JPS634019A - Production of steel for using at low temperature - Google Patents
Production of steel for using at low temperatureInfo
- Publication number
- JPS634019A JPS634019A JP14558786A JP14558786A JPS634019A JP S634019 A JPS634019 A JP S634019A JP 14558786 A JP14558786 A JP 14558786A JP 14558786 A JP14558786 A JP 14558786A JP S634019 A JPS634019 A JP S634019A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- temperature
- rolling
- low
- temp
- 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 64
- 239000010959 steel Substances 0.000 title claims abstract description 64
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 238000001816 cooling Methods 0.000 claims abstract description 21
- 238000005098 hot rolling Methods 0.000 claims abstract description 14
- 238000005096 rolling process Methods 0.000 claims abstract description 11
- 230000009466 transformation Effects 0.000 claims abstract description 8
- 239000012535 impurity Substances 0.000 claims abstract description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 230000001186 cumulative effect Effects 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 239000013078 crystal Substances 0.000 abstract description 7
- 229910052748 manganese Inorganic materials 0.000 abstract description 5
- 239000000203 mixture Substances 0.000 abstract description 5
- 229910052698 phosphorus Inorganic materials 0.000 abstract description 5
- 230000007704 transition Effects 0.000 abstract description 4
- 230000000694 effects Effects 0.000 description 11
- 229910001562 pearlite Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 229910000975 Carbon steel Inorganic materials 0.000 description 2
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 239000010962 carbon steel Substances 0.000 description 2
- 239000003949 liquefied natural gas Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- 229910001563 bainite Inorganic materials 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
童栗上少肌里充互
本発明は低温用鋼に関し、詳しくは、シャルピー衝撃値
遷移温度が一１２０℃以下である低温用鋼、特に、線材
及び棒鋼の制御冷却による製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to low-temperature steel, and more particularly to low-temperature steel having a Charpy impact value transition temperature of 1120°C or lower, particularly for controlled cooling of wire rods and steel bars. Relating to a manufacturing method.
従来の技術
近年、液化天然ガスの需要の増大を前景として、その貯
蔵施設及び設備の建設用として低温特性にすぐれる鉄筋
棒鋼が多く用いられるに至っている。BACKGROUND OF THE INVENTION In recent years, with the increasing demand for liquefied natural gas, reinforced steel bars with excellent low-temperature properties have come into widespread use in the construction of storage facilities and equipment for liquefied natural gas.
従来、このような低温用鋼としては高Ｎｉ鋼が一般的に
用いられており、例えば、条鋼類においては焼入れ焼戻
しを施した調質鋼が、また、鋼板類においては、調質鋼
のほかに非調質鋼が用いられている。しかし、高Ｎｉ鋼
は非常に高価であるので、これに代わる低温用鋼が強く
要望されている。Hitherto, high Ni steel has generally been used as such low-temperature steel. For example, in the case of long steel products, quenched and tempered steels are used, and in the case of steel plates, in addition to heat-treated steels, heat-treated steels are used. Non-thermal steel is used for this purpose. However, since high Ni steel is very expensive, there is a strong demand for a low temperature steel to replace it.
明が解決しようとする間 点
本発明者らは、低温用鋼における上記した問題を解決す
るために鋭意研究した結果、Ｃ量を低減すると共に、所
定量のＢを添加してなる低炭素鋼を制御冷却することに
よって、低温靭性に著しくすぐれる低炭素鋼を得ること
ができることを見出して、本発明に至ったものである。As a result of intensive research to solve the above-mentioned problems in low-temperature steel, the present inventors have developed a low-carbon steel in which the amount of C is reduced and a predetermined amount of B is added. The present invention was achieved based on the discovery that a low-carbon steel with significantly superior low-temperature toughness can be obtained by controlled cooling of the steel.
従って、本発明は、低温靭性にすぐれる非調質炭素鋼、
特に、シャルピー衝撃値遷移温度が一１２０℃以下であ
る低温用鋼、特に、線材及び棒鋼の制御冷却による製造
方法を提供することを目的とする。Therefore, the present invention provides a non-thermal carbon steel with excellent low-temperature toughness,
In particular, it is an object of the present invention to provide a method for producing low-temperature steel, particularly wire rods and steel bars, whose Charpy impact value transition temperature is 1120° C. or less by controlled cooling.
