JP2718734B2 - Steel pipe for boiler which is resistant to sulfidation corrosion and erosion - Google Patents
Steel pipe for boiler which is resistant to sulfidation corrosion and erosionInfo
- Publication number
- JP2718734B2 JP2718734B2 JP1004605A JP460589A JP2718734B2 JP 2718734 B2 JP2718734 B2 JP 2718734B2 JP 1004605 A JP1004605 A JP 1004605A JP 460589 A JP460589 A JP 460589A JP 2718734 B2 JP2718734 B2 JP 2718734B2
- Authority
- JP
- Japan
- Prior art keywords
- steel pipe
- self
- boiler
- fluxing alloy
- corrosion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 229910000831 Steel Inorganic materials 0.000 title claims description 44
- 239000010959 steel Substances 0.000 title claims description 44
- 238000005260 corrosion Methods 0.000 title claims description 31
- 230000007797 corrosion Effects 0.000 title claims description 31
- 230000003628 erosive effect Effects 0.000 title claims description 13
- 238000005486 sulfidation Methods 0.000 title claims description 13
- 229910045601 alloy Inorganic materials 0.000 claims description 43
- 239000000956 alloy Substances 0.000 claims description 43
- 238000005507 spraying Methods 0.000 claims description 17
- 229910020637 Co-Cu Inorganic materials 0.000 claims description 2
- 229910017061 Fe Co Inorganic materials 0.000 claims description 2
- 229910017112 Fe—C Inorganic materials 0.000 claims description 2
- 229910017315 Mo—Cu Inorganic materials 0.000 claims description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 15
- 239000007789 gas Substances 0.000 description 14
- 239000003245 coal Substances 0.000 description 13
- 238000012360 testing method Methods 0.000 description 11
- 238000000576 coating method Methods 0.000 description 10
- 239000011248 coating agent Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 150000001875 compounds Chemical class 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 230000009471 action Effects 0.000 description 5
- 239000000571 coke Substances 0.000 description 5
- 239000004576 sand Substances 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 238000011084 recovery Methods 0.000 description 4
- 238000012546 transfer Methods 0.000 description 4
- 229910018487 Ni—Cr Inorganic materials 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000005987 sulfurization reaction Methods 0.000 description 3
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000010953 base metal Substances 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000009628 steelmaking Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 230000001012 protector Effects 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000003476 subbituminous coal Substances 0.000 description 1
- 238000007751 thermal spraying Methods 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Rigid Pipes And Flexible Pipes (AREA)
- Coating By Spraying Or Casting (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、耐硫化腐食性・耐エロージョン性を有する
ボイラ用鋼管に関し、石炭流動床ボイラ、コークスの乾
式冷却システムの排ガス回収ボイラ、セメントキルンの
排熱回収ボイラ、石炭燃焼ボイラ及び製鉄用焼結装置排
熱回収ボイラなどの伝熱管に有利に適用することができ
るボイラ用鋼管に関する。Description: TECHNICAL FIELD The present invention relates to a steel pipe for a boiler having resistance to sulfidation corrosion and erosion, and relates to a coal fluidized bed boiler, an exhaust gas recovery boiler for a coke dry cooling system, and a cement kiln. The present invention relates to a steel pipe for a boiler which can be advantageously applied to a heat transfer pipe such as an exhaust heat recovery boiler, a coal combustion boiler, and a sintering apparatus for steelmaking.
昭和48年の石油危機以来、エネルギー源としての石炭
が見直される一方、エネルギーの有効利用が一段と促進
されるようになった。Since the oil crisis in 1973, coal has been reviewed as an energy source, while effective use of energy has been further promoted.
流動床ボイラは、世界的に見て大量に埋蔵されている
低品位炭(例えば亜瀝青炭)を有効に利用できる上熱効
率がよく、炉内で脱硫できる利点があるため低公害石炭
燃焼プラントとしての価値が高く、多数運転されるよう
になってきた。Fluidized bed boilers have the advantage of being able to effectively utilize low-grade coal (for example, sub-bituminous coal) that has been buried in large quantities worldwide and have high thermal efficiency, and have the advantage of desulfurization in the furnace. It has high value and is being driven in large numbers.
