながら、第1の支持手段により支持されるとともに、加圧ロールが、第1の支持手段の下流側に配置されるとともにその位置が二次元または三次元に移動自在である第2の支持手段によって回転自在に支持され、さらに、この鋼材の加熱が、この第2の支持手段と第1の支持手段との間であってこの鋼材の外周にこの鋼材から離間して配置される加熱手段によって行われるとともに、冷却が、この加熱手段と第2の支持手段との間に配置される冷却手段によって行われることが、好ましい。
In these present inventions, the center line average roughness Ra (hereinafter, simply referred to as “surface roughness Ra”) defined by JIS B 0610 on the surface of the plating layer is not particularly defined.
In the manufacturing method of the coated heat-treated steel material according to the present invention described above, the steel material obtained by alloying the steel material having the high melting point plating film-forming element-based plating film at a temperature of Ac 3 points or less is intermittently directed toward the longitudinal direction. Alternatively, while being continuously fed, it is supported by the first support means, and the pressure roll is disposed on the downstream side of the first support means, and its position is movable in two dimensions or three dimensions. The steel material is rotatably supported by the second support means, and further, the heating of the steel material is disposed between the second support means and the first support means and spaced from the steel material on the outer periphery of the steel material. It is preferable that the cooling is performed by the cooling means disposed between the heating means and the second support means.

これらの本発明における「鋼材」とは、平板材のみならず、丸形、矩形、台形等の断面形状を有する閉断面材、ロールフォーミング等により製造されるチャンネル材等の開断面材、押し出し加工により製造されるチャンネル材等の異型断面材、または例えば丸棒、角棒さらには異形棒等の各種の断面形状を有する棒材等を意味するものであり、長手方向へ断面形状がテーパー状に変化するテーパー形状のものも包含する。   These “steel materials” in the present invention are not only flat plate materials but also closed cross-sectional materials having a cross-sectional shape such as round, rectangular, trapezoidal, open cross-sectional materials such as channel materials manufactured by roll forming, etc., extrusion processing Means a cross-sectional material such as a channel material manufactured by the above, or a bar material having various cross-sectional shapes such as a round bar, a square bar, or a deformed bar, etc., and the cross-sectional shape is tapered in the longitudinal direction. Also includes a tapered shape that changes.

本発明によれば、少なくとも片面にめっき皮膜を有する鋼材の少なくとも一部を焼入れ可能温度域に加熱した後に冷却する熱処理を行っても、自動車用部材としての塗装後の適正な耐食性を有するとともに、熱処理に伴うスケールの発生を抑制でき、さらにはスケールの発生を抑制できるとともに硬質であることから高温での加工時にも優れた潤滑性と、優れた溶接性および装飾性とを有する被覆熱処理鋼材を提供できるようになる。   According to the present invention, even when performing heat treatment to cool after heating at least a part of the steel material having a plating film on at least one side to a quenchable temperature range, it has appropriate corrosion resistance after painting as a member for automobiles, A coated heat-treated steel material that can suppress the generation of scales due to heat treatment, and further suppresses the generation of scales and is hard and has excellent lubricity, high weldability, and decorativeness even when processed at high temperatures. Can be provided.

図1は、本発明に係る被覆熱処理鋼材を製造するための製造装置の構成を例示する説明図である。FIG. 1 is an explanatory view illustrating the configuration of a production apparatus for producing a coated heat-treated steel material according to the present invention. 図2は、本発明に係る被覆熱処理鋼材を製造するための製造装置における高周波加熱コイルおよび冷却装置の構成の概略を例示する断面図である。FIG. 2 is a cross-sectional view illustrating the outline of the configuration of the high-frequency heating coil and the cooling device in the manufacturing apparatus for manufacturing the coated heat-treated steel material according to the present invention. 図3は、本発明に係る被覆熱処理鋼材の製造に用いることができる可動ローラダイスの形状を例示する説明図であり、図3(a)はめっき鋼材が丸管などの閉断面材である場合に2つの加圧ロールにより構成される場合であり、図3(b)はめっき鋼材が矩形管等の閉断面材である場合に2つの加圧ロールにより構成される場合であり、さらに図3(c)はめっき鋼材が矩形管などの閉断面材である場合に4つの加圧ロールにより構成される場合である。FIG. 3 is an explanatory view illustrating the shape of a movable roller die that can be used for the production of the coated heat-treated steel material according to the present invention, and FIG. 3A is a case where the plated steel material is a closed cross-section material such as a round tube. 3 (b) shows a case in which the plated steel material is a closed cross-section material such as a rectangular tube, and further comprises two pressure rolls. (C) is a case where it comprises four pressure rolls when the plated steel material is a closed cross-section material such as a rectangular tube.

本発明を実施するための形態を、添付図面を参照しながら説明する。
本発明に係る被覆熱処理鋼材は、「高融点めっき皮膜形成元素系めっき皮膜を備える鋼材をAc点以下の温度で合金化処理された鋼材」を素材とし、この鋼材の少なくとも一部を焼入れ可能温度域に加熱する熱処理を行われてなるものである。
A mode for carrying out the present invention will be described with reference to the accompanying drawings.
The coated heat-treated steel material according to the present invention is made of “a steel material having a high melting point plating film-forming element-based plating film alloyed at a temperature of Ac 3 points or less”, and at least a part of this steel material can be quenched. A heat treatment for heating to a temperature range is performed.

本発明における素材としての鋼材は、平板材のみならず、丸形、矩形、台形等の断面形状を有する閉断面材、ロールフォーミング等により製造されるチャンネル材等の開断面材、押し出し加工により製造されるチャンネル材等の異型断面材、または例えば丸棒、角棒さらには異形棒等の各種の断面形状を有する棒材等の中実材を包含する。また、この鋼材には、断面形状が、長手方向へ一定であるもののみならず、長手方向へテーパー状に変化するテーパー形状のものも包含する。   The steel material as a material in the present invention is manufactured not only by a flat plate material but also by a closed cross-sectional material having a cross-sectional shape such as a round shape, a rectangular shape, and a trapezoid shape, an open cross-sectional material such as a channel material produced by roll forming, and the like. Or a solid material such as a rod having various cross-sectional shapes such as a round bar, a square bar, or a deformed bar. Moreover, this steel material includes not only those whose cross-sectional shape is constant in the longitudinal direction but also those having a tapered shape that changes in a tapered shape in the longitudinal direction.

本発明における素材である鋼材として高強度鋼を採用すれば、熱間曲げ加工を施した後に、その表面に自動車用部材としての下地化成被膜および塗装被膜を施すことにより、塗装後耐食性を具備する高強度の曲げ加工部材とすることができる。また、本発明における素材として用いる鋼材として、焼入性を有する鋼材を使用し、低強度の鋼材を出発材料として熱間加工を行った後、焼入によって強度を上げ、高強度の被覆熱処理鋼材とすることもできる。   If high-strength steel is adopted as a steel material as a material in the present invention, after applying hot bending, the surface is provided with a base chemical conversion coating and a coating coating as an automobile member, thereby providing post-coating corrosion resistance. A high-strength bending member can be obtained. In addition, as a steel material used as a material in the present invention, a steel material having hardenability is used, and after hot working using a low-strength steel material as a starting material, the strength is increased by quenching, and a high-strength coated heat-treated steel material It can also be.

