JPH0555584B2 - - Google Patents
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- Publication number
- JPH0555584B2 JPH0555584B2 JP60205374A JP20537485A JPH0555584B2 JP H0555584 B2 JPH0555584 B2 JP H0555584B2 JP 60205374 A JP60205374 A JP 60205374A JP 20537485 A JP20537485 A JP 20537485A JP H0555584 B2 JPH0555584 B2 JP H0555584B2
- Authority
- JP
- Japan
- Prior art keywords
- less
- weld
- affected zone
- steel
- bead
- 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.)
- Expired - Lifetime
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- 229910000831 Steel Inorganic materials 0.000 claims description 29
- 239000010959 steel Substances 0.000 claims description 29
- 239000011324 bead Substances 0.000 claims description 22
- 239000000203 mixture Substances 0.000 claims description 18
- 238000003466 welding Methods 0.000 claims description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 11
- 229910052799 carbon Inorganic materials 0.000 claims description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 8
- 238000005336 cracking Methods 0.000 claims description 8
- 239000012535 impurity Substances 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 230000000694 effects Effects 0.000 description 22
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 5
- 238000001816 cooling Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000010953 base metal Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 238000005275 alloying Methods 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- RMLPZKRPSQVRAB-UHFFFAOYSA-N tris(3-methylphenyl) phosphate Chemical compound CC1=CC=CC(OP(=O)(OC=2C=C(C)C=CC=2)OC=2C=C(C)C=CC=2)=C1 RMLPZKRPSQVRAB-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Arc Welding In General (AREA)
Description
〔発明の技術分野〕
この発明は、小入熱およびシヨートビード溶接
用高張力鋼に関するものである。
〔従来技術とその問題点〕
鋼材を溶接した場合、その溶接熱影響部が硬化
する程、溶接熱影響部に割れが発生し易すいこと
から、溶接熱影響部の硬さが、その指標として従
来から用いられている。一般に、溶接熱影響部の
硬さは、JISZ3101で規定された試験法によつて、
熱影響部最高硬さ（Hvnax）として求めている。
上記溶接熱影響部の硬さは、鋼の化学組成およ
び溶接時における冷却速度によつて決定される。
鋼の化学組成が、溶接熱影響部の硬化に及ぼす影
響を定量的に示す代表的なものとして、下記炭素
当量式がある。
Ceq＝Ｃ＋Mn／６＋Si／24＋Ni／40＋Cr／５＋Mo／４＋
Ｖ／14
（％） ……(1)
上記炭素当量（Ceq）と上記熱影響部最高硬さ
