JPH10130778A - Fine grain dispersed type steel for large heat input welding - Google Patents
Fine grain dispersed type steel for large heat input weldingInfo
- Publication number
- JPH10130778A JPH10130778A JP29061196A JP29061196A JPH10130778A JP H10130778 A JPH10130778 A JP H10130778A JP 29061196 A JP29061196 A JP 29061196A JP 29061196 A JP29061196 A JP 29061196A JP H10130778 A JPH10130778 A JP H10130778A
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- Prior art keywords
- steel
- heat input
- large heat
- dispersed
- toughness
- 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
【０００１】[0001]
【発明が属する技術分野】この発明は、構造物に用いて
好適な溶接構造用鋼材に関し、とくに大入熱溶接特性の
優れた引張強さ400 〜600MPa級溶接構造用鋼材に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel material for a welded structure suitable for use in a structure, and more particularly to a steel material for a welded structural material having excellent heat input welding characteristics and a tensile strength of 400 to 600 MPa.
【０００２】[0002]
【従来の技術】近年、船舶、海洋構造物等の大型構造物
に使用される溶接構造用鋼材の材質特性に対する要望は
厳しさを増しており、母材特性のみでなく、溶接熱影響
部靱性が優れていることが要求されている。とくに、構
造物の大型化に伴い、溶接作業の効率化を促進するた
め、片面１パス溶接法のような大入熱溶接法の適用が不
可欠となっている。このため、優れた大入熱溶接特性を
有する鋼材が要望されていた。2. Description of the Related Art In recent years, demands for material properties of steel materials for welded structures used for large structures such as ships and marine structures have been increasing strictly. Is required to be excellent. In particular, with the increase in the size of the structure, application of a large heat input welding method such as a single-sided single-pass welding method is indispensable in order to promote the efficiency of welding work. For this reason, a steel material having excellent large heat input welding characteristics has been demanded.
【０００３】大入熱溶接においては、溶接熱影響部（HA
Z 部）のオーステナイト（γ）粒が粗大化し、靱性が劣
化する。HAZ 部のγ粒粗大化を抑制し、HAZ 部靱性を向
上させるためには、鋼中に微細粒子を析出あるいは分散
させることが有効であることが知られている。この方法
は、微細粒子による、γ粒界のピンニング作用や、γ→
α変態核生成サイトとしての作用を利用してHAZ 部組織
の微細化を図ろうとするものである。In large heat input welding, the heat affected zone (HA)
The austenite (γ) grains in the (Z part) are coarsened and the toughness is deteriorated. It is known that precipitation or dispersion of fine particles in steel is effective in suppressing the coarsening of γ grains in the HAZ portion and improving the toughness of the HAZ portion. This method uses the pinning action of the γ grain boundary by the fine particles and the γ →
The aim is to refine the microstructure of the HAZ using the action of the α transformation nucleation site.
【０００４】例えば、特公昭55-26164号公報には、微細
なTiN を鋼中に析出させることによりHAZ 部のγ粒を微
細化し靱性を向上させる方法が提案されている。しかし
ながら、TiN は1400℃を超える高温まで加熱される溶接
ボンド部近傍ではほとんど固溶してしまうため、この方
法では溶接ボンド部近傍の靱性劣化を抑制することは困
難であるという問題があった。[0004] For example, Japanese Patent Publication No. 55-26164 proposes a method of precipitating fine TiN in steel to refine the γ grains in the HAZ to improve the toughness. However, TiN almost completely forms a solid solution in the vicinity of the weld bond portion heated to a high temperature exceeding 1400 ° C., and therefore, there is a problem that it is difficult to suppress the toughness deterioration in the vicinity of the weld bond portion by this method.
