JPS63149354A - High tension steel sheet for high heat input welding and manufacture thereof - Google Patents
High tension steel sheet for high heat input welding and manufacture thereofInfo
- Publication number
- JPS63149354A JPS63149354A JP29630486A JP29630486A JPS63149354A JP S63149354 A JPS63149354 A JP S63149354A JP 29630486 A JP29630486 A JP 29630486A JP 29630486 A JP29630486 A JP 29630486A JP S63149354 A JPS63149354 A JP S63149354A
- Authority
- JP
- Japan
- Prior art keywords
- less
- toughness
- heat input
- welding
- steel
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 41
- 239000010959 steel Substances 0.000 title claims abstract description 41
- 238000003466 welding Methods 0.000 title claims abstract description 32
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 10
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 10
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 5
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 5
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 4
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 4
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 4
- 238000000034 method Methods 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 abstract description 7
- 238000005496 tempering Methods 0.000 abstract description 6
- 229910052802 copper Inorganic materials 0.000 abstract description 2
- 238000010791 quenching Methods 0.000 abstract description 2
- 238000005098 hot rolling Methods 0.000 abstract 1
- 229910052748 manganese Inorganic materials 0.000 abstract 1
- 230000000171 quenching effect Effects 0.000 abstract 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 18
- 239000010953 base metal Substances 0.000 description 17
- 230000000694 effects Effects 0.000 description 17
- 239000000463 material Substances 0.000 description 10
- 238000005096 rolling process Methods 0.000 description 9
- 239000000203 mixture Substances 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- 238000001816 cooling Methods 0.000 description 6
- 230000008901 benefit Effects 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 238000007670 refining Methods 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 229910001566 austenite Inorganic materials 0.000 description 3
- 229910052761 rare earth metal Inorganic materials 0.000 description 3
- 239000006104 solid solution Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 230000002542 deteriorative effect Effects 0.000 description 2
- 238000009863 impact test Methods 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 230000002195 synergetic effect Effects 0.000 description 2
- 238000009864 tensile test Methods 0.000 description 2
- USWINTIHFQKJTR-UHFFFAOYSA-N 3-hydroxynaphthalene-2,7-disulfonic acid Chemical compound C1=C(S(O)(=O)=O)C=C2C=C(S(O)(=O)=O)C(O)=CC2=C1 USWINTIHFQKJTR-UHFFFAOYSA-N 0.000 description 1
- 229910052684 Cerium Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 101150104182 MOB2 gene Proteins 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000010979 ruby Substances 0.000 description 1
- 229910001750 ruby Inorganic materials 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、溶接部靭性のすぐれた大入熱溶接用高張力鋼
板、特にＴｉＮおよびＺｒＮを均一に分散析出させて成
る大人熱溶接用高張力鋼板およびその製法に間する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is a high tensile strength steel plate for high heat input welding with excellent weld toughness, particularly a high tensile strength steel plate for large heat welding in which TiN and ZrN are uniformly dispersed and precipitated. Regarding tensile steel plates and their manufacturing method.
（従来の技術）
従来の高張力鋼板（降伏点３６ｋｇｆ／ｍｏｂ２以上）
は大入熱溶接部（溶接入熱量１００ｋＪ／ｃｍ以上）の
靭性を改善するために以下のような対策を行ってきたｑ
Φ銅鋼中Ｎ含有量を３０ρρ−以下というふうに極力低
減し、これに微量のＴｉおよびＢを含有させることによ
り、靭性に有害な固溶ＮＭの低減を図り、かつＴｉＮお
よびＢＮの析出物を核としてミクロ組織の微細化を図っ
た低Ｎ −Ｔｉ−Ｂ鋼〔「鉄とｔａｌＪ Ｖｏｌ、６８
’ （１９８２） ５６３８〜５６３９） −■Ｃｅな
どの希土類元素（ＲＥ？Ｉ）とＢとを含有することによ
り、ＲＥＭ介在物を起点として析出したＢＮを核として
ミクロ組織の微細化を図ったＲＥＭ −Ｂ鋼Ｃ「鉄と綱
Ｊ Ｖｏｌ、６３（１９７７） ９９．３０３〜３１２
） 。(Conventional technology) Conventional high-strength steel plate (yield point 36 kgf/mob2 or more)
has taken the following measures to improve the toughness of high heat input welds (welding heat input of 100 kJ/cm or more).
By reducing the N content in the Φ copper steel as much as possible to 30ρρ- or less, and incorporating trace amounts of Ti and B, we aim to reduce solid solution NM that is harmful to toughness, and eliminate TiN and BN precipitates. Low N-Ti-B steel with a finer microstructure with a core of
' (1982) 5638-5639) -■ REM containing a rare earth element (RE?I) such as Ce and B to refine the microstructure using BN precipitated from REM inclusions as a core. -B Steel C “Tetsu to Tsuna J Vol, 63 (1977) 99.303-312
).
■Ｔｉ添加鋼においてｓｏｌ、Ｍ量を低減させることに
より酸素を増加させて析出したＴｉＯを核としてミクロ
組織の微細化を図った低ＡＱ−ＴｉｗＪ（ｒ鉄と鋼Ｊ
Ｖｏｌ、７２（１９８６） ５６２５〜５６２７）。■Low AQ-TiwJ (iron and steel J
Vol. 72 (1986) 5625-5627).