焼入性を有する鋼材として、例えば、その化学組成がC:0.1%以上0.3%以下、Si:0.01%以上0.5%以下、Mn:0.5%以上3.0%以下、P:0.003%以上0.05%以下、S:0.05%以下、Cr:0.1%以上0.5%以下、Ti:0.01%以上0.1%以下、Al:1%以下、B:0.0002%以上0.004%以下、N:0.01%以下を含有し、残部Feおよび不純物からなり、必要に応じて、Cu:1%以下、Ni:2%以下、Mo:1%以下、V:1%以下、およびNb:1%以下から選ばれた1種または2種以上を含有する焼入用鋼からなる素地鋼が例示される。   As a steel material having hardenability, for example, the chemical composition thereof is C: 0.1% to 0.3%, Si: 0.01% to 0.5%, Mn: 0.5% to 3.0% % Or less, P: 0.003% or more and 0.05% or less, S: 0.05% or less, Cr: 0.1% or more and 0.5% or less, Ti: 0.01% or more and 0.1% or less, Al: not more than 1%, B: not less than 0.0002% and not more than 0.004%, N: not more than 0.01%, the balance consisting of Fe and impurities, and if necessary, Cu: not more than 1%, Ni: Examples include a base steel made of a quenching steel containing one or more selected from 2% or less, Mo: 1% or less, V: 1% or less, and Nb: 1% or less.

この素地鋼を素板とする鋼材から製造されたチャンネル部材等の部材であれば、焼入可能な温度まで加熱してから急冷を施すことにより、引張強さが1200MPa以上の被覆熱処理鋼材とすることが可能になる。   If it is a member such as a channel member manufactured from a steel material using this base steel as a base plate, it is heated to a quenchable temperature and then rapidly cooled to obtain a coated heat-treated steel material having a tensile strength of 1200 MPa or more. It becomes possible.

この鋼材の少なくとも一つの面には、高融点めっき皮膜形成元素系めっき皮膜を備える鋼材を、Ac点以下の温度で合金化処理されためっき皮膜が形成されている。
本発明において「高融点めっき皮膜形成元素系めっき皮膜」とは、例えば溶融亜鉛めっき皮膜や合金化溶融亜鉛めっき皮膜よりも高い融点を有するめっき皮膜を意味しており、「高融点めっき皮膜形成元素」として、例えば、Ni、Cr、CuまたはCoからなる群から選ばれた一種または二種以上の組み合わせを用いることが好ましい。
On at least one surface of the steel material, a plating film is formed by alloying a steel material having a high melting point plating film-forming element-based plating film at a temperature of Ac 3 points or less.
In the present invention, the “high melting point plating film forming element-based plating film” means, for example, a plating film having a higher melting point than a hot dip galvanized film or an alloyed hot dip galvanized film, For example, it is preferable to use one or a combination of two or more selected from the group consisting of Ni, Cr, Cu, and Co.

参考として、表1に、Fe原子、Ni原子、Cr原子、Cu原子、Co原子、Ni−10%P無電解めっき皮膜それぞれの物性値(線膨張係数、融点Tmおよび沸点Tb)をまとめて示す。   For reference, Table 1 summarizes the physical properties (linear expansion coefficient, melting point Tm, and boiling point Tb) of each of the Fe atom, Ni atom, Cr atom, Cu atom, Co atom, and Ni-10% P electroless plating film. .

Figure 2011046993
Figure 2011046993

このため、本発明における「高融点めっき皮膜」として、Niめっき皮膜、Crめっき皮膜、Cuめっき皮膜、Coめっき皮膜、または、Ni、Cr、CuまたはCoからなる群から選ばれた二種以上を合計で50%以上含有する合金めっき皮膜が例示される。   Therefore, as the “high melting point plating film” in the present invention, two or more kinds selected from the group consisting of Ni plating film, Cr plating film, Cu plating film, Co plating film, or Ni, Cr, Cu or Co are used. An alloy plating film containing 50% or more in total is exemplified.

また、Ni、Cr、CuまたはCoからなる群から選ばれた二種以上を合計で50%以上含有する合金めっき皮膜としては、Ni−Co合金めっき皮膜やNi−10%P合金めっき皮膜が例示される。   Examples of the alloy plating film containing at least 50% of two or more selected from the group consisting of Ni, Cr, Cu or Co include Ni-Co alloy plating film and Ni-10% P alloy plating film. Is done.

めっき皮膜の形成手段は、公知の各種手段によればよく、特定の手段には限定されない。例えば、Niめっき皮膜はワット浴ないしウッド浴の電解めっき、または無電解めっきにより形成することが例示され、Crめっき皮膜はサージェント浴、ふっ化浴または黒色クロムめっき浴等を用いて形成することが例示され、Cuめっき皮膜はシアン化銅、硫酸銅またはピロりん酸銅をめっき液として形成することが例示され、Coめっき皮膜の場合には硫酸浴、塩化物浴、スルファミン酸浴等のめっき浴を用いて形成することが例示され、Ni−Co合金めっき皮膜の場合には塩化物浴を用いて形成することが例示され、さらに、Ni−10%P合金めっき皮膜の場合には無電解ニッケルめっき浴を用いて形成することが例示される。   The plating film forming means may be any of various known means and is not limited to a specific means. For example, it is exemplified that the Ni plating film is formed by watt bath or wood bath electrolytic plating or electroless plating, and the Cr plating film may be formed using a sergeant bath, a fluoride bath, a black chrome plating bath, or the like. The Cu plating film is exemplified by forming copper cyanide, copper sulfate or copper pyrophosphate as a plating solution. In the case of a Co plating film, a plating bath such as a sulfuric acid bath, a chloride bath, a sulfamic acid bath, etc. In the case of a Ni—Co alloy plating film, it is exemplified to use a chloride bath. Further, in the case of a Ni-10% P alloy plating film, electroless nickel is used. It is exemplified to form using a plating bath.

これらのめっき皮膜の付着量は、一面当たり、Niめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Crめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Cuめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Coめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Ni−Co合金めっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、さらに、Ni−10%P合金めっき皮膜の場合には0.1g/m以上50g/m以下であることが、熱処理後の塗装後耐食性を十分に確保する観点から、好ましい。 Adhesion amount of these plating film per one surface, is preferably 0.1 g / m 2 or more 30 g / m 2 or less in the case of Ni plating film, in the case of Cr plating film 0.1 g / m 2 It is preferably 30 g / m 2 or less, in the case of a Cu plating film, preferably 0.1 g / m 2 or more and 30 g / m 2 or less, and in the case of a Co plating film, 0.1 g / m 2. It is preferably 30 g / m 2 or less, and in the case of a Ni—Co alloy plating film, it is preferably 0.1 g / m 2 or more and 30 g / m 2 or less, and further, a Ni-10% P alloy plating film In this case, it is preferably from 0.1 g / m 2 to 50 g / m 2 from the viewpoint of sufficiently ensuring the post-coating corrosion resistance after the heat treatment.