【０００５】このような溶接ボンド部の靱性劣化を抑制
するために、鋼中に分散させる微細粒子として酸化物が
利用されるようになった。例えば、特開昭58-204116 号
公報には、REM とＢを添加して大入熱溶接部のHAZ 部靱
性を向上させた大入熱溶接構造用鋼が提案されている。
この鋼では、鋼中にREM オキシサルファイド粒子を微細
に分散させることにより、この粒子を核にBN粒子が析出
し、これら粒子がフェライト変態核として作用し、HAZ
部靱性が向上するというものである。[0005] In order to suppress such toughness degradation of the weld bond, oxides have come to be used as fine particles dispersed in steel. For example, Japanese Patent Application Laid-Open No. 58-204116 proposes a large heat input welding structural steel in which REM and B are added to improve the HAZ toughness of a large heat input weld.
In this steel, by dispersing REM oxysulfide particles finely in the steel, BN particles precipitate at the core of these particles, and these particles act as ferrite transformation nuclei, and HAZ
The toughness is improved.
【０００６】また、鋼中に分散させる微細粒子として、
特開昭57-51243号公報には TiOX （X=0.65〜1.3)が、特
開昭61-213322 号公報にはTiO およびTiO2が、特開昭60
-77958号公報には、Al2O3 が開示されている。さらに、
特開平1-159356号公報には、TiとZrを同時に添加し、鋼
中に粒子径が0.05〜10μm のTiとZrの複合酸化物を形成
し、分散させた溶接熱影響部靱性の優れた高張力鋼が提
案されている。また、特開平1-180948号公報には、粒子
径が0.1 〜3.0 μm のMnを固溶したTi酸化物（Ti2O3 ,T
i3O5）とこれら酸化物とTiN 、MnS の複合体を分散させ
た溶接部靱性の優れた低温用高張力鋼が、特開平1-1917
65号公報には、粒子径が0.1 〜3.0 μm のMnを固溶した
Ti酸化物（Ti2O3 ,Ti3O5）とMnS の複合体を分散させた
溶接部靱性の優れた低温用高張力鋼が、特開平7-268540
号公報には、粒子径が0.01〜1.0 μm のTiとAlの複合酸
化物を分散させた溶接用低温用鋼が提案されている。Further, as fine particles dispersed in steel,
JP-A-57-51243 discloses TiO X (X = 0.65 to 1.3), JP-A-61-213322 discloses TiO and TiO 2 ,
-77958 discloses Al 2 O 3 . further,
Japanese Patent Application Laid-Open No. 1-159356 discloses that Ti and Zr are simultaneously added to form a composite oxide of Ti and Zr having a particle diameter of 0.05-10 μm in steel, and the welded heat-affected zone toughness is excellently dispersed. High strength steel has been proposed. Japanese Patent Application Laid-Open No. 1-180948 discloses a Ti oxide (Ti 2 O 3 , T 2) having a solid solution of Mn having a particle diameter of 0.1 to 3.0 μm.
i 3 O 5) and these oxides and TiN, high tensile steel excellent low temperature of the weld zone toughness by dispersing a complex of MnS is, JP-A-1-1917
No. 65 discloses a solid solution of Mn having a particle size of 0.1 to 3.0 μm.
Japanese Patent Laid-Open No. 7-268540 discloses a low-temperature high-strength steel having excellent weld toughness in which a composite of Ti oxide (Ti 2 O 3 , Ti 3 O 5 ) and MnS is dispersed.
In Japanese Patent Application Laid-Open Publication No. H11-157, a low-temperature welding steel in which a composite oxide of Ti and Al having a particle size of 0.01 to 1.0 μm is dispersed is proposed.
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、これら
の酸化物を分散させた鋼材において、分散させた酸化物
の効果を十分発揮させるためには、製鋼工程における脱
酸、成分添加方法や、圧延工程における熱履歴等を厳密
に制御する必要があるが、酸化物の性能を安定して得る
ことが困難で、鋼材の大入熱溶接特性のばらつきが大き
い場合や、さらに、酸化物の分散により大入熱溶接特性
以外の鋼材特性に悪影響を及ぼすといった問題があっ
た。However, in a steel material in which these oxides are dispersed, in order to sufficiently exert the effect of the dispersed oxides, a method of deoxidizing and adding components in a steel making process, a rolling process, and the like. It is necessary to strictly control the heat history, etc., at the same time, but it is difficult to obtain the performance of the oxide stably, and when the dispersion of the large heat input welding characteristics of the steel material is large, There was a problem that the steel material properties other than the heat input welding properties were adversely affected.