（発明が解決しようとする問題点）
しかし、構造物の大型化に伴って使用鋼材は肉厚が増加
する傾向にある。これに伴って、溶接入熱量が増加する
傾向にあり、５００ｋＪ／ｃｎ＋程度までの溶接部での
靭性確保が要求されつつある。(Problems to be Solved by the Invention) However, as structures become larger, the thickness of steel materials used tends to increase. Along with this, there is a tendency for welding heat input to increase, and it is becoming necessary to ensure toughness in welded parts up to about 500 kJ/cn+.
さらに、構造物の運転環境の寒冷地化に伴って、靭性要
求温度は低温化の傾向にあり、−７０℃程度までの要求
がされつつある。Furthermore, as the operating environment for structures becomes colder, the required temperature for toughness tends to be lower, and is now required to be as low as about -70°C.
すなわち、最近の最も苛酷な要求である溶接入熱量５０
０ｋＪ／ｃ＋ｍの溶接部でｖＥ−１６≧３．５ｋｇｆ−
ｒａを満足することは上述の対策では不可能である。In other words, the welding heat input is 50, which is the most severe requirement these days.
vE-16≧3.5kgf- at welded part of 0kJ/c+m
It is impossible to satisfy ra with the above measures.
かくして、本発明の目的は、溶接入熱！５００ｋＪ／ｃ
ｍの溶接部でｖＥ−ｑ。≧３．５ｋｇｆ−ｒｅを満足す
る大人熱溶接用高張力鋼板を提供することである。Thus, the purpose of the present invention is to reduce welding heat input! 500kJ/c
vE-q at the weld of m. An object of the present invention is to provide a high-strength steel plate for adult heat welding that satisfies ≧3.5 kgf-re.
（問題点を解決するための手段）
本発明者らは、上述の目的を達成する手段として高温加
熱部において安定に存在するＺｒＮを核としたミクロＭ
ｉ織の微細化に着目した。(Means for Solving the Problems) As a means to achieve the above-mentioned object, the present inventors have developed a micro-M with ZrN as a core that stably exists in a high-temperature heating section.
We focused on making the i-weave finer.
一連の実験、研究を続けたところ、ＴｉＮ 、 ＺｒＮ
の共存下において初めて溶接入熱量１００ｋＪ／ｃｎ＋
以上という大入熱溶接による溶接部靭性が著しく改善さ
れたことを知り、本発明を完成した。After a series of experiments and research, we found that TiN, ZrN
Welding heat input of 100kJ/cn+ was achieved for the first time under the coexistence of
The present invention was completed based on the knowledge that the toughness of the weld zone was significantly improved by the above-mentioned high heat input welding.
ここに、本発明の要旨とするところは、重量％で、
Ｃ：０．０３〜０．１２％、Ｓｉ：０．０５〜０．４％
、Ｍｎ： ０．７０〜１．６％、Ｐ ：０．０１５％以
下、ｓ ：０．０１％以下、Ｓ０１．八Ｑ：０−００１
〜０．０５０％、Ｔｉ：０．００５〜０．０２％、Ｚｒ
：０．００５〜０．０１５％、Ｎ ：０．００３〜０．
００８％、
さらに、所望により、Ｃｕ：０．５％以下、Ｎｉ：１．
０％以下、Ｖ：０．０４％以下、Ｎｂ：０．０３ ％以
下、およびＣａ：０．００４％以下の少なくとも１種、
Ｆｅおよび付随不純物：残部
かつ
Ｔｉ Ｚｒ
□＋□
１４．０
Ｃｅｑ ＝０．３６％以下
である組成を有することを特徴とする、溶接入熱１）０
０〜５００ｋＪ／ｃｍの溶接部の靭性（ｖＥ−、ａ）が
３．５ｋｇｆ一層以上、降伏点３６ｋｇｆ／ａｍ”以上
の大入熱溶接用高張力鋼板である。Here, the gist of the present invention is, in weight%, C: 0.03 to 0.12%, Si: 0.05 to 0.4%.
, Mn: 0.70-1.6%, P: 0.015% or less, s: 0.01% or less, S01. Eighth Q: 0-001
~0.050%, Ti:0.005~0.02%, Zr
:0.005~0.015%, N:0.003~0.
008%, further, if desired, Cu: 0.5% or less, Ni: 1.
0% or less, V: 0.04% or less, Nb: 0.03% or less, and Ca: 0.004% or less,
Welding heat input 1) 0 characterized by having a composition in which Fe and accompanying impurities: balance and Ti Zr □+□ 14.0 Ceq = 0.36% or less
It is a high-strength steel plate for high heat input welding with a welded part toughness (vE-, a) of 0 to 500 kJ/cm of 3.5 kgf or more and a yield point of 36 kgf/am'' or more.
ただし、
Ｓｔ Ｍｎ Ｃｕ Ｎｉ Ｃｒ Ｍｏ Ｖ
Ｃｅｑ ＝Ｃ＋−＋−十−＋−＋−＋−＋ −さらに
、別の面からは、本発明は、上記組成を有する鋼を、９
００℃〜１２００℃の温度域に加熱した後、熱間圧延に
よって８００℃以上の温度で所定の板厚とし、次いで、
直ちに水冷によって室温にまで急冷し、その後２００〜
４５０℃の温度域で焼戻しを行うことから成る、溶接入
熱量１００〜５００ｋＪ／ｃｍの溶接部の靭性（ｖＥ
−ｙ。）が３．５ｋｇｆ−ｍ以上を満足することを特徴
とする、降伏点３６ｋｇｆ／ｌ１ｌｓ”以上の大入熱溶
接用高張力鋼板の製法である。However, St Mn Cu Ni Cr Mo V
Ceq =C+-+-10-+-+-+-+ -Furthermore, from another aspect, the present invention provides steel having the above composition with 9
After heating to a temperature range of 00°C to 1200°C, the plate is hot rolled to a predetermined thickness at a temperature of 800°C or higher, and then
Immediately quench with water to room temperature, then heat to 200~
The toughness (vE
-y. ) is 3.5 kgf-m or more, and has a yield point of 36 kgf/l1ls" or more and a method for producing a high-strength steel plate for high heat input welding.