流動床ボイラは通常第1図に示すように、流動媒体粒
子(例えば石灰石)1を炉内に適当量充填し、下部の空
気分散板2から上方へ空気を送り、空塔速度を流動開始
速度より早くして媒体粒子1を分散板2上から塔内に浮
上させて流動状態をつくり出し、この中に石炭供給ノズ
ル3から粉炭等を投入して流動媒体粒子1と接触させな
がら燃焼させるもので、この流動床中には蒸気を発生さ
せるボイラ鋼管ときには過熱水蒸気管などの層内管4が
設置されている。なお、図中、5は灰の排出口、6は対
流部の伝熱管、7は起動用バーナ、8は空気ダクトであ
る。As shown in FIG. 1, a fluidized bed boiler normally fills a furnace with a fluid medium particle (eg, limestone) 1 in an appropriate amount, sends air upward from a lower air dispersion plate 2, and sets the superficial velocity to the flow start velocity. In a shorter time, the medium particles 1 are floated from the dispersing plate 2 into the tower to create a fluidized state, into which pulverized coal or the like is injected from the coal supply nozzle 3 and burned while being brought into contact with the fluidized medium particles 1. In the fluidized bed, an in-layer pipe 4 such as a boiler steel pipe for generating steam and sometimes a superheated steam pipe is provided. In the figure, 5 is an ash discharge port, 6 is a convection section heat transfer tube, 7 is a starter burner, and 8 is an air duct.
これらの流動床中のボイラ鋼管(層内管)4は、粉炭
の流動媒体粒子の運動作用の流れに対しほぼ水平に設置
されているため、粉炭、媒体粒子などの固形物が層内管
4に激しく衝突し、その表面を著しく摩耗させる。この
ため層内管4の下面部にステンレス製のプロテクターを
取付けているが、これらは熱伝達率を低下させる一方、
多額の費用を要す欠点がある。Since the boiler steel pipes (in-layer pipes) 4 in these fluidized beds are installed substantially horizontally with respect to the flow of the kinetic action of the pulverized coal fluidized medium particles, solid matter such as pulverized coal, medium particles, etc. Violently, causing significant wear on its surface. For this reason, stainless steel protectors are attached to the lower surface of the inner layer tube 4. These reduce the heat transfer coefficient,
It has the disadvantage of requiring a great deal of money.
このような状況に鑑み、特開昭61-41756号公報では層
内管に対し、Ni-Cr合金を溶射するか、又はCo-Ni-Cr-W-
B-Si自溶合金を溶射することを提案している。しかしな
がら、前者の合金は耐食性に優れているものの耐摩耗性
に乏しい。また、後者の自溶合金は硬質ではあるが溶射
皮膜をフュージング処理する際微細な亀裂が多数発生す
る欠点がある。このため後者の自溶合金は耐摩耗性に優
れていても、溶射皮膜の亀裂部から腐食性ガス(石炭中
に含まれているS化合物の分解ガス、例えばH2S,COS,SO
xなど)が内部へ侵入し鋼管そのものを腐食損傷させる
欠点がある。In view of such a situation, Japanese Patent Application Laid-Open No. 61-41756 discloses that a Ni-Cr alloy is sprayed on an inner layer tube or Co-Ni-Cr-W-
We propose to spray B-Si self-fluxing alloy. However, the former alloy is excellent in corrosion resistance but poor in wear resistance. Although the latter self-fluxing alloy is hard, it has a drawback that many fine cracks are generated when the sprayed coating is subjected to the fusing treatment. For this reason, even though the latter self-fluxing alloy has excellent wear resistance, a corrosive gas (decomposed gas of S compound contained in coal, such as H 2 S, COS, SO
x etc.) penetrates into the inside and corrodes and damages the steel pipe itself.
一方、製鉄所では製鉄用のコークスを製造するため、
実用上の無酸素環境下で石炭を赤熱した後これを急冷す
るプロセスを採用している。従来は赤熱状態のコークス
に対し水を直接投入して冷却していたが、最近では多量
のN2ガスを送り込んで赤熱コークスを消化する一方、そ
の顕熱をうばった高温のN2ガスをボイラへ導いてその熱
を回収する方法が採用されるようになってきた。この排
熱回収ボイラはCoke Dry Quenching Boiler(CDQボイ
ラ)と呼ばれ、エネルギー回収ボイラとして多用されつ
つある。このプロセスから解るようにボイラへ導かれる
高温のN2ガス中にはO2が含まれていないため、石炭中に
含まれているS化合物がH2S,COSなどの腐食反応性に富
んだ化合物として存在し、厳しい高温硫化腐食を発生さ
せる原因となっている。On the other hand, steel mills produce coke for steelmaking,
It employs a process in which coal is glowed and quenched in a practically oxygen-free environment. Conventionally, was cooled by introducing water to coke redness directly while digesting red hot coke is fed into a large amount of N 2 gas recently, boiler hot N 2 gas took the sensible heat A method of recovering the heat by introducing the heat to the air has come to be adopted. This waste heat recovery boiler is called a Coke Dry Quenching Boiler (CDQ boiler) and is being widely used as an energy recovery boiler. As understood from this process, the high-temperature N 2 gas led to the boiler does not contain O 2 , so the S compound contained in the coal is rich in corrosion reactivity such as H 2 S, COS It exists as a compound and causes severe high-temperature sulfidation corrosion.