【０００８】また、従来提案されている分散粒子では、
フェライト生成作用が十分でなく、十分な組織微細化が
達成できていないという問題が残されていた。本発明
は、上記した問題点を有利に解決し、微細粒子を分散さ
せ、溶接熱影響部靱性が優れた大入熱溶接用鋼材を提供
することを目的とする。[0008] Further, in the conventionally proposed dispersed particles,
There remains a problem that the ferrite generating action is not sufficient and sufficient structure refinement has not been achieved. An object of the present invention is to provide a steel material for large heat input welding that advantageously solves the above-mentioned problems, disperses fine particles, and has excellent weld heat affected zone toughness.
【０００９】[0009]
【課題を解決するための手段】本発明者らは、鋼中での
微細粒子のフェライト生成作用について鋭意検討した結
果、SiおよびＢを含有する鋼に微細なTiMnO3粒子を分散
させることにより、大入熱溶接の熱影響部においても、
微細な粒内フェライトが生成し組織が微細化され、大入
熱溶接部靱性が向上することを新たに知見した。Means for Solving the Problems The present inventors have conducted intensive studies on the ferrite generation action of fine particles in steel, and as a result, by dispersing fine TiMnO 3 particles in steel containing Si and B, Even in the heat affected zone of large heat input welding,
It was newly found that fine intragranular ferrite was formed, the structure was refined, and the toughness of a large heat input weld was improved.
【００１０】本発明は、上記した知見をもとに完成され
たものである。すなわち、本発明は、mass％で、Ｃ：0.
02〜0.15％、Si：0.10〜0.40％、Mn：0.50〜1.80％、
Ｐ：0.020 ％以下、Ｓ：0.005 ％以下、Ｂ：0.0005〜0.
0030％、かつ粒径0.05〜1.5 μm のTiMnO3粒子を0.0010
〜0.05％の割合で鋼中に分散させ、残部Feおよび不可避
的不純物からなることを特徴とする微細粒子分散型大入
熱溶接用鋼材である。The present invention has been completed based on the above findings. That is, in the present invention, in mass%, C: 0.
02 to 0.15%, Si: 0.10 to 0.40%, Mn: 0.50 to 1.80%,
P: 0.020% or less, S: 0.005% or less, B: 0.0005-0.
0030% and TiMnO 3 particles having a particle size of 0.05-1.5 μm
It is a steel material for high heat input welding with fine particles dispersed therein, characterized by being dispersed in steel at a ratio of about 0.05% and comprising a balance of Fe and unavoidable impurities.
【００１１】また、本発明では、上記組成に加え、mass
％で、Ni：0.05〜5.0 ％、Cu：0.05〜1.0 ％、Cr：0.05
〜1.0 ％、Mo：0.05〜1.0 ％のうちから選ばれた１種ま
たは２種以上および／またはNb：0.02〜0.10％、Ｖ：0.
02〜0.10％のうちから選ばれた１種または２種を含有し
てもよい。In the present invention, in addition to the above composition,
%, Ni: 0.05-5.0%, Cu: 0.05-1.0%, Cr: 0.05
-1.0%, Mo: 0.05-1.0%, one or more selected from among them, and / or Nb: 0.02-0.10%, V: 0.
One or two selected from 02 to 0.10% may be contained.
【００１２】[0012]
【発明の実施の形態】本発明鋼材の成分組成の限定理由
について説明する。 Ｃ：0.02〜0.15％ Ｃは鋼の強度を増加させる元素であり、構造用部材とし
て十分な強度を確保するためには0.02％以上の含有を必
要とする。しかし、0.15％を超えると、溶接性が劣化す
る。このため、Ｃは0.02〜0.15％の範囲に限定した。DESCRIPTION OF THE PREFERRED EMBODIMENTS The reasons for limiting the composition of the steel material of the present invention will be described. C: 0.02 to 0.15% C is an element that increases the strength of steel, and it is necessary to contain 0.02% or more in order to secure sufficient strength as a structural member. However, if it exceeds 0.15%, the weldability deteriorates. For this reason, C was limited to the range of 0.02 to 0.15%.
