JPS581060A - Steel plate for spiral fins of heat exchanger and production thereof - Google Patents

Abstract

PURPOSE:To provide a steel plate of superior workability and high temp. oxidation resistance for spiral fins of heat exchangers by contg. C, Si, Mn, P, S, Cr, Al, N in iron under spicified ratio thereof. CONSTITUTION:The steel contg. <=0.015% C, <=0.5% Si, 0.10-0.35% Mn, <=0.03% P, <=0.01% S, 0.5-5% Cr, 0.01-0.08% Al, <=0.0060% N, and the balance consisting of iron and unavoidable impurities is hot rolld and is coiled at about <=650 deg.C. After this is descaled, it is cold rolled at 40-75% drafts percent. Such cold rolled steel plate is slit to narrow widths, for example, about 10-30mm., and is annealed at >=707 deg.C and <=Ar3 transformation point in a gaseous atmosphere contg. >=30% H2.

Description

【発明の詳細な説明】 本発明は加工性と耐高温酸化性のすぐれた熱交換器のス
パイラルフィン用鋼板とその製造法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steel plate for spiral fins of a heat exchanger having excellent workability and high temperature oxidation resistance, and a method for manufacturing the same.

例えば高温燃焼排ガス又は高温蒸気等を、熱交換器のバ
イづを通して熱交換することが行なわれている。For example, high-temperature combustion exhaust gas or high-temperature steam is exchanged with heat through the pipes of a heat exchanger.

前記高濡懲焼排ガス又は′高温蒸気−Ｗが通されるバイ
づの外周には熱交換を効率的に行なうために、スλイラ
ル状にフィシが設けられている。In order to efficiently exchange heat, a fissure is provided in a spiral shape on the outer periphery of the via through which the highly wet combustion exhaust gas or high-temperature steam W is passed.

ところで、該スパイラルフィンは第１図に示す如く、パ
イづｌに狭巾例えば１０〜３０ｍｍ巾の条鋼板２をスパ
イラルに巻回し、次いで溶接接合して製作される。Incidentally, as shown in FIG. 1, the spiral fin is manufactured by spirally winding a steel bar 2 having a narrow width, for example, 10 to 30 mm, around a pipe, and then welding and joining.

前記スパイラルフィシの製作時において、パイづ１に接
合されない側２−１ｅｉ接合される側２−２に比らべ大
きな伸び変形を受けるので、これに耐え得る加工性が必
要である。During manufacture of the spiral fin, the side 2-1 which is not joined to the piezo 1 is subjected to greater elongation deformation than the side 2-2 which is joined, so it is necessary to have workability that can withstand this.

一方、熱交換器のスパイラルフィンは言うまでもなく高
湿になるので、高温度における耐酸化性を有する必要が
ある。On the other hand, the spiral fins of the heat exchanger need to have oxidation resistance at high temperatures, as they are subject to high humidity.

一般に耐高温酸化性を向上する添加成分例えばＯｒ　、
　Ｍｇ等を鋼に含有させると、加工性の劣化が著るしい
。Additives that generally improve high-temperature oxidation resistance, such as Or,
When steel contains Mg or the like, the workability deteriorates significantly.

このようなことから、従来においては熱交換器のスパイ
ラルフィシに供し得る耐高温酸化性のすぐれた鋼板の製
造は殆んど内需とされていた。For this reason, in the past, the production of steel sheets with excellent high-temperature oxidation resistance that can be used in spiral fins of heat exchangers has been mostly for domestic demand.

本発明は係る実情から、鋼成分、製造法について詳細な
検討を行なった結果、Ｓｌを０．５％以下、Ｏｒを０．
５〜５％含有して耐高温酸化性を具備させ、一方Ｃｔ０
．０ｔｓ％以下、Ｍｎを０．１０〜０．３５％、Ｓを０
．０１％以下、さらにＮを０．００６０％以下として加
工性を高めた熱交換器のスパイラルフィン用鋼板とその
製造法を開発した。In view of the above-mentioned circumstances, the present invention was developed after detailed study of the steel composition and manufacturing method.
Contains 5 to 5% to provide high temperature oxidation resistance, while Ct0
．． 0ts% or less, Mn 0.10-0.35%, S 0
．． We have developed a steel plate for spiral fins of heat exchangers with improved workability by setting N at 0.01% or less, and furthermore, 0.0060% or less, and a method for manufacturing the same.