（Hvnax）との関係を第１図に示す。
なお、上記JIS Z3101の試験条件は、板厚20mm
以下、入熱16，3KJ／cm、溶接ビード長さ125mm、
800℃から500℃までの冷却時間６秒である。
また、溶接熱影響部の硬化性と溶性割れ感受性
とは本来異なるものであるという観点から、次の
炭素当量式がある。
PCM＝Ｃ＋Mn／20＋Si／30＋Ni／60＋Cr／20＋Mo／15＋
Ｖ／10＋
Cu／20
＋5B（％） ……(2)
この他、最近では、精度向上の観点から新しい
炭素当量式が提案されているが、溶接熱影響部の
硬度および割れ感受性に影響を及ぼす合金元素の
関係式は、上記(1)、(2)式に代表される。
熱影響部最高硬さ（Hvnax）は、上述したよう
に、溶接熱サイクル中の冷却速度に依存するた
め、鋼材の初期温度や入熱等の溶接条件の他、ビ
ード長さや板厚等によつても変化する。即ち、ビ
ード長さが短かくなるにつれて、溶接熱影響部の
冷却速度は速くなる。この傾向は、ビード長さが
約50mm以下の場合、特に顕著に現われ、熱影響部
最高硬さ（Hvnax）も急激に上昇することがわか
つている。（第２図参照）
このために日本鋼船工作法精度標準（JSQS）
では、ビード長さの許容値を50Kgｆ／mm2級高張力
鋼の場合、50mm以上に制限している。
一方、最近、造船業界の一部では、例えば、船
体外板に補強材を仮付け溶接する場合、仮付け溶
接のビード長さを10mmから50mmと短かくして、即
ち、シヨートビードにして、仮付け溶接時間の短
縮化を図り、且つ、入熱もできるだけ少なくでき
る（例えば、ビード長さ10mmでは入熱14KJ／cm、
ビード長さ20mmから30mmでは入熱7KJ／cm）鋼の
開発が望まれている。
しかし、例えば、第２図に示すように、通常圧
延によつて得られる50Kgｆ／mm2級の従来鋼では、
ビード長さを10mmから50mmとした場合の熱影響部
最高硬さ（Hvnax）を割れ発生の虞れがない350
以下にすることはできない。
また、近年、加工熱処理（TMCP）技術によ
り、炭素当量（Ceq）を小さくした鋼が開発され
ているが、第２図に示すように、全ての鋼が
Hvnax≦350を満足することはできない。
〔発明の目的〕
従つて、この発明の目的は、シヨートビード溶
接を行なつても溶接熱影響部の硬化、即ち、溶接
硬化を抑制でき、且つ、小入熱で溶接を行なうこ
とができる、小入熱およびシヨートビード溶接用
高張力鋼を提供することにある。
〔発明の概要〕
第１発明は、Ｃ：0.05〜0.17％、Si：0.02〜0.60
％、Mn：0.30〜2.00％、Ti：0.003〜0.020％、
Ｂ：0.0005％以下、Ｎ：0.0010〜0.0150％、Al：
0.10％以下、Ti／Ｎ：1.5〜3.0、残部：鉄および
不可避不純物からなる基本成分組成に、さらに、
Ni：2.0％以下、Cu：0.5％以下、のうちの少なく
とも一種を含有し、さらに、Nb：0.005〜0.08％、
Ｖ：0.010〜0.10％（以上、重量％）、のうちの少
なくとも一種を含有し、炭素当量（Ceq）が0.28
から0.40％、溶接割れ感受性組成（PCM）が0.24
％以下を満足する、入熱４〜20KJ／cmおよびビ
ード長さ10〜50mmの溶接条件下で、熱影響部最高
硬さ（HvMAX）を350以下にすることができるこ
とに特徴を有するもので、
第２発明は、Ｃ：0.05〜0.17％、Si：0.02〜0.60
％、Mn：0.30〜2.00％、Ti：0.003〜0.020％、
Ｂ：0.0005％以下、Ｎ：0.0010〜0.0150％、Al：
0.10％以下、Ti／Ｎ：1.5〜3.0、残部：鉄および
不可避不純物からなる基本成分組成に、さらに、
Ni：2.0％以下、Cu：0.5％以下、のうちの少なく
とも一種を含有し、さらに、Nb：0.005〜0.08％、
Ｖ：0.010〜0.10％（以上、重量％）、のうちの少
なくとも一種を含有し、炭素当量（Ceq）が0.28
から0.40％、溶接割れ感受性組成（PCM）が0.24
％以下を満足する、入熱４〜20KJ／cmおよびビ
ード長さ10〜50mmの溶接条件下で、熱影響部最高
硬さ（HvMAX）を350以下にすることができる、
ことに特徴を有するものである。
〔発明の構成〕
次に、この発明において、成分組成を上述した
範囲に限定した理由について説明する。
Ｃ：
Ｃは、鋼の強度を向上させる作用を有し且つ安
価な元素であるが、0.05％未満では所望の強度が
得られず、一方、0.17％を越えると溶接硬化が著
しくなる。従つて、0.05〜0.17％の範囲に限定し
た。
Si：
Siは、溶鋼の脱酸および強度付与効果を有する
が、0.02％未満では、その効果が十分に現われな
い。一方、0.60％を越えると、鋼の清浄性が劣化
し且つ溶接性や靭性が低下する。従つて、0.02〜
0.60％の範囲に限定した。
Mn：
Mnは、鋼の強度および延性を向上させる作用