硫化腐食は加速酸化腐食に比べ一般に低温側で発生す
るため、腐食の発生温度範囲が広く、そのうえ腐食生成
物(硫化物)が多孔質であって金属面から剥離しやすい
性質を有し、酸化物品皮膜のような腐食反応の障壁とし
ての機能をもっていない。このため硫化腐食によるボイ
ラ鋼管の損耗速度は非常に大きくなる特徴がある。さら
に高温のN2ガス中には硬質の微細なコークス粉が多量に
含まれているため、摩耗による損耗が加味される結果、
CDQボイラでは流動床ボイラ同様硫化腐食と摩耗損傷対
策が重要な問題となっている。Sulfidation corrosion generally occurs at a lower temperature than accelerated oxidation corrosion, so the temperature range of corrosion occurrence is wide, and the corrosion products (sulfides) are porous and easily peel off from metal surfaces. It does not function as a barrier to corrosion reactions like an article film. For this reason, the rate of wear of the boiler steel pipe due to sulfidation corrosion is very large. Furthermore, since high-temperature N 2 gas contains a large amount of hard fine coke powder, as a result of the wear due to abrasion,
Sulfidation corrosion and wear damage countermeasures have become important issues in CDQ boilers as in fluidized bed boilers.
現在、この対策としても前述の特開昭61-41756号公報
が提案したNi-Cr合金溶射法及び自溶合金溶射法が適用
されているが、先に述べたように、この環境においても
Ni-Cr合金皮膜は耐摩耗性に乏しく、また自溶合金皮膜
は亀裂の発生による局部硫化腐食損傷に弱い欠点があ
る。At present, as a countermeasure, the Ni-Cr alloy spraying method and the self-fluxing alloy spraying method proposed in the above-mentioned JP-A-61-41756 are applied, but as described above, even in this environment,
Ni-Cr alloy films have poor abrasion resistance, and self-fluxing alloy films have the disadvantage that they are vulnerable to local sulfide corrosion damage due to cracking.
また、特開昭60-142103号公報では、JIS H8303で規定
しているMSFNi1〜5、MSFCo1、2及びMSFWC1、2などの
自溶合金を被覆したボイラ用伝熱管の製造方法を提案し
ている。しかしこの方法はボイラ用鋼管の表面に、硬質
で溶融することにより密着性のよい溶射皮膜を得るため
に制定された既知の自溶合金を単に溶射したものに過ぎ
ず、このような自溶合金を被覆させても合金皮膜には亀
裂が発生し、亀裂部を通しての腐食性ガスの侵入とこれ
による母材鋼管の腐食の発生は防止することはできな
い。Further, Japanese Patent Application Laid-Open No. 60-142103 proposes a method for manufacturing a heat transfer tube for a boiler coated with a self-fluxing alloy such as MSFNi1 to 5, MSFCo1, 2 and MSFWC1, 2 specified in JIS H8303. . However, this method is simply spraying a known self-fluxing alloy established in order to obtain a spray coating with good adhesion by hard and melting on the surface of a steel tube for a boiler. Does not prevent the corrosion of the base steel pipe due to the intrusion of corrosive gas through the cracks and the corrosion of the base steel pipe.
上述した硫化腐食の発生機構から明らかなように、硬
質の自溶合金皮膜が形成されていても腐食性のH2S,COS
などの硫化物ガスが亀裂部を通って内部へ侵入し、鋼管
を腐食させる。この腐食反応は自溶合金皮膜自体でも発
生するが、多くの場合、皮膜中には耐食性元素としての
Crが鋼管より多く含まれているため比較的緩やかであ
る。このため運転時間の経過に伴い自溶合金溶射皮膜直
下の鋼管が腐食損耗し腐食面積が拡大するにつれて溶射
皮膜が鋼管との接触面から剥離脱落する現象が屡々経験
されている。As is clear from the above-mentioned mechanism of sulfidation corrosion, even if a hard self-fluxing alloy film is formed, the corrosive H 2 S, COS
And other sulfide gases penetrate into the interior through the cracks and corrode the steel pipe. This corrosion reaction occurs in the self-fluxing alloy film itself, but in many cases, the film contains a corrosion-resistant element.
