JPS61560A - Steel having superior toughness at welded joint - Google Patents
Steel having superior toughness at welded jointInfo
- Publication number
- JPS61560A JPS61560A JP11911784A JP11911784A JPS61560A JP S61560 A JPS61560 A JP S61560A JP 11911784 A JP11911784 A JP 11911784A JP 11911784 A JP11911784 A JP 11911784A JP S61560 A JPS61560 A JP S61560A
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- Prior art keywords
- steel
- toughness
- welded joint
- tndt
- joint
- 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.)
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Abstract
Description
【発明の詳細な説明】 (産業上の利用分野) 本発明は溶接継手部靭性に優れた鋼に関する。[Detailed description of the invention] (Industrial application field) The present invention relates to steel with excellent weld joint toughness.
(従来の技術)
近年圧力容器や原子炉格納容器、海洋構造物等の鋼構造
物においては使用環境の寒冷地化や安全性基準の厳格化
が進み、鋼板に対して従来にも増した厳しい靭性値が要
求されるようになっている。(Conventional technology) In recent years, steel structures such as pressure vessels, reactor containment vessels, and offshore structures are being used in colder regions and safety standards have become more stringent. Toughness values are now required.
さらに対象部位としては母材に加えて溶接継手部につい
て靭性要求がなされる場合が多い。そして靭性試験につ
いては従来のシャルピー試験に加えてASTM E2
08に定める薄型試験から求まるTNDT (無延性遷
移温度)を規制する例が増加している。Furthermore, toughness is often required for welded joints in addition to the base metal. For toughness testing, in addition to the conventional Charpy test, ASTM E2
There are an increasing number of cases in which the TNDT (non-ductile transition temperature) determined from the thin-film test specified in 2008 is regulated.
従来この種の鋼板の母材靭性向上手段としてラインパイ
プ用鋼等では制御圧延の実施による細粒化による方法が
採用されている。一方、溶接継手部の靭性向上に対して
は例えば鉄と調節61年(1975)第11号65〜7
9頁に大入熱溶接用鋼にTiを添加する方法、鉄と調節
63年(1977)第2号105〜114頁に大入熱溶
接用鋼にREMとBを添加する方法及び1982年4月
鉄鋼協会第103回講演大会′82−8′638,56
39に大入熱溶接用鋼にTiとBを複合添加する方法が
提案され継手部の靭性が向上するという報告がある。Conventionally, as a means of improving the base material toughness of this type of steel plate, a method of grain refinement through controlled rolling has been adopted for steel for line pipes and the like. On the other hand, for improving the toughness of welded joints, for example, iron and adjustment 61 (1975) No. 11, 65-7
A method of adding Ti to a steel for high heat input welding, page 9, a method of adding REM and B to a steel for high heat input welding, and a method of adding REM and B to a steel for high heat input welding, and a method of adding REM and B to a steel for high heat input welding, and a method of adding Ti to a steel for high heat input welding, and a method of adding Ti to a steel for high heat input welding, and a method of adding Ti to a steel for high heat input welding, and a method of adding Ti to a steel for high heat input welding. Monthly Iron and Steel Association 103rd Lecture Conference'82-8'638,56
39, a method of adding Ti and B in combination to steel for high heat input welding was proposed, and it was reported that the toughness of the joint was improved.
しかしながらこれらはいずれも靭性評価をシャルピー試
験の吸収エネルギーで評価しており、継手部のTNDT
について研究したものは見当らない。However, in all of these methods, the toughness is evaluated based on the absorbed energy of the Charpy test, and the TNDT of the joint is
I can't find any research on this.
したがってTNDTを確保するためにはどうすれば良い
のかについては定説がないのが実状である。Therefore, the reality is that there is no established theory as to what should be done to secure TNDT.
(発明が解決しようとする問題点)
本発明はこれらの問題を解決するため適切な鋼成分の組
合せにより、母材はもとより特に溶接継手部において?