また、これらのめっき皮膜の表面粗さRaは、特に規定しないが、熱処理後の塗装後耐食性を十分に確保する観点から、5.0μm以下、より望ましくは2.0μm以下であることが好ましい。   Further, the surface roughness Ra of these plating films is not particularly specified, but is preferably 5.0 μm or less, more preferably 2.0 μm or less, from the viewpoint of sufficiently securing the post-coating corrosion resistance after the heat treatment.

本発明における素材である鋼材は、その少なくとも一部を焼入れ可能温度域に加熱する熱処理を行われる。焼入れ可能温度域とは、例えば、鋼材のAc点以上の温度域に60秒間以内程度の短時間で急速に加熱し、0.1秒間以上30秒間以下程度、この温度以上の温度域に滞在させ、30℃/秒以上の冷却速度で急速に冷却することが、例示される。 The steel material which is a raw material in the present invention is subjected to a heat treatment for heating at least a part thereof to a quenchable temperature range. The quenchable temperature range is, for example, that the steel is rapidly heated to a temperature range of 3 or more points of steel in a short time of about 60 seconds or less and stays in a temperature range of about 0.1 seconds or more and 30 seconds or less. And rapid cooling at a cooling rate of 30 ° C./second or more is exemplified.

上述した特許文献1により開示した発明に基づいて本発明に係る被覆熱処理鋼材を製造する場合には、この熱処理は、上述したいずれかのめっき皮膜を有する鋼材を、その長手方向へ向けて断続的または連続的に送られながら、第1の支持手段により支持されるとともに、加圧ロールが、第1の支持手段の下流側に配置されるとともにその位置が二次元または三次元に移動自在である第2の支持手段によって回転自在に支持され、さらに、この鋼材の加熱が、この第2の支持手段と第1の支持手段との間であってこの鋼材の外周にこの鋼材から離間して配置される加熱手段によって行われるとともに、冷却が、この加熱手段と第2の支持手段との間に配置される冷却手段によって行われることが、望ましい。   When the coated heat-treated steel material according to the present invention is manufactured based on the invention disclosed in Patent Document 1 described above, this heat treatment is performed by intermittently moving the steel material having any of the above-described plating films in the longitudinal direction. Alternatively, while being continuously fed, it is supported by the first support means, and the pressure roll is disposed on the downstream side of the first support means, and its position is movable in two dimensions or three dimensions. The steel material is rotatably supported by the second support means, and further, the heating of the steel material is disposed between the second support means and the first support means and spaced from the steel material on the outer periphery of the steel material. Desirably, the cooling is performed by the heating means, and the cooling is performed between the heating means and the second support means.

鋼材の、この熱処理を行われた部分の少なくとも一部の表面には、鉄−高融点めっき皮膜形成元素が合金化された固溶相を有する、本発明に係る被覆熱処理鋼材が得られる。
この皮膜の付着量は、一面当たり、Niめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Crめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Cuめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Coめっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、Ni−Co合金めっき皮膜の場合には0.1g/m以上30g/m以下であることが好ましく、さらに、Ni−10%P合金めっき皮膜の場合には0.1g/m以上30g/m以下であることが、熱処理後の塗装後耐食性を十分に確保する観点から、好ましい。
The coated heat-treated steel material according to the present invention having a solid solution phase in which an iron-high melting point plating film-forming element is alloyed is obtained on at least a part of the surface of the steel material subjected to the heat treatment.
Adhesion amount of the coating per one surface, is preferably 0.1 g / m 2 or more 30g / m 2 or less in the case of Ni plating film, in the case of Cr plating film 0.1 g / m 2 or more 30g is preferably / m 2 or less, preferably 0.1 g / m 2 or more 30g / m 2 or less in the case of Cu plating film, in the case of Co plating film 0.1 g / m 2 or more 30g is preferably / m 2 or less, preferably 0.1 g / m 2 or more 30 g / m 2 or less in the case of Ni-Co alloy plating film, further, in the case of Ni-10% P alloy plating film Is preferably from 0.1 g / m 2 to 30 g / m 2 from the viewpoint of sufficiently ensuring the post-coating corrosion resistance after the heat treatment.

また、このため、本発明に係る被覆熱処理鋼材は、熱処理後の優れた塗装後耐食性を有する。また、この鉄−高融点めっき皮膜形成元素が合金化された固溶相を有する皮膜は、高温で潤滑機能を確保し得る皮膜である。このため、本発明に係る被覆熱処理鋼材は、自動車用部材として好適に用いることができる。   For this reason, the coated heat-treated steel material according to the present invention has excellent post-coating corrosion resistance after heat treatment. In addition, a film having a solid solution phase in which the iron-high melting point plating film forming element is alloyed is a film that can ensure a lubricating function at a high temperature. For this reason, the coated heat-treated steel material according to the present invention can be suitably used as an automobile member.

本発明に係る被覆熱処理鋼材は、この鋼材の少なくとも一部が本発明で規定する条件を満足するものであればよい。例えば、自動車用の曲げ部材を想定した場合に、この部材の全てに曲げ加工や焼入れが施される必要はなく、端部は曲げ加工も焼入れも行われない部材も対象となる。このような場合には、部材の一部に熱間曲げや焼入れが施されることになるが、この部材の全ての部分において本発明で規定する皮膜を有する必要はない。すなわち、部材として特に重要な面や部分についてのみ本発明で規定する条件を満足すれば、本発明に係る被覆熱処理鋼材に包含される。   The coated heat-treated steel material according to the present invention may be any material as long as at least a part of the steel material satisfies the conditions defined in the present invention. For example, when a bending member for an automobile is assumed, it is not necessary to perform bending or quenching on all of the members, and the end portion is also a member that is neither bent nor quenched. In such a case, hot bending or quenching is performed on a part of the member, but it is not necessary to have the coating film defined in the present invention in all parts of the member. That is, if the conditions specified by the present invention are satisfied only for the surfaces and portions that are particularly important as members, they are included in the coated heat-treated steel material according to the present invention.

また、上述した皮膜を有する本発明に係る被覆熱処理鋼材は、めっき皮膜を有さない裸鋼材や、溶融亜鉛めっき鋼材さらには合金化溶融亜鉛めっき鋼材と対比すると、以下に列記する優れた特徴を有すると解される。   In addition, the coated heat-treated steel material according to the present invention having the above-described coating has the following excellent features as compared with a bare steel material without a plating film, a hot-dip galvanized steel material, or an alloyed hot-dip galvanized steel material. It is understood to have.