【００１３】Si：0.10〜0.40％ Siは、本発明において重要な元素である。Siは、大入熱
溶接時の熱サイクル中にTiMnO3粒子の周りにSiO2を主体
としたSi、Mn系複合酸化物として析出し、粒内フェライ
ト生成の核として、γ→α変態を促進する作用を有し、
組織を微細化する。この効果を得るためには、0.10％以
上の添加を必要とするが、0.40％を超えると、溶接性が
劣化する。このため、Siは0.10〜0.40％の範囲に限定し
た。Si: 0.10 to 0.40% Si is an important element in the present invention. Si is, Si mainly containing SiO 2 around TiMnO 3 particles in the thermal cycle during high heat input welding, precipitated as Mn-based composite oxide, as nuclei for intragranular ferrite formation, promote gamma → alpha transformation Has the action of
Refine the tissue. To obtain this effect, it is necessary to add 0.10% or more, but if it exceeds 0.40%, the weldability deteriorates. For this reason, Si was limited to the range of 0.10 to 0.40%.
【００１４】Mn：0.50〜1.80％ Mnは焼入れ性を向上させ、強度を増加させる元素であ
る。構造用部材として十分な強度を確保するためには0.
50％以上の含有を必要とするが、1.80％を超えると、溶
接性が劣化する。このため、Mnは0.50〜1.80％の範囲に
限定した。なお、好ましくは0.60〜1.50％である。Mn: 0.50 to 1.80% Mn is an element that improves the hardenability and increases the strength. To ensure sufficient strength for structural members
A content of 50% or more is required, but if it exceeds 1.80%, the weldability deteriorates. For this reason, Mn was limited to the range of 0.50 to 1.80%. In addition, it is preferably 0.60 to 1.50%.
【００１５】Ｐ：0.020 ％以下 Ｐは靱性、溶接性を劣化させる元素であり、できるだけ
低減するのが望ましいが、0.020 ％までは許容できる。
したがって、Ｐは0.020 ％以下に限定した。 Ｓ：0.005 ％以下 ＳはＰと同様に靱性、溶接性を劣化させる元素であり、
できるだけ低減するのが望ましいが、0.005 ％までは許
容できる。したがって、Ｓは0.005 ％以下に限定した。P: 0.020% or less P is an element that deteriorates toughness and weldability, and it is desirable to reduce P as much as possible, but up to 0.020% is acceptable.
Therefore, P is limited to 0.020% or less. S: 0.005% or less S is an element that deteriorates toughness and weldability like P,
It is desirable to reduce as much as possible, but up to 0.005% is acceptable. Therefore, S is limited to 0.005% or less.
【００１６】Ｂ：0.0005〜0.0030％ Ｂは、Siとともに本発明では重要な元素である。Ｂはγ
粒界に偏析し、γ粒界からのフェライトの生成を抑制
し、γ粒内からの微細な粒内フェライトの生成を促進す
る。この効果を得るためには0.0005％以上の添加を必要
とするが、0.0030％を超えると靱性が劣化する。このた
め、Ｂは0.0005〜0.0030％の範囲に限定した。なお、好
ましくは0.0010〜0.0025％である。B: 0.0005 to 0.0030% B is an important element in the present invention together with Si. B is γ
Segregates at the grain boundaries, suppresses the formation of ferrite from the γ grain boundaries, and promotes the formation of fine intragranular ferrite from within the γ grains. To obtain this effect, 0.0005% or more must be added, but if it exceeds 0.0030%, toughness deteriorates. For this reason, B was limited to the range of 0.0005 to 0.0030%. In addition, it is preferably 0.0010 to 0.0025%.