かかる本発明による製法によれば、ＴｉＮおよびＺｒＮ
は均一に分散析出し、母材の機械的特性の改善、特に強
度および靭性の改善は著しい、溶接部に関しては加工履
歴は消失し、もともと含有されているＴｉおよびＺｒの
窒化物の均一分散析出が影響するが、その余の部分に関
しては鋼板製造段階でのＴｔＮ、ＺｒＮの均一分散析出
が影響するのである。According to the manufacturing method according to the present invention, TiN and ZrN
is uniformly dispersed and precipitated, and the mechanical properties of the base metal are improved, especially the strength and toughness are significantly improved. As for the welded part, the processing history disappears, and the originally contained Ti and Zr nitrides are uniformly dispersed and precipitated. However, the rest is influenced by the uniformly dispersed precipitation of TtN and ZrN during the steel plate manufacturing stage.
（作用）
本発明の化学的組成範囲および加工条件を上述のように
限定した理由について以下詳述する。(Function) The reason why the chemical composition range and processing conditions of the present invention are limited as described above will be explained in detail below.
Ｃ：母材の強度（降伏点が３６ｋｇｆ／ａｍ２以上）を
確保するため０．０３％以上が必要であり、０．１２％
を超えると溶接部の靭性が劣化する。C: 0.03% or more is required to ensure the strength of the base material (yield point is 36 kgf/am2 or more), and 0.12%
If it exceeds this, the toughness of the weld will deteriorate.
Ｓｉ：鋼のＲ酸と母材の強度確保のため０．０５％以上
が必要であるが、０．４％を超えると溶接部の靭性が劣
化する。Si: 0.05% or more is required to ensure the strength of the R acid of the steel and the base metal, but if it exceeds 0.4%, the toughness of the weld will deteriorate.
Ｍｎ：母材の強度を確保するため０．７％以上が必要で
あるが、１．６％を超えると溶接部の靭性が劣化する。Mn: 0.7% or more is required to ensure the strength of the base metal, but if it exceeds 1.6%, the toughness of the weld will deteriorate.
Ｐ；Ｐは凝固時に偏析しやすい元素であり、Ｐの偏析等
が溶接部を硬化させて靭性劣化の原因となるため、その
含有量が低いほど望ましい０本発明の鋼板において溶接
部の靭性を確保するためにはＯ，０１５％以下とするこ
とが必要である。P; P is an element that tends to segregate during solidification, and segregation of P hardens the weld and causes toughness deterioration, so the lower the content, the better. In order to ensure this, it is necessary to keep it below 0.015%.
好ましくは０．０１％以下である。Preferably it is 0.01% or less.
ＳＯ３は鋼中ではＭｎＳ等の介在物となって、靭性、延
性を劣化させるため、０．０１％以下にすることが必要
である。SO3 becomes inclusions such as MnS in steel and deteriorates toughness and ductility, so it is necessary to keep the content to 0.01% or less.
ｓｏｌ、ＩＶｌ： ｓｏｌ、ＡＱは鋼の脱酸作用を有す
るとともに、ＭＮとして析出してオーステナイト粒の微
細化による母材靭性改善作用を有しており、かかる作用
効果を得るために、ｏ、ｏｏｔ％以上のｓｏｌ、Ｍが必
要である。しかし、過剰のｓｏｌ、Ａｌ１は母材および
溶接部の靭性を劣化させるため０．０５％以下とするこ
とが必要である。sol, IVl: sol, AQ has a deoxidizing effect on steel, and also has an effect of improving base metal toughness by precipitating as MN and refining austenite grains. In order to obtain this effect, o, oot % or more of sol, M is required. However, excessive sol and Al1 deteriorate the toughness of the base metal and the welded part, so it is necessary to limit it to 0.05% or less.
Ｔｉ： ＴｉはＴｉＮを析出させて、溶接部のＭｉ織機
微細化もたらし、溶接部の靭性を改善する。この効果を
得るためには、ｏ、ｏｏｓ％以上が必要であるが、０．
０２％を超えると、母材および溶接部の靭性を低下させ
る。好ましくは、０．０１〜０．０１５％である。Ti: Ti precipitates TiN, brings about Mi loom refinement in the weld zone, and improves the toughness of the weld zone. In order to obtain this effect, o,oos% or more is required, but 0.
If it exceeds 0.02%, the toughness of the base metal and weld zone will be reduced. Preferably it is 0.01 to 0.015%.
Ｚｒ： Ｚｒは１）と同様にＺｒＮを析出させて、溶接
部の＆［ｌ機微細化をもらし、溶接部の靭性を改善する
。Zr: Zr precipitates ZrN in the same way as in 1), makes the weld zone finer, and improves the toughness of the weld zone.
