JP3348793B2 - Manufacturing method of refractory steel for building structures - Google Patents
Manufacturing method of refractory steel for building structuresInfo
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- JP3348793B2 JP3348793B2 JP03977293A JP3977293A JP3348793B2 JP 3348793 B2 JP3348793 B2 JP 3348793B2 JP 03977293 A JP03977293 A JP 03977293A JP 3977293 A JP3977293 A JP 3977293A JP 3348793 B2 JP3348793 B2 JP 3348793B2
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Description
【０００１】[0001]
【産業上の利用分野】この発明は、建築構造物に使用さ
れる鋼材に関し、とくに常温における強度、靭性および
溶接性などはＪＩＳ規格構造用鋼（ＳＭ490 など）と同
等の特性をもち、高温での耐力向上を図ったものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel material used for a building structure, and in particular, has properties such as strength, toughness and weldability at room temperature which are equivalent to those of JIS standard structural steel (such as SM490). This is to improve the proof stress.
【０００２】[0002]
【従来の技術】従来、建築構造用鋼材としては、ＪＩＳ
Ｇ 3106「溶接構造用圧延鋼材」及びＪＩＳ Ｇ 31
14「溶接構造用耐候性熱間圧延鋼材」などに規定されて
いる鋼材が使用されているが、この種の鋼材は 350℃以
上の高温にさらされると耐力が著しく低下するため、建
築物に火災が発生した場合でも、鋼材の温度が 350℃を
超えないように耐火被覆を施すことが義務づけられてい
る。2. Description of the Related Art Conventionally, as steel for building structures, JIS has been used.
G 3106 “Rolled steel for welded structures” and JIS G 31
14 Steel materials specified in `` Weather-resistant hot-rolled steel materials for welded structures, '' etc. are used.However, when this type of steel is exposed to high temperatures of 350 ° C or more, its proof strength is significantly reduced. In the event of a fire, it is mandatory to apply a fireproof coating so that the temperature of the steel does not exceed 350 ° C.
【０００３】このような耐火被覆の実施は、施工コスト
を上昇させるだけでなく、支柱などの占有面積の増大を
招き、居住空間の有効利用を阻害する。そこでかような
耐火被覆処理の軽減または削減を可能とするため高温に
おいても高い耐力を有する鋼材の使用が種々検討されて
いる。しかしながら、従来の 1/2Mo鋼や 1Cr− 1/2Mo鋼
などの高温用鋼では常温強度が高すぎて加工性に難点が
あるだけでなく、溶接性もSM50などの構造用鋼に比べ大
幅に劣ることから、建築構造物としては適用できない。[0003] Implementation of such a fireproof coating not only increases construction costs, but also increases the area occupied by columns and the like, and hinders effective use of living space. Accordingly, various studies have been made on the use of steel materials having high proof stress even at high temperatures in order to enable the reduction or reduction of such refractory coating treatment. However, conventional high-temperature steels, such as 1 / 2Mo steel and 1Cr-1 / 2Mo steel, have too high a normal temperature strength to have difficulties in workability and also have a significantly higher weldability than structural steels such as SM50. Because it is inferior, it cannot be applied as a building structure.
【０００４】また、特公昭56 -31867 号公報、特開平57
−140855号公報および特開平57−174435号公報などに上
記 1/2Mo鋼や 1Cr− 1/2Mo鋼などの合金元素量を低減し
て溶接性を改良した高温用鋼が提案されているが、これ
らの鋼も建築構造物用耐火鋼としては高温耐力が十分と
はいい難く、しかも常温強度が高く、溶接性に劣るとい
う欠点もある。Further, Japanese Patent Publication No. 56-31867, Japanese Patent Laid-Open No. 57-31867,
-140855 and Japanese Patent Application Laid-Open No. 57-174435 disclose high temperature steels having improved weldability by reducing the amount of alloy elements such as the above 1 / 2Mo steel and 1Cr-1 / 2Mo steel, These steels also have drawbacks that it is difficult to say that the high-temperature proof stress is sufficient as fire-resistant steel for building structures, and that they have high room temperature strength and poor weldability.