(a)鋼材高温(例えばAc点以上)加熱時の皮膜残存性
本発明に係る被覆熱処理鋼材は、鉄−高融点めっき皮膜形成元素が合金化された高融点めっき皮膜を有するので、高温に加熱された場合には、溶融亜鉛めっき鋼材や合金化溶融亜鉛めっき鋼材よりも、優れた皮膜残存性を有する。
(A) Steel film high temperature (for example, Ac 3 points or more) film survivability at the time of heating Since the coated heat-treated steel material according to the present invention has a high melting point plating film in which an iron-high melting point plating film forming element is alloyed, When heated, it has better film survivability than hot-dip galvanized steel and alloyed hot-dip galvanized steel.

(b)鋼材加熱時の鋼スケール生成性
裸鋼材では鋼スケールが不可避的に生成するが、本発明に係る被覆熱処理鋼材は、溶融亜鉛めっき鋼材や合金化溶融亜鉛めっき鋼材と同様に、鋼スケールが発生しない。
(B) Steel scale formation during heating of steel material Steel scale is inevitably generated in bare steel material, but the coated heat-treated steel material according to the present invention is similar to hot-dip galvanized steel material and alloyed hot-dip galvanized steel material. Does not occur.

(c)鋼材加熱時の潤滑性
本発明に係る被覆熱処理鋼材は、高融点であって硬質な皮膜を有するので、溶融亜鉛めっき鋼材や合金化溶融亜鉛めっき鋼材よりも、優れた潤滑性を有する。
(C) Lubricity at the time of heating steel material The coated heat-treated steel material according to the present invention has a high melting point and a hard film, and therefore has better lubricity than a hot-dip galvanized steel material or an alloyed hot-dip galvanized steel material. .

(d)鋼材加熱後に残存する皮膜の表面粗度
溶融亜鉛めっき鋼材や合金化溶融亜鉛めっき鋼材では、残存する低融点の皮膜が溶融したり蒸発したりするために、残存する皮膜の表面粗度は加熱前よりも低下するのに対し、本発明に係る被覆熱処理鋼材では、残存する高融点の皮膜が溶融したり蒸発したりすることがないために、残存する皮膜の表面粗度は加熱前と同等に低く抑えられる。
(D) Surface roughness of the film remaining after heating the steel In the case of hot-dip galvanized steel or alloyed hot-dip galvanized steel, the remaining low-melting film melts or evaporates, so the surface roughness of the remaining film In contrast, in the coated heat-treated steel material according to the present invention, the remaining high melting point film does not melt or evaporate. Can be kept as low as

(e)鋼材の溶接性(含むスポット溶接性)
本発明に係る被覆熱処理鋼材は、高融点であって硬質な皮膜を有するので、溶融亜鉛めっき鋼材や合金化溶融亜鉛めっき鋼材よりも、優れた溶接性を有する。
(E) Weldability of steel (including spot weldability)
Since the coated heat-treated steel material according to the present invention has a high melting point and a hard film, the coated heat-treated steel material has better weldability than a hot-dip galvanized steel material or an alloyed hot-dip galvanized steel material.

(f)鋼材の意匠性・装飾性
本発明に係る被覆熱処理鋼材は、光沢や色調が良好な皮膜を有するので、溶融亜鉛めっき鋼材や合金化溶融亜鉛めっき鋼材よりも、優れた意匠性・装飾性を有する。
(F) Designability / decoration of steel material The coated heat-treated steel material according to the present invention has a coating with good gloss and color tone, and therefore has better designability / decoration than hot-dip galvanized steel material and alloyed hot-dip galvanized steel material. Have sex.

(g)鋼材の耐摩耗性
本発明に係る被覆熱処理鋼材は、硬質で耐摩耗性が良好な皮膜を有するので、溶融亜鉛めっき鋼材や合金化溶融亜鉛めっき鋼材よりも、優れた耐摩耗性を有する。
(G) Abrasion resistance of steel material Since the coated heat-treated steel material according to the present invention has a hard and wear-resistant film, it has better wear resistance than hot-dip galvanized steel and alloyed hot-dip galvanized steel. Have.

(h)特許文献1により開示された加工方法への適用性
上記(a)〜(g)項の特徴から明らかなように、本発明に係る被覆熱処理鋼材は、溶融亜鉛めっき鋼材や合金化溶融亜鉛めっき鋼材よりも、特許文献1により開示された加工方法への適用性が極めて優れている。
(H) Applicability to the processing method disclosed in Patent Document 1 As is apparent from the features of the above-mentioned items (a) to (g), the coated heat-treated steel material is a hot-dip galvanized steel material or an alloyed molten steel. The applicability to the processing method disclosed in Patent Document 1 is extremely superior to galvanized steel.

本発明に係る被覆熱処理鋼材は、以上のように構成される。次に、本発明に係る製造方法を説明する。
本発明では、少なくとも一つの面に被覆された高融点めっき皮膜形成元素系めっき皮膜を備える鋼材を、Ac点以下の温度で合金化処理された鋼材の少なくとも一部を焼入れ可能温度域に加熱し、加熱された部分の少なくとも一部の表面に液相が存在しないうちに冷却することにより、この加熱および冷却を行われた部分の少なくとも一部の表面に、鉄−高融点めっき皮膜形成元素が合金化され、耐食性を有するとともに高温で潤滑機能を確保することができ、さらに、溶接性および装飾性が良好な皮膜を形成することによって、被覆熱処理鋼材を製造する。
The coated heat-treated steel material according to the present invention is configured as described above. Next, the manufacturing method according to the present invention will be described.
In the present invention, a steel material provided with a high melting point plating film-forming element-based coating film coated on at least one surface is heated to a temperature range in which at least a part of the steel material alloyed at a temperature of Ac 3 or less can be quenched. Then, by cooling before the liquid phase is present on at least a part of the surface of the heated part, at least part of the surface of the heated and cooled part is provided with an iron-high melting point plating film forming element. Is alloyed, has corrosion resistance, can ensure a lubricating function at high temperatures, and further forms a coating with good weldability and decorativeness to produce a coated heat-treated steel material.

本発明に係る製造方法において、実用的な価値が高いのは、素材である鋼材として、なくとも一つの面に被覆された高融点めっき皮膜形成元素系めっき皮膜を備える鋼材を、Ac点以下の温度で合金化処理されためっき皮膜を有する素地鋼板から製管された鋼管等からなる自動車用の長尺部材を用い、焼入れ、若しくは加熱後に熱間曲げ加工、または焼入と熱間曲げ加工とを同時に施すことにより、本発明に係る被覆熱処理鋼材を得ることである。 In the production method according to the present invention, the practical value is high, the steel material which is a material, a steel with a high melting plating film formed element-based plating film which is coated on one surface even without the following Ac 3 point Using a long member for automobiles made of a steel pipe made of a base steel plate having a plating film alloyed at a temperature of, for example, quenching or hot bending after heating, or quenching and hot bending Is to obtain the coated heat-treated steel material according to the present invention.