【００１７】TiMnO3粒子：0.0010〜0.05％ TiMnO3粒子は、微細粒子として鋼中に分散して、溶接時
の熱サイクル中にSi、Mn系酸化物をその周りに析出させ
てSi、Mn系酸化物とともに粒内フェライトの核生成サイ
トとして作用し、溶接部の組織の微細化に寄与する。こ
の効果を得るためには、0.0010％以上の添加が必要であ
るが、0.05％を超えると、靱性が劣化する。このため、
TiMnO3粒子の添加量は0.0010〜0.05％の範囲に限定し
た。また、添加するTiMnO3粒子は粒径0.05〜1.5 μm の
範囲の粒子に限定される。粒径が0.05μm 未満、あるい
は1.5 μm を超えると、粒内フェライトの核生成サイト
として機能しなくなる。このため、TiMnO3粒子の粒径は
0.05〜1.5 μm の範囲に限定した。TiMnO 3 particles: 0.0010 to 0.05% TiMnO 3 particles are dispersed in steel as fine particles, and Si and Mn-based oxides are precipitated around the heat cycle during welding to precipitate Si and Mn-based oxides. Together with the oxide, it acts as a nucleation site for intragranular ferrite and contributes to the refinement of the structure of the weld. In order to obtain this effect, 0.0010% or more must be added, but if it exceeds 0.05%, toughness deteriorates. For this reason,
The addition amount of TiMnO 3 particles was limited to the range of 0.0010 to 0.05%. Further, TiMnO 3 particles to be added are limited to particles having a particle size in the range of 0.05 to 1.5 μm. If the grain size is less than 0.05 μm or more than 1.5 μm, it will not function as a nucleation site for intragranular ferrite. Therefore, the particle size of the TiMnO 3 particles is
The range was limited to the range of 0.05 to 1.5 μm.
【００１８】なお、TiMnO3粒子の鋼中への分散は、TiMn
O3粒子粉末とFe粉等の金属粉を混合し圧粉体として出鋼
直前あるいは、凝固直前の溶鋼中に添加し分散させるの
が好ましい。本発明では、上記組成に加え、必要に応
じ、Ni、Cu、Cr、Moのうちから選ばれた１種または２種
以上および／またはNb、Ｖのうちから選ばれた１種また
は２種を含有してもよい。The dispersion of TiMnO 3 particles in steel is based on TiMnO 3.
It is preferable that the O 3 particle powder and a metal powder such as Fe powder are mixed and added as a green compact to a molten steel immediately before tapping or immediately before solidification and dispersed. In the present invention, in addition to the above composition, if necessary, one or more selected from Ni, Cu, Cr, and Mo and / or one or two selected from Nb, V May be contained.
【００１９】Ni：0.05〜5.0 ％、Cu：0.05〜1.0 ％、C
r：0.05〜1.0 ％、Mo：0.05〜1.0 ％のうちから選ばれ
た１種または２種以上 Niは焼入れ性を向上させ、さらに靱性を向上させる有効
な元素であるが、0.05％未満の添加ではその効果が認め
られない。しかし、5.0 ％を超えて添加しても、効果が
飽和するうえ、高価となるため経済的に不利となる。こ
のため、Niは0.05〜5.0 ％の範囲に限定した。Ni: 0.05-5.0%, Cu: 0.05-1.0%, C
r: 0.05 to 1.0%, Mo: 0.05 to 1.0% One or more selected from Ni Ni is an effective element for improving hardenability and further improving toughness, but less than 0.05% is added. Does not show that effect. However, the addition of more than 5.0% saturates the effect and increases the cost, which is economically disadvantageous. For this reason, Ni is limited to the range of 0.05 to 5.0%.