を有し、且つＣにつづいて安価な元素であるが、
0.30％未満では、その効果が十分に現われない。
一方、2.00％を越えると、溶接硬化が著しくな
る。従つて、0.30〜2.00％の範囲に限定した。
Ti：
Tiは、溶接硬化を抑制する作用を有する。即
ち、溶接熱影響部において、TiNのピンニング
効果によるγ粒粗大化を阻止して溶接硬化を抑制
する作用を有する。TiNにおけるTi／Ｎは、3.43
であるが、実際に最も加熱粒が細粒になるTi／
Ｎは、1.5〜3.0である。従つて、この発明におい
ては、Ti／Ｎを1.5〜3.0の範囲に限定した。Ti含
有量が0.003％未満であると、上述した溶接硬化
の抑制効果が十分に現われず、一方、0.020％を
越えると、通常方法では微細なTiNが得られず、
やはり溶接硬化を十分に抑制することが困難であ
る。従つて、この発明においては、Tiの含有割
合を0.003〜0.020％の範囲に限定した。
Ｂ：
Ｂは、鋼の強度低下を補なう作用を有するが、
BNとなるためのＮは、TiNで固定されている。
このために過剰にＢを含有させると、固溶Ｂが溶
接硬化を助長する。従つて、この発明において
は、Ｂ含有量を0.0005％未満とした。
Ｎ：
Ｎは、TiNを有効利用するために不可欠な元
素であり、Ti／Ｎを1.5〜3.0の範囲にするために
は、0.0010〜0.0150％の範囲にすべきである。
Al：
Alは、溶鋼の脱酸作用および結晶粒の微細化
作用を有するが、0.10％を超えてもその効果の向
上が望めない。従つて、0.10％以下に限定した。
次に、上述した成分組成に、さらに選択的に含
有させる成分組成の限定理由について説明する。
Nb：
Nbは、鋼の強度および靭性向上に役立つが、
0.005％未満では、その効果が十分に現われない。
一方、0.08％を越えても上述した効果の向上は望
めない。従つて、0.005〜0.08％の範囲に限定し
た。
Ｖ：
Ｖは、鋼の強度向上効果を有するが、0.010％
未満では、その効果が十分に現われない。一方、
0.10％を越えても、上述した効果の向上は望めな
い。従つて、0.010〜0.10％の範囲に限定した。
Ni：
Niは、鋼の強度および靭性を向上させる作用
を有するが、高価な元素であり、経済性の観点か
ら2.0％以下に限定した。
Cu：
Cuは、鋼の強度を向上させる作用を有するが、
0.5％を越えると、溶接割れ感受性が高まる。従
つて、0.5％以下に限定した。
次に、この発明において、炭素当量（Ceq）を
0.28〜0.40％の範囲に限定し、且つ、溶接割れ感
受性組成（PCM）を0.24％以下に限定したのは、
本発明鋼は、50Kgｆ／mm2級の高張力鋼を対象とし
ているため、母材および溶接継手部の強度確保と
溶接熱影響部の硬化性を確保するためである。即
ち、炭素当量（Ceq）が0.28％未満であると、母
材の強度が低下し且つ溶接熱影響部の軟化が大き
く現われ、一方、0.40％を越えると溶接熱影響部
が硬化しすぎて割れが発生し易くなるからであ
る。また、溶接割れ感受性組成（PCM）が0.24％
を越えると、化学成分組成が本発明範囲内であつ
ても、溶接熱影響部の硬化性が増して、耐溶接割
れ性および溶接延性が著しく劣化するからであ
る。
〔実施例〕
次に、この発明の実施例について説明する。
第１表に示す成分組成を有する鋼材をビードオ
ンプレート溶接に供した。このときの条件は、板
厚18〜48mm、入熱４〜20KJ／cm、ビード長さ10
〜125mmであつた。このようにして溶接した後の
鋼材の溶接熱影響部における熱影響部最高硬さ
（Hvnax）の結果を、引張り試験結果と合わせて
第２表に示す。
なお、第１表中（Ceq）、（PCM）は、前述した
(1)、(2)式の通りである。
TECHNICAL FIELD OF THE INVENTION This invention relates to high tensile strength steel for low heat input and short bead welding. [Prior art and its problems] When steel materials are welded, the harder the weld heat affected zone is, the more likely it is that cracks will occur in the weld heat affected zone, so the hardness of the weld heat affected zone is used as an indicator. Traditionally used. Generally, the hardness of the weld heat affected zone is determined by the test method specified in JISZ3101.