【０００５】[0005]
【発明が解決しようとする課題】この発明の目的は、従
来の高温用低合金鋼に比べて溶接性に優れ、また従来の
溶接構造用鋼よりも高温強度（特に降伏強さおよび耐
力）が高く、しかも常温強度、靭性、溶接性などは同等
の特性を有する建築構造物用耐火鋼材の製造方法を提案
することにある。OBJECTS OF THE INVENTION It is an object of this invention is excellent in weldability as compared with the conventional high temperature for low alloy steels and high-temperature strength than conventional welding structural steel (particularly yield strength and yield strength) are An object of the present invention is to propose a method for producing a refractory steel material for a building structure which has high properties at room temperature, toughness, weldability, and the like.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、上記の目
的を達成すべく鋼材の成分組成について鋭意研究を行っ
た。その結果、以下の知見をえた。 Mo,Nb 炭化物の析出強化により高温強度を高めること
ができ、かつその炭化物をより微細化することによって
高温強度を一層向上することができる。Means for Solving the Problems The present inventors have conducted intensive studies on the composition of steel materials in order to achieve the above object. As a result, the following findings were obtained. The high-temperature strength can be increased by strengthening the precipitation of Mo, Nb carbide, and the high-temperature strength can be further improved by making the carbide finer.
【０００７】圧延仕上温度が 950℃未満に低下すると
γ域でNb炭化物が粗大析出するが、このγ域で析出する
Nb炭化物は、高温強度の向上にほとんど効果がないこ
と、さらにその後のα域で析出する微細なNb炭化物の量
を減少させること、またα域で析出するMo,Nb 炭化物の
析出核となり析出物サイズが大きくなることにより、結
果的に高温強度を低下させる。そこで、圧延仕上温度を
950℃以上とし、 950℃未満の冷却を急冷することによ
って、γ域で析出するNb炭化物の析出が防止でき、それ
による高温強度の低下が防止できる。When the rolling finishing temperature falls below 950 ° C., Nb carbide precipitates coarsely in the γ region, but precipitates in the γ region.
Nb carbide has little effect on improving high-temperature strength, further reduces the amount of fine Nb carbide precipitated in the α region, and precipitates as Mo, Nb carbide precipitate nuclei in the α region. Larger sizes result in lower high temperature strength. Therefore, the rolling finishing temperature
By setting the temperature to 950 ° C. or higher and rapidly cooling the temperature below 950 ° C., it is possible to prevent the precipitation of Nb carbide precipitated in the γ region, thereby preventing the reduction in high-temperature strength.
【０００８】800 〜600 ℃間のα変態温度域を急冷す
ることにより、変態温度が低下し、その結果α変態後の
冷却中および再加熱時に析出する炭化物がより微細析出
すため、高温強度が一層向上する。 圧延後の加速冷却を適正温度で停止することにより、
高温強度を低下させることなく、およびによって生
じる常温強度の過大化を抑制することができる。By rapidly cooling the α-transformation temperature range between 800 ° C. and 600 ° C., the transformation temperature is lowered, and as a result, carbides that precipitate during cooling and reheating after the α-transformation are more finely precipitated. Further improve. By stopping accelerated cooling after rolling at an appropriate temperature,
Without reducing the high-temperature strength, it is possible to suppress the increase in the normal-temperature strength caused by the reduction.
【０００９】本発明は上記知見に立脚するものである。
すなわち、 本発明は、重量％として、Ｃ： 0.03 〜0.
15％、Si： 0.01 〜0.60％、Mn：0.40〜1.20％、Mo：0.
15〜0.60％、Nb： 0.005〜0.100 ％、Al：0.050 ％以
下、Ｎ: 0.0010 〜0.060 ％を含み、残部がFe及び不可
避的不純物からなり、かつ下記式の値Ａ（％）が0.60〜
1.60の範囲を満足する鋼材を1050〜1300℃に加熱し、つ
いで熱間圧延を 950℃以上の温度で終了した後、直ちに
750 〜600℃の温度範囲まで急冷し、その後空冷するこ
とを特徴とする建築構造物用耐火鋼材の製造方法であ
り、ここで、 Ａ（％）＝Mn＋Cr＋Cu＋Ni＋ 500Ｂ であり、また本発明は、重量％として、Ｃ： 0.03 〜0.
