JPH0971821A - Heat treatment of welded joint of maraging steel - Google Patents
Heat treatment of welded joint of maraging steelInfo
- Publication number
- JPH0971821A JPH0971821A JP7247068A JP24706895A JPH0971821A JP H0971821 A JPH0971821 A JP H0971821A JP 7247068 A JP7247068 A JP 7247068A JP 24706895 A JP24706895 A JP 24706895A JP H0971821 A JPH0971821 A JP H0971821A
- Authority
- JP
- Japan
- Prior art keywords
- heat treatment
- welded joint
- maraging steel
- welded
- temperature
- 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
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K2103/00—Materials to be soldered, welded or cut
- B23K2103/02—Iron or ferrous alloys
- B23K2103/04—Steel or steel alloys
Landscapes
- Laser Beam Processing (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は時効硬化鋼であるマ
ルエージング鋼溶接継手の熱処理方法に関し、特にマル
エージング鋼を用いた全ての溶接構造物、特にロケット
チャンバの製作に有利に適用しうる方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment method for a maraging steel welded joint which is an age-hardening steel, and particularly to a method which can be advantageously applied to the production of all welded structures using maraging steel, especially rocket chambers. Regarding
【０００２】[0002]
【従来の技術】従来、マルエージング鋼を用いて製作さ
れるロケットチャンバは１次溶体化熱処理（８９０℃×
０．５時間）を施した材料を、電子ビーム溶接で円筒形
状に組み立てた後、チャンバ全体を炉中に入れて、２次
溶体化熱処理（８２０℃×３時間）、時効熱処理（５３
０℃×１０時間）を実施する施工法をとっていた。2. Description of the Related Art Conventionally, rocket chambers made of maraging steel have been subjected to a primary solution heat treatment (890 ° C. ×
(0.5 hours), the material was assembled into a cylindrical shape by electron beam welding, then the entire chamber was put into a furnace, and a second solution heat treatment (820 ° C. × 3 hours) and an aging heat treatment (53
The construction method was to carry out 0 ° C. × 10 hours).
【０００３】[0003]
【発明が解決しようとする課題】従来の施工方法では、
溶接継手の破壊靱性は母材の破壊靱性より低い値となっ
ていた。この原因は種々調査の結果、溶接金属部の凝固
偏析による微小な低靱性部の存在に起因するものと判明
した。一方、母材製造時には凝固速度が溶接部より遙か
に遅いため、更に大きな凝固偏析が生じているが、オー
ステナイト化温度を超える１０００℃以上の高温で長時
間の拡散熱処理を実施して偏析を解消しており、良好な
破壊靱性を得ている。このことから溶接施工後もチャン
バ全体を拡散熱処理を施工することにより偏析を解消
し、溶接継手部の靱性を母材と同等に改善する方法が考
えられるが、ロケットチャンバは薄肉構造（例えば、直
径約２５００ｍｍに対して、板厚約７ｍｍ）であるた
め、チャンバ全体の高温での拡散熱処理を行うと大きな
変形が生じるため、実際には施工不可能であった。In the conventional construction method,
The fracture toughness of the welded joint was lower than the fracture toughness of the base metal. As a result of various investigations, the cause was found to be due to the presence of minute low toughness portions due to solidification segregation of the weld metal. On the other hand, when the base metal is manufactured, the solidification rate is much slower than that of the welded part, so that a larger solidification segregation occurs. It has been resolved and good fracture toughness is obtained. From this, it is possible to eliminate the segregation by performing diffusion heat treatment on the entire chamber even after welding, and improve the toughness of the welded joint part to the same level as the base metal, but the rocket chamber has a thin wall structure (for example, diameter). Since the plate thickness is about 7 mm with respect to about 2500 mm), a large deformation occurs when the diffusion heat treatment of the entire chamber is performed at a high temperature, so that it is practically impossible.
【０００４】本発明は上記技術水準に鑑み、溶接継手部
の破壊靱性を向上する熱処理方法を提供しようとするも
のである。In view of the above technical level, the present invention is to provide a heat treatment method for improving the fracture toughness of a welded joint.
