JPS59144591A - Filler for welding ultrahigh tension steel - Google Patents

Abstract

PURPOSE:To provide a filler for welding ultrahigh tension steel which prevents the formation of coarse grains in the weld metal structure and improves a joint effect by incorporating Co in said filler in the content larger by a specific amt. than in the base metal. CONSTITUTION:A filler for welding ultrahigh tension steel is a filler for welding ultrahigh tension maraging steel base metal consisting essentially of 17- 19% Ni, 8-12% Co, 4-6% Mo and 0.4-1.8% Ti and has the compsn. consisting essentially of 17-19% Ni, 9-20% Co, 4-6% Mo and 0.4-1.8% Ti in which the content of Co is increased by 1-8% than in said base material. If such filler is used, the decrease in the strength owing to the formation of corse grains in the weld metal structure is prevented, by which the joint effect is improved by 100% and a full advantage is developed for the ultrahigh tension steel. Such filler is applicable to a space developing rocket, ocean developing equipment and apparatus, equipment and apparatus for nuclear power, etc.

Description

【発明の詳細な説明】 本発明は超高力鋼溶接用充塀材に関し、特に溶接金属組
織の粗大化防止を図り、継手効率を１００係とすること
のできる上記充填材に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filler for welding ultra-high strength steel, and more particularly to the filler described above, which can prevent coarsening of the weld metal structure and achieve a joint efficiency of 100.

宇宙、海洋開発、原子力等の分野で強度１５０〜２５０
Ｋｆｌｔｗｍ級の超高張力マルエージング鋼が応用され
ている。Strength 150-250 in fields such as space, ocean development, nuclear power, etc.
Kfltwm class ultra-high tensile strength maraging steel is applied.

その母材の主成分はＮ１１７〜１９チ、Ｃ０８〜１２％
、Ｍｏ４〜６ｓ、Ｔｉｏ４〜１．８％で、強度に応じて
Ｃｏ、　　Ｍｏ、　　Ｔｉ等の添加量を変え、所定の強
度を得ている１、 その溶接に当っては、母材と同材質（共金）を充填材と
してアーク溶接するか、或は充填材を用いないでエレク
トロンビーム溶接を行うなどの方式がとられている、そ
のために、母材部は調質され細粒化組織になり、充分な
強度、延性、靭性が得られていても、溶接継手部は溶接
熱による組織の粗大化や溶接金属特有の柱状晶組織を呈
し、強度、延性、靭性が劣るので、市むなく継手効率を
８０〜９０％にせざるを得す、折角の超高張力鋼の利点
を充分に発揮できない、強度１５０〜２５０　Ｋｇ　／
　ｔａｎ２級の超高張力マルエージング鋼は表１上段に
示すような主要成！ 分のものが用いられ、要求強度に応じてＣｏ。The main components of the base material are N117-19% and C08-12%.
, Mo4~6s, Tio4~1.8%, and the amount of added Co, Mo, Ti, etc. is changed according to the strength to obtain the specified strength1.For welding, the same material as the base material is used. Methods such as arc welding using (common metal) as a filler or electron beam welding without using a filler are used.For this purpose, the base metal is tempered and has a fine-grained structure. Therefore, even if sufficient strength, ductility, and toughness are obtained, the welded joint will coarsen its structure due to welding heat and exhibit a columnar crystal structure peculiar to weld metal, resulting in poor strength, ductility, and toughness. The joint efficiency has to be 80-90%, and the advantages of ultra-high tensile steel cannot be fully utilized, and the strength is 150-250 kg/
Tan2 grade ultra-high tensile strength maraging steel has the main components shown in the upper row of Table 1. Co is used depending on the required strength.

Ｍｏ、Ｔｉ　　の含有量を変えて所定の強度を得ている
、例えば、２００〜／燗２の要求強度に対しては表１下
段に示すような成分のものが用いられ、その時の母材の
機械的性質は１例として表２に示すような特性をもつ。For example, for the required strength of 200~/kan2, the composition shown in the lower part of Table 1 is used, and the content of Mo and Ti is changed to obtain a predetermined strength. As an example, the mechanical properties are as shown in Table 2.