この効果を得るためには、０．００５％以上が必要であ
るが、０．０１５％を超えると、母材および溶接部の靭
性を低下させる。好ましくは０．００７〜０．０１２％
である。In order to obtain this effect, a content of 0.005% or more is required, but if it exceeds 0.015%, the toughness of the base metal and weld zone will be reduced. Preferably 0.007-0.012%
It is.
ただし、
□ の比が０．４１未満では
１４．０
ＴｉＮおよびＺｒＮの析出物の数が少なく、上記の効果
が得られない。However, if the ratio of □ is less than 0.41, the number of 14.0 TiN and ZrN precipitates is small, and the above effect cannot be obtained.
また、１．０を超えるとＴｉＣおよびＺｒＣを析出して
溶接部の靭性が劣化する。そこで０．４〜１．０の範囲
とすることが必要である。更に好ましくは０．５〜０．
８である。Moreover, if it exceeds 1.0, TiC and ZrC will precipitate and the toughness of the weld will deteriorate. Therefore, it is necessary to set it in the range of 0.4 to 1.0. More preferably 0.5-0.
It is 8.
ここで、ＴｉとＺｒを同時に添加する理由は次のとおり
である。Here, the reason for adding Ti and Zr at the same time is as follows.
ＴｉＮおよびＺｒＮは溶接時の高温加熱におけるオース
テナイト粒の粗大化抑制およびその後の冷却時のフェラ
イト変態における核としての働きによる１）１ｍｍ細化
の二つの効果により最終のミクロ組織を微細化して靭性
を改善する。TiN and ZrN have two effects: 1) suppressing coarsening of austenite grains during high-temperature heating during welding, and serving as nuclei during ferrite transformation during subsequent cooling; 1) refining the final microstructure by 1 mm, improving toughness Improve.
しかし、ＴｉＮおよびＺｒＮには各々長所と短所がある
。すなわち、ＴｉＮはＺｒＮに比べて微細に均一分散し
やすく、細粒化の効果が大きい長所を有している。ただ
し、１３５０ ’Ｃを超えるとＴｉＮは再溶解して微細
化効果が低下する。これに対してＺｒＮは１４５０℃程
度まで安定に存在するため、ＴｉＮが再溶解するような
高温加熱部（１３５０〜１４５［Ｃ）の微細化に有効で
ある。ただし、ＺｒＮはＴｉＮに比べて微細に均一分散
しにくいため、１３５０’Ｃ以下に加熱された部分の細
粒化に対してはＴｉＮに比べてその効果が少ない。However, TiN and ZrN each have advantages and disadvantages. That is, TiN has the advantage that it is easier to disperse finely and uniformly than ZrN, and has a large grain refining effect. However, if the temperature exceeds 1350'C, TiN will be re-dissolved and the refinement effect will be reduced. On the other hand, since ZrN exists stably up to about 1450[deg.] C., it is effective in miniaturizing high-temperature heated parts (1350 to 145[C]) where TiN is remelted. However, since ZrN is more difficult to disperse finely and uniformly than TiN, it is less effective than TiN in refining the grains of the portion heated to 1350'C or less.
そこで本発明ではＴｉＮとＺｒＮの各々の特色を生かし
た複合添加による相乗効果を利用しようとするものであ
る。Therefore, the present invention attempts to take advantage of the synergistic effect resulting from the combined addition of TiN and ZrN, taking advantage of their respective characteristics.
Ｎ：Ｎは固溶状態で鋼中に存在した場合、溶接部の靭性
を劣化させるためできるだけ低い方が望ましい、しかし
、大入熱溶接部は固溶Ｎｆｉの低減だけでは十分な靭性
が得られず、組織の微細化を行うことが良好な靭性を得
るためには不可欠である。N: If N is present in steel in a solid solution state, it deteriorates the toughness of the weld, so it is desirable to keep it as low as possible. However, in high heat input welds, sufficient toughness cannot be obtained just by reducing solid solution Nfi. First, it is essential to refine the structure in order to obtain good toughness.
すでに述べたように、本発明にあって、溶接部の組織の
微細化は、ＴｉＮおよびＺｒＮの均一な分散析出によっ
てもたらされるものであり、ＴｔおよびＺｒと結合する
Ｎの量を最適量に制御することが必要である。すなわち
、本発明において、大入熱溶接部の靭性改善に有効な量
のＴｉＮおよびＺｒＮを確保するためには、Ｎは０．０
０３％以上が必要である。しかし、Ｎが０．００８％を
超えると固溶Ｎ量が増加して溶接部の靭性が劣化する。As already mentioned, in the present invention, the refinement of the structure of the weld zone is brought about by uniformly dispersed precipitation of TiN and ZrN, and the amount of N combined with Tt and Zr is controlled to an optimum amount. It is necessary to. That is, in the present invention, in order to ensure an effective amount of TiN and ZrN for improving the toughness of a high heat input weld, N should be 0.0
0.3% or more is required. However, when N exceeds 0.008%, the amount of solid solute N increases and the toughness of the weld zone deteriorates.
そこで、Ｎ量は０．００３〜０．００８％とした。Therefore, the amount of N was set to 0.003 to 0.008%.
上述のＩ１）＆Ｉｌ成に、所望により、下記の成分を少
なくとも１種更に添加することにより、母材の強度と靭
性および溶接部の靭性を安定化することができる。The strength and toughness of the base metal and the toughness of the welded part can be stabilized by further adding at least one of the following components to the above-mentioned compositions I1) and Il, if desired.