間Ｂｐを解決するための 段
本発明による低温用鋼の製造方法は、重量％でＣ０．０
３〜０．１５％、
Ｓｉ０．０５〜０．５０％、
Ｍｎ 、 １．３０〜２．００％、
ｐ ｏ、ｏｉｓ％以下、
Ｓ ０．０１５％以゛下、
Ｂ ０．０００５〜０．００３０％、残部鉄及び不
可避的不純物よりなる鋼をＡｃ＝変態点以上であって、
且つ、１１００℃以下の範囲の温度に加熱し、熱間圧延
において、その累積圧延率を４５％以上とすると共に、
Ａｒ、点板上であって、且つ、８５０℃以下の範囲の温
度にて仕上熱間圧延した後、０．３℃／秒以上の平均冷
却速度にて冷却することを特徴とする。In order to solve the gap Bp, the manufacturing method of low temperature steel according to the present invention has a C0.0
3-0.15%, Si 0.05-0.50%, Mn, 1.30-2.00%, po, ois% or less, S 0.015% or less, B 0.0005-0. 0030%, balance iron and unavoidable impurities, Ac=transformation point or higher,
And heating to a temperature in the range of 1100 ° C. or less, and in hot rolling, the cumulative rolling ratio is 45% or more,
It is characterized by finishing hot rolling on an Ar dot plate at a temperature in the range of 850°C or less, and then cooling at an average cooling rate of 0.3°C/sec or more.
先ず、本発明において用いる鋼の化学成分について説明
する。First, the chemical composition of the steel used in the present invention will be explained.
Ｃは、パーライトを生成させ、鋼強度を確保するうえか
らは有効であるが、他方、低温靭性を高めるためには、
その添加量を低減することが必要である。Ｃ量が０．１
５％を越えるときは、降伏強度が増す反面、靭性が劣化
し、他方、０．０３％よりも少ないときは、強度が十分
でないので、本発明においては、Ｃ量は０．０３〜０．
１５％の範囲とする。C is effective in generating pearlite and ensuring steel strength, but on the other hand, in order to improve low temperature toughness,
It is necessary to reduce the amount added. C amount is 0.1
When it exceeds 5%, the yield strength increases, but the toughness deteriorates.On the other hand, when it is less than 0.03%, the strength is insufficient, so in the present invention, the C content is 0.03 to 0.
The range is 15%.
Ｓｉは、製鋼段階における鋼の脱酸及び鋼の強化のため
に少な（とも０．０５％を添加することが必要であるが
、過多に添加するときは、靭性を劣化させるので、添加
量の上限を０．５０％とする。It is necessary to add a small amount of Si (both 0.05%) in order to deoxidize the steel and strengthen the steel in the steel manufacturing stage, but when adding too much, the toughness deteriorates, so the amount of Si added should be controlled. The upper limit is set to 0.50%.
Ｍｎは、本発明鋼においては、低炭素化に伴う鋼強度を
補うと共に、結晶粒を微細化して、靭性を向上させる効
果を有し、かかる効果を有効に得るためには、少なくと
も１．３０％を添加することが必要である。しかし、過
多に添加するときは、却って靭性を低下させるので、そ
の上限は２．５０％とする。In the steel of the present invention, Mn has the effect of supplementing the steel strength due to low carbonization, as well as refining crystal grains and improving toughness. In order to effectively obtain this effect, Mn must be at least 1.30 It is necessary to add %. However, when added in excess, the toughness is reduced, so the upper limit is set at 2.50%.
更に、本発明においては、Ｍ ｎ ／ Ｃ重量比が１３
以上であることが好ましい。Ｃは、前記したように、鋼
強度を高めるのに有効であるが、反面、その添加量が増
加するにつれて、セメンタイト量が増大し、パーライト
体積率が高まる結果、硬質の第２相の体積率が高まるの
で、吸収エネルギーが減少する。Ｍｎは、Ｃの添加によ
るかかる不利を解消するために有効であり、且つ、ＣＭ
に対して十分な量を添加することが好ましい。特に、本
発明に従って、Ｍ ｎ ／ Ｃ重量比を１３以上とする
ことによって、低温靭性を著しく高めることができる。Furthermore, in the present invention, the M n /C weight ratio is 13
It is preferable that it is above. As mentioned above, C is effective in increasing the steel strength, but on the other hand, as its addition amount increases, the amount of cementite increases and the volume fraction of pearlite increases, resulting in a decrease in the volume fraction of the hard second phase. increases, so the absorbed energy decreases. Mn is effective in eliminating such disadvantages caused by the addition of C, and
It is preferable to add a sufficient amount. In particular, according to the present invention, by setting the M n /C weight ratio to 13 or more, low-temperature toughness can be significantly improved.