【０００５】[0005]
【課題を解決するための手段】本発明は（１）溶接施工
後、時効熱処理によって所定の強度を得るマルエージン
グ鋼材料の溶接継手において、溶接施工後、時効熱処理
前に、溶接継手部近傍のみを局所的にオーステナイト化
温度以上融点以下の温度に昇温、保持したのち冷却した
上で時効熱処理を行い、結果的にマルテンサイト基地に
析出物の析出している組織とすることを特徴とするマル
エージング鋼溶接継手の熱処理方法、（２）高密度エネ
ルギビームを溶接継手部に照射することにより、溶接継
手部近傍のみを局所的にオーステナイト化温度以上融点
以下の温度に昇温、保持することを特徴とする上記
（１）記載のマルエージング鋼溶接継手の熱処理方法及
び（３）上記（１）または（２）のマルエージング鋼溶
接継手の熱処理後、時効熱処理あるいは溶体化熱処理＋
時効熱処理を施工することを特徴とするマルエージング
鋼材料を使用した溶接構造物の製造方法である。Means for Solving the Problems The present invention (1) In a welded joint of a maraging steel material which obtains a predetermined strength by aging heat treatment after welding, only in the vicinity of the welded joint after welding and before aging heat treatment Is locally heated to a temperature not lower than the austenitizing temperature and not higher than the melting point, and is then held and cooled before aging heat treatment, resulting in a structure in which precipitates are precipitated in the martensite base. Method for heat treatment of maraging steel welded joint, (2) By irradiating the welded joint with a high-density energy beam, only the vicinity of the welded joint is locally heated to a temperature above the austenitizing temperature and below the melting point and held. (1) The heat treatment method for the maraging steel welded joint according to (1) above, and (3) the heat treatment for the maraging steel welded joint according to (1) or (2) above, Heat treatment or solution heat treatment +
A method for manufacturing a welded structure using a maraging steel material, characterized by performing an aging heat treatment.
【０００６】本発明において対象とするマルエージング
鋼の一般的な成分組成は特定することができないが、Ｉ
ｎｃｏ社の標準マルエージング鋼の３種類の成分組成を
代表例として下記表１に示す。The general composition of the maraging steel targeted in the present invention cannot be specified.
Table 1 below shows the typical composition of the three types of standard maraging steel manufactured by Nco.
【０００７】[0007]
【表１】 ＜０．０３％Ｃ、＜０．２０％Ｍｎ＋Ｓｉ、＜０．０１
０％Ｐ、＜０．０１０％Ｓ その他添加元素（０．００
３％Ｂ、０．０２％Ｚｒ、０．０５％Ｃａ）[Table 1] <0.03% C, <0.20% Mn + Si, <0.01
0% P, <0.010% S Other additive elements (0.00
3% B, 0.02% Zr, 0.05% Ca)
【０００８】[0008]
【発明の実施の形態】溶接継手部近傍のみを局所的にオ
ーステナイト化温度以上融点以下（マルエージング鋼の
成分によって異なるが、一般的にオーステナイト化温度
は５００〜８００℃、融点は１５００℃前後）の高温に
昇温・保持することにより、溶接部の粒界に凝固偏析し
ている元素（チタン、モリブデン等）が拡散し偏析が解
消され、時効熱処理後の溶接継手部は母材と同等の破壊
靱性となる。なお、マルエージング鋼等の時効硬化鋼で
は、室温に冷却後の溶接継手部の組織は他の母材部と同
様のマルテンサイト組織となる。また、溶接継手部近傍
のみを局所的に昇温するため、溶接構造物の一般部は通
常の強度を保持するため構造物全体としては大きな変形
を生じない。BEST MODE FOR CARRYING OUT THE INVENTION Only in the vicinity of a welded joint is locally austenitizing temperature or more and melting point or less (although the austenitizing temperature is 500 to 800 ° C and the melting point is around 1500 ° C, depending on the composition of the maraging steel). By increasing the temperature and holding at a high temperature, the elements that solidify and segregate (titanium, molybdenum, etc.) in the grain boundaries of the welded part diffuse and the segregation is eliminated, and the welded joint part after aging heat treatment is equivalent to the base metal Fracture toughness. In addition, in age-hardening steel such as maraging steel, the structure of the welded joint after cooling to room temperature has the same martensite structure as that of the other base metal parts. Further, since the temperature is locally raised only in the vicinity of the welded joint portion, the general portion of the welded structure maintains normal strength, so that the entire structure does not significantly deform.
【０００９】本発明の加熱手段としては、電子ビーム、
レーザビーム等の高密度エネルギビームを溶接継手部に
照射することにより、母材一般部を昇温することなく溶
接継手近傍のみをオーステナイト温度以上に昇温保持す
ることができる。As the heating means of the present invention, an electron beam,
By irradiating the welded joint with a high-density energy beam such as a laser beam, only the vicinity of the welded joint can be heated to the austenite temperature or higher without heating the general base material.