ヤルピー試験に加えて近時要求の高いTNDTについて
、TNDT−aot:以下の高水準な靭性を満足する鋼
の提供を目的とする。(Problems to be Solved by the Invention) The present invention solves these problems by combining appropriate steel components, not only in the base metal but also in the welded joint in particular.
In addition to the Yalpie test, our objective is to provide a steel that satisfies the following high-level toughness for TNDT, which has been in high demand recently: TNDT-aot.
(発明の構成) 本発明は以上のような問題点を解決するための。(Structure of the invention) The present invention aims to solve the above problems.
種々実験の結果、(1)重量〃でc : o、os〜0
.20%、Si : 0.05〜0.50%、Mn=0
.50〜2.00%、V : 0.0054 〜0
.025%、Ti : 0.005〜0.015%、N
b : 0.005〜0.025%、Sol、 Al
: 0.01(1−0,040%、残部Feおよび不可
避不純物からなることを特徴とする溶接継学部靭性に優
れた鋼。As a result of various experiments, (1) weight c: o, os ~ 0
.. 20%, Si: 0.05-0.50%, Mn=0
.. 50-2.00%, V: 0.0054-0
.. 025%, Ti: 0.005-0.015%, N
b: 0.005-0.025%, Sol, Al
: 0.01 (1-0,040%, balance Fe and unavoidable impurities) A steel with excellent weld joint toughness.
(2)上記(1)にNi : 0.70%以下、Mo
: 0.30%以下、Cu : 0.50%以下の1種
又は2種以上含有せしめた溶接継学部靭性に優れた鋼と
して構成される。(2) In (1) above, Ni: 0.70% or less, Mo
Cu: 0.30% or less, Cu: 0.50% or less, and is constructed as a steel with excellent weld joint toughness.
次に各成分を定めた限定理由を述る。Next, the reasons for limiting each component will be described.
Cは強度保持上必要であり、0.05%未満では強度の
確保が困難になる。一方多量の添加は溶接継手の靭性に
悪影響を及ぼすため上限は0.20%とする。Siは脱
酸元素として有効であり、その効果を得るため0.05
%以上は必要である。Siも多量に添加すると溶接継手
の靭性を損うため上限は0.50%とする。C is necessary for maintaining strength, and if it is less than 0.05%, it will be difficult to ensure strength. On the other hand, the upper limit is set at 0.20% since addition of a large amount has a negative effect on the toughness of the welded joint. Si is effective as a deoxidizing element, and in order to obtain this effect, 0.05
% or more is necessary. If a large amount of Si is added, the toughness of the welded joint will be impaired, so the upper limit is set at 0.50%.
肚は強度確保のほか靭性向上にも有効な元素であり、0
.50%以上の添加が必要であるが、2.00%を超え
るとその効果は非常に小さくなるため2.00%を上限
とする。Calf is an element that is effective in securing strength and improving toughness.
.. It is necessary to add 50% or more, but if it exceeds 2.00%, the effect becomes very small, so 2.00% is the upper limit.
Tiは後に述べるNb、、■と共に本発明構成上重要な
元素であり、その適正範囲は以下のようになる。Ti is an important element in the composition of the present invention along with Nb, .
すなわち、Tiの添加は母材の靭性にはほとんど影響を
示さないが、溶接継手の靭性特にTNDTを大幅に改善
する。そしてこの効果は第2図に示すようにTi量が0
.005%以上で顕著となるが、0.015%を超すと
TNDTはかえって劣化する。このため適正範囲を0.
005〜0.015%とした。That is, although the addition of Ti has little effect on the toughness of the base metal, it significantly improves the toughness of the welded joint, especially TNDT. As shown in Figure 2, this effect occurs when the amount of Ti is 0.
.. 0.005% or more, but if it exceeds 0.015%, TNDT actually deteriorates. Therefore, the appropriate range is set to 0.
005 to 0.015%.
Nbは組織の細粒化効果があり、この効果により母材強
度の向上と靭性および溶接継手部のTNDT向上に有効
である。その効果はo、oos%以上でtR察されるが
、多くなると溶接継手の靭性を劣化するので上限を0.