15％、Si： 0.01 〜0.60％、Mn：0.40〜1.20％、Mo：0.
15〜0.60％、Nb： 0.005〜0.100 ％、Al：0.050％以
下、Ｎ: 0.0010 〜0.060 ％を含み、さらにCu：0.50％
以下、Ni：0.40％以下、Cr：0.80％以下、Ｂ：0.0030％
以下、Ti： 0.005〜0.03％、ＲＥＭ： 0.001〜0.020 ％
から選ばれた少なくとも一種以上を含有し、残部がFe及
び不可避的不純物からなり、かつ下記式の値Ａ（％）が
0.60〜1.60の範囲を満足する鋼材を1050〜1300℃に加熱
し、ついで熱間圧延を 950℃以上の温度で終了した後、
直ちに750 〜600 ℃の温度範囲まで急冷し、その後空冷
することを特徴とする建築構造物用耐火鋼材の製造方法
であり、ここで、 Ａ（％）＝Mn＋Cr＋Cu＋Ni＋ 500Ｂ である。The present invention is based on the above findings.
That is, in the present invention, C: 0.03 to 0.
15%, Si: 0.01-0.60%, Mn: 0.40-1.20%, Mo: 0.
15 to 0.60%, Nb: 0.005 to 0.100%, Al: 0.050% or less, N: 0.0010 to 0.060%, the balance consists of Fe and unavoidable impurities, and the value A (%) of the following equation is 0.60 to 0.60 %.
Heat a steel material satisfying the range of 1.60 to 1050-1300 ° C, then finish hot rolling at a temperature of 950 ° C or more and immediately
A method for producing a refractory steel material for building structures, characterized by quenching to a temperature range of 750 to 600 ° C. and then air cooling, wherein A (%) = Mn + Cr + Cu + Ni + 500B. %: C: 0.03-0.
15%, Si: 0.01-0.60%, Mn: 0.40-1.20%, Mo: 0.
15 to 0.60%, Nb: 0.005 to 0.100%, Al: 0.050% or less, N: 0.0010 to 0.060%, Cu: 0.50%
Below, Ni: 0.40% or less, Cr: 0.80% or less, B: 0.0030%
Below , Ti : 0.005 to 0.03%, REM: 0.001 to 0.020%
At least one selected from the group consisting of Fe and unavoidable impurities, and the value A (%) of the following formula is
After heating steel material satisfying the range of 0.60 to 1.60 to 1050 to 1300 ° C, and then completing hot rolling at a temperature of 950 ° C or more,
This is a method for producing a refractory steel material for building structures, characterized by immediately cooling to a temperature range of 750 to 600 ° C. and then air cooling, where A (%) = Mn + Cr + Cu + Ni + 500B.
【００１０】[0010]
【作用】まず、本発明において、成分組成を上記の範囲
に限定した理由について説明する。 Ｃ： 0.03 〜0.15％ Ｃは、所定の強度を確保するために添加するが、0.03％
未満ではその添加効果が小さく、一方、0.15％を越える
と溶接性、靭性が劣化するため、 0.03 〜0.15％の範囲
に限定した。First, the reason for limiting the component composition to the above range in the present invention will be described. C: 0.03 to 0.15% C is added to secure a predetermined strength.
If it is less than 0.15%, the effect of addition is small. On the other hand, if it exceeds 0.15%, the weldability and toughness deteriorate, so the content is limited to the range of 0.03 to 0.15%.
【００１１】Si： 0.01 〜0.60％ Siは製鋼時の脱酸剤及び常温強度向上元素として添加す
るが、0.01未満ではその効果が小さく、一方、0.60％を
超えると溶接ＨＡＺ靭性が劣化するので 0.01〜0.60％
の範囲とした。 Mn：0.40〜1.20％ Mnは常温強度確のために少なくとも0.40％以上必要とす
るが、Mo共存下におけるMnの多量添加は常温強度が高く
なりすぎるだけでなく、溶接性も劣化すのでMnは0.40〜
1.20％の範囲に限定した。Si: 0.01 to 0.60% Si is added as a deoxidizing agent and an element for improving the room temperature strength at the time of steel making. If it is less than 0.01, its effect is small, while if it exceeds 0.60%, the welding HAZ toughness is deteriorated. ~ 0.60%
Range. Mn: 0.40 to 1.20% Mn must be at least 0.40% or more to ensure room temperature strength. However, the addition of a large amount of Mn in the presence of Mo not only increases the room temperature strength too much, but also deteriorates the weldability. 0.40 ~
Limited to 1.20% range.