【００１０】本発明の好ましい実施態様として、上記の
熱処理後、時効熱処理あるいは溶体化熱処理＋時効熱処
理を施工する。時効熱処理としては、目的の機械的性質
に合わせて選定されるもので、一般的に保持温度：４０
０〜６００℃、保持時間：１〜２０時間程度である。ま
た、溶体化熱処理としては一般的に製品の変形が許容さ
れる限界の温度であるオーステナイト化温度以上９００
℃以下であり、好ましくは７９０〜８５０℃、更に好ま
しくは８００〜８４０℃である。As a preferred embodiment of the present invention, after the above heat treatment, aging heat treatment or solution heat treatment + aging heat treatment is applied. The aging heat treatment is selected according to the desired mechanical properties, and generally the holding temperature: 40
0 to 600 ° C., holding time: about 1 to 20 hours. In addition, as a solution heat treatment, generally, the austenitization temperature, which is the limit temperature at which product deformation is allowed, is 900 or more.
C. or lower, preferably 790 to 850.degree. C., more preferably 800 to 840.degree.
【００１１】[0011]
【実施例】以下本発明の具体的な実施例をあげ、本発明
の効果を明らかにする。EXAMPLES The effects of the present invention will be clarified by giving concrete examples of the present invention.
【００１２】（実施例１）本発明の一実施例を図１によ
って説明する。オーステナイト化温度：７４０℃、融
点：約１５００℃のマルエージング鋼（重量％で、Ｃ：
０．００４、Ｓｉ：０．０５、Ｐ：０．００３、Ｓ：
０．００１、Ｎｉ：１８．２、Ｃｏ：１０．２、Ｍｏ：
５．００、Ａｌ：０．０９、Ｔｉ：０．５２、Ｂ：０．
０００７、Ｃｒ：０．１１、Ｚｒ：＜０．００１）で円
筒容器を製作する場合のものであり、ロケットのチャン
バ１の長手溶接継手２である電子ビーム溶接継手部を、
真空チャンバ（図示省略）内において電子銃４からの電
子ビーム３の照射により局部的に昇温している状況を示
す。当然、周溶接継手にも同様に本発明を適用すること
ができる。(Embodiment 1) An embodiment of the present invention will be described with reference to FIG. Austenitizing temperature: 740 ° C, melting point: about 1500 ° C maraging steel (% by weight, C:
0.004, Si: 0.05, P: 0.003, S:
0.001, Ni: 18.2, Co: 10.2, Mo:
5.00, Al: 0.09, Ti: 0.52, B: 0.
0007, Cr: 0.11, Zr: <0.001) in the case of manufacturing a cylindrical container, the electron beam welded joint portion which is the longitudinal welded joint 2 of the chamber 1 of the rocket,
A situation in which the temperature is locally raised by irradiation of the electron beam 3 from the electron gun 4 in a vacuum chamber (not shown) is shown. Of course, the present invention can be similarly applied to the circumferentially welded joint.
【００１３】本実施例では、ロケットチャンバの板厚は
７．５ｍｍで、本発明の熱処理のための電子ビーム照射
条件は下記表２に示すとおりのものである。In this embodiment, the rocket chamber has a plate thickness of 7.5 mm, and the electron beam irradiation conditions for the heat treatment of the present invention are as shown in Table 2 below.
【００１４】[0014]
【表２】 [Table 2]
【００１５】上記のような条件で溶接継手部を局部的に
昇温し本発明の熱処理を施工し、電子ビーム照射面の反
対面で温度履歴を計測したところ、最高到達温度が約１
２５０℃、１２００℃以上に保持された時間が約８０秒
であった。また、１００ｍｍ×３０ｍｍの小さい範囲を
移動しながら照射し昇温する方法であるため他の部分は
温度が上がらず、熱処理後も大きな変形は生じなかっ
た。When the heat treatment of the present invention was carried out by locally raising the temperature of the welded joint under the above conditions and measuring the temperature history on the surface opposite to the electron beam irradiation surface, the maximum temperature reached was about 1.
The time at which the temperature was kept at 250 ° C, 1200 ° C or higher was about 80 seconds. Further, since the temperature is raised by irradiating while moving in a small area of 100 mm × 30 mm, the temperature of other parts does not rise, and no large deformation occurs even after the heat treatment.