Ｐ及びＳは、鋼を脆化させる元素であるので、できる限
り低減することが望ましいが、製造上の実用性及び費用
を考慮して、本発明においては、これらの元素をそれぞ
れ０．０１５％以下に規制する。Since P and S are elements that make steel brittle, it is desirable to reduce them as much as possible, but in consideration of manufacturing practicality and cost, in the present invention, these elements are each reduced to 0.015%. The following regulations apply.
Ｂは、鋼中のＮを固定して、低温靭性を高める効果を有
する。かかる効果を有効に得るためには、少な（とも０
．０００５％を添加することが必要であるが、過多に添
加しても、上記効果が飽和し、それ以上の添加は無意味
であるので、添加量の上限は０．００３０％とする。B has the effect of fixing N in the steel and improving low-temperature toughness. In order to effectively obtain this effect, it is necessary to use a small
．． It is necessary to add 0.0005%, but even if added in excess, the above effect will be saturated and further addition is meaningless, so the upper limit of the addition amount is set at 0.0030%.
本発明においては、鋼中におけるＮを更に固定して、す
ぐれた低温靭性を得るために、鋼に前記した元素に加え
て、
Ｍｏ０．０５〜０．２０％、
Ｔｉ ０．００５〜０．０３０％、及びＡＩ ０．０
０５〜０．０５０％
よりなる群から選ばれる少なくとも１種の元素を添加す
ることができる。In the present invention, in order to further fix N in the steel and obtain excellent low-temperature toughness, in addition to the above-mentioned elements, Mo0.05 to 0.20% and Ti 0.005 to 0.030 are added to the steel. %, and AI 0.0
05 to 0.050% of at least one element selected from the group consisting of:
これらの元素は、上述したように、いずれも鋼中の遊離
のＮを固定して、鋼の低温靭性を更に向上させる効果を
有し、更に、炭化物を形成することによって、強度を高
める効果を有する。また、ＡＩは、脱酸効果を高める効
果も有する。しかし、いずれの元素も過多に添加すると
きは、上記した強度向上効果が飽和すると共に、鋼の靭
性を却って劣化させる。従って、本発明においては、添
加量の上限は、Ｔｉについては０．０３０％、ＡＩにつ
いてはｏ、 ｏ ｓ ｏ％とする。As mentioned above, these elements all have the effect of fixing free N in the steel, further improving the low-temperature toughness of the steel, and further increasing the strength by forming carbides. have Moreover, AI also has the effect of increasing the deoxidizing effect. However, when adding too much of either element, the above-mentioned strength improvement effect is saturated and the toughness of the steel is actually deteriorated. Therefore, in the present invention, the upper limit of the amount added is 0.030% for Ti and 0.030% for AI.
ＭＯは、焼入れ性を向上させ、冷却中のフェライト・パ
ーライト変態を遅らせて、熱間加工後の再結晶温度を低
くする効果を有する。この効果を有効に得るためには、
少なくとも０．ＯＳ％を添加することが必要であるが、
しかし、過多量の添加は、ベイナイト変態を引き起こし
て、却って、鋼の靭性を劣化させるので、添加量の上限
は０．２０％とする。MO has the effect of improving hardenability, delaying ferrite-pearlite transformation during cooling, and lowering the recrystallization temperature after hot working. In order to effectively obtain this effect,
At least 0. Although it is necessary to add OS%,
However, addition of an excessive amount causes bainite transformation and actually deteriorates the toughness of the steel, so the upper limit of the addition amount is set to 0.20%.
次に、本発明による低温用鋼の製造方法について説明す
る。Next, a method for manufacturing steel for low temperature use according to the present invention will be explained.
本発明による低温用鋼は、上記したような化学成分を有
する鋼をＡｃ３変態点（約９００℃）以上であって、且
つ、１１００℃以下の範囲の温度に加熱し、熱間圧延に
おいて、その累積圧延率を４５％以上とすると共に、Ａ
ｒ３ （約７００℃）点板上であって、且つ、８５０℃
以下の範囲の温度にて仕上熱間圧延した後、０．３〜ｂ
平均冷却速度にて冷却することによって製造することが
できる。The low-temperature steel according to the present invention is produced by heating the steel having the above-mentioned chemical composition to a temperature in the range of above the Ac3 transformation point (approximately 900°C) and below 1100°C, and then hot rolling it. The cumulative rolling ratio is 45% or more, and A
r3 (approximately 700°C) on the point plate and 850°C
It can be produced by finishing hot rolling at a temperature in the following range and then cooling at an average cooling rate of 0.3 to b.