【００１２】Mo：0.15〜0.60％ Moは高温強度の向上に極めて有効な元素であり、その効
果を発揮させるためには少なくとも0.15％以上を必要と
するが、0.60％を超えると溶接性、靭性に悪影響を及ぼ
すだけでなく、常温強度が高くなりすぎるので、0.15〜
0.60％の範囲とした。Mo: 0.15 to 0.60% Mo is an extremely effective element for improving the high-temperature strength, and at least 0.15% or more is required to exert its effect, but if it exceeds 0.60%, the weldability and toughness are increased. Not only adversely affect the temperature but also the room temperature strength becomes too high,
The range was 0.60%.
【００１３】Nb： 0.005〜0.100 ％ Nbは常温強度、高温強度の向上に有効な元素であり、こ
の効果を発揮させるためには、少なくとも 0.005％を必
要とするが、0.100 ％を超えると溶接性及び靭性の劣化
を招くので、 0.005〜0.100 ％の範囲に限定した。 Al:0.050％以下 Alは脱酸元素として活用するとともに、鋼中のフリーＮ
を固定し靭性向上に有効であるが、0.050 ％を越えると
靭性を低下させるので、0.050 ％以下に限定した。Nb: 0.005 to 0.100% Nb is an element effective for improving the strength at room temperature and high temperature. To exhibit this effect, at least 0.005% is required. Therefore, the content is limited to the range of 0.005 to 0.100% because it causes deterioration of toughness. Al: 0.050% or less Al is used as a deoxidizing element and free N in steel
Is effective for improving toughness by fixing, but if it exceeds 0.050%, the toughness is reduced. Therefore, it is limited to 0.050% or less.
【００１４】Ｎ：0.0010〜0.0060％ Ｎは不可避的不純物として鋼中に含まれるものである
が、Tiと結合しTiN を形成して、溶接ＨＡＺの結晶粒粗
大化を抑制するのでＨＡＺ靭性の向上に効果を発揮す
る。このため最少量として0.0010％必要であるが、0.00
60％を越えて過剰に含有するとＨＡＺ靭性が著しく低下
するので、0.0010〜0.0060％の範囲に限定した。N: 0.0010 to 0.0060% N is contained in steel as an unavoidable impurity. However, it combines with Ti to form TiN and suppresses coarsening of the grain size of the welded HAZ, thereby improving the HAZ toughness. Effective for For this reason, the minimum amount of 0.0010% is necessary, but 0.0010%
If the content exceeds 60%, the HAZ toughness is significantly reduced. Therefore, the content is limited to the range of 0.0010 to 0.0060%.
【００１５】Cu：0.50％以下 Cuは常温強度を向上させるが、0.50％を越えると常温強
度を過剰に上昇させるだけでなく、熱間加工性を劣化さ
せるので、0.50％以下に限定した。 Ni：0.40％以下 Niは強度と靭性を向上させるために添加するが、0.40％
を越えると常温強度が高くなりすぎ、また経済的にも高
価となるため0.40％以下とした。Cu: 0.50% or less Cu improves the room temperature strength. However, if it exceeds 0.50%, not only does the room temperature strength rise excessively, but also the hot workability deteriorates, so it was limited to 0.50% or less. Ni: 0.40% or less Ni is added to improve strength and toughness, but 0.40%
If it exceeds, the room temperature strength becomes too high, and it becomes economically expensive.