すなわち２００　Ｋ９／閲２以上の引張強度と、９チ前
後の伸び率、２００以上のに、Ｏ値、約３　Ｋｑ−ｍ／
ｃｎ？のＶＨＯ値を示す。In other words, it has a tensile strength of 200 K9/cm2 or more, an elongation rate of around 9 inches, an O value of about 3 Kq-m/
cn? shows the VHO value of

表　　　　１ 表２ 溶体化処理　８５０℃×１ｈ（Ａ、ｃ）時効］Ｑ　　４
ｓｏ℃ｘｓｈ（Ａ、ａ）このマルエージング鋼を用いて
構造物を製作するには、溶接により接合され組立てられ
る。Table 1 Table 2 Solution treatment 850°C x 1h (A, c) aging] Q 4
so°C xsh (A, a) To fabricate a structure using this maraging steel, it is joined and assembled by welding.

この場合、第１図に示すように被接合材１．を突合せた
１１充填材を用いることなく表５上段に示す条件でエレ
クトロンビーム溶接するか、あるいは第２図に示すよう
に被溶接材１に開先をとシ、母材と同成分の充填材（共
金充填材）を用いて表３下段に示す条件でＴ工Ｇ溶接を
行う等の方法がとられる。In this case, as shown in FIG. Electron beam welding is performed under the conditions shown in the upper row of Table 5 without using a filler, or by cutting a groove in the welded material 1 as shown in Figure 2 and using a filler with the same composition as the base material. A method such as performing T-welding using (common metal filler) under the conditions shown in the lower row of Table 3 is used.

表　　　３ このようにして接合された溶接継手部は、溶°接の熱影
響によって金属組織が粗大化し、また溶接金桝特有の柱
状晶組織を呈するので、時効処理を行っても所定の強度
、延性、靭性が得られない入これを確認した際の実験結
果を表４に示すっ なお、表４中の充填材Ａ、Ｂ、（、、Ｄは表５に示すも
のである。また、被溶接材としては一表１下段に示すマ
ルエージング鋼を用いた。Table 3 The metal structure of the welded joint joined in this way becomes coarse due to the thermal effects of welding, and it also exhibits a columnar crystal structure peculiar to welding holes, so even after aging treatment, it will not maintain the specified strength or strength. Table 4 shows the experimental results to confirm that ductility and toughness cannot be obtained. Maraging steel shown in the lower row of Table 1 was used as the welding material.

表　　　４ 表　　　　５ 溶体化処理　　８５０℃Ｘ１ｈ（Ａ、Ｃ）時効処理　４
５０℃Ｘ５ｈ　（Ａ、Ｏ）表４から明らかなようｔｉ、
ｒｌ、ｚのものは表２に示す母材の機械的性質に比し、
引張強さは母材の８５〜９５係に低下し、また隘３〜５
のものは伸び、絞シが低下する。従って、継手効率は８
０〜９０チにしか取ることができなかった。Table 4 Table 5 Solution treatment 850°C x 1h (A, C) Aging treatment 4
50℃×5h (A, O) As is clear from Table 4, ti,
Compared to the mechanical properties of the base material shown in Table 2, those with rl and z have
The tensile strength is lowered to 85-95 of the base material, and 3-5
The material stretches and the shrinkage decreases. Therefore, the joint efficiency is 8
I was only able to get it between 0 and 90 inches.

本発明は、これらの欠点を解決するため罠なされだもの
で、特殊な充填材を用いることによシ、溶接金属組織の
粗大化による強度低下を防止し、継手効率を１００％に
向−ヒして超高張力鋼の利点を１００係発揮させようと
するものである。The present invention was developed to solve these drawbacks, and by using a special filler, it prevents a decrease in strength due to coarsening of the weld metal structure and increases the joint efficiency to 100%. The aim is to fully utilize the advantages of ultra-high tensile strength steel.