このため、本発明に係る製造方法は、少なくとも一部に形成される上述しためっき層の付着量が片面当たり、Niめっき皮膜の場合には0.1g/m以上30g/m以下であり、Crめっき皮膜の場合には0.1g/m以上30g/m以下であり、Cuめっき皮膜の場合には0.1g/m以上30g/m以下であり、Coめっき皮膜の場合には0.1g/m以上30g/m以下であり、Ni−Co合金めっき皮膜の場合には0.1g/m以上30g/m以下であり、さらに、Ni−10%P合金めっき皮膜の場合には0.1g/m以上30g/m以下であるめっき鋼板からなる長尺部材に、10℃/秒以上の昇温速度で、焼入が可能な温度域への加熱を行い、この加熱をされた部分に、曲げモーメントを付与してから30℃/秒以上の冷却速度での冷却を行った後、必要に応じて、このめっき鋼材の表面に当接する加圧ロールによってこのめっき鋼材の表面に残存するめっき層の表面粗度を調整する。 For this reason, in the manufacturing method according to the present invention, the amount of the above-mentioned plating layer formed on at least a part is per side, and in the case of a Ni plating film, it is 0.1 g / m 2 or more and 30 g / m 2 or less. In the case of Cr plating film, it is 0.1 g / m 2 or more and 30 g / m 2 or less, in the case of Cu plating film, it is 0.1 g / m 2 or more and 30 g / m 2 or less, and in the case of Co plating film Is 0.1 g / m 2 or more and 30 g / m 2 or less, and in the case of a Ni—Co alloy plating film, it is 0.1 g / m 2 or more and 30 g / m 2 or less, and further, a Ni-10% P alloy In the case of a plated film, heating to a long member made of a plated steel sheet of 0.1 g / m 2 or more and 30 g / m 2 or less to a temperature range in which quenching can be performed at a temperature rising rate of 10 ° C./second or more. And apply a bending moment to the heated part. Then, after cooling at a cooling rate of 30 ° C./second or more, if necessary, the surface roughness of the plating layer remaining on the surface of the plated steel material by a pressure roll in contact with the surface of the plated steel material Adjust.

本発明に係る製造方法に用いられるめっき鋼材は、めっき付着量を片面当たり、Niめっき皮膜の場合には0.1g/m以上30g/m以下で、Crめっき皮膜の場合には
0.1g/m以上30g/m以下で、Cuめっき皮膜の場合には0.1g/m以上30g/m以下で、Coめっき皮膜の場合には0.1g/m以上30g/m以下で、
Ni−Co合金めっき皮膜の場合には0.1g/m以上30g/m以下で、さらに、
Ni−10%P合金めっき皮膜の場合には0.1g/m以上30g/m以下で、管理する。
The plated steel material used in the production method according to the present invention has a plating adhesion amount of 0.1 g / m 2 or more and 30 g / m 2 or less in the case of a Ni plating film, and 0. 1 g / m 2 or more and 30 g / m 2 or less, in the case of Cu plating film, 0.1 g / m 2 or more and 30 g / m 2 or less, and in the case of Co plating film, 0.1 g / m 2 or more and 30 g / m 2 2 or less,
In the case of a Ni—Co alloy plating film, it is 0.1 g / m 2 or more and 30 g / m 2 or less.
In the case of a Ni-10% P alloy plating film, it is controlled at 0.1 g / m 2 or more and 30 g / m 2 or less.

本発明では、焼入れが可能な温度域として最高到達温度は850℃以上となり、熱処理後に十分な耐食性を確保するには、0.1g/mの付着量を残存させることが望ましい。このため、熱処理前のNi,Cr,Cu,Co,Ni−Co,Ni−10%P系めっき鋼材におけるめっき付着量は上述したように0.1g/m以上30g/m以下とする。 In the present invention, the maximum temperature that can be quenched is 850 ° C. or higher, and it is desirable to leave an adhesion amount of 0.1 g / m 2 to ensure sufficient corrosion resistance after heat treatment. For this reason, the plating adhesion amount in the Ni, Cr, Cu, Co, Ni—Co, and Ni-10% P-based plated steel before heat treatment is set to 0.1 g / m 2 or more and 30 g / m 2 or less as described above.

本発明では、加熱された部分の少なくとも一部の表面に液相が存在しないうちに冷却することにより、この加熱および冷却を行われた部分の少なくとも一部の表面に、鉄−高融点めっき皮膜形成元素が合金化された固溶相を有し、耐食性を有するとともに高温で潤滑機能を確保し得る皮膜を形成する。   In the present invention, the iron-high melting point plating film is formed on at least a part of the surface of the heated and cooled part by cooling before the liquid phase is present on the part of the heated part. It forms a film that has a solid solution phase in which the forming elements are alloyed, has corrosion resistance, and can ensure a lubricating function at high temperatures.

本発明に係る鋼材の製造方法では、このめっき層を形成しためっき鋼材を、焼入れが可能な温度域としてAc点以上に加熱する。このときの熱処理パターンとしては、昇温速度が10℃/秒以上で加熱し、300℃/秒以上の冷却速度で冷却することが好ましい。昇温速度や上記のように規定する速度より低下すると生産性が低下し、冷却速度が上記で規定する速度より遅くなると焼き入れが入らなくなるからである。 In the method for manufacturing a steel material according to the present invention, the plated steel material on which the plated layer is formed is heated to Ac 3 or more as a temperature range where quenching is possible. As the heat treatment pattern at this time, it is preferable to heat at a temperature rising rate of 10 ° C./second or more and to cool at a cooling rate of 300 ° C./second or more. This is because when the temperature rise rate is lower than the rate specified as described above, the productivity is lowered, and when the cooling rate is lower than the rate specified above, quenching cannot be performed.

本発明に係る製造方法では、最高到達温度またはその近傍温度域での保持時間は規定しないが、30秒間以下とすることが望ましく、さらに望ましくは20秒間以下である。高温域での保持時間が長くなると、生産コストが掛かる上、生産性も低下するからである。   In the manufacturing method according to the present invention, the holding time at the maximum temperature or in the vicinity of the temperature is not specified, but it is preferably 30 seconds or less, and more preferably 20 seconds or less. This is because, if the holding time in the high temperature range becomes long, the production cost increases and the productivity also decreases.

本発明に係る製造方法では、必要に応じて、上述しためっき鋼材を加熱および冷却して得られた熱処理鋼材を、後述する図3に示す可動ローラダイスに装着された加圧ロールまたはローラ等により加圧することによって、残存するめっき層の表面粗度の調整を行う。   In the manufacturing method according to the present invention, the heat-treated steel material obtained by heating and cooling the above-described plated steel material is applied by a pressure roll or a roller mounted on a movable roller die shown in FIG. By applying pressure, the surface roughness of the remaining plating layer is adjusted.