【００１６】Cr：0.80％以下 Crは常温強度および高温強度を向上させる元素である
が、0.80％を越えると常温強度が高くなりすぎるととも
に溶接性の劣化を招くので、Crは0.80％以下に限定し
た。 Ｂ：0.0030％以下 Ｂは焼入性を高め常温強度および高温強度を向上させる
が、0.0030％超の添加は溶接性、ＨＡＺ靭性の劣化を招
くだけであるので、0.0030％以下に限定した。Cr: 0.80% or less Cr is an element that improves the room temperature strength and high temperature strength. However, if it exceeds 0.80%, the room temperature strength becomes too high and the weldability deteriorates, so Cr is limited to 0.80% or less. did. B: 0.0030% or less B enhances hardenability and improves room-temperature strength and high-temperature strength. However, the addition of more than 0.0030% only causes deterioration of weldability and HAZ toughness, so it was limited to 0.0030% or less.
【００１７】Ti：0.005 〜0.03％ Tiは大入熱溶接ＨＡＺの靭性向上に有効に寄与するが、
0.005 ％未満ではその効果が小さく、一方、0.03％越え
になるとかえってＨＡＺ靭性が低下するので0.005 〜0.
03％の範囲に限定した。 Ti : 0.005 to 0.03% Ti effectively contributes to improving the toughness of the high heat input welding HAZ.
If it is less than 0.005%, the effect is small, while if it exceeds 0.03%, the HAZ toughness is rather reduced, so that 0.005 to 0.2%.
Limited to the range of 03%.
【００１８】REM ：0.001 〜0.020 ％ REM は大入熱溶接ＨＡＺの靭性向上に有効に寄与する
が、0.0010％未満ではその効果が小さく、一方、0.0200
％越えになると清浄性が著しく低下するので0.001 〜0.
020 ％の範囲に限定した。 Ｐ： 0.020％以下、Ｓ： 0.015％以下 Ｐ、Ｓ、は不可避的不純物として含有されるが、鋼材の
延靭性を低下させ溶接ＨＡＺ靭性を低下させるのででき
るかぎり低減するのが好ましいが、Ｐは 0.020％、Ｓは
0.015％以下であれば許容できる。REM: 0.001 to 0.020% REM effectively contributes to the improvement of the toughness of large heat input welding HAZ, but less than 0.0010%, the effect is small, while 0.0200%.
%, The cleanliness is significantly reduced.
Limited to the 020% range. P: 0.020% or less, S: 0.015% or less P and S are contained as unavoidable impurities, but it is preferable to reduce as much as possible because the ductility of the steel material is reduced and the HAZ toughness of the weld is reduced. 0.020%, S is
0.015% or less is acceptable.
【００１９】なお、この発明においては各成分について
上記の範囲を満足するだけでは不十分であり、高温強度
を確保し、かつ常温強度をＪＩＳ規格溶接構造用SM400
、SM490 などと同等にするためには、Mnを含めてNi,C
u,Cr, Ｂの５成分の量を調整する必要がある。図１に、
常温および 600℃における耐力と（Mn＋Cr＋Cu＋Ni＋ 5
00Ｂ）量との関係を示す。同図から明らかなように（Mn
＋Cr＋Cu＋Ni＋ 500Ｂ）量が0.60〜1.60の範囲にある場
合においてのみ、常温強度および高温強度とも満足な強
度が得られる。そこで Ａ（％）＝Mn＋Cr＋Cu＋Ni＋ 5
00Ｂ を0.60〜1.60の範囲に限定した。In the present invention, it is not sufficient to satisfy the above ranges for each component, and it is not sufficient to secure high-temperature strength and to increase normal-temperature strength to JIS standard SM400 for welded structures.
, SM490, etc., Ni, C including Mn
It is necessary to adjust the amounts of the five components u, Cr, and B. In FIG.
Strength at room temperature and 600 ℃ and (Mn + Cr + Cu + Ni + 5
00B) shows the relationship with quantity. As is clear from the figure, (Mn
+ Cr + Cu + Ni + 500B) Only when the amount is in the range of 0.60 to 1.60, a satisfactory strength can be obtained for both normal temperature strength and high temperature strength. Therefore, A (%) = Mn + Cr + Cu + Ni + 5
00B was limited to the range of 0.60 to 1.60.