【００２０】Cu、Cr、Moは、いずれも焼入れ性を向上さ
せる元素であり、母材の強度を増加させるのに有効であ
るが、0.05％未満ではその効果が認められない。また、
1.0％を超えて添加すると、溶接部の靱性を劣化させ
る。このため、Cu、Cr、Moとも0.05〜1.0 ％の範囲に限
定した。 Nb：0.02〜0.10％、Ｖ：0.02〜0.10％のうちから選ばれ
た１種または２種 Nb、Ｖは、いずれも炭窒化物を形成して、組織を微細化
させ、強度と靱性を向上させるのに有効であるが、0.02
％未満ではその効果が認められない。また、0.10％を超
えて添加すると、靱性を劣化させる。このため、Nb、Ｖ
は、ともに0.02〜0.10％の範囲に限定した。Cu, Cr, and Mo are all elements that improve the hardenability and are effective in increasing the strength of the base material, but the effect is not recognized at less than 0.05%. Also,
If added in excess of 1.0%, the toughness of the weld is degraded. For this reason, Cu, Cr and Mo are all limited to the range of 0.05 to 1.0%. Nb: 0.02 to 0.10%, V: One or two selected from 0.02 to 0.10% Nb and V both form carbonitrides, refine the structure and improve strength and toughness Effective to get
%, The effect is not recognized. Further, if added in excess of 0.10%, the toughness is deteriorated. Therefore, Nb, V
Are limited to the range of 0.02 to 0.10%.
【００２１】その他、残部Feおよび不可避的不純物であ
る。なお、Alは強力な脱酸元素であり、過剰に添加する
と溶鋼中の溶存酸素が低減し、添加したTiMnO3が分解さ
れるため、好ましくは0.08％以下に制限するのが望まし
い。また、Ｎは、過剰に含有するとＢと結合し有効な固
溶Ｂが減少しγ粒界からの粗大フェライトが生成しやす
くなるため、Ｎは0.010 ％以下に制限するのが望まし
い。Others are Fe and inevitable impurities. Note that Al is a strong deoxidizing element, and if added excessively, the dissolved oxygen in the molten steel is reduced and the added TiMnO 3 is decomposed, so that it is preferable to limit the content to 0.08% or less. If N is contained excessively, N bonds with B and effective solid solution B decreases, so that coarse ferrite from the γ grain boundary is easily generated. Therefore, it is desirable to limit N to 0.010% or less.
【００２２】本発明鋼の溶製方法は、通常公知の溶製方
法がいずれも好適に用いることができ、特に限定しな
い。例えば、転炉、電気炉、真空溶解炉等で、上記組成
の溶鋼を溶製し、連続鋳造法あるいは造塊法で凝固させ
るのが好ましい。さらに、転炉、電気炉等で溶製したの
ち、取鍋でさらに真空脱ガス等の精錬を行っても良い。The method of smelting the steel of the present invention is not particularly limited, and any known smelting method can be suitably used. For example, it is preferable that molten steel having the above composition is melted in a converter, an electric furnace, a vacuum melting furnace, or the like, and then solidified by a continuous casting method or an ingot casting method. Furthermore, after smelting in a converter, an electric furnace or the like, refining such as vacuum degassing may be further performed in a ladle.
【００２３】[0023]
【実施例】表１に示す組成の鋼を真空溶解炉で溶製し、
造塊法により鋼塊とした。微細粒子の鋼中への分散は、
微細粒子粉末（TiMnO3）を粒径40〜80μm のFe粉と１：
99の割合で混合し、混合粉を25mmφ×20mmの圧粉体とし
て、出鋼直前の溶鋼上部から添加する方法で行った。EXAMPLES Steel having the composition shown in Table 1 was melted in a vacuum melting furnace.
It was made into steel ingot by ingot making method. Dispersion of fine particles in steel
Fine particle powder (TiMnO 3 ) is mixed with Fe powder having a particle size of 40-80 μm:
The mixture was mixed at a ratio of 99, and the mixed powder was added as a green compact of 25 mmφ × 20 mm from the top of molten steel immediately before tapping.