すなわち本発明はＮ１１７〜１９係、Ｃｏ　　８〜１２
ｑ６、Ｍｏ　４〜６係、Ｔｉ０．４〜１．８％を主成分
とする超高張力マルエージング鋼母材の溶接用充填材に
おいて、Ｃｏ　含有量を該母材の１〜８％多くしたＮｉ
１７〜１９％、Ｃｏ　９〜２０チ、Ｍｏ４〜６％、Ｔｉ
０．４〜１．８％を主成分とすることを特徴とする超高
張力鋼溶接用充填材に関するものであるっ 本発明充填材は、宇宙開発ロケット、海洋開発用機器、
原子力用機器等に利用できる。That is, the present invention relates to N117-19, Co 8-12
In a filler for welding an ultra-high tensile maraging steel base material whose main components are q6, Mo 4-6, and Ti 0.4-1.8%, the Co content was increased by 1-8% of the base material. Ni
17-19%, Co 9-20%, Mo 4-6%, Ti
The present invention relates to a filler for ultra-high tensile steel welding, which is characterized by containing 0.4 to 1.8% as a main component.
Can be used for nuclear power equipment, etc.

本発明充填材は、前記した従来の充填材Ａ〜Ｄ［比し、
Ｃｏ含有量のみを１〜８係多くした点に特徴があり、こ
のＣｏ含有量のみの増加によシ、強度の増加を図ると共
に、金属組織を細粒化させるものである。なお、ｃｏ　
含有量を１〜８チ多くした理由は次の通シである。The filler of the present invention is different from the conventional fillers A to D described above [compared to
It is characterized in that only the Co content is increased by a factor of 1 to 8, and by increasing the Co content alone, the strength is increased and the metal structure is made finer. In addition, co
The reason why the content was increased by 1 to 8 chips is as follows.

例えば、１８％Ｎ１マルエージング鋼の強度は、第３図
（出典：日本金属学会会報ＶＯＩ　１４、Ｎｈｌｏ、阿
部義部著）に示すようにＭｏ等量（Ｍｏｅｑ　−％　Ｍ
ｏ　＋Ｍｘ　（％Ｃｏ　）＋３ｘ（％Ｔｔ　）　）にほ
ぼ比例して増加し、母材は領域αのようになシ、溶−接
金属は一般に直線βのような傾向を示す。すなわち、溶
接金属は母材と異なり、凝固時に必ず柱状組織となり、
強度レベルが低い範囲では溶接金属の強度は母材の９７
チ程度を示すが、強度レベルが上るに従って９５〜９０
チと柱状細織の影響が頒著になシ、強度の低下率が大に
なって行く。一方、溶接金属の柱状組織は通常の熱処理
を行つ′ても消滅させるととは、できない。言い換えれ
ば、母材と同一成分の溶接金属の場合には、熱処理条件
を変えても、強度レベルが高い範囲では母材と同一の強
度を得ることはできない。For example, the strength of 18% N1 maraging steel is determined by the Mo equivalent (Moeq -% M
o + Mx (%Co) + 3x (%Tt)), the base metal shows a trend like the area α, and the weld metal generally shows a trend like a straight line β. In other words, unlike the base metal, the weld metal always forms a columnar structure during solidification.
In the range where the strength level is low, the strength of the weld metal is 97% that of the base metal.
As the intensity level increases, it increases from 95 to 90.
The influence of the fibers and columnar weave becomes more pronounced, and the rate of decrease in strength increases. On the other hand, it is impossible to eliminate the columnar structure of weld metal even by ordinary heat treatment. In other words, if the weld metal has the same composition as the base metal, even if the heat treatment conditions are changed, it is not possible to obtain the same strength as the base metal within a high strength level range.