以下に本発明の詳細な説明する。The present invention will be explained in detail below.

まず鋼成分について述べる。First, let's talk about the steel components.

でその含有量は少ないほうが好ましい。ことに本発明に
おいては高い伸び特性とするために、０．０１５％以下
とする。The lower the content, the better. In particular, in the present invention, the content is set to 0.015% or less in order to obtain high elongation properties.

Ｓｌは含有蓋が増えると加工性か劣化し、スパイラルに
条鋼板を巻回するとき破断あるいはり５ツクが生じるの
で上限を０．５％以下とする。The upper limit of Sl is set to 0.5% or less because as the content increases, workability deteriorates and breakage or cracking occurs when the steel strip is spirally wound.

Ｍｎは熱間加工時の脆化防止に有効な成分であるが、そ
の含有量が増えると硬質化し伸びが劣化するので０．１
０〜０．３５％とする。Mn is an effective component for preventing embrittlement during hot working, but as its content increases, it becomes hard and elongation deteriorates, so 0.1
0 to 0.35%.

ｐＦｉその含有量が増えると−を脆化し、伸びの劣化が
著るしいので、０．０３％以下とする。If the pFi content increases, it becomes brittle and the elongation deteriorates significantly, so it is set at 0.03% or less.

Ｓは介在物を形成し、伸び、ことに局部伸びを劣化する
ので、その含有量は０．０１％以下に規制する。Since S forms inclusions and deteriorates elongation, especially local elongation, its content is regulated to 0.01% or less.

Ｏｒは耐高温酸化性を具備させるのに有効な成分である
が、一方その含有量が増えると加工性が劣化しスパイラ
ルに条鋼板を巻回するさい割れを生じることがあるので
０．５〜５％とする。Or is an effective component for providing high-temperature oxidation resistance, but on the other hand, if its content increases, workability may deteriorate and cracks may occur when the steel strip is spirally wound, so it should be 0.5~ 5%.

ｋｌは製鋼時の脱醗に必要な成分であるが、一方その緻
が多くなると熱間脆性を生ずる一因となるので０．０１
〜０．０８％とする。kl is a necessary component for removing alcohol during steelmaking, but on the other hand, if its density increases, it becomes a cause of hot brittleness, so it should be set at 0.01.
~0.08%.

Ｎは伸びを劣化する成分で、その含有蓋が増えると条−
板をスパイラルに巻回するさい加工割れが生じるので、
０．００６０％以下に規制する。N is a component that deteriorates elongation, and as its content increases, the
Processing cracks occur when the board is wound spirally, so
Regulated to 0.0060% or less.

以上の成分からなる鋼は、転炉あるいは電気炉等で溶製
され、連続鋳みまたは造塊分塊圧延によりスラつとされ
、次いで熱間圧延される。Steel comprising the above components is melted in a converter or electric furnace, made into a slug by continuous casting or ingot-blushing rolling, and then hot rolled.

この熱間１−圧延においては圧嬌後の捲取温度を６５０
℃以下にすることが臭化物の粗大化を防ぎ加工性を鴫保
する面から好ましい。In this hot 1-rolling, the winding temperature after rolling was set at 650.
It is preferable to keep the temperature below 0.degree. C. from the viewpoint of preventing bromide from becoming coarse and maintaining processability.

次いで脱スケ−しされ九後、冷間圧延される。It is then descaled and then cold rolled.

この冷間圧延における圧下率はｇ２図に示す叩く耐高温
酸化性成分のＳｉ、Ｏｒを含む鋼の伸び特性に及ぼす影
響が大きく、該圧下率を適正範囲にしなければ伸びが劣
化することが見出された。The reduction rate in this cold rolling has a large effect on the elongation properties of the steel containing Si and Or, which are high-temperature oxidation-resistant components shown in Figure G2, and if the reduction rate is not within the appropriate range, the elongation will deteriorate. Served.