本発明による上記の製造方法において、鋼加熱温度は、
炭化物及びフェライトをオーステナイトに固溶させるた
めに、Ａｃ、変態点以上とする。しかし、１１００℃を
越えるときは、圧延後の結晶粒が粗大になり、微細な結
晶粒を有する組織を得ることができない。In the above manufacturing method according to the present invention, the steel heating temperature is
In order to dissolve carbides and ferrite into austenite, the Ac temperature is set to be above the transformation point. However, when the temperature exceeds 1100°C, the crystal grains after rolling become coarse, making it impossible to obtain a structure having fine crystal grains.
同様に、仕上温度が８５０℃を越える場合は、結晶粒が
粗大化し、靭性の低下を招く。他方、仕上温度が余りに
低いときは、鋼材に歪が残留して、靭性の低下を招く。Similarly, if the finishing temperature exceeds 850° C., the crystal grains become coarse, leading to a decrease in toughness. On the other hand, if the finishing temperature is too low, strain remains in the steel material, resulting in a decrease in toughness.
従って、本発明においては、微細な結晶粒を得るために
、仕上温度をＡｒ３点以上であって、且つ、８５０℃以
下の範囲の温度とすると共に、熱間圧延における累積圧
延率を４５％以上とする。Therefore, in the present invention, in order to obtain fine crystal grains, the finishing temperature is set at Ar 3 or above and at a temperature below 850°C, and the cumulative rolling ratio during hot rolling is set at 45% or above. shall be.
かかる熱間圧延後の平均冷却速度は、フェライト・パー
ライト組織を得るために、０．３〜ｂ／秒の範囲とする
。The average cooling rate after such hot rolling is in the range of 0.3 to b/sec in order to obtain a ferrite-pearlite structure.
本発明においては、熱間圧延を適冷オーステナイト域で
行なうので、場合によっては、組成量が生じることがあ
る。従って、必要に応じて、７５０℃以下の温度で焼戻
し処理を行なってもよい。In the present invention, since hot rolling is performed in an appropriately cooled austenite region, a compositional amount may occur depending on the case. Therefore, the tempering treatment may be performed at a temperature of 750° C. or lower, if necessary.
本発明においては、このようにして得られる鋼は、フェ
ライト・パーライト組織を有すると共に、フェライト結
晶粒度が９番以上であることが好ましい。結晶粒度が９
番よりも粗い場合は、所期の低温靭性を得ることが困難
であるからである。In the present invention, the steel thus obtained preferably has a ferrite-pearlite structure and a ferrite grain size of No. 9 or more. Grain size is 9
This is because if the thickness is coarser than the roughness, it is difficult to obtain the desired low-temperature toughness.
１皿皇四果
以上のように、本発明による低温用炭素鋼は、Ｃ量を低
減規制すると共に、特に、所定量のＢを含有する鋼を制
御冷却してなるために、微細な結晶粒からなり、シャル
ピー衝撃値が一１２０℃において１２ｋｇ−ｍ７ｃｍ２
以上であって、すぐれた低温靭性を有する。As described above, the carbon steel for low temperature use according to the present invention is made by controlling the amount of C to be reduced and, in particular, by controlling and cooling the steel containing a predetermined amount of B, so that it has fine crystal grains. It has a Charpy impact value of 12kg-m7cm2 at 1120°C.
In addition, it has excellent low-temperature toughness.
実施例
以下に実施例を挙げて本発明を説明するが、本発明はこ
れら実施例により何ら限定されるものではない。EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples in any way.
以下に示す成分組成を有する１５５ｍｍ角鋼片を９２０
℃に加熱した後、圧延の途中にて中間水冷を施し、仕上
温度７９０℃で直径３２ｗ１鋼に熱間圧延した後、冷却
床上で空冷する（平均冷却速度２℃／秒）制御冷却を施
して、本発明鋼及び比較鋼としての低温用鋼を製造した
。A 155mm square steel piece having the composition shown below is 920mm
After heating to ℃, intermediate water cooling is performed in the middle of rolling, and after hot rolling to diameter 32W1 steel at a finishing temperature of 790℃, controlled cooling is performed by air cooling on a cooling bed (average cooling rate 2℃/sec). , low-temperature steels were produced as the invention steel and comparative steel.