従って、溶接部の強度を母材と同等にするためには、母
材より溶接金属のＭｏ等量を高くして溶接金属の強度を
上げればよい。Ｍｏ　当量を高くするには、Ｃｔｆ、　
Ｍｏ　、−Ｔｉの含有量を多くすればよいのであるが、
延性、靭性に最も良い結果を与えるのはＣｏ　　である
。そこで本発明では、ｃｏのみを増加してＭ′ｂ　等量
を高く１〜、延性、靭性を低下させないで溶接金属の強
度を上げることとし、溶接金属のＭｏ等量を高くする手
段として充填材のＣｏ含有量を母材よシ増加させること
を採用したものである、 ところで、実際には、溶接金属のＭｏ　当量は溶接金属
中に溶は込む母材と充填材の計によって左右されるので
、母材成分の変化、溶込量の変化、歩留シ率等の検討が
必要となる。溶接条件と充填材の挿入方法が決まれば、
残りは母材成分の変化だけとなる。母材成分は表１に示
したように、要求強度によってＮ１１７〜１９チ、Ｃ０
８〜１２チ、Ｍｏ４〜６％、Ｔ、１０．４〜１．８チの
範囲内で変化するが、ここではＧｏの量が問題なのでＯ
ｏ　のみについて検討する。Therefore, in order to make the strength of the welded part equivalent to that of the base metal, it is sufficient to increase the strength of the weld metal by making the Mo equivalent content of the weld metal higher than that of the base metal. To increase the Mo equivalent, Ctf,
It would be better to increase the content of Mo and -Ti, but
Co gives the best results in terms of ductility and toughness. Therefore, in the present invention, the strength of the weld metal is increased without reducing the ductility and toughness by increasing only co to raise the M'b equivalent to 1 or more, and as a means of increasing the Mo equivalent of the weld metal, filler By the way, in reality, the Mo equivalent of the weld metal is influenced by the total of the base metal and filler that are injected into the weld metal. It is necessary to consider changes in base material components, changes in penetration amount, yield rate, etc. Once the welding conditions and filler insertion method are determined,
The rest is only a change in the base material components. As shown in Table 1, the base material components are N117-19, C0 depending on the required strength.
It changes within the range of 8 to 12 inches, Mo 4 to 6%, T, and 10.4 to 1.8 inches, but since the amount of Go is the issue here, O
Consider only o.

先ず、Ｏｏ　　８％の場合の一例として、Ｃｏ　８係、
ＭＯ５，４チ、ＴｉＯ，５％、ＭＯ当量−９５６、強度
２００　Ｋ４／１ｍｒ＋２級の母材を溶接する場合、第
３図から明らかなように溶接金属のＭｏ　当量が約１０
であれば、母材とほぼ同等の強度が得られることが判る
。従って、充填材の成分は、ＣＯ約９チ、すなわち母材
中のＣｏ　　Ｂチの１％増でよいことが判る。First, as an example in the case of Oo 8%, Co 8,
MO5.4, TiO, 5%, MO equivalent -956, strength 200 When welding K4/1mr+2 class base metal, as is clear from Figure 3, the Mo equivalent of the weld metal is approximately 10.
If so, it can be seen that almost the same strength as the base material can be obtained. Therefore, it can be seen that the content of the filler may be approximately 9% CO, ie, 1% more than the Co2B in the base material.

次に、００１２％の場合の一例として、００１２％、Ｍ
Ｏ５，４係、ＴｉＯ，５俤、ＭＯ当量−１０，９、強度
２２５　Ｋｇ／箭２級の母材を溶接する場合、第３図か
ら明らかなように溶接金属の当量が約１３．５であれば
、母材とほぼ同等の強度となる。従って、充填材の成分
は、ｃｏ　約２０チ、すなわち母材中のＣ！ｏ１２％の
８チ増でよいことが判る。Next, as an example of 0012%, 0012%, M
When welding a base metal of O5.4, TiO, 5, MO equivalent -10,9, strength 225 Kg/2nd grade, as is clear from Figure 3, the equivalent weight of the weld metal is approximately 13.5. If so, the strength will be almost the same as that of the base material. Therefore, the composition of the filler is about 20 co, or C! in the matrix. It turns out that an increase of 8 inches (o12%) is sufficient.

更に、ＣＯ含有量を上記のように母材よりも１〜８チ増
加することにより、溶接金属が凝固する際に結晶粒が細
粒化する効果があシ、その後の熱処理によって微細なマ
ルテンサイト組織に調整するととができ、充分な強度と
延性を得ることかできる。この現象はＣＯ含有量の増加
において顕著であシ、ＭＯやＴｉの増加の場合よシも優
れている。Furthermore, by increasing the CO content by 1 to 8 cm compared to the base metal as described above, the crystal grains become finer when the weld metal solidifies, and the subsequent heat treatment produces fine martensite. By adjusting the structure, it is possible to obtain sufficient strength and ductility. This phenomenon is remarkable when the CO content increases, and is even better when the MO and Ti contents increase.