It is determined as the maximum hardness of the heat-affected zone (H vnax ). The hardness of the weld heat affected zone is determined by the chemical composition of the steel and the cooling rate during welding.
The following carbon equivalent formula is a typical example that quantitatively shows the influence of the chemical composition of steel on the hardening of the weld heat affected zone. Ceq=C+Mn/6+Si/24+Ni/40+Cr/5+Mo/4+
V/14 (%) (1) The relationship between the carbon equivalent (Ceq) and the maximum hardness of the heat affected zone (H vnax ) is shown in FIG. The above JIS Z3101 test conditions are for a plate thickness of 20 mm.
Below, heat input 16.3KJ/cm, weld bead length 125mm,
The cooling time from 800°C to 500°C is 6 seconds. Furthermore, from the viewpoint that the hardenability of the weld heat affected zone and the susceptibility to soluble cracking are fundamentally different, there is the following carbon equivalent formula. P CM =C+Mn/20+Si/30+Ni/60+Cr/20+Mo/15+
V/10 + Cu/20 +5B (%) ...(2) In addition to this, a new carbon equivalent formula has recently been proposed from the perspective of improving accuracy, but it has an effect on the hardness and cracking susceptibility of the weld heat affected zone. The relational expressions of alloying elements are represented by the above equations (1) and (2). As mentioned above, the maximum hardness of the heat-affected zone (H vnax ) depends on the cooling rate during the welding heat cycle, so it depends on welding conditions such as the initial temperature and heat input of the steel material, as well as bead length and plate thickness. It changes even when it twists. That is, as the bead length becomes shorter, the cooling rate of the weld heat affected zone becomes faster. This tendency is particularly noticeable when the bead length is approximately 50 mm or less, and it is known that the maximum hardness of the heat affected zone (H vnax ) also increases rapidly. (See Figure 2) For this purpose, the Japanese Steel Ship Construction Method Accuracy Standard (JSQS)
The allowable bead length is limited to 50Kgf/mm for class 2 high tensile strength steel to 50mm or more. On the other hand, recently, in some parts of the shipbuilding industry, for example, when tack welding reinforcing materials to the hull shell, the length of the tack weld bead has been shortened from 10 mm to 50 mm, that is, a short bead is used for tack welding. In addition to shortening the time, the heat input can also be minimized (for example, with a bead length of 10 mm, the heat input is 14 KJ/cm,
It is desired to develop steel with a heat input of 7 KJ/cm for bead lengths of 20 mm to 30 mm. However, as shown in Fig. 2, for example, in conventional steel of 50Kgf/mm 2 grade obtained by normal rolling,
When the bead length is set from 10 mm to 50 mm, the maximum hardness of the heat affected zone (H vnax ) is 350 without the risk of cracking.
It cannot be less than that. In addition, in recent years, steels with lower carbon equivalents (Ceq) have been developed using processing heat treatment (TMCP) technology, but as shown in Figure 2, all steels are
H vnax ≦350 cannot be satisfied. [Object of the Invention] Therefore, an object of the present invention is to suppress hardening of the weld heat affected zone, that is, weld hardening even when short bead welding is performed, and to perform welding with a small heat input. The purpose of the present invention is to provide high tensile strength steel for heat input and short bead welding. [Summary of the invention] The first invention has C: 0.05 to 0.17%, Si: 0.02 to 0.60.