Ｃｕ： Ｃｕは溶接部の靭性を劣化させることなく母材
の強度を上昇させる効果を有するため、その添加が母材
の強度の安定化に有効である。しかし、０．５％を超え
ると、熱間延性を低下させ、溶接時の高温割れ感受性を
高める。Cu: Since Cu has the effect of increasing the strength of the base metal without deteriorating the toughness of the weld, its addition is effective in stabilizing the strength of the base metal. However, when it exceeds 0.5%, hot ductility decreases and susceptibility to hot cracking during welding increases.
Ｎｉ二Ｎｉは１．０％までは溶接部の靭性を劣化させる
ことなく母材の強度および靭性を上昇させるため、その
添加は母材の強度と靭性の安定化に有効である。しかし
、１．０％を超えると、溶接部の靭性が劣化する。Up to 1.0% of Ni increases the strength and toughness of the base metal without deteriorating the toughness of the weld, so its addition is effective in stabilizing the strength and toughness of the base metal. However, if it exceeds 1.0%, the toughness of the weld will deteriorate.
ｖ：ｖは母材の強度上昇に有効である。しかし、０．０
４％を超えると溶接部の靭性が劣化する。v: v is effective in increasing the strength of the base material. However, 0.0
If it exceeds 4%, the toughness of the weld will deteriorate.
Ｎｂ： Ｎｂは母材の強度および靭性の上昇に有効であ
る。しかし、０．０３％を趙えると溶接部の靭性が劣化
する。Nb: Nb is effective in increasing the strength and toughness of the base metal. However, if it exceeds 0.03%, the toughness of the weld will deteriorate.
Ｃａ： Ｃａは硫化物を球状化して母材の機械的性質の
異方性を減少させる効果を存すると共に、Ｃａ（０、Ｓ
）として鋼中に均一に分散させることによって溶接部の
＆ＩＮ織を微細化して靭性を改善する。しかし、０．０
０４％を超えると、その効果が飽和すると同時に、鋼の
清浄度を劣化させる。Ca: Ca has the effect of spheroidizing sulfide and reducing the anisotropy of the mechanical properties of the base material, and also has the effect of reducing the anisotropy of the mechanical properties of the base material.
), it refines the &IN weave in the weld and improves toughness by uniformly dispersing it in the steel. However, 0.0
If it exceeds 0.4%, the effect reaches saturation and at the same time the cleanliness of the steel deteriorates.
本発明では、以上のように化学成分に制限を加えると共
に、更にＣｅｑの制限を加える。すなわち、以上の化学
成分の限定を行っても、大入熱溶接部は低温靭性（シＥ
−？。）を安定して３．５ｋｇｆ−僧以上とすることは
できず、Ｃｅｑを０．３６％以下とすることによっては
じめてこの低温靭性３．５ｋｇｆ−一以上の条件が満足
される。In the present invention, in addition to limiting the chemical components as described above, Ceq is further limited. In other words, even if the chemical components are limited as described above, high heat input welds have poor low-temperature toughness (Sheet E).
−? . ) cannot be stably maintained at 3.5 kgf-1 or more, and this condition of low-temperature toughness of 3.5 kgf-1 or more is satisfied only by setting Ceq to 0.36% or less.
圧延加熱温度ニ
オーステナイト中に炭化物を均一に固溶させるために、
９００℃以上に加熱することが必要であるが、１２００
℃を超えて加熱するとオーステナイト粒が粗大化し、圧
延、再結晶によっても十分に微細化されず、母材の靭性
が劣化する場合がある。好ましくはこの加熱温度は９５
０〜１）５０℃である。In order to uniformly dissolve carbides in the rolling heating temperature niostenite,
It is necessary to heat to 900℃ or higher, but 1200℃
If heated above ℃, austenite grains become coarse and cannot be sufficiently refined even by rolling or recrystallization, and the toughness of the base material may deteriorate. Preferably this heating temperature is 95
0-1) 50°C.
圧延仕上温度および圧延後の冷却：
本発明の鋼は大入熱溶接部の靭性を確保するためにＣｅ
ｑを低く制限しており、母材の強度を確保するためには
圧延後の冷却速度を速くすることが必要である。Finishing temperature of rolling and cooling after rolling: The steel of the present invention contains Ce in order to ensure the toughness of the high heat input welded part.
q is limited to a low value, and in order to ensure the strength of the base material, it is necessary to increase the cooling rate after rolling.
したがって、圧延終了後直ちに水冷を行って室温まで急
冷することが必要である。さらに、水冷における冷却速
度を確保するためには、圧延仕上温度を８００℃以上と
することが必要である。一般にはこの仕上げ温度は８２
０℃以上である。Therefore, it is necessary to perform water cooling immediately after finishing rolling to rapidly cool the product to room temperature. Furthermore, in order to ensure the cooling rate in water cooling, it is necessary to set the finishing rolling temperature to 800° C. or higher. Generally, this finishing temperature is 82
The temperature is 0°C or higher.