【００１６】上記の本発明熱処理を施した後、マルエー
ジング鋼本来の強度を確保するために、チャンバ全体
に、８２０℃で３時間保持の溶体化熱処理及び５２０℃
で１０時間保持の時効熱処理を与えた。After the above-mentioned heat treatment of the present invention, in order to secure the original strength of the maraging steel, the whole chamber is subjected to solution heat treatment at 820 ° C. for 3 hours and 520 ° C.
Then, the aging heat treatment was performed for 10 hours.
【００１７】実施例１に示した本発明の熱処理方法を適
用した溶接継手の機械的性質と、本発明の熱処理を適用
しない従来の方法による溶接継手の機械的性質を計測し
た結果を比較して表３と表４に示す。なお、従来法の溶
接継手は、本発明熱処理を受けていないこと以外は、材
料組成その他の熱履歴、溶接条件とも全て実施例と同一
である。継手の機械的性質の内、継手引張試験結果を表
３に示す。本発明による熱処理を受けない従来法による
継手の引張強さは平均１９６．５ｋｇｆ／ｍｍ2 となっ
ているが、本発明の熱処理を受けた継手では、引張強さ
は従来法の継手とほぼ同等であるが、０．２％耐力が高
く、また、破断伸びも大きくなっており、性能が改善さ
れていることがわかる。さらに、継手の破壊靱性試験結
果を表４に示すが、本発明による熱処理を受けない従来
法による継手の破壊靱性は平均１６４．９ｋｇｆ／ｍｍ
1.5 となっているが、本発明の熱処理を受けた継手では
平均２１２．７ｋｇｆ／ｍｍ1.5 と、拡散熱処理を受け
ない継手より約３０％高い値となっており、大きな改善
効果が見られる。The results of measuring the mechanical properties of the welded joint to which the heat treatment method of the present invention shown in Example 1 was applied and the mechanical properties of the welded joint by the conventional method to which the heat treatment of the present invention was not applied were compared. It is shown in Table 3 and Table 4. The weld joint of the conventional method has the same material composition and other heat history and welding conditions as in the embodiment except that it is not subjected to the heat treatment of the present invention. Among the mechanical properties of the joint, the joint tensile test results are shown in Table 3. The average tensile strength of the conventional joint not subjected to the heat treatment of the present invention is 196.5 kgf / mm 2 , but the tensile strength of the joint subjected to the heat treatment of the present invention is almost equal to that of the conventional joint. However, the 0.2% proof stress is high and the elongation at break is also large, indicating that the performance is improved. Further, the results of the fracture toughness test of the joint are shown in Table 4. The fracture toughness of the conventional joint which is not subjected to the heat treatment according to the present invention has an average fracture toughness of 164.9 kgf / mm.
Although it is 1.5 , the joint subjected to the heat treatment of the present invention has an average of 212.7 kgf / mm 1.5 , which is about 30% higher than that of the joint not subjected to the diffusion heat treatment, which shows a great improvement effect.
【００１８】[0018]
【表３】 * ；Ｇ．Ｌ．＝５０ｍｍ[Table 3] * ; G. L. = 50 mm
【００１９】[0019]
【表４】 [Table 4]
【００２０】また、図３には従来法の溶接継手部の断面
マクロ組織を、図２に本発明を適用した溶接継手部の断
面マクロ組織の光学顕微鏡写真（倍率：３倍）を示す
が、本発明の適用により再結晶がすすみ、偏析が拡散に
よって解消されて溶接による凝固組織が消滅しているこ
とが認められる。Further, FIG. 3 shows a cross-sectional macrostructure of the welded joint of the conventional method, and FIG. 2 shows an optical micrograph (magnification: 3 times) of the cross-sectional macrostructure of the welded joint to which the present invention is applied. It is recognized that the application of the present invention promotes recrystallization, eliminates segregation by diffusion, and eliminates the solidification structure due to welding.
【００２１】（実施例２）実施例１と同じ供試材、電子
ビーム照射条件を採用した後、５２０℃で１０時間の時
効処理のみを実施した。その結果、得られた溶接継手の
機械的性質を表５、表６に示す。表５及び表６より、こ
の実施例２の方法によっても実施例１と同様な効果が奏
されることが明らかである。Example 2 After employing the same test material and electron beam irradiation conditions as in Example 1, only aging treatment was carried out at 520 ° C. for 10 hours. The mechanical properties of the resulting welded joint are shown in Tables 5 and 6. It is clear from Tables 5 and 6 that the same effect as in Example 1 can be obtained by the method of Example 2 as well.