【００２４】上記組成の鋼を熱間圧延により16mm厚の厚
鋼板としたのち、試験に供した。母材について、引張試
験、衝撃試験を実施し、強度と靱性を調査した。また、
これら厚鋼板から、溶接熱サイクル再現試験用試験片を
採取し、入熱240kJ/cmサブマージアーク溶接粗粒域HAZ
部相当の再現熱サイクル（最高加熱温度1400℃）を付与
し、２mmノッチシャルピー試験片を採取して−60℃にお
ける吸収エネルギー（vE-60 ）を求め、溶接熱影響部靱
性を評価した。それらの結果を表２に示す。また、鋼 N
o.Ａについて、TiMnO3の粒度分布を測定し、図１に示
す。臭素−メタノール溶液により酸化物を抽出し、これ
をメタノール中に分散させたのち、レーザー回折散乱法
により粒度分布を測定した。なお、抽出された酸化物を
化学分析した結果から、90％以上がTiとMnであった。A steel plate having the above composition was hot-rolled into a thick steel plate having a thickness of 16 mm, and then subjected to a test. The base material was subjected to a tensile test and an impact test, and the strength and toughness were investigated. Also,
From these thick steel plates, specimens for welding heat cycle reproduction test were sampled and heat input 240 kJ / cm submerged arc welding coarse grain area HAZ
A heat cycle (maximum heating temperature of 1400 ° C.) equivalent to the part was applied, a 2 mm notch Charpy test piece was sampled, the absorbed energy at −60 ° C. (vE −60 ) was determined, and the toughness of the heat affected zone was evaluated. Table 2 shows the results. Also, steel N
For o.A, the particle size distribution of TiMnO 3 was measured and is shown in FIG. After extracting the oxide with a bromine-methanol solution and dispersing it in methanol, the particle size distribution was measured by a laser diffraction scattering method. From the result of chemical analysis of the extracted oxide, 90% or more was Ti and Mn.
【００２５】[0025]
【表１】 [Table 1]
【００２６】[0026]
【表２】 [Table 2]
【００２７】本発明範囲の鋼 No.Ａ〜Ｄ、 No.Ｍ〜Ｐ
は、母材の引張強さが450MPa以上、vE -60 が150 Ｊ以上
と母材の強度・靱性に優れ、かつ溶接熱影響部のvE-60
が110Ｊ以上と溶接熱影響部靱性にも優れている。これ
に対し、微細粒子を添加しない比較鋼Ｅでは、溶接熱影
響部靱性がvE-60 で52Ｊと低い。一方、本発明の範囲を
外れた鋼Ｆ〜Ｌは、溶接熱影響部靱性が著しく劣化して
いる。また、Ｃ量が本発明の範囲を外れる鋼Ｋ、Mn量が
本発明の範囲を外れる鋼Ｌは、母材の靱性が劣化してい
る。No. A to D, No. M to P in the range of the present invention
Means that the tensile strength of the base material is 450MPa or more and vE -60Is 150 J or more
Excellent strength and toughness of base metal and vE of heat affected zone-60
Is 110 J or more, which is excellent in the toughness of the heat affected zone. this
On the other hand, in comparative steel E without adding fine particles,
Sound section toughness is vE-60It is as low as 52J. On the other hand, the scope of the present invention
The degraded steels FL have significantly deteriorated weld heat affected zone toughness.
I have. In addition, steel K and Mn whose C content is out of the range of the present invention are
Steel L out of the range of the present invention has a deteriorated toughness of the base material.
You.
【００２８】[0028]
【発明の効果】本発明によれば、大入熱溶接を行っても
なお、溶接熱影響部組織が微細化し、溶接熱影響部靱性
が優れた大入熱溶接用鋼材を安価に提供でき、溶接構造
用鋼材の品質、溶接能率の向上に大きく貢献し、産業上
多大の効果を奏する。According to the present invention, even when large heat input welding is performed, the structure of the weld heat affected zone is refined, and a large heat input welded steel material having excellent weld heat affected zone toughness can be provided at low cost. It greatly contributes to the improvement of the quality and welding efficiency of steel materials for welded structures, and has great industrial effects.
【図１】本発明鋼材中のTiMnO3酸化物の粒度分布の１例
を示すグラフである。FIG. 1 is a graph showing one example of a particle size distribution of a TiMnO 3 oxide in a steel material of the present invention.