通常、めっき層の表面粗度を調整するための加圧は、線荷重を1kgf/mm以上100kgf/mm以下の範囲で変更させて制御することにより行われる。
図1は、本発明に係る被覆熱処理鋼材1bを製造するための製造装置7の構成を例示する説明図である。
Usually, pressurization for adjusting the surface roughness of the plating layer is performed by changing and controlling the line load in the range of 1 kgf / mm to 100 kgf / mm.
FIG. 1 is an explanatory view illustrating the configuration of a manufacturing apparatus 7 for manufacturing the coated heat-treated steel material 1b according to the present invention.

図1に例示する製造装置7では、被加工材1の断面形状を丸形(丸管)とし、被加工材であるめっき鋼材1aを逐次連続的に加熱し、局部的な加熱部に可動ローラダイス4を用いて塑性変形を生じさせ、その直後に冷却することにより、被覆熱処理鋼材1bを製造する。   In the manufacturing apparatus 7 illustrated in FIG. 1, the cross-sectional shape of the workpiece 1 is a round shape (round tube), and the plated steel material 1 a that is the workpiece is sequentially and continuously heated, and a movable roller is used as a local heating unit. A plastic heat treatment is generated using the die 4 and cooled immediately after that to produce the coated heat-treated steel material 1b.

このため、めっき鋼材1aを保持するための二組の回転可能な支持手段である支持ロール2、2と、その上流側にはめっき鋼材1aを断続的または連続的に送り移動させる送り装置3が配置される。一方、二対の支持ロール2、2の下流側には、めっき鋼材1aを支持し、この支持位置または/および移動速度を制御させるための可動ローラダイス4が配置される。図1に示すように、可動ローラダイス4は、めっき鋼材1aの表面に当接する孔型ロールである加圧ロール4a、4bを二つ備える。   For this reason, the support rolls 2 and 2 which are two sets of rotatable support means for hold | maintaining the plating steel material 1a, and the feeder 3 which moves the plating steel material 1a intermittently or continuously to the upstream side are provided. Be placed. On the other hand, on the downstream side of the two pairs of support rolls 2 and 2, a movable roller die 4 for supporting the plated steel material 1a and controlling the support position or / and the moving speed is disposed. As shown in FIG. 1, the movable roller die 4 includes two pressure rolls 4a and 4b, which are hole rolls that come into contact with the surface of the plated steel material 1a.

可動ローラダイス4の入り側には、めっき鋼材1aの外周にめっき鋼材1aから離間して配置されてめっき鋼材1aを部分的に急速に加熱する高周波加熱コイル5と、高周波加熱コイル5により急速に加熱されためっき鋼材1aに冷却媒体を噴射することによってめっき鋼材1aを急速に冷却する冷却装置6とが配置される。   On the entrance side of the movable roller die 4, a high-frequency heating coil 5 that is disposed on the outer periphery of the plated steel material 1 a and is spaced apart from the plated steel material 1 a and partially heats the plated steel material 1 a rapidly. A cooling device 6 for rapidly cooling the plated steel material 1a by spraying a cooling medium onto the heated plated steel material 1a is disposed.

図2は、この製造装置7における高周波加熱コイル5および冷却装置6の構成の概略を例示する断面図である。加熱部を形成すべきめっき鋼材1aの外周にこのめっき鋼材1aから離間させて、環状の高周波加熱コイル5を配置して、この高周波加熱コイル5によりめっき鋼材1aを部分的に急速に加熱し、次いで、必要に応じて、冷却装置6から冷却媒体(例えば水)を噴射することにより、高周波加熱コイル5により急速に加熱されためっき鋼材1aを急速に冷却する。   FIG. 2 is a cross-sectional view illustrating the schematic configuration of the high-frequency heating coil 5 and the cooling device 6 in the manufacturing apparatus 7. An annular high-frequency heating coil 5 is arranged on the outer periphery of the plated steel material 1a to form the heating part, and an annular high-frequency heating coil 5 is arranged, and the high-frequency heating coil 5 partially heats the plated steel material 1a rapidly, Next, as necessary, the plated steel material 1a rapidly heated by the high-frequency heating coil 5 is rapidly cooled by spraying a cooling medium (for example, water) from the cooling device 6.

このとき、二組の支持ロール2、2を通過しためっき鋼材1aを可動ローラダイス4の加圧ロール4a、4bにより支持し、めっき鋼材1aの外周に配置した高周波加熱コイル5および冷却装置6を用いて、めっき鋼材1aを局部的に加熱および冷却しながら、可動ローラダイス4の位置を二次元または三次元で制御するとともにその移動速度も適宜調整することによって、めっき鋼材1aにおける部分的に高温にある部分に曲げモーメントを与えて曲げ加工を行うことができるとともに、加熱装置5による加熱速度および加熱温度と冷却装置6による冷却速度とを適宜調整することによってめっき鋼材1aの所望の部分に焼入れを行うことができるので、所望の高強度を有するとともに所望の曲率の二次元または三次元の曲げ加工部を有する被覆熱処理鋼材1bを製造することができる。   At this time, the plated steel material 1a that has passed through the two support rolls 2 and 2 is supported by the pressure rolls 4a and 4b of the movable roller die 4, and the high-frequency heating coil 5 and the cooling device 6 disposed on the outer periphery of the plated steel material 1a are provided. Using the partially heated steel plate 1a, the position of the movable roller die 4 is controlled two-dimensionally or three-dimensionally and the moving speed thereof is adjusted appropriately while locally heating and cooling the plated steel member 1a. Can be bent by applying a bending moment to a portion of the steel plate, and by appropriately adjusting the heating rate and heating temperature by the heating device 5 and the cooling rate by the cooling device 6, the desired portion of the plated steel material 1 a is quenched. Has a desired high strength and has a 2D or 3D bending part with a desired curvature. It is possible to produce a coated heat treatment steel 1b.

図3は、本発明に係る被覆熱処理鋼材1bの製造に用いることができる可動ローラダイス4の形状を例示する説明図であり、図3(a)はめっき鋼材1aが丸管などの閉断面材である場合に2つの加圧ロール4a、4bにより構成される場合であり、図3(b)はめっき鋼材1aが矩形管等の閉断面材である場合に2つの加圧ロール4c、4dにより構成される場合であり、さらに図3(c)はめっき鋼材1aが矩形管などの閉断面材である場合に4つの加圧ロール4e、4f、4g、4hにより構成される場合である。   FIG. 3 is an explanatory view illustrating the shape of the movable roller die 4 that can be used for the production of the coated heat-treated steel material 1b according to the present invention, and FIG. 3 (b) is a case where the plated steel material 1a is a closed cross-sectional material such as a rectangular tube, the two pressure rolls 4c and 4d are used. Further, FIG. 3 (c) shows a case in which the four steel rolls 1a are a closed section material such as a rectangular tube and are constituted by four pressure rolls 4e, 4f, 4g, and 4h.