鋼Ａ（発明鋼）
Ｃ０．０９％、
Ｓｉ０．４６％、
Ｍｎ １．４２％、
Ｐ ０．０１５％、
ｓ ｏ、ｏｏｓ％、
Ｃｕ０．０１％、
Ｎｉ０．０２％、
Ｃｒ０．０３％、
Ａｌ ０．０２６％、
Ｎ ０．００６６％、
Ｂ ０．００１５％
調」−リトル毀と
ｃ ｏ、ｉｏ％、
Ｓｉ０．４６％、
Ｍｎ １．４２％、
Ｐ ０．０１５％、
Ｓ ０．００９％、
Ｃｕ０．０１ ％、
Ｎｉ０．０２％、
Ｃｒ０．０２％、
Ｍｏ０．１３％、
Ａｌ ０．０２５％、
Ｎ ０．００７２％、
Ｂ ０．００２０％
鋼Ｃ（従来鋼）
Ｃ０．０９％、
Ｓｉ０．４４％、
Ｍｎ１．５１％、
Ｐ ０．０１３％、
Ｓ ０．００７％、
Ｃｕ０．０１％、
Ｎｉ０．０２％、
Ｃｒ０．０４％、
Ａｌ ０．０２２％、
Ｎ ０．００７０％、
Ｂ ０．０００２％
このようにして得た棒鋼からＪＩＳ ４号試験片を製作
し、０〜−１５０℃の温度範囲でシャルピー試験を行な
って、第１図に示すように、衝撃値遷移曲線を得た。本
発明による低温用鋼が一１２０℃において１２ｋｇ−ｍ
／ｃｍ”以上のシャルピー衝撃値を有して、すぐれた低
温靭性を有することが明らかである。Steel A (invention steel) C0.09%, Si0.46%, Mn 1.42%, P 0.015%, so, oos%, Cu0.01%, Ni0.02%, Cr0.03%, Al 0.026%, N 0.0066%, B 0.0015% - Little crack and co, io%, Si 0.46%, Mn 1.42%, P 0.015%, S 0.009% , Cu0.01%, Ni0.02%, Cr0.02%, Mo0.13%, Al 0.025%, N 0.0072%, B 0.0020% Steel C (conventional steel) C0.09%, Si0 .44%, Mn 1.51%, P 0.013%, S 0.007%, Cu 0.01%, Ni 0.02%, Cr 0.04%, Al 0.022%, N 0.0070%, B 0 .0002% A JIS No. 4 test piece was made from the steel bar obtained in this way, and a Charpy test was conducted in the temperature range of 0 to -150°C to obtain an impact value transition curve as shown in Figure 1. . Low-temperature steel according to the present invention: 12 kg-m at 1120°C
It is clear that the material has a Charpy impact value of more than /cm'' and has excellent low-temperature toughness.
第１図は、シャルピー衝撃試験の結果を示すグラフであ
る。
特許出願人 株式会社神戸製鋼所
代理人 弁理士 牧 野 逸 部
第１図
一１５Ｑ −１００−５００莱友（°じ）FIG. 1 is a graph showing the results of the Charpy impact test. Patent Applicant Kobe Steel Co., Ltd. Agent Patent Attorney Ittsu Makino Department Figure 1-15Q -100-500 Raiyu (°ji)
Claims (2)
以上であつて、且つ、１１００℃以下の範囲の温度に加
熱し、熱間圧延において、その累積圧延率を４５％以上
とすると共に、Ａｒ＿３点以上であつて、且つ、８５０
℃以下の範囲の温度にて仕上熱間圧延した後、０．３〜
３０℃／秒の平均冷却速度にて冷却することを特徴とす
る低温用鋼の製造方法。(1) C0.03-0.15% by weight, Si0.05-0.50%, Mn0.50% or less, P0.015% or less, S0.015% or less, B0.0005-0.0030% , The steel consisting of the remainder iron and unavoidable impurities is heated to a temperature in the range of Ac_3 transformation point or higher and 1100°C or less, and in hot rolling, the cumulative rolling reduction is 45% or more, and Ar_3 points or more, and 850
After finish hot rolling at a temperature in the range of 0.3~
A method for producing steel for low temperature use, characterized by cooling at an average cooling rate of 30° C./sec.