025%とする。Nb has the effect of refining the structure, and this effect is effective in improving the base metal strength, toughness, and TNDT of the welded joint. The effect can be seen at tR above o, oos%, but if it increases, the toughness of the welded joint will deteriorate, so the upper limit should be set at 0.
025%.
■は母材強度の向上に有効であり、この効果は添加量0
.05%以上で認められるが、多くなると溶接継手部の
TNDTを劣化させるので0.025%以下とする。■ is effective in improving the strength of the base material, and this effect can be achieved with an addition amount of 0.
.. It is recognized at 0.05% or more, but if it increases, it deteriorates the TNDT of the welded joint, so it should be kept at 0.025% or less.
Sol、 Alは組織の細粒化を介して母材の靭性向上
に不可欠であり、その効果は0.010%以上で発揮さ
れる。一方0.040%を超えると介在物の生成等によ
る靭性の低下が起こるため上限は0.040%とする。Sol and Al are essential for improving the toughness of the base material through grain refinement, and their effects are exhibited at 0.010% or more. On the other hand, if it exceeds 0.040%, the toughness will decrease due to the formation of inclusions, so the upper limit is set to 0.040%.
本発明の鋼は圧力容器や原子炉格納容器、海洋構造物等
の素材を主用途とするもので引張強度で40〜60 k
gf/we”級の鋼種を含む、この強度レベルでも低い
範囲では上記の基本成分だけで十分であるが板厚が厚い
場合高い強度を得るには適当な強化成分の添加や熱処理
法の選択が必要である。このような強化成分は鋼の溶接
部継手靭性を劣化させないこと及び溶接性に悪影響を及
ぼさないことを考慮してその種類と量を決定しなければ
ならない。本発明ではその成分として0.7%以下のN
i、0.30%以下のMolo、5%以下のCuを選ん
だ。これらの成分はそれぞれの限定量以下で単独又は2
種以上組合せて添加されて鋼の強度上昇に寄与する。The steel of the present invention is mainly used as a material for pressure vessels, nuclear reactor containment vessels, marine structures, etc., and has a tensile strength of 40 to 60 k.
In the low strength range, including gf/we'' class steels, the above basic ingredients are sufficient, but in the case of thick plates, it is necessary to add appropriate reinforcing ingredients and select a heat treatment method to obtain high strength. The type and amount of such reinforcing components must be determined taking into consideration that they do not deteriorate the joint toughness of the welded joint of steel and do not have a negative effect on weldability.In the present invention, as the component N less than 0.7%
i, Molo of 0.30% or less, and Cu of 5% or less. These ingredients may be used singly or in combination within their respective limited amounts.
When added in combination, they contribute to increasing the strength of steel.
Niは強度向上に有効であるが、0.7%を越える必要
はなく、高価な元素であるためコスト上から0.7%以
下とする。Although Ni is effective in improving strength, it does not need to exceed 0.7%, and since it is an expensive element, it is set to 0.7% or less from cost considerations.
Moは特にPWHT (溶接後熱処理)後の母材強度確
保に有効であるが、多量に添加すると溶接継学部靭性を
損なうため0.30%以下とする。Cuは母材強度向上
に有効であるが、0.40%を越えると強度向上効果が
少なくなるので上限を0.40%とする。Mo is particularly effective in ensuring the strength of the base material after PWHT (post-weld heat treatment), but if added in a large amount, the toughness of the weld joint will be impaired, so the content should be 0.30% or less. Cu is effective in improving the strength of the base material, but if it exceeds 0.40%, the strength improving effect decreases, so the upper limit is set to 0.40%.
尚、不可避不純物としてのP、Sは特に限定されないが
偏析及び介在物の形成により鋼の材質を悪化させるので
それぞれ0.010%以下に抑制することが好ましい。Although P and S as unavoidable impurities are not particularly limited, it is preferable to suppress each to 0.010% or less since they deteriorate the quality of the steel due to segregation and formation of inclusions.