焼戻し処理：
水冷ままの鋼板は歪みが多いため降伏点および靭性が低
い、２００℃以上の温度で焼戻しを行うことにより、降
伏点および靭性が向上する。しかし、４５０℃を超えた
温度で焼戻しを行うと引張強さが著しく低下する。好ま
しくは３００〜４００℃で焼戻し処理を行う。Tempering treatment: A steel plate as water-cooled has a lot of distortion, so its yield point and toughness are low. By tempering at a temperature of 200° C. or higher, the yield point and toughness are improved. However, when tempering is performed at a temperature exceeding 450°C, the tensile strength is significantly reduced. Preferably, the tempering treatment is performed at 300 to 400°C.
かくして、本発明によれば、大人熱溶接に際して溶接部
の凝固過程においてＴｉＮ、ＺｒＮの均一分散析出が行
われ、溶接部の組織は微細に分割され靭性の改善効果が
見られ、溶接入熱量１００〜５００ｋＪ／ｃｍの溶接部
の靭性（ｖＥ −ｔｏ）が３．５ｋｇｆ−ｍ以上および
降伏点３６ｋｇｆ／＋ｍｍ”以上を満足する。一方、溶
接部以外の母材部分には、その好適Ｇ様によれば、予め
鋼板製造段階でＴｉＮ、ＺｒＮの均一分散析出が行われ
ており、同様の所要靭性、強度は確保されている。Thus, according to the present invention, TiN and ZrN are uniformly dispersed and precipitated during the solidification process of the weld during adult heat welding, the structure of the weld is finely divided, the effect of improving toughness is observed, and the welding heat input is 100. The toughness (vE -to) of the welded part of ~500kJ/cm satisfies 3.5kgf-m or more and the yield point of 36kgf/+mm'' or more.On the other hand, the base metal part other than the welded part is According to the above, TiN and ZrN are uniformly dispersed and precipitated in advance at the steel sheet manufacturing stage, and the same required toughness and strength are ensured.
次に、本発明の効果を実施例により例示する。Next, the effects of the present invention will be illustrated by examples.
なお、本明細書において、実施例を含めて「％」は特に
指定のない限り、「重量％」である。In addition, in this specification, including the examples, "%" means "% by weight" unless otherwise specified.
実施例
第１表に示した化学組成を有する鋼塊（Ａ−Ｔ）を、熱
間鍛造によって、板厚１５０ｓ＋ｍのスラブとした後、
第２表に示した条件で板厚３５ＩＩ１）の鋼板を製造し
た。Example After forming a steel ingot (A-T) having the chemical composition shown in Table 1 into a slab with a thickness of 150 s+m by hot forging,
A steel plate having a thickness of 35II1) was manufactured under the conditions shown in Table 2.
母材の機械的性質は、鋼板の板厚中心部、圧延直角方向
よりＪＩＳ Ａ号丸棒引張試験片（平行部の直径１４翔
糟、平行部長さ５０ｓ＋ｍ） 、およびＪＩＳＡ号シ中
ルビー衝撃試験片（２ｍｍＶノツチ）を採取して調査し
た。The mechanical properties of the base material were determined by JIS No. A round bar tensile test piece (parallel part diameter 14 mm, parallel part length 50 s + m) from the center of the thickness of the steel plate, in the direction perpendicular to rolling, and the JISA No. A round bar tensile test piece (parallel part diameter 14 mm, parallel part length 50 s + m), and JISA No. 2 medium ruby impact test. A piece (2 mm V notch) was taken and examined.
溶接継手部のシャルピー衝撃特性は、第３表の溶接条件
を用いて溶接を行った溶接継手部の表面から６ｍ−の部
分よりＪＩＳ ４号シャルピー衝撃試験片（２麿−■ノ
ツチ）を採取して調査した。The Charpy impact properties of the welded joint were determined by taking a JIS No. 4 Charpy impact test piece (2mm-■ notch) from a section 6 m from the surface of the welded joint that was welded using the welding conditions shown in Table 3. We investigated.
このようにして得られた母材および溶接継手部の機械的
特性は第２表にまとめて示した。The mechanical properties of the base metal and welded joint thus obtained are summarized in Table 2.
本発明にかかる組成範囲内の１ｇ （ｆ！４Ａ−鋼Ｌ）
を本発明の条件を用いて製造した鋼板（試験陽１〜１２
）は、母材の強度および靭性、ならびに溶接継手部の靭
性がいずれも優れている。1g within the composition range according to the present invention (f!4A-Steel L)
steel sheets manufactured using the conditions of the present invention (test positives 1 to 12)
) is excellent in both the strength and toughness of the base metal and the toughness of the welded joint.
これに対し、比較鋼（鋼Ｍ〜鋼Ｔ）は本発明の条件下で
製造した鋼板（試験磁１３〜２０）において母材の強度
と靭性は良好であるが、溶接継手部の靭性が劣る。On the other hand, in comparison steels (steel M to steel T), the strength and toughness of the base metal are good in the steel plates manufactured under the conditions of the present invention (test magnets 13 to 20), but the toughness of the welded joint is poor. .
比較例の中で鋼０はＴｉ量が少ない（Ｔｉ：０．００３
％）ため、ＨＡＺ １ｍｍおよびＨＡＺ ３ｍｍの靭性
が低い。Among the comparative examples, Steel 0 has a small amount of Ti (Ti: 0.003
%), the toughness of HAZ 1mm and HAZ 3mm is low.
また、ｔｌｉｌＱはＺｒ１ｌが少ない（Ｚｒ：０．００
２％）ため、溶接ボンド部の靭性が低い。In addition, tlilQ has less Zr1l (Zr: 0.00
2%), the toughness of the weld bond is low.