図3(a)〜図3(c)に示すように、可動ローラダイス4における加圧ロール4aおよび4b、4cおよび4d、4e〜4hは、いずれも、めっき鋼材1aの表面に当接してめっき鋼材1aをその長手方向へ送りながらめっき鋼材1aを保持するため、高温域での加熱に伴ってめっき鋼材1aの表面におけるめっき層の表面性状が悪化しやすい状況にあっても、加圧ロール4aおよび4b、4cおよび4d、4e〜4hを用いて加圧力を付与しながらめっき鋼材1aの表面を押圧することができるので、めっき層の表面粗さRaを調整することができ、これにより、その表面にめっき層を残存させた被覆熱処理鋼材1bの表面性状を改善することができる。   As shown in FIGS. 3A to 3C, the pressure rolls 4a and 4b, 4c and 4d and 4e to 4h in the movable roller die 4 are all in contact with the surface of the plated steel material 1a and plated. In order to hold the plated steel material 1a while feeding the steel material 1a in the longitudinal direction, the pressure roll 4a is used even in a situation where the surface properties of the plating layer on the surface of the plated steel material 1a are likely to deteriorate with heating in a high temperature region. 4b, 4c and 4d, 4e to 4h can be used to press the surface of the plated steel material 1a while applying pressure, so that the surface roughness Ra of the plating layer can be adjusted. The surface properties of the coated heat-treated steel material 1b with the plating layer remaining on the surface can be improved.

可動ローラダイス4が、上下方向へのシフト機構、左右方向へのシフト機構、上下方向に傾斜するチルト機構、あるいは左右方向に傾斜するチルト機構を具備すること、望ましくはさらに前後方向への移動機構を具備することによって、3次元的にめっき鋼材1aを支持し、必要により曲げモーメントを付与することができる。   The movable roller die 4 includes a vertical shift mechanism, a horizontal shift mechanism, a vertical tilt mechanism, or a horizontal tilt mechanism, and preferably a forward / backward movement mechanism. , The plated steel material 1a can be supported three-dimensionally, and a bending moment can be applied if necessary.

図3に示す可動ローラダイス4による加圧によってめっき鋼材1aのめっき層の表面粗度を調整するには、具体的には、めっき鋼材1aに対する加圧ロール4aおよび4b、4cおよび4d、4e〜4hの押圧力を制御することによって行えばよく、そのときの押し付け圧は、加圧ロール4aおよび4b、4cおよび4d、4e〜4hのロール径が30mm程度である場合には、線荷重として1kgf/mm以上100kgf/mm以下であることが望ましい。押圧力は、可動ローラダイス4に油圧シリンダーやエアシリンダーを装着して制御することが例示される。   In order to adjust the surface roughness of the plating layer of the plated steel material 1a by pressing with the movable roller die 4 shown in FIG. 3, specifically, the pressure rolls 4a and 4b, 4c and 4d, 4e to the plated steel material 1a It is sufficient to control the pressing force of 4h, and the pressing pressure at that time is 1 kgf as a linear load when the roll diameters of the pressure rolls 4a and 4b, 4c and 4d, and 4e to 4h are about 30 mm. / Mm or more and 100 kgf / mm or less is desirable. For example, the pressing force is controlled by attaching a hydraulic cylinder or an air cylinder to the movable roller die 4.

このようにして、本実施の形態によれば、めっき鋼材1aに高温加熱および冷却による熱処理を施す場合であっても、所定のめっき付着量を残存させることができ、これにより、めっき層の表面性状(表面粗さRa)の改善を図ることが可能である。このようにして製造される被覆熱処理鋼材1bは、自動車用部材としての塗装後の適正な耐食性を確保することができる。   Thus, according to the present embodiment, even when the plated steel material 1a is subjected to heat treatment by high-temperature heating and cooling, a predetermined amount of plating can be left, and thereby the surface of the plating layer It is possible to improve the properties (surface roughness Ra). The coated heat-treated steel material 1b thus manufactured can ensure appropriate corrosion resistance after painting as a member for an automobile.

すなわち、本発明によれば、少なくとも片面にめっき皮膜を有する鋼材の少なくとも一部を焼入れ可能温度域に加熱した後に冷却する熱処理を行っても、自動車用部材としての塗装後の適正な耐食性を有するとともに、熱処理に伴うスケールの発生を抑制でき、さらにはスケールの発生を抑制できるとともに硬質であることから高温での加工時にも優れた潤滑性を有する被覆熱処理鋼材を提供することができる。   That is, according to the present invention, even if heat treatment is performed by cooling at least a part of a steel material having a plating film on at least one surface to a quenchable temperature range, the steel material has appropriate corrosion resistance after coating as an automobile member. At the same time, it is possible to provide a coated heat-treated steel material that can suppress the generation of scale due to heat treatment, and further suppress the generation of scale and is hard and has excellent lubricity even during processing at high temperatures.

以下、本発明を、実施例を参照しながらより具体的に説明する。
供試材は、鋼成分がC:0.21%、Si:0.23%、Mn:1.3%、P:0.013%、S:0.002%、sol.Al:0.044%、Cr:0.2%、残部Fe及び不純物である焼鈍板を用いた。
Hereinafter, the present invention will be described more specifically with reference to examples.
The test materials have steel components of C: 0.21%, Si: 0.23%, Mn: 1.3%, P: 0.013%, S: 0.002%, sol. An annealing plate which is Al: 0.044%, Cr: 0.2%, the remaining Fe and impurities is used.

両面に被覆されたNiめっき皮膜、Crめっき皮膜、Cuめっき皮膜、Coめっき皮膜、または、Ni−P合金めっき皮膜を備える鋼材を、Ac点以下の温度で合金化処理された鋼材の少なくとも一部を、850〜1000℃に加熱し、加熱された部分の少なくとも一部の表面に液相が存在しないうちに冷却することにより、加熱および冷却を行われた部分の少なくとも一部の表面に、鉄−高融点めっき皮膜形成元素が合金化された皮膜を形成して、本発明例とした。 At least one of steel materials alloyed at a temperature of Ac 3 or less with a steel material provided with Ni plating film, Cr plating film, Cu plating film, Co plating film, or Ni-P alloy plating film coated on both surfaces. Part is heated to 850 to 1000 ° C., and cooled before at least a part of the surface of the heated part has a liquid phase, so that at least part of the surface of the part that has been heated and cooled, A film in which the iron-high melting point plating film forming element was alloyed was formed as an example of the present invention.

これら本発明例と、比較例である裸鋼板、溶融亜鉛めっき鋼板または合金化溶融亜鉛めっき鋼板とについて、焼入れ性、スケールの有無、耐食性、高温での潤滑性、溶接性および装飾性を、下記基準で評価した。   About these examples of the present invention and comparative steel sheets, hot-dip galvanized steel sheets or alloyed hot-dip galvanized steel sheets, hardenability, presence of scale, corrosion resistance, lubricity at high temperatures, weldability and decorative properties are as follows. Evaluated by criteria.