しかして上記の成分を含む本発明鋼は熱間圧延のままで
も、又、熱延後、焼ならし、焼もどし、或いは焼入−焼
もどしの熱処理を行っても、及び熱延後オンライン制御
冷却酸いは制御冷却後続もどし等の熱処理を行っても優
れた溶接継平部靭性を備える。Therefore, the steel of the present invention containing the above components can be used as hot-rolled, or after hot-rolled, normalized, tempered, or quenched-tempered heat treated, and after hot-rolled online control. Cooled acid has excellent weld joint toughness even after heat treatment such as controlled cooling and subsequent recovery.
したがって圧延後熱処理を行うか否か或いはどんな熱処
理を施すかは鋼材に要求される強度、靭性等の機械的性
質の面から決定すればよい。Therefore, whether or not to perform post-rolling heat treatment, and what kind of heat treatment to perform, can be determined from the viewpoint of mechanical properties such as strength and toughness required of the steel material.
(発明の作用)
従来の靭性向上研究の多くはシャルピー試験を指標に行
なわれてきている。このシャルピー試験値とTNDTは
母材ではかなりの相関を持つとされているが溶接継手部
についての検討例は非常に少なく、本発明者等の経験か
らも両者の相関は非常に悪く、従来の知見から溶接継手
部のTNDT向上を図イ ることは困難で
ある。(Action of the Invention) Most conventional studies on improving toughness have been conducted using the Charpy test as an indicator. This Charpy test value and TNDT are said to have a considerable correlation in the base metal, but there are very few studies on welded joints, and from the experience of the present inventors, the correlation between the two is very poor, and the conventional Based on knowledge, it is difficult to improve the TNDT of welded joints.
本発明者等の検討によれば溶接継手部のTNDTを向上
させるためには落電試験時に脆性亀裂が伝播するHAZ
(溶接時に生じる溶接熱影響部)の亀裂伝播停止靭性
を向上させることが重要なポイントであることが分った
。According to the study by the present inventors, in order to improve the TNDT of welded joints, it is necessary to
It was found that an important point is to improve the crack propagation arresting toughness of the weld heat affected zone (which occurs during welding).
すなわち、第1図に示すように機械切欠1から発生する
脆性亀裂7が伝播するHAZは2種類に区分される。そ
の1は焼入れ状態で存在する溶接熱影響部(これをHA
ZIとする)で、図中5がそれである。もう1つはHA
ZIが次の溶接パスで焼もどしを受けた状態で存在する
熱影響部(これをHAZIIとする)で1図中6がそれ
である。That is, as shown in FIG. 1, the HAZ in which the brittle crack 7 generated from the mechanical notch 1 propagates is classified into two types. The first is the weld heat affected zone (HA) that exists in the quenched state.
ZI), and 5 in the figure is it. The other is HA
ZI is a heat-affected zone (this is referred to as HAZII) that exists in a state where it has been tempered in the next welding pass, and 6 in Fig. 1 is the heat-affected zone.
尚、図中2はASTM E208に従って形成した落
電試験片の脆化ビード、3は溶接継手の溶接金属、4は
母材、tは落電試験片厚さを示す。In the figure, 2 indicates the embrittlement bead of the electric drop test piece formed according to ASTM E208, 3 the weld metal of the welded joint, 4 the base material, and t the thickness of the electric drop test piece.
しかして溶接継手部のTNDTを向上させるためにはH
AZI 、HAZn両者の亀裂伝播停止靭性を向上させ
る必要がある。このため種々冶金因子の影響を検討した
結果、以下のことが判明した。However, in order to improve the TNDT of the welded joint, H
It is necessary to improve the crack propagation arresting toughness of both AZI and HAZn. For this reason, as a result of examining the influence of various metallurgical factors, the following was found.
すなわちHAZIの靭性向上のためにはTiの添加が有
効である。第2図はC: 0.05〜0.20%、Si
: 0.05〜0.50%、Mn : 0.50〜2.