【００２０】次に圧延及び加速冷却条件について説明す
る。 加熱温度：1050〜1300℃ 0.005 ％以上のNbを十分に溶体化するには少なくとも10
50℃の加熱温度が必要であるが、一方1300℃超では結晶
粒が粗大化して靭性が低下するので、加熱温度は1050〜
1300℃の範囲とした。Next, rolling and accelerated cooling conditions will be described. Heating temperature: 1050-1300 ° C At least 10% to sufficiently dissolve 0.005% or more of Nb
A heating temperature of 50 ° C. is required, whereas if it exceeds 1300 ° C., the crystal grains become coarse and the toughness decreases, so the heating temperature is 1050 ° C.
The range was 1300 ° C.
【００２１】熱間仕上温度： 950℃以上 圧延温度が 950℃以下に低下すると圧延中のγ域でNb炭
化物が粗大析出し高温耐力を低下させるので仕上温度を
950℃とした。 圧延後の冷却速度 圧延後の冷却は加速冷却を行うが、1 ℃／Ｓ以上の冷却
速度が望ましい。こうすることにより 950℃以上で圧延
終了後のγ域でのNb炭化物の析出を防止できる。また、
800℃以下のα変態域を急冷することにより、α変態温
度を 750℃以下に低下し、Nb、Mo炭化物がより微細に析
出する基地組織が得られる。Hot finishing temperature: 950 ° C. or more When the rolling temperature is lowered to 950 ° C. or less, Nb carbide precipitates coarsely in the γ region during rolling and lowers the high-temperature yield strength.
It was 950 ° C. Cooling rate after rolling Cooling after rolling is performed by accelerated cooling, but a cooling rate of 1 ° C / S or more is desirable. By doing so, precipitation of Nb carbide in the γ region after the completion of rolling at 950 ° C. or higher can be prevented. Also,
By rapidly cooling the α-transformation region below 800 ° C, the α-transformation temperature is lowered to 750 ° C or less, and a matrix structure in which Nb and Mo carbides precipitate more finely can be obtained.
【００２２】冷却停止温度： 750〜 600℃ 冷却停止温度の低下とともに常温強度、高温強度はとも
に上昇する。冷却停止温度が 750℃以上より高いと十分
な常温強度、高温強度が得られない。一方、 600℃を下
回ると常温強度が高くなりすぎるとともに、鋼板の残留
応力および歪が大きくなるので、冷却停止温度は 750〜
600℃の範囲に限定した。Cooling stop temperature: 750 to 600 ° C. As the cooling stop temperature decreases, both the room temperature strength and the high temperature strength increase. If the cooling stop temperature is higher than 750 ° C, sufficient room-temperature strength and high-temperature strength cannot be obtained. On the other hand, if the temperature is lower than 600 ° C, the room temperature strength becomes too high, and the residual stress and strain of the steel sheet increase.
The range was limited to 600 ° C.
【００２３】なお上記のようにして得られた鋼材は、Ａ
c1変態点以下の温度で焼もどししても、常温強度および
高温強度の低下はない。The steel material obtained as described above is A
Even when tempered at a temperature lower than the c1 transformation point, there is no decrease in room temperature strength and high temperature strength.
【００２４】[0024]
【実施例】表１に示す種々の化学組成（記号Ａ〜Ｋ）の
鋼を1100〜1250℃に加熱し、表２に示す種々の条件で熱
間圧延、急冷処理を施した後、空冷した。得られた鋼材
の常温および 600℃における引張特性を表２に示した。
表１中のＡ〜Ｈ鋼が本発明による鋼で、Ｉ〜Ｋ鋼が比較
鋼である。Ｋ鋼は通常の溶接構造用圧延鋼材ＳＭ 490で
あるが、高温での耐力低下が著しい。また、Ｉ鋼は、本
発明の範囲に対してＣ量が高すぎる鋼であるが、常温強
度が高くなりすぎ、ＳＭ 490鋼の常温規格の上限（YS≦
421MPa,TS≦ 608MP）を超過している。さらにＪ鋼は
（Mn＋Cr＋Cu＋Ni＋ 500Ｂ）含有量が2.02％と適正範囲
の上限を越える鋼であり、高温強度は良好であるが、常
温強度が高くなりすぎている。EXAMPLES Steels having various chemical compositions (symbols A to K) shown in Table 1 were heated to 1100 to 1250 ° C., subjected to hot rolling and quenching under various conditions shown in Table 2, and then air-cooled. . Table 2 shows the tensile properties of the obtained steel at normal temperature and 600 ° C.