、 残部鉄及び不可避的不純物よりなる鋼をＡｃ＿３変態点
以上であつて、且つ、１１００℃以下の範囲の温度に加
熱し、熱間圧延において、その累積圧延率を４５％以上
とすると共に、Ａｒ＿３点以上であつて、且つ、８５０
℃以下の範囲の温度にて仕上熱間圧延した後、０．３〜
３０℃／秒の平均冷却速度にて冷却することを特徴とす
る低温用鋼の製造方法。(2) In weight% (a) C0.03-0.15%, Si0.05-0.50%, Mn1.30-2.00%, P0.015% or less, S0.015% or less, B0. 0005 to 0.0030%, and (b) at least one selected from the group consisting of Mo0.05 to 0.20%, Ti0.005 to 0.030%, and Al0.005 to 0.050%. A steel containing certain elements and the balance consisting of iron and unavoidable impurities is heated to a temperature above the Ac_3 transformation point and below 1100°C, and in hot rolling, the cumulative rolling reduction is 45%. In addition to the above, Ar_3 points or more, and 850
After finish hot rolling at a temperature in the range of 0.3~
A method for producing steel for low temperature use, characterized by cooling at an average cooling rate of 30° C./sec.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14558786A JPS634019A (en) | 1986-06-20 | 1986-06-20 | Production of steel for using at low temperature |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14558786A JPS634019A (en) | 1986-06-20 | 1986-06-20 | Production of steel for using at low temperature |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS634019A true JPS634019A (en) | 1988-01-09 |
Family
ID=15388534
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14558786A Pending JPS634019A (en) | 1986-06-20 | 1986-06-20 | Production of steel for using at low temperature |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS634019A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001207240A (en) * | 1999-11-16 | 2001-07-31 | Kobe Steel Ltd | Steel product excellent in straightness after cold drawing |
| CN105256223A (en) * | 2015-11-12 | 2016-01-20 | 首钢总公司 | Micro-carbon steel with low yield strength and production method thereof |
-
1986
- 1986-06-20 JP JP14558786A patent/JPS634019A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001207240A (en) * | 1999-11-16 | 2001-07-31 | Kobe Steel Ltd | Steel product excellent in straightness after cold drawing |
| CN105256223A (en) * | 2015-11-12 | 2016-01-20 | 首钢总公司 | Micro-carbon steel with low yield strength and production method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4938266A (en) | Method of producing steel having a low yield ratio | |
| JPH08176659A (en) | Production of high tensile strength steel with low yield ratio | |
| JPH07278656A (en) | Production of low yield ratio high tensile strength steel | |
| CN106636920A (en) | High-hardenability and high-strength ultra-thick marine steel plate and production method thereof | |
| JPS63286517A (en) | Manufacture of high-tensile steel with low yielding ratio | |
| JP3228986B2 (en) | Manufacturing method of high strength steel sheet | |
| JPS6156235A (en) | Manufacture of high toughness nontemper steel | |
| JPS6250411A (en) | Production of rolled steel material having excellent homogeneity | |
| JPS634019A (en) | Production of steel for using at low temperature | |
| JPS5852458A (en) | Nonquenched and tempered steel with high strength and toughness | |
| JPH0159333B2 (en) | ||
| JPH0219175B2 (en) | ||
| JPS63183123A (en) | Production of high tensile steel having excellent low-temperature toughness after linear and spotty reheating | |
| JP3327065B2 (en) | Method for producing tempered high-strength steel sheet excellent in brittle crack propagation arrestability | |
| JPS589816B2 (en) | Manufacturing method of non-thermal rolled steel bar | |
| KR910003883B1 (en) | Making process for high tension steel | |
| JPH03207814A (en) | Manufacture of low yield ratio high tensile strength steel plate | |
| JPS62139821A (en) | Production of high-ductility high-strength cold rolled steel sheet | |
| CN110144521B (en) | High-strength and high-toughness bridge cable steel and preparation method thereof | |
| JPH01195242A (en) | Manufacture of high tension steel plate having superior toughness at low temperature with uniformity in thickness direction | |
| JPS6324013A (en) | Production of low yielding ratio high-tensile steel plate by direct hardening and tempering method | |
| JPH0229727B2 (en) | DORIRUKARAAYOBOKONOSEIZOHOHO | |
| JPH0670249B2 (en) | Manufacturing method of tempered high strength steel sheet with excellent toughness | |
| JPS6311617A (en) | Production of low temperature steel | |
| JPH04173922A (en) | Production of high strength steel for reinforcing bar having high yield elongation |