00%、v二〇、OO5〜0.025%、Nb : 0
.005〜0.025%、Sol、 At : 0.0
10〜0.040%の範囲で含有しTi添加量を種々変
えた鋼を用い、熱間圧延後続ならし熱処理を施した鋼板
を試料とし、相当入熱45KJ/lxrの再現熱サイク
ル(HAZIに相当)を与えた後−60℃でのプレスノ
ツチシャルピー吸収エネルギーとTi添加量の関係を示
したものである。That is, addition of Ti is effective for improving the toughness of HAZI. Figure 2 shows C: 0.05-0.20%, Si
: 0.05-0.50%, Mn: 0.50-2.
00%, v20, OO5~0.025%, Nb: 0
.. 005-0.025%, Sol, At: 0.0
Using steel sheets containing various amounts of Ti in the range of 10 to 0.040% and subjected to hot rolling and subsequent conditioning heat treatment, the samples were subjected to a simulated thermal cycle (HAZI) with an equivalent heat input of 45 KJ/lxr. This figure shows the relationship between the press notch Charpy absorbed energy and the amount of Ti added at -60° C. after applying an equivalent amount of Ti.
なおここでをプレスノツチシャルピーを実施した理由は
一般に行なわれるVノツチシャルピーカて亀裂発生時の
靭性を示すの対し、プレスノツチシャルピーは亀裂伝播
停止靭性を示すからである。The reason why press notch Charpy was carried out here is that while V-notch Charpy, which is generally performed, shows the toughness at the time of crack initiation, press notch Charpy shows the toughness at which crack propagation is stopped.
図から明白な如く、Tiを0.005〜o、ois%の
範囲で添加すると靭性が向上することが分る。この理由
はTiの適量添加によりHAZIの組織が細かくなりそ
の結果核部の亀裂伝播停止靭性が向上したも。As is clear from the figure, it can be seen that adding Ti in the range of 0.005 to 0.05% improves the toughness. The reason for this is that by adding an appropriate amount of Ti, the structure of HAZI becomes finer, which improves the crack propagation arresting toughness of the core.
のである。It is.
一方、HAZI[の靭性向上に対する冶金因子の関係を
調査するため上記HAZIの入熱45KJ/(至)相当
熱サイクルを与えた試料に650℃5秒間保持の焼戻し
を施して一60℃でのプレスノツチシャルピー吸収エネ
ルギーを調査し第1表を結果を得た。On the other hand, in order to investigate the relationship of metallurgical factors to the improvement of toughness of HAZI, the above-mentioned HAZI sample subjected to a heat input of 45 KJ/(to) equivalent thermal cycle was tempered at 650°C for 5 seconds and then pressed at -60°C. The Notch Charpy absorbed energy was investigated and the results shown in Table 1 were obtained.
第1表
(注1)熱サイクル条件二人熱45Kj/C相当熱サイ
クル+650℃X5sec焼戻し
く注2) PE−ao ニー60℃のプレス
ノツチシャルピー吸収エネルギー
HAZnの靭性向上に対しては第1表に示すようにC量
の上限を低く抑えると共にNbおよび■を複合添加する
ことが有効である。この理由はNb。Table 1 (Note 1) Heat cycle conditions Two-person heat cycle equivalent to 45 Kj/C + 650°C x 5 sec tempering Note 2) PE-ao knee press notch at 60°C As shown in Figure 2, it is effective to keep the upper limit of the amount of C low and to add Nb and (2) in combination. The reason for this is Nb.
■の微量複合添加によりHAZIIの炭化物が微細に分
散すると共に組織が細粒化し亀裂伝播停止靭性が向上す
るからである。そしてこの効果はNb。This is because the addition of a small amount of compound (2) causes the carbides of HAZII to be finely dispersed and the structure to be fine-grained, thereby improving crack propagation arresting toughness. And this effect is Nb.
Vとも0.05〜0.025%において良好に発揮され
る。V is well exhibited at 0.05 to 0.025%.