Cr is relatively slow because it contains more Cr than steel pipe. For this reason, a phenomenon has often been experienced in which the steel pipe immediately below the self-fluxing alloy spray coating is corroded and worn with the elapse of the operation time and the thermal spray coating is peeled off from the contact surface with the steel pipe as the corrosion area increases.
上記技術水準に鑑み、本発明は耐硫化腐食性・耐エロ
ージョン性に優れたボイラ用鋼管を提供しようとするも
のである。In view of the above technical level, the present invention aims to provide a steel pipe for a boiler having excellent resistance to sulfidation corrosion and erosion.
本発明は、鋼管外表面にAlを溶射した後、その上にNi
-Cr-B-Si-C-Fe-Coからなる自溶合金、又は、Ni-Cr-B-Si
-C-Fe-Co-Cuからなる自溶合金、又はNi-Cr-B-Si-C-Fe-C
o-Mo-Cuからなる自溶合金、又は、Ni-Cr-B-Si-C-Fe-Co-
Mo-Wからなる自溶合金を溶射し、フュージング処理を施
してなることを特徴とする耐硫化腐食性・耐エロージョ
ン性ボイラ鋼管である。The present invention, after spraying Al on the outer surface of the steel pipe, Ni
-Cr-B-Si-C-Fe-Co self-fluxing alloy or Ni-Cr-B-Si
-C-Fe-Co-Cu self-fluxing alloy or Ni-Cr-B-Si-C-Fe-C
Self-fluxing alloy consisting of o-Mo-Cu, or Ni-Cr-B-Si-C-Fe-Co-
A boiler steel tube resistant to sulfidation corrosion and erosion, which is obtained by spraying a self-fluxing alloy made of Mo-W and performing a fusing treatment.
石炭の還元燃焼過程で発生するH2S,COSなどのガス状
S化合物の耐食に耐える金属元素としてCrが最もよく知
られている。このCrは耐熱、耐酸化元素としても有名で
あり、耐熱金属中には必ず含まれている有用な元素であ
り、ボイラ用鋼管や多くの自溶合金中にも含まれてい
る。Cr is best known as a metal element that resists the corrosion resistance of gaseous S compounds such as H 2 S and COS generated during the reduction combustion process of coal. This Cr is also famous as a heat-resistant and oxidation-resistant element, is a useful element that is always contained in heat-resistant metals, and is also contained in steel tubes for boilers and many self-fluxing alloys.
一方、本発明の特徴的な成分であるAlに関しては、Cr
以上の耐硫化、耐酸化性能を保有しているにも拘らず、
JIS H8303記載の自溶合金類には一切添加されていな
い。これは自溶合金の目的が元来その優れた硬さ、密着
性、緻密性などの物理的性質のみに主眼がおかれていた
からであり、したがって、耐酸化性、耐硫化特性などの
化学的性質は、Crが含有されていない自溶合金は極めて
乏しく、またCrを含んでいる自溶合金でも本来含まれて
いる程度の含有量では本発明の目的としているH2S,COS
などによる硫化腐食作用には自ら限界があり、寿命が短
い。On the other hand, regarding Al which is a characteristic component of the present invention, Cr
Despite possessing the above sulfuration and oxidation resistance performance,
No addition is made to the self-fluxing alloys described in JIS H8303. This is because the purpose of the self-fluxing alloy was originally focused only on its physical properties such as its excellent hardness, adhesion, and denseness, and therefore, its chemical properties such as oxidation resistance and sulfidation resistance. is self-fluxing alloy of Cr is not contained is very poor, also H 2 S being the object of the present invention at a content enough to have originally included in the self-fluxing alloy which contains Cr, COS
Sulfidation corrosion action by itself has its own limit and its life is short.
そこで、本発明は、ボイラ鋼管表面に予めAl溶射層を
形成した後、その上に自溶合金を溶射し、フュージング
処理して自溶合金及膜を形成することにより、仮に、自
溶合金皮膜に亀裂が発生して外部から腐食性のS化合物
が侵入してきても、上記のAl溶射層では硫化腐食を完全
に防止することができる。Accordingly, the present invention provides a method for forming a self-fluxing alloy film on a surface of a boiler steel pipe by forming a sprayed self-fluxing alloy thereon, forming a self-fluxing alloy and a film by fusing, and forming a self-fluxing alloy film. Even if cracks occur in the steel and corrosive S compounds enter from the outside, the above-mentioned Al sprayed layer can completely prevent sulfide corrosion.