[焼入れ性]
作成した試作材を樹脂に埋込み、断面を機械研磨した。表表面と裏表面とから等距離にある部位を、測定荷重1kgfでビッカース硬度を測定した。ビッカース硬度450以上を焼入性合格とした。
[Hardenability]
The prepared prototype was embedded in resin and the cross section was mechanically polished. Vickers hardness was measured at a measurement load of 1 kgf at a site equidistant from the front surface and the back surface. A Vickers hardness of 450 or higher was considered acceptable for hardenability.

[スケールの有無]
作成した試作材の外観を目視で観察し、鋼材にFeスケールが発生していなければ合格、発生していれば不合格とした。
[With or without scale]
The external appearance of the produced prototype material was visually observed, and it was determined to be acceptable if no Fe scale was generated on the steel material, and was rejected if generated.

[装飾性]
試作材のうち、白色ないし淡赤色の明るい金属光沢をもつものを装飾性○、そうでないものを×とした。
[Decoration]
Among the prototype materials, those having a bright metallic luster of white to light red were designated as “decorative”, and those other than that were designated as “x”.

結果を表2にまとめて示す。   The results are summarized in Table 2.

Figure 2011046993
Figure 2011046993

表2に示す結果から、本発明によれば、めっき鋼材1aに高温加熱および冷却による熱処理を施す場合であっても、所定のめっき付着量を残存させることができ、これにより、めっき層の表面性状(表面粗さRa)の改善を図ることが可能である。このようにして製造される被覆熱処理鋼材1bは、自動車用部材としての塗装後の適正な耐食性を確保することができる。   From the results shown in Table 2, according to the present invention, even when the plated steel material 1a is subjected to heat treatment by high-temperature heating and cooling, a predetermined amount of plating can be left, and thereby the surface of the plating layer It is possible to improve the properties (surface roughness Ra). The coated heat-treated steel material 1b thus manufactured can ensure appropriate corrosion resistance after painting as a member for an automobile.

1 被加工材
1a めっき鋼材
1b めっき熱処理鋼材
2 支持手段、支持ロール
3 押し出し装置
4 可動ローラダイス
5 高周波加熱コイル
6 冷却装置
7 製造装置
DESCRIPTION OF SYMBOLS 1 Work material 1a Plating steel material 1b Plating heat treatment steel material 2 Support means, support roll 3 Extruding device 4 Movable roller die 5 High frequency heating coil 6 Cooling device 7 Manufacturing device

Claims (4)

少なくとも一つの面に被覆された高融点めっき皮膜形成元素系めっき皮膜を備える鋼材を、Ac点以下の温度で合金化処理された鋼材の少なくとも一部を焼入れ可能温度域に加熱する熱処理を行われてなる被覆熱処理鋼材であって、該熱処理を行われた部分の少なくとも一部の表面に鉄−高融点めっき皮膜形成元素が合金化された高融点めっき皮膜を有し、当該高融点めっき皮膜が、耐食性を有するとともに高温で潤滑機能を確保することができ、さらに、溶接性および装飾性が良好な皮膜であることを特徴とする被覆熱処理鋼材。 A heat treatment is carried out to heat at least a part of the steel material alloyed at a temperature of 3 points or less to a quenchable temperature range in a steel material having a high melting point plating film-forming element-based coating film coated on at least one surface. A coated heat-treated steel material having a high-melting-point plating film in which an iron-high-melting-point plating film-forming element is alloyed on at least a part of the surface of the heat-treated portion, and the high-melting-point plating film However, the coated heat-treated steel material is characterized by having a corrosion resistance and a lubricating function at a high temperature and having a good weldability and decorativeness. 前記高融点めっき皮膜形成元素は、Ni、Cr、CuまたはCoからなる群から選ばれた一種または二種以上の組み合わせである請求項1に記載された被覆熱処理鋼材。   The coated heat-treated steel material according to claim 1, wherein the refractory plating film forming element is one or a combination of two or more selected from the group consisting of Ni, Cr, Cu, and Co. 前記高融点めっき皮膜は、Niめっき皮膜、Crめっき皮膜、Cuめっき皮膜、Coめっき皮膜、または、Ni、Cr、CuまたはCoからなる群から選ばれた二種以上を合計で50質量%以上含有する合金めっき皮膜である請求項1または請求項2に記載された被覆熱処理鋼材。   The high melting point plating film contains a Ni plating film, a Cr plating film, a Cu plating film, a Co plating film, or two or more selected from the group consisting of Ni, Cr, Cu or Co in a total of 50% by mass or more. The coated heat-treated steel material according to claim 1 or 2, which is an alloy plating film to be coated. 少なくとも一つの面に被覆された高融点めっき皮膜形成元素系めっき皮膜を備える鋼材を、Ac点以下の温度で合金化処理された鋼材の少なくとも一部を焼入れ可能温度域に加熱し、加熱された部分の少なくとも一部の表面に液相が存在しないうちに冷却することにより、該加熱および冷却を行われた部分の少なくとも一部の表面に、鉄−高融点めっき皮膜形成元素が合金化され、耐食性を有するとともに高温で潤滑機能を確保することができ、さらに、溶接性および装飾性が良好な皮膜を形成することを特徴とする被覆熱処理鋼材の製造方法。 At least a part of the steel material that has been alloyed at a temperature of Ac 3 or lower is heated to a quenchable temperature range, and the steel material having a high melting point plating film-forming element-based plating film coated on at least one surface is heated. By cooling before the liquid phase is present on at least a part of the surface of the part, the iron-refractory plating film forming element is alloyed on the part of the part that has been heated and cooled. A method for producing a coated heat-treated steel material, which has a corrosion resistance and can ensure a lubricating function at a high temperature, and further forms a film having good weldability and decorativeness.
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JP2013047368A (en) * 2011-07-25 2013-03-07 Jfe Steel Corp Method for production of steel pipe having partially different strengths
CN103911063A (en) * 2014-04-10 2014-07-09 攀钢集团攀枝花钢铁研究院有限公司 Self-lubricating treating agent composition, hot aluminum/zinc-plated sheet and preparation method thereof
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013047368A (en) * 2011-07-25 2013-03-07 Jfe Steel Corp Method for production of steel pipe having partially different strengths
CN103911063A (en) * 2014-04-10 2014-07-09 攀钢集团攀枝花钢铁研究院有限公司 Self-lubricating treating agent composition, hot aluminum/zinc-plated sheet and preparation method thereof
CN103911063B (en) * 2014-04-10 2016-07-27 攀钢集团攀枝花钢铁研究院有限公司 A kind of self-lubrication treatment agent compositions and hot dip aluminum zinc plate and preparation method thereof
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