Steels A to H in Table 1 are steels according to the present invention, and steels I to K are comparative steels. The K steel is a normal rolled steel material for welded structure SM490, but its proof stress at high temperatures is remarkably reduced. Further, the steel I is a steel whose C content is too high with respect to the range of the present invention, but the room temperature strength is too high, and the upper limit of the room temperature specification of SM 490 steel (YS ≦
421MPa, TS ≦ 608MP). Further, the J steel has a (Mn + Cr + Cu + Ni + 500B) content of 2.02%, which exceeds the upper limit of the appropriate range, and has good high-temperature strength but too high normal-temperature strength.
【００２５】また、Ａ５，Ａ６，Ａ７は成分組成は適正
範囲であるものの、圧延仕上温度、冷却処理、さらに冷
却適正範囲からはずれているため、常温強度が高くなり
すぎたり、強度が不足している。これに対し、Ａ１〜Ａ
４，Ｂ〜Ｈ鋼はいずれも高温での耐力低下が少なく（YS
600 ／YSRT≧60％）、また 600℃の高温においてYS600
≧ 157MPa の高い強度が得られている。しかも常温強度
は現行のＳＭ 400〜 490級鋼と同レベルであり、建築構
造物用耐火鋼材として優れた鋼であることがわかる。A5, A6, and A7 have proper component compositions.
Although it is in the range, rolling finish temperature, cooling treatment, and further cooling
Room temperature strength because it is out of the proper range
Too strong or lacking in strength. In contrast, A1 to A
All 4, B to H steels show little decrease in proof stress at high temperatures (YS
600/ YSRT≧ 60%) and YS at high temperature of 600 ℃600
High strength of ≧ 157MPa is obtained. And room temperature strength
Is the same level as the current SM 400-490 grade steel,
It turns out that it is an excellent steel as a fire-resistant steel material for structures.
【００２６】[0026]
【表１】 [Table 1]
【００２７】[0027]
【表２】 [Table 2]
【００２８】[0028]
【発明の効果】本発明により、建築構造物に使用される
鋼材として、常温特性が従来の溶接構造用圧延鋼材と同
等であって、しかも高温における耐力低下が小さい耐火
鋼材を得ることができる。According to the present invention, it is possible to obtain a refractory steel material having a normal temperature characteristic equivalent to that of a conventional rolled steel material for a welded structure and having a small decrease in proof stress at high temperatures as a steel material used for a building structure.
【図１】常温および 600℃における耐力と（Mn＋Cr＋Cu
＋Ni＋ 500Ｂ）量との関係を示すグラフである。Fig. 1 Yield strength at normal temperature and 600 ° C and (Mn + Cr + Cu
+ Ni + 500B) is a graph showing the relationship with the amount.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 天野 虔一 千葉県千葉市中央区川崎町１番地 川崎 製鉄株式会社 技術研究本部内 (56)参考文献 特開 平４−308033（ＪＰ，Ａ) 特開 平５−59433（ＪＰ，Ａ) 特開 平２−254134（ＪＰ，Ａ) 特開 平３−6322（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C21D 8/00 - 8/10 C22C 38/00 - 38/60 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichi Amano 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Engineering Co., Ltd. (56) References JP-A-4-308033 (JP, A) JP-A-5-59433 (JP, A) JP-A-2-254134 (JP, A) JP-A-3-6322 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C21D8 / 00-8/10 C22C 38/00-38/60
Claims (2)
i： 0.01 〜0.60％、Mn：0.40〜1.20％、Mo：0.15〜0.6
0％、Nb： 0.005〜0.100 ％、Al：0.050 ％以下、Ｎ:
0.0010 〜0.060 ％を含み、残部がFe及び不可避的不純
物からなり、かつ下記式の値Ａ（％）が0.60〜1.60の範
囲を満足する鋼材を1050〜1300℃に加熱し、ついで熱間
圧延を 950℃以上の温度で終了した後、直ちに750 〜60
0 ℃の温度範囲まで急冷し、その後空冷することを特徴
とする建築構造物用耐火鋼材の製造方法。 Ａ（％）＝Mn＋Cr＋Cu＋Ni＋ 500Ｂ(1) C: 0.03 to 0.15% by weight,