これらの比較例を対比することにより、Ｚｒの添加効果
、特にＴｉおよびＺｒの共存による相乗効果が明らかで
ある。By comparing these comparative examples, the effect of adding Zr, especially the synergistic effect of the coexistence of Ti and Zr, becomes clear.
他の比較例ではいずれの溶接法においても靭性が著しく
低い。In other comparative examples, the toughness was extremely low in all welding methods.
なお、同じく比較例である試験１）ｈ２Ｌ〜２４では、
化学組成は本発明で規定する範囲内であるが、製造条件
が本発明の条件とは異なるため、母材の機械的特性が劣
る。具体的には、試験ｍ２１は圧延加熱温度が高いため
靭性が低い、試験磁２２は仕上温度が低いため強度が低
い、試験嵐２３は焼戻しを行っていないため、降伏点お
よび靭性が低い、試験−２４は焼戻し温度が高いため引
張強さが低い、これらについては、このように機械的特
性が充分でなかったため溶接試験は行なわなかった。In addition, in Test 1) h2L-24, which is also a comparative example,
Although the chemical composition is within the range specified by the present invention, the mechanical properties of the base material are inferior because the manufacturing conditions are different from the conditions of the present invention. Specifically, test m21 has low toughness due to high rolling heating temperature, test magnetic 22 has low strength due to low finishing temperature, and test arashi 23 has low yield point and toughness because it is not tempered. -24 had a low tensile strength due to the high tempering temperature, and no welding tests were conducted on these because their mechanical properties were insufficient.
（発明の効果）
以上詳述したように、本発明によれば、溶接入熱量１０
０〜５００ｋＪ／ｃｍという大入熱溶接用であって、そ
の溶接部の靭性（ｖＥ−７゜）が３．５ｋｇｆ−ｍ以上
を満足するとともに、降伏点も３６ｋｇｆ／ｍｎ＋”以
上という大熱溶接用高張力鋼板が得られるのであって、
特にこれは本発明に規定する製法によれば母材について
も同様の機械的特性が得られるのであって、今日要求さ
れている一７０℃という寒冷地での大型構造物の溶接施
工を可能とし、その斯界に及ぼす利益には大きいものが
ある。(Effects of the Invention) As detailed above, according to the present invention, the welding heat input is 10
High heat welding for high heat input welding of 0 to 500 kJ/cm, the toughness of the welded part (vE-7°) satisfies 3.5 kgf-m or more, and the yield point is 36 kgf/mn+" or more. A high tensile strength steel plate for use can be obtained,
In particular, this is because the manufacturing method specified in the present invention allows similar mechanical properties to be obtained for the base material, making it possible to weld large structures in today's cold regions of -70°C. , the benefits it brings to this industry are significant.
Claims (3)
、Ｍｎ：０．７０〜１．６％、Ｐ：０．０１５％以下、
Ｓ：０．０１０％以下、ｓｏｌ．Ａｌ：０．００１〜０
．０５％、Ｔｉ：０．００５〜０．０２％、Ｚｒ：０．
００５〜０．０１５％、Ｎ：０．００３〜０．００８％
、 Ｆｅおよび付随不純物：残部 かつ （Ｔｉ／４７．９＋Ｚｒ／９１．２）／（Ｎ／１４．０
）：０．４〜１．０、Ｃｅｑ＝０．３６％以下 である組成を有することを特徴とする、溶接入熱量１０
０〜５００ｋＪ／ｃｍの溶接部の靭性（ｖＥ＿−＿７＿
０）が３．５ｋｇｆ・ｍ以上、降伏点３６ｋｇｆ／ｍｍ
＾２以上の大入熱溶接用高張力鋼板。(1) In weight%, C: 0.03-0.12%, Si: 0.05-0.4%
, Mn: 0.70 to 1.6%, P: 0.015% or less,
S: 0.010% or less, sol. Al: 0.001~0
．． 05%, Ti: 0.005-0.02%, Zr: 0.05%, Ti: 0.005-0.02%, Zr: 0.
005-0.015%, N: 0.003-0.008%
, Fe and accompanying impurities: balance and (Ti/47.9+Zr/91.2)/(N/14.0
): 0.4 to 1.0, Ceq = 0.36% or less, welding heat input 10
Toughness of weld zone from 0 to 500 kJ/cm (vE_-_7_
0) is 3.5 kgf/m or more, yield point 36 kgf/mm
High tensile strength steel plate for large heat input welding of ^2 or more.
、Ｍｎ：０．７０〜１．６０％、Ｐ：０．０１５％以下
、Ｓ：０．０１％以下、ｓｏｌ．Ａｌ：０．００１〜０
．０５％、Ｔｉ：０．００５〜０．０２％、Ｚｒ：０．
００５〜０．０１５％、Ｎ：０．００３〜０．００８％
、 さらに、Ｃｕ：０．５％以下、Ｎｉ：１．０％以下、Ｖ
：０．０４％以下、Ｎｂ：０．０３％以下、およびＣａ
：０．００４％以下の少なくとも１種、 Ｆｅおよび付随不純物：残部 かつ （Ｔｉ／４７．９＋Ｚｒ／９１．２）／（Ｎ／１４．０
）：０．４〜１．０、Ｃｅｑ＝０．３６％以下 である組成を有することを特徴とする、溶接入熱量１０
０〜５００ｋＪ／ｃｍの溶接部の靭性（ｖＥ＿−＿７＿
０）が３．５ｋｇｆ・ｍ以上、降伏点３６ｋｇｆ／ｍｍ
＾２以上の大入熱溶接用高張力鋼板。(2) In weight%, C: 0.03-0.12%, Si: 0.05-0.4%
, Mn: 0.70-1.60%, P: 0.015% or less, S: 0.01% or less, sol. Al: 0.001~0
．． 05%, Ti: 0.005-0.02%, Zr: 0.05%, Ti: 0.005-0.02%, Zr: 0.