【００２２】[0022]
【表５】 * ；Ｇ．Ｌ．＝５０ｍｍ[Table 5] * ; G. L. = 50 mm
【００２３】[0023]
【表６】 [Table 6]
【００２４】[0024]
【発明の効果】本発明を適用することによって、マルエ
ージング鋼溶接継手部の機械的性質は大幅に改善され、
マルエージング鋼を使用した溶接構造物の信頼性が大い
に向上する効果が奏された。By applying the present invention, the mechanical properties of the maraging steel welded joint are greatly improved,
The effect is that the reliability of the welded structure using maraging steel is greatly improved.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明の一実施例の熱処理方法の説明図。FIG. 1 is an explanatory diagram of a heat treatment method according to an embodiment of the present invention.
【図２】本発明の実施例１の熱処理方法による溶接継手
部の断面組織を示す光学顕微鏡写真。FIG. 2 is an optical micrograph showing a cross-sectional structure of a welded joint portion according to the heat treatment method of Example 1 of the present invention.
【図３】従来のマルエージング鋼の熱処理方法による溶
接継手部の断面組織を示す光学顕微鏡写真。FIG. 3 is an optical micrograph showing a cross-sectional structure of a welded joint portion obtained by a conventional heat treatment method for maraging steel.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 青木 繁幸 兵庫県神戸市兵庫区和田崎町一丁目１番１ 号 三菱重工業株式会社神戸造船所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeyuki Aoki 1-1-1 Wadazaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd. Kobe Shipyard
Claims (3)
強度を得るマルエージング鋼材料の溶接継手において、
溶接施工後、時効熱処理前に、溶接継手部近傍のみを局
所的にオーステナイト化温度以上融点以下の温度に昇
温、保持したのち冷却した上で時効熱処理を行い、結果
的にマルテンサイト基地に析出物の析出している組織と
することを特徴とするマルエージング鋼溶接継手の熱処
理方法。1. A welded joint of a maraging steel material, which has a predetermined strength by aging heat treatment after welding,
After welding and before aging heat treatment, only the vicinity of the welded joint is locally heated to a temperature above the austenitizing temperature and below the melting point, held and cooled, and then subjected to aging heat treatment, resulting in precipitation in the martensite matrix. A heat treatment method for a maraging steel welded joint, which is characterized in that a structure in which a substance is precipitated is formed.
射することにより、溶接継手部近傍のみを局所的にオー
ステナイト化温度以上融点以下の温度に昇温、保持する
ことを特徴とする請求項１記載のマルエージング鋼溶接
継手の熱処理方法。2. The irradiation of the welded joint with a high-density energy beam locally raises and holds only the vicinity of the welded joint to a temperature not lower than the austenitizing temperature and not higher than the melting point. A method for heat treatment of a maraging steel welded joint as described.
ジング鋼溶接継手の熱処理後、時効熱処理あるいは溶体
化熱処理＋時効熱処理を施工することを特徴とするマル
エージング鋼材料を使用した溶接構造物の製造方法。3. A welded structure using a maraging steel material, characterized in that after the heat treatment of the maraging steel welded joint according to claim 1 or 2, an aging heat treatment or a solution heat treatment + aging heat treatment is applied. Manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7247068A JPH0971821A (en) | 1995-09-01 | 1995-09-01 | Heat treatment of welded joint of maraging steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7247068A JPH0971821A (en) | 1995-09-01 | 1995-09-01 | Heat treatment of welded joint of maraging steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0971821A true JPH0971821A (en) | 1997-03-18 |
Family
ID=17157956
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7247068A Pending JPH0971821A (en) | 1995-09-01 | 1995-09-01 | Heat treatment of welded joint of maraging steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0971821A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101272147B1 (en) * | 2012-03-09 | 2013-06-07 | 주식회사 파워엠엔씨 | A manufacturing method of magnetic load cell |
| JP2013193143A (en) * | 2012-03-16 | 2013-09-30 | Toyota Motor Corp | Method for manufacturing endless metal ring |
-
1995
- 1995-09-01 JP JP7247068A patent/JPH0971821A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101272147B1 (en) * | 2012-03-09 | 2013-06-07 | 주식회사 파워엠엔씨 | A manufacturing method of magnetic load cell |
| JP2013193143A (en) * | 2012-03-16 | 2013-09-30 | Toyota Motor Corp | Method for manufacturing endless metal ring |
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