なお第２図における鋼はＣ’　０．００５　％　、　Ｍ
ｎ　二〇、２８％　、　ＳＩ：０．２５％、Ｏｒ：１．
０％をベースとし、残部鉄及び不０Ｔｉ１成分からなる
板厚が１．４ｍ＋の冷延鋼板である。In addition, the steel in Fig. 2 has C' 0.005%, M
n 20, 28%, SI: 0.25%, Or: 1.
It is a cold-rolled steel sheet with a thickness of 1.4 m+, with the balance being iron and 1 component of non-Ti.

この知見から、高い伸びを得るために圧下率は４０〜７
５％とする。このようにした理由は圧下率が低くくなっ
ても、また高くなっても伸びの値は低下し、スパイラル
フイ、７製作時に割れを発生するので下限を４０％、上
限ｆ７５％とした。From this knowledge, in order to obtain high elongation, the reduction ratio is 40 to 7.
5%. The reason for doing this is that even if the rolling reduction becomes low or high, the elongation value decreases and cracks occur during the manufacture of spiral fillets, so the lower limit was set at 40% and the upper limit was set at 75%.

伸び特性を高める上で好ましい圧下率は５０〜７０％で
ある。In order to improve the elongation properties, the preferable rolling reduction is 50 to 70%.

冷間圧延した後、冷延板は狭巾に多条にスリットされる
。このスリットされた条鋼板の巾は例えば１０〜３０＋
＋ｗ＋＋である。After cold rolling, the cold rolled sheet is slit into multiple narrow strips. The width of this slit steel strip is, for example, 10 to 30+
+w++.

多条にスリットされた条鋼板は倦取られ、次いで焼鈍工
程にて焼鈍される。The steel strip that has been slit into multiple strips is removed and then annealed in an annealing process.

この焼鈍において留意すべきことは、本発明鋼はＯｒを
含有している関係かる焼鈍雰囲気によっては吸Ｎし、加
工性とくに伸びが劣化する。What should be noted in this annealing is that the steel of the present invention contains Or, so depending on the annealing atmosphere, it absorbs N, which deteriorates workability, especially elongation.

これを避るためには焼鈍雰囲気ガス中に３０％以上のＨ
！を含ませる必要がある。前記３０％以上のＨ２を含ん
でいると鋼中にＮが浸入する城は少なく、高い伸び特性
が得られる。To avoid this, it is necessary to contain 30% or more H in the annealing atmosphere gas.
! must be included. If the steel contains H2 of 30% or more, there will be less N infiltration into the steel, resulting in high elongation properties.

この焼鈍における焼鈍温度は７００℃以上、Ａｒ３変態
点以下とする。この理由は焼鈍湿度が低いと結晶粒が小
さく加工性が低くなるので下限を７００℃とする。また
焼鈍温度がＡｒ３変励点以上になると相変態に伴なう結
晶組織の変化があり、加工性を劣化するので上限をＡｒ
３変塾点とする。The annealing temperature in this annealing is 700°C or higher and lower than the Ar3 transformation point. The reason for this is that if the annealing humidity is low, the crystal grains will be small and the workability will be low, so the lower limit is set at 700°C. In addition, when the annealing temperature exceeds the Ar3 excitation point, the crystal structure changes due to phase transformation, which deteriorates workability, so the upper limit is set to Ar3.
3 odd cram school points.

以上により熱交換器のスパイラルフィシ用の条鋼板が製
造される。Through the above process, a steel bar plate for a spiral fin of a heat exchanger is manufactured.

次に実施例を示す。Next, examples will be shown.

第１表に本発明−の化学成分を示す。Table 1 shows the chemical components of the present invention.

第１表に示す化学成分をイする鋼を、同表に示す熱間圧
延、冷間圧延、スリットおよび焼鈍の各条件で製造し、
その機械的性質と高温酸化減量と、熱交換器のパイプに
条鋼板をスパイラル状に巻回したときの割れ発生の有無
を調査し几結果を第２表に示す。Steel having the chemical composition shown in Table 1 is manufactured under the hot rolling, cold rolling, slitting and annealing conditions shown in the same table,
The mechanical properties, high-temperature oxidation loss, and the occurrence of cracks when the steel strip was spirally wound around the pipe of a heat exchanger were investigated, and the results are shown in Table 2.