%, Mn: 0.30~2.00%, Ti: 0.003~0.020%,
B: 0.0005% or less, N: 0.0010 to 0.0150%, Al:
In addition to the basic component composition consisting of 0.10% or less, Ti/N: 1.5 to 3.0, balance: iron and inevitable impurities,
Contains at least one of Ni: 2.0% or less, Cu: 0.5% or less, and further contains Nb: 0.005 to 0.08%,
V: Contains at least one of 0.010 to 0.10% (weight%), and has a carbon equivalent (Ceq) of 0.28
from 0.40%, weld cracking susceptibility composition (P CM ) to 0.24
% or less, the maximum hardness of the heat affected zone (H vMAX ) can be reduced to 350 or less under welding conditions of heat input of 4 to 20 KJ/cm and bead length of 10 to 50 mm. , the second invention is C: 0.05-0.17%, Si: 0.02-0.60
%, Mn: 0.30~2.00%, Ti: 0.003~0.020%,
B: 0.0005% or less, N: 0.0010 to 0.0150%, Al:
In addition to the basic component composition consisting of 0.10% or less, Ti/N: 1.5 to 3.0, balance: iron and inevitable impurities,
Contains at least one of Ni: 2.0% or less, Cu: 0.5% or less, and further contains Nb: 0.005 to 0.08%,
V: Contains at least one of 0.010 to 0.10% (weight%), and has a carbon equivalent (Ceq) of 0.28
from 0.40%, weld cracking susceptibility composition (P CM ) to 0.24
% or less, the maximum hardness of the heat affected zone (H vMAX ) can be reduced to 350 or less under welding conditions of heat input of 4 to 20 KJ/cm and bead length of 10 to 50 mm.
It has particular characteristics. [Structure of the Invention] Next, the reason why the component composition is limited to the above-mentioned range in this invention will be explained. C: C is an inexpensive element that has the effect of improving the strength of steel, but if it is less than 0.05%, the desired strength cannot be obtained, while if it exceeds 0.17%, weld hardening becomes significant. Therefore, it was limited to a range of 0.05 to 0.17%. Si: Si has the effect of deoxidizing molten steel and imparting strength, but if it is less than 0.02%, the effect will not be sufficiently manifested. On the other hand, if it exceeds 0.60%, the cleanliness of the steel will deteriorate and the weldability and toughness will decrease. Therefore, 0.02~
It was limited to a range of 0.60%. Mn: Mn has the effect of improving the strength and ductility of steel, and is the second cheapest element after C.
If it is less than 0.30%, its effect will not be sufficiently manifested.
On the other hand, if it exceeds 2.00%, weld hardening becomes significant. Therefore, it was limited to a range of 0.30 to 2.00%. Ti: Ti has the effect of suppressing weld hardening. That is, it has the effect of inhibiting the coarsening of γ grains due to the pinning effect of TiN in the weld heat affected zone and suppressing weld hardening. Ti/N in TiN is 3.43
However, in reality, the heated grains become the finest Ti/
N is 1.5 to 3.0. Therefore, in this invention, Ti/N is limited to a range of 1.5 to 3.0. If the Ti content is less than 0.003%, the above-mentioned effect of suppressing weld hardening will not be sufficiently exhibited, while if it exceeds 0.020%, fine TiN cannot be obtained by normal methods.
After all, it is difficult to sufficiently suppress weld hardening. Therefore, in this invention, the content ratio of Ti is limited to a range of 0.003 to 0.020%. B: B has the effect of compensating for the decrease in strength of steel, but
N for forming BN is fixed at TiN.
For this reason, when B is contained in excess, the solid solution B promotes weld hardening. Therefore, in this invention, the B content is set to less than 0.0005%. N: N is an essential element for effectively utilizing TiN, and should be in the range of 0.0010 to 0.0150% in order to keep Ti/N in the range of 1.5 to 3.0. Al: Al has the effect of deoxidizing molten steel and refining grains, but even if it exceeds 0.10%, no improvement in the effect can be expected. Therefore, it was limited to 0.10% or less. Next, the reasons for limiting the component composition to be further selectively included in the above-mentioned component composition will be explained. Nb: Nb helps improve the strength and toughness of steel, but
If it is less than 0.005%, its effect will not be sufficiently manifested.