以上の結果からTi : 0.005〜0.015%、
V : 0.005〜0.0025%、Nb : 0.
005〜0.025%にコントロールして添加するとH
AZ I、HAZIIとも高い亀裂伝播停止靭性が得ら
れ、その結果溶接継手のTNDTが非常に優れた値を示
す。From the above results, Ti: 0.005 to 0.015%,
V: 0.005-0.0025%, Nb: 0.
When added in a controlled manner at 0.005 to 0.025%,
Both AZ I and HAZ II have high crack propagation arrest toughness, and as a result, the welded joints exhibit very excellent TNDT values.
(実施例)
厚板圧延して得た鋼板の化学成分を第2表に示し熱処理
種別と得られた機械的性質を第3表に示す。(Example) Table 2 shows the chemical composition of the steel plate obtained by rolling a thick plate, and Table 3 shows the type of heat treatment and the mechanical properties obtained.
第2表及び第3表に示すように鋼F−Hは本願第1発明
の実施例、鋼1〜Nは本願第2発明の実施例を示し、何
わもTuor−aot”を越える良好な継手部靭性を備
えている。As shown in Tables 2 and 3, steels F-H are examples of the first invention of the present application, and steels 1 to N are examples of the second invention of the present application, which have excellent properties exceeding Tuor-aot. The joint has good toughness.
これに対し鋼0−Qは第1発明の比較例、鋼R〜Uは第
2発明の比較例を示すが、鋼0はTiを含有せずNb含
有量が多いため、鋼PはV、Tiを含有しないため、鋼
QはV、Nb含有量が多すぎるため何れも継手部のTN
DTが悪い。On the other hand, steels 0-Q are comparative examples of the first invention, steels R to U are comparative examples of the second invention, but since steel 0 does not contain Ti and has a high Nb content, steel P has V, Since steel Q does not contain Ti, the V and Nb contents are too high, so both TN at the joint part
DT is bad.
また#sRはV、Tiを含有していないため、鋼SはC
含有量が高すぎることのほかTiを含有しないため、鋼
TはC,Nb含有量が高いことのほかVを含有しないた
め、鋼UはC,Noが高いことのほか’J 、 Ti、
Nbを含有しないため、何れも継手部のTNDTが悪
い。Also, since #sR does not contain V or Ti, steel S is C
Besides having too high a content, it does not contain Ti; steel T has a high C and Nb content and does not contain V; steel U has a high C and No content, as well as 'J, Ti,
Since they do not contain Nb, the TNDT of the joints is poor.
(発明の効果)
本発明は鋼中にTi、 Nb、 Vを複合添加すること
により特に溶接継手部のTNDTを向上しうろことを見
い出し、40〜60 kg3/mm2級鋼で近時要求の
高いTNDT−3ot:以下の高い継手部靭性を備えた
鋼板を安価に提供できるようになしたもので産業上益す
るところまことに大きい効果を奏するものである。(Effects of the Invention) The present invention has found that the TNDT of welded joints can be improved by adding Ti, Nb, and V in a composite manner to the steel, and it has been found that the TNDT of the welded joint can be improved, which is highly demanded in 40-60 kg3/mm2 class steel. TNDT-3ot: A steel plate with the following high joint toughness can be provided at a low cost, and it has great industrial benefits.
第1図は溶接継手部の落電試験における脆性亀裂の進展
面と進展面上の組織の関係を説明する模式図、
第2図はHAZI部脆性亀裂伝播停止靭性とTi含有量
の関係を示す説明図である。
1・・・機械切欠
2・・・落電試験片の脆化ビード
3・・・溶接継手の溶接金属
4・・・母材
5−・・溶接熱影響部(HAZI)
6・・・溶接熱影響部(HAZII)
7・・・脆性亀裂
t・・・落電試験片厚さ
第1図
口 :HAIZ(718誇に生
U゛う熱影響部)
口:HA’lπ(HAII:It”’次の1、
784咄四/マズ乙”itと゛さφc−1イト)第2図
?