この結果からも明かなように、本発明によるサンプル１
，２，３．４は伸びが大きくて、条鋼板をスパイラルフ
ィシとして巻回したとき割れが全く生ぜず加工性がすぐ
れていることが確認された。As is clear from this result, sample 1 according to the present invention
, 2, 3.4 had a large elongation, and when the steel strip was wound as a spiral fin, no cracking occurred at all, and it was confirmed that the workability was excellent.

また高温酸化減磁も少なく、耐高温酸化性もすぐれてい
ることが認められた。It was also found that high-temperature oxidation demagnetization was low and high-temperature oxidation resistance was excellent.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は熱交換器のスパイラ１しフィシの製作説明図、
第２図は伸びに及ぼす冷延圧下率の影響を示す図である
。 ｌ・・・パイプ　　　　　２・・・条鋼板上ね 本　　多　　小　　半睡 岸　１）正　行１票詰ｌ ！ｌＴ　ｓ　興　治じ二Figure 1 is an explanatory diagram for manufacturing the spiral 1 and fissure of the heat exchanger.
FIG. 2 is a diagram showing the influence of cold rolling reduction on elongation. l...Pipe 2...Long steel plate top, large, small, semi-dark 1) Correct line, 1 vote packed l! lTs Kojiji

Claims (1)

【特許請求の範囲】 ｔ　　Ｃ：０．０１５％以下、ｓＩ：ｏ、ｓ％以下、Ｍ
ｎ’：０．１０〜０．３５％＋ｐ：ｏ、ｏ３％以下、Ｓ
ｉＯ，０１％以下、０ｒ＝０．５〜５％、Ａｚ：ｏ、ｏ
ｔ二〇、０８％、Ｎ：０．００６０襲以下を含み残部鉄
及び不可避不純物よりなる加工性と耐高温酸化性のすぐ
れ比熱交換器のλ゛バイラルフイン用Ｍ。 ２　　ｃ：ｏ、ｏｉｓ％以下、Ｓｔ：０．５％以下、Ｍ
ｎ：０．１０〜０．３５％、Ｐ：０．０３％以下、ｓ：
ｏ、ｏｔ％以下、０ｒ＝０．５〜５％、Ａ／、：０．０
１〜０．０８％、　Ｎ：０．００６０％以下を含み残部
鉄及び不可避不純物よりなる鋼を熱間圧延し、次いで圧
下率４０〜７５％で冷間圧延した後、狭巾にスリットし
、このスリットされた鋼板を７００℃以上Ａｒ３変態点
の温度でＨ２を３０％以上含む雰囲気カス中で焼鈍する
ことを特徴とする加工性と耐高温酸化性のすぐれた熱交
換器のスパイラルフィシ用鋼板の製造法。[Claims] t C: 0.015% or less, sI: o, s% or less, M
n': 0.10-0.35% + p: o, o3% or less, S
iO, 01% or less, 0r=0.5-5%, Az: o, o
M for λ Viral Fin, a specific heat exchanger with excellent workability and high temperature oxidation resistance, consisting of t20.08%, N: 0.0060 or less, and the balance iron and unavoidable impurities. 2 c: o, ois% or less, St: 0.5% or less, M
n: 0.10-0.35%, P: 0.03% or less, s:
o, ot% or less, 0r=0.5-5%, A/, :0.0
1 to 0.08%, N: 0.0060% or less, the balance consisting of iron and unavoidable impurities, is hot rolled, then cold rolled at a rolling reduction of 40 to 75%, and then slit into narrow widths. This slit steel plate is annealed in an atmosphere containing 30% or more of H2 at a temperature of 700°C or higher and the Ar3 transformation point, for use in spiral fins of heat exchangers with excellent workability and high-temperature oxidation resistance. Manufacturing method of steel plate.