On the other hand, even if the content exceeds 0.08%, the above-mentioned effects cannot be expected to improve. Therefore, it was limited to a range of 0.005 to 0.08%. V: V has the effect of improving the strength of steel, but 0.010%
If it is less than that, the effect will not be fully manifested. on the other hand,
Even if it exceeds 0.10%, the above-mentioned effects cannot be expected to improve. Therefore, it was limited to a range of 0.010 to 0.10%. Ni: Ni has the effect of improving the strength and toughness of steel, but it is an expensive element, and from the viewpoint of economic efficiency, it was limited to 2.0% or less. Cu: Cu has the effect of improving the strength of steel, but
If it exceeds 0.5%, weld cracking susceptibility increases. Therefore, it was limited to 0.5% or less. Next, in this invention, carbon equivalent (Ceq) is
The reason why we limited it to the range of 0.28 to 0.40% and the weld crack susceptibility composition (P CM ) to 0.24% or less is because
Since the steel of the present invention is intended for high tensile strength steel of 50 Kgf/mm 2 class, this is to ensure the strength of the base metal and welded joint and the hardenability of the weld heat affected zone. That is, if the carbon equivalent (Ceq) is less than 0.28%, the strength of the base metal will decrease and the weld heat affected zone will soften significantly, while if it exceeds 0.40%, the weld heat affected zone will become too hard and crack. This is because it becomes more likely to occur. In addition, the weld crack susceptibility composition (P CM ) is 0.24%.
This is because, if the chemical composition exceeds this range, even if the chemical composition is within the range of the present invention, the hardenability of the weld heat-affected zone will increase and the weld cracking resistance and weld ductility will significantly deteriorate. [Example] Next, an example of the present invention will be described. Steel materials having the composition shown in Table 1 were subjected to bead-on-plate welding. The conditions at this time are plate thickness 18 to 48 mm, heat input 4 to 20 KJ/cm, and bead length 10.
It was ~125mm. The results of the maximum heat affected zone hardness (H vnax ) of the welded heat affected zone of the steel materials after welding in this manner are shown in Table 2 together with the tensile test results. In addition, (Ceq) and (P CM ) in Table 1 are as described above.
As shown in equations (1) and (2).
【表】【table】
以上説明したように、この発明によれば、シヨ
ートビード、小入熱の溶接条件下で、溶接熱影響
部の硬化を抑制することができるといつたきわめ
て有用な効果がもたらされる。
As described above, the present invention provides extremely useful effects such as being able to suppress hardening of the weld heat affected zone under short bead welding conditions and low heat input.
第１図は、熱影響部最高硬さ（Hvnax）と
（Ceq）との関係を示すグラフ、第２図は、熱影
響部最高硬さ（Hvnax）とビード長さとの関係を
示すグラフ、第３図は、本発明鋼１の金属組織の
顕微鏡写真、第４図は、比較鋼１５の金属組織の
顕微鏡写真である。
Figure 1 is a graph showing the relationship between the maximum heat-affected zone hardness (H vnax ) and (Ceq), and Figure 2 is a graph showing the relationship between the maximum heat-affected zone hardness (H vnax ) and bead length. , FIG. 3 is a microscopic photograph of the metal structure of Invention Steel 1, and FIG. 4 is a microscopic photograph of the metal structure of Comparative Steel 15.