以上のような理由によって本発明では充填材のＣＯ含有
量を母材のＣＯ含有量の１〜８チ増加としたのである。For the reasons mentioned above, in the present invention, the CO content of the filler is increased by 1 to 8 inches compared to the CO content of the base material.

なお、本発明における充填材の量は、余り少な過ぎても
充填材の効果を得ることはできず、また余シ多過ぎても
工学的に使用は無理なので、全溶接金属量に対して１５
〜７５％とすることが望ましい。In addition, the amount of filler in the present invention is 15% of the total weld metal amount, because if it is too small, the effect of the filler cannot be obtained, and if it is too large, it is impossible to use it from an engineering perspective.
It is desirable to set it to 75%.

次に、具体例により本発明の効果を示す。Next, the effects of the present invention will be illustrated by specific examples.

充填材として、Ｃｏ：ＩＫ５１チ、ＭＯ＝５．４６チ、
Ｔｉ：０．６１チのものを用い、表１下段に示すマルエ
ージング鋼を、表３上段に示す条件にてエレクトロンビ
ーム溶接を行った。As a filler, Co: IK51chi, MO=5.46chi,
The maraging steel shown in the lower row of Table 1 was subjected to electron beam welding under the conditions shown in the upper row of Table 3 using a material with Ti: 0.61 inch.

なお、充填材は板厚０．８調のストリップ状にして突合
せ開先内に予め充填しておいた。勿論ワイヤ状にして溶
融地に自動供給してもよいことは言うまで本たい− このようにして溶接した継手の機械的性質は表６の通り
であった。Note that the filler was in the form of a strip having a thickness of 0.8 and was filled in advance into the butt groove. Needless to say, it is also possible to automatically feed it into the molten material in the form of a wire.The mechanical properties of the joint welded in this manner are shown in Table 6.

表　　６ 溶体化処理　　８５０℃ｘｔｈ（Ａ、ｃ）時効処理　４
５０℃Ｘ５ｈ（Ａ、Ｃり 表６と表４１表２を比較して明らかなようＫ、本発明充
填材を用いることにより、引張強度は母材とには同等、
伸び、靭性等においても、従来のものよ！ｌｌはるかに
良好となることが↑４ｆる。Table 6 Solution treatment 850°C x th (A, c) Aging treatment 4
50°C x 5h (A, C) As is clear by comparing Table 6 and Table 41 and Table 2, by using the filler of the present invention, the tensile strength is equivalent to that of the base material.
Even in terms of elongation, toughness, etc., it is the same as before! ll will be much better ↑4f.

従って、継手効率を１００％にすることができ、超高張
力鋼の利点を充分に発揮させ得メことが明らかである。Therefore, it is clear that the joint efficiency can be increased to 100% and the advantages of ultra-high tensile strength steel can be fully exhibited.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図および第２図は本発明の効果を確認するために用
いられた溶接時の開先形状を示す図、第３図はＭＯ当一
般と引張強度との関係を示す図表である。 復代理人　　内　１）　　明 復代理人　　　萩　　原　　亮　　−FIGS. 1 and 2 are diagrams showing groove shapes during welding used to confirm the effects of the present invention, and FIG. 3 is a chart showing the relationship between MO in general and tensile strength. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (1)

【特許請求の範囲】[Claims] Ｎ１１７〜１９チ、ＣＱ　８〜１２係、Ｍｏ４〜６チ、
Ｔｉ０．４〜１．８チを主成分とする超高張力マルエー
ジング鋼母材の溶接用充」信材において、ＣＯ含有量を
該母材の１〜８％多くしたＮ１１７〜１９チ、Ｃｏ　　
９〜２０％、Ｍｏ　　４〜６チ、Ｔ１０４〜１．８　’
Ｉ！を主成分とすることを特徴とする超高張力鋼溶接用
充填材。N117-19chi, CQ 8-12, Mo4-6chi,
In the welding reinforcement material for ultra-high tensile maraging steel base material whose main component is Ti0.4~1.8CH, N117~19CH and Co
9-20%, Mo 4-6chi, T104-1.8'
I! A filler for ultra-high tensile steel welding, which is characterized by having as its main component.