Ti (%)Figure 1 is a schematic diagram illustrating the relationship between the brittle crack propagation surface and the structure on the propagation surface in an electric drop test of a welded joint. Figure 2 shows the relationship between brittle crack propagation arrest toughness and Ti content in the HAZI part. It is an explanatory diagram. 1... Mechanical notch 2... Brittle bead of electric drop test piece 3... Weld metal of welded joint 4... Base metal 5 - Weld heat affected zone (HAZI) 6... Welding heat Affected zone (HAZII) 7...Brittle crack t...Electrical drop test specimen thickness Figure 1 Opening: HAIZ (Heat affected zone that is proudly produced in 718) Opening: HA'lπ (HAII: It"' Next 1,
784 咄4/Mazutsu"it and ゛saφc-1ite) Figure 2? Ti (%)
Claims (2)
05〜0.50%、Mn:0.50〜2.00%、V:
0.005〜0.025%、Ti:0.005〜0.0
15%、Nb:0.005〜0.025%、Sol.A
l:0.010〜0.040%、残部Feおよび不可避
不純物からなることを特徴とする溶接継手部靭性に優れ
た鋼(1) C: 0.05-0.20%, Si: 0.0% by weight.
05-0.50%, Mn: 0.50-2.00%, V:
0.005-0.025%, Ti: 0.005-0.0
15%, Nb: 0.005-0.025%, Sol. A
A steel with excellent weld joint toughness characterized by having l: 0.010 to 0.040%, the balance being Fe and unavoidable impurities.
5〜0.50%、Mn:0.50〜2.00%、V:0
.005〜0.025%、Ti:0.005〜0.01
5%、Nb:0.005〜0.025%、Sol.Al
:0.010〜0.040%、およびNi:0.70%
以下、Mo:0.30%以下、Cu:0.50%以下の
1種又は2種以上残部Feおよび不可避不純物からなる
ことを特徴とする溶接継手部靭性に優れた鋼。(2) C: 0.05-0.20%, Si: 0.0 by weight
5-0.50%, Mn: 0.50-2.00%, V: 0
.. 005-0.025%, Ti: 0.005-0.01
5%, Nb: 0.005-0.025%, Sol. Al
:0.010~0.040%, and Ni:0.70%
Hereinafter, a steel having excellent welded joint toughness characterized by comprising one or more of Mo: 0.30% or less, Cu: 0.50% or less, the balance being Fe and unavoidable impurities.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11911784A JPS61560A (en) | 1984-06-12 | 1984-06-12 | Steel having superior toughness at welded joint |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11911784A JPS61560A (en) | 1984-06-12 | 1984-06-12 | Steel having superior toughness at welded joint |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS61560A true JPS61560A (en) | 1986-01-06 |
Family
ID=14753349
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP11911784A Pending JPS61560A (en) | 1984-06-12 | 1984-06-12 | Steel having superior toughness at welded joint |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS61560A (en) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5524935A (en) * | 1978-08-10 | 1980-02-22 | Nippon Kokan Kk <Nkk> | Manufacture of high tensile hot rolled steel plate having excellent low-temperature toughness |
JPS58171526A (en) * | 1982-03-31 | 1983-10-08 | Nippon Steel Corp | Manufacture of steel for extra-low temperature use |
JPS5923854A (en) * | 1982-07-28 | 1984-02-07 | Nippon Steel Corp | High tension steel having superior property for stopping transmission of brittle fracture |
-
1984
- 1984-06-12 JP JP11911784A patent/JPS61560A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5524935A (en) * | 1978-08-10 | 1980-02-22 | Nippon Kokan Kk <Nkk> | Manufacture of high tensile hot rolled steel plate having excellent low-temperature toughness |
JPS58171526A (en) * | 1982-03-31 | 1983-10-08 | Nippon Steel Corp | Manufacture of steel for extra-low temperature use |
JPS5923854A (en) * | 1982-07-28 | 1984-02-07 | Nippon Steel Corp | High tension steel having superior property for stopping transmission of brittle fracture |
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