Claims (1)
（Ceq）が0.28から0.40％、溶接割れ感受性組成
（PCM）が0.24％以下を満足する、入熱４〜
20KJ／cmおよびビード長さ10〜50mmの溶接条件
下で、熱影響部最高硬さ（HvMAX）を350以下に
することができることを特徴とする、小入熱およ
びシヨートビード溶接用高張力鋼。 ２ Ｃ：0.05〜0.17％、 Si：0.02〜0.60％、 Mn：0.30〜2.00％、 Ti：0.003〜0.020％、 Ｂ：0.0005％未満、 Ｎ：0.0010〜0.0150％、 Al：0.10％以下、 Ti／Ｎ：1.5〜3.0、 残部：鉄および不可避不純物 からなる基本成分組成に、さらに、 Ni：2.0％以下、 Cu：0.5％以下、 のうちの少なくとも一種を含有し、さらに、 Nb：0.005〜0.08％、 Ｖ：0.010〜0.10％（以上、重量％）、 のうちの少なくとも一種を含有し、炭素当量
（Ceq）が0.28から0.40％、溶接割れ感受性組成
（PCM）が0.24％以下を満足する、入熱４〜
20KJ／cmおよびビード長さ10〜50mmの溶接条件
下で、熱影響部最高硬さ（HvMAX）を350以下に
することができることを特徴とする、小入熱およ
びシヨートビード溶接用高張力鋼。[Claims] 1 C: 0.05-0.17%, Si: 0.02-0.60%, Mn: 0.30-2.00%, Ti: 0.003-0.020%, B: less than 0.0005%, N: 0.0010-0.0150%, Al: 0.10% or less, Ti/N: 1.5 to 3.0, balance: basic component composition consisting of iron and unavoidable impurities, and further Nb: 0.005 to 0.08%, V: 0.010 to 0.10% (or more, weight %), Heat input 4 to 4, containing at least one kind, satisfying carbon equivalent (Ceq) of 0.28 to 0.40% and weld cracking susceptibility composition (P CM ) of 0.24% or less
A high-strength steel for low heat input and short bead welding, characterized in that the maximum heat-affected zone hardness (H vMAX ) can be reduced to 350 or less under welding conditions of 20 KJ/cm and a bead length of 10 to 50 mm. 2 C: 0.05-0.17%, Si: 0.02-0.60%, Mn: 0.30-2.00%, Ti: 0.003-0.020%, B: less than 0.0005%, N: 0.0010-0.0150%, Al: 0.10% or less, Ti/ N: 1.5 to 3.0, balance: basic component composition consisting of iron and unavoidable impurities, further containing at least one of Ni: 2.0% or less, Cu: 0.5% or less, furthermore, Nb: 0.005 to 0.08% , V: 0.010 to 0.10% (or more, weight %), and satisfies a carbon equivalent (Ceq) of 0.28 to 0.40% and a weld crack susceptibility composition (P CM ) of 0.24% or less, Heat input 4~
A high-strength steel for low heat input and short bead welding, characterized in that the maximum heat-affected zone hardness (H vMAX ) can be reduced to 350 or less under welding conditions of 20 KJ/cm and a bead length of 10 to 50 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20537485A JPS6267151A (en) | 1985-09-19 | 1985-09-19 | High tensile strength steel for small heat input and short bead welding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20537485A JPS6267151A (en) | 1985-09-19 | 1985-09-19 | High tensile strength steel for small heat input and short bead welding |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6267151A JPS6267151A (en) | 1987-03-26 |
| JPH0555584B2 true JPH0555584B2 (en) | 1993-08-17 |
Family
ID=16505776
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20537485A Granted JPS6267151A (en) | 1985-09-19 | 1985-09-19 | High tensile strength steel for small heat input and short bead welding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6267151A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4736193B2 (en) * | 2001-01-29 | 2011-07-27 | Ｊｆｅスチール株式会社 | Fillet welded joint with excellent fatigue characteristics and gas shielded arc fillet welding method |
| US20190226048A1 (en) * | 2016-09-30 | 2019-07-25 | Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | Steel parts, production method therefor, and steel sheet for steel parts |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5179624A (en) * | 1974-12-31 | 1976-07-12 | Nippon Steel Corp | |
| JPS59200724A (en) * | 1983-04-27 | 1984-11-14 | Nippon Steel Corp | Manufacture of steel for low temperature use with superior toughness at weld zone |
| JPS60169516A (en) * | 1983-10-07 | 1985-09-03 | Nippon Steel Corp | Production of low-temperature steel having excellent weld zone toughness |
-
1985
- 1985-09-19 JP JP20537485A patent/JPS6267151A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5179624A (en) * | 1974-12-31 | 1976-07-12 | Nippon Steel Corp | |
| JPS59200724A (en) * | 1983-04-27 | 1984-11-14 | Nippon Steel Corp | Manufacture of steel for low temperature use with superior toughness at weld zone |
| JPS60169516A (en) * | 1983-10-07 | 1985-09-03 | Nippon Steel Corp | Production of low-temperature steel having excellent weld zone toughness |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6267151A (en) | 1987-03-26 |
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