005-0.015%, N: 0.003-0.008%
, Furthermore, Cu: 0.5% or less, Ni: 1.0% or less, V
: 0.04% or less, Nb: 0.03% or less, and Ca
: 0.004% or less of at least one kind, Fe and accompanying impurities: the balance and (Ti/47.9+Zr/91.2)/(N/14.0
): 0.4 to 1.0, Ceq = 0.36% or less, welding heat input 10
Toughness of weld zone from 0 to 500 kJ/cm (vE_-_7_
0) is 3.5 kgf/m or more, yield point 36 kgf/mm
High tensile strength steel plate for large heat input welding of ^2 or more.
、Ｍｎ：０．７〜１．６％、Ｐ：０．０１５％以下、Ｓ
：０．０１％以下、ｓｏｌ．Ａｌ：０．００１〜０．０
５％、Ｔｉ：０．００５〜０．０２％、Ｚｒ：０．００
５〜０．０１５％、Ｎ：０．００３〜０．００８％、 さらに、所望によりＣｕ：０．５％以下、Ｎｉ：１．０
％以下、Ｖ：０．０４％以下、Ｎｂ：０．０３％以下、
およびＣａ：０．００４％以下の少なくとも１種、 Ｆｅおよび付随不純物：残部 （Ｔｉ／４７．９＋Ｚｒ／９１．２）／（Ｎ／１４．０
）：０．４〜１．０、Ｃｅｑ＝０．３６％以下 である組成を有する鋼を９００℃〜１２００℃の温度域
に加熱した後、熱間圧延によって８００℃以上の温度で
所定の板厚とし、次いで、直ちに水冷によって室温にま
で急冷し、その後２００〜４５０℃の温度域で焼戻しを
行うことから成る、溶接入熱量１００〜５００ｋＪ／ｃ
ｍの溶接部の靭性（ｖＥ＿−＿７＿０）が３．５ｋｇｆ
・ｍ以上を満足することを特徴とする、降伏点３６ｋｇ
ｆ／ｍｍ＾２以上の大入熱溶接用高張力鋼板の製法。(3) In weight%, C: 0.03-0.12%, Si: 0.05-0.4%
, Mn: 0.7 to 1.6%, P: 0.015% or less, S
: 0.01% or less, sol. Al: 0.001-0.0
5%, Ti: 0.005-0.02%, Zr: 0.00
5 to 0.015%, N: 0.003 to 0.008%, further optionally Cu: 0.5% or less, Ni: 1.0
% or less, V: 0.04% or less, Nb: 0.03% or less,
and Ca: 0.004% or less of at least one kind, Fe and accompanying impurities: balance (Ti/47.9+Zr/91.2)/(N/14.0
): 0.4-1.0, Ceq = 0.36% or less is heated to a temperature range of 900°C to 1200°C, and then hot-rolled into a predetermined plate at a temperature of 800°C or higher. Welding heat input is 100 to 500 kJ/c.
The toughness (vE_-_7_0) of the welded part of m is 3.5 kgf
・Yield point 36kg, characterized by satisfying m or more
A method for manufacturing high tensile strength steel plates for large heat input welding of f/mm^2 or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29630486A JPS63149354A (en) | 1986-12-12 | 1986-12-12 | High tension steel sheet for high heat input welding and manufacture thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29630486A JPS63149354A (en) | 1986-12-12 | 1986-12-12 | High tension steel sheet for high heat input welding and manufacture thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63149354A true JPS63149354A (en) | 1988-06-22 |
Family
ID=17831817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29630486A Pending JPS63149354A (en) | 1986-12-12 | 1986-12-12 | High tension steel sheet for high heat input welding and manufacture thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63149354A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03291356A (en) * | 1990-04-06 | 1991-12-20 | Nippon Steel Corp | Steel having excellent toughness in weld heat affected zone |
| EP1254275A1 (en) * | 2000-12-14 | 2002-11-06 | Posco | STEEL PLATE TO BE PRECIPITATING TiN + ZrN FOR WELDED STRUCTURES, METHOD FOR MANUFACTURING THE SAME AND WELDING FABRIC USING THE SAME |
-
1986
- 1986-12-12 JP JP29630486A patent/JPS63149354A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03291356A (en) * | 1990-04-06 | 1991-12-20 | Nippon Steel Corp | Steel having excellent toughness in weld heat affected zone |
| EP1254275A1 (en) * | 2000-12-14 | 2002-11-06 | Posco | STEEL PLATE TO BE PRECIPITATING TiN + ZrN FOR WELDED STRUCTURES, METHOD FOR MANUFACTURING THE SAME AND WELDING FABRIC USING THE SAME |
| EP1254275A4 (en) * | 2000-12-14 | 2004-11-10 | Posco | STEEL PLATE TO BE PRECIPITATING TiN + ZrN FOR WELDED STRUCTURES, METHOD FOR MANUFACTURING THE SAME AND WELDING FABRIC USING THE SAME |
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