i: 0.01 to 0.60%, Mn: 0.40 to 1.20%, Mo: 0.15 to 0.6
0%, Nb: 0.005 to 0.100%, Al: 0.050% or less, N:
A steel material containing 0.0010 to 0.060%, the balance being Fe and unavoidable impurities, and having a value A (%) of the following formula satisfying the range of 0.60 to 1.60 is heated to 1050 to 1300 ° C, and then hot-rolled. Immediately after finishing at 950 ° C or higher, 750-60
A method for producing refractory steel for building structures, characterized by quenching to a temperature range of 0 ° C., followed by air cooling. A (%) = Mn + Cr + Cu + Ni + 500B
i： 0.01 〜0.60％、Mn：0.40〜1.20％、Mo：0.15〜0.6
0％、Nb： 0.005〜0.100 ％、Al：0.050 ％以下、Ｎ:
0.0010 〜0.060 ％を含み、さらにCu：0.50％以下、N
i：0.40％以下、Cr：0.80％以下、Ｂ：0.0030％以下、T
i： 0.005〜0.03％、ＲＥＭ： 0.001〜0.020 ％から選
ばれた少なくとも一種以上を含有し、残部がFe及び不可
避的不純物からなり、かつ下記式の値Ａ（％）が0.60〜
1.60の範囲を満足する鋼材を1050〜1300℃に加熱し、つ
いで熱間圧延を 950℃以上の温度で終了した後、直ちに
750〜600 ℃の温度範囲まで急冷し、その後空冷するこ
とを特徴とする建築構造物用耐火鋼材の製造方法。 Ａ（％）＝Mn＋Cr＋Cu＋Ni＋ 500Ｂ2. C: 0.03 to 0.15% as weight%, S
i: 0.01 to 0.60%, Mn: 0.40 to 1.20%, Mo: 0.15 to 0.6
0%, Nb: 0.005 to 0.100%, Al: 0.050% or less, N:
0.0010 to 0.060%, Cu: 0.50% or less, N
i: 0.40% or less, Cr: 0.80% or less, B: 0.0030% or less , T
i : 0.005 to 0.03%, REM: at least one selected from 0.001 to 0.020%, the balance being Fe and unavoidable impurities, and a value A (%) of the following formula of 0.60 to
Heat a steel material satisfying the range of 1.60 to 1050-1300 ° C, then finish hot rolling at a temperature of 950 ° C or more and immediately
A method for producing refractory steel for building structures, characterized by quenching to a temperature range of 750 to 600 ° C. and then air cooling. A (%) = Mn + Cr + Cu + Ni + 500B
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03977293A JP3348793B2 (en) | 1993-03-01 | 1993-03-01 | Manufacturing method of refractory steel for building structures |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03977293A JP3348793B2 (en) | 1993-03-01 | 1993-03-01 | Manufacturing method of refractory steel for building structures |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06248334A JPH06248334A (en) | 1994-09-06 |
| JP3348793B2 true JP3348793B2 (en) | 2002-11-20 |
Family
ID=12562229
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03977293A Expired - Fee Related JP3348793B2 (en) | 1993-03-01 | 1993-03-01 | Manufacturing method of refractory steel for building structures |
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| Country | Link |
|---|---|
| JP (1) | JP3348793B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6238493B1 (en) * | 1999-02-05 | 2001-05-29 | Bethlehem Steel Corporation | Method of making a weathering grade plate and product thereform |
| EP1319731A1 (en) * | 2001-12-14 | 2003-06-18 | V & M Deutschland GmbH | Fireproof steel for a steel construction and process for manufacturing warm rolled hollow profiles, supports, a shape steel or a plate made thereof |
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1993
- 1993-03-01 JP JP03977293A patent/JP3348793B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06248334A (en) | 1994-09-06 |
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