Claims (4)
10〜0.05％の割合で鋼中に分散させ、残部Feおよび不可
避的不純物からなることを特徴とする微細粒子分散型大
入熱溶接用鋼材。1. Mass%, C: 0.02 to 0.15%, Si: 0.10 to 0.40%, Mn: 0.50 to 1.80%, P: 0.020% or less, S: 0.005% or less, B: 0.0005 to 0.0030% And 0.005 to 1.5 μm TiMnO 3 particles
A fine particle dispersed large heat input welding steel material characterized by being dispersed in steel at a ratio of 10 to 0.05%, the balance being Fe and unavoidable impurities.
粒径0.05〜1.5 μm のTiMnO3粒子を0.0010〜0.05％の割
合で鋼中に分散させ、残部Feおよび不可避的不純物から
なることを特徴とする微細粒子分散型大入熱溶接用鋼
材。2. In mass%, C: 0.02 to 0.15%, Si: 0.10 to 0.40%, Mn: 0.50 to 1.80%, P: 0.020% or less, S: 0.005% or less, B: 0.0005 to 0.0030% Ni: 0.05 to 5.0%; Cu: 0.05 to 1.0%; Cr: 0.05 to 1.0%; Mo: 0.05 to 1.0%. A fine particle dispersed large heat input welding steel material characterized in that 0.05 to 1.5 μm TiMnO 3 particles are dispersed in steel at a ratio of 0.0010 to 0.05% and the balance is Fe and unavoidable impurities.
0.05〜1.5 μm のTiMnO3粒子を0.0010〜0.05％の割合で
鋼中に分散させ、残部Feおよび不可避的不純物からなる
ことを特徴とする微細粒子分散型大入熱溶接用鋼材。3. In mass%, C: 0.02 to 0.15%, Si: 0.10 to 0.40%, Mn: 0.50 to 1.80%, P: 0.020% or less, S: 0.005% or less, B: 0.0005 to 0.0030% And Nb: 0.02 to 0.10%; V: 0.02 to 0.10%;
A fine particle dispersed large heat input welding steel material characterized in that 0.05 to 1.5 μm TiMnO 3 particles are dispersed in steel at a ratio of 0.0010 to 0.05% and the balance is Fe and unavoidable impurities.
0.05〜1.5 μm のTiMnO3粒子を0.0010〜0.05％の割合で
鋼中に分散させ、残部Feおよび不可避的不純物からなる
ことを特徴とする微細粒子分散型大入熱溶接用鋼材。4. In mass%, C: 0.02 to 0.15%, Si: 0.10 to 0.40%, Mn: 0.50 to 1.80%, P: 0.020% or less, S: 0.005% or less, B: 0.0005 to 0.0030% Ni: 0.05 to 5.0%, Cu: 0.05 to 1.0%, Cr: 0.05 to 1.0%, Mo: 0.05 to 1.0%, and Nb: 0.02 to 0.10 %, V: 0.02 to 0.10%, containing one or two selected from the group consisting of:
A fine particle dispersed large heat input welding steel material characterized in that 0.05 to 1.5 μm TiMnO 3 particles are dispersed in steel at a ratio of 0.0010 to 0.05% and the balance is Fe and unavoidable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29061196A JPH10130778A (en) | 1996-10-31 | 1996-10-31 | Fine grain dispersed type steel for large heat input welding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29061196A JPH10130778A (en) | 1996-10-31 | 1996-10-31 | Fine grain dispersed type steel for large heat input welding |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10130778A true JPH10130778A (en) | 1998-05-19 |
Family
ID=17758247
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29061196A Pending JPH10130778A (en) | 1996-10-31 | 1996-10-31 | Fine grain dispersed type steel for large heat input welding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10130778A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010139341A (en) * | 2008-12-11 | 2010-06-24 | Jfe Steel Corp | Method for analyzing ti-based precipitate in welding part of steel member |
| CN103774037A (en) * | 2012-10-25 | 2014-05-07 | 吴雪 | Low-cost constructional steel |
-
1996
- 1996-10-31 JP JP29061196A patent/JPH10130778A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010139341A (en) * | 2008-12-11 | 2010-06-24 | Jfe Steel Corp | Method for analyzing ti-based precipitate in welding part of steel member |
| CN103774037A (en) * | 2012-10-25 | 2014-05-07 | 吴雪 | Low-cost constructional steel |
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