なお、鋼管上のAl溶射皮膜は、その上に自溶合金を溶
射し、これをフュージング処理するために1100〜1200℃
に加熱すると、660℃前後の融点を有するAlは当然溶融
して自溶合金と冶金的結合をするのみならず、鋼管中へ
も浸透するので、Al溶射皮膜と自溶合金皮膜の結合はも
とより、鋼管とも強く密着するので剥離するようなこと
はない。In addition, the Al sprayed coating on the steel pipe is sprayed with a self-fluxing alloy on it, and this is subjected to fusing treatment at 1100 to 1200 ° C.
When heated to a temperature of approximately 660 ° C, Al not only melts and forms a metallurgical bond with the self-fluxing alloy, but also penetrates into the steel pipe. Also, since it adheres strongly to the steel pipe, it does not peel off.
なお、鋼管表面へ直接コーティングするAlは、JIS H5
202(1977)AC1A〜AC9BのようにSiを含むものでも十分
適用することができる。これは、SiがAl及び鋼管との親
和性に富むとともにS化合物に対しても高い抵抗性をも
っているからである。The aluminum that is directly coated on the steel pipe surface is JIS H5
Even those containing Si such as 202 (1977) AC1A to AC9B can be applied sufficiently. This is because Si has a high affinity for Al and steel pipes and also has a high resistance to S compounds.
本発明で採用するAlの溶射法の概要は、例えばAlの線
を電気アーク、可燃ガス炎、プラズマアークによって溶
射しつつ圧縮空気で噴射する極く一般的な方法である。The outline of the thermal spraying method of Al employed in the present invention is, for example, a very general method of spraying compressed aluminum while spraying an Al wire with an electric arc, a combustible gas flame, or a plasma arc.
また、本発明で採用するフュージング処理条件は、一
般的に電気炉、高周波誘導加熱、又は、天然ガス、プロ
パン、アセチレンなどの燃焼炎によって溶射皮膜を大気
中で1000〜1300℃に加熱することによって行われる。Further, the fusing treatment conditions employed in the present invention are generally an electric furnace, high-frequency induction heating, or natural gas, propane, by heating a sprayed coating to 1000 to 1300 ° C. in the atmosphere by a combustion flame such as acetylene. Done.
本発明において使用される自溶合金としては、JIS H8
303(1976)で規定されているMSFi1、MSFi2、MSFi4及び
MSFCo1が使用し得る。その化学組成を第1表に示す。As the self-fluxing alloy used in the present invention, JIS H8
MSFi1, MSFi2, MSFi4 and
MSFCo1 can be used. Table 1 shows the chemical composition.
〔実施例〕 供試ボイラ鋼管として、STB42及びSTBA24の外径54m
m、厚さ3.2mmの鋼管を用い、これにAlを厚さ60μm溶射
してAl溶射皮膜を形成した後、MSFNi4合金に属するCr:1
4.8、B:3.2、Si:3.9、C:0.7、Fe:3.6、Co:0.6、Mo:3.
4、Cu:3.0、Ni:残なる組成(いずれも重量%)の自溶合
金を300μm溶射し、これを1100〜1200℃に加熱フュー
ジング処理を施した。 (Example) As a test boiler steel pipe, the outer diameter of STB42 and STBA24 is 54 m.
m, using a 3.2 mm thick steel pipe, after spraying Al 60 μm thick on this to form an Al sprayed film, Cr belonging to the MSFNi4 alloy:
4.8, B: 3.2, Si: 3.9, C: 0.7, Fe: 3.6, Co: 0.6, Mo: 3.
4. Cu: 3.0, Ni: A self-fluxing alloy having the remaining composition (all in weight%) was sprayed at 300 μm and subjected to a heat fusing treatment at 1100 to 1200 ° C.
実施例において、Al溶射を省略した以外は、実施例と
同様に自溶合金を300μm溶射し、同様に加熱フュージ
ング処理を施した。In the example, a self-fluxing alloy was sprayed at 300 μm in the same manner as in the example, except that the Al spraying was omitted, and a heat fusing treatment was performed similarly.
(評価) 実施例及び比較例で得た表面処理済みボイラ鋼管の表
面をカラーチェックしたところ、実施例及び比較例とも
に自溶合金皮膜面に亀裂が発生していた。(Evaluation) The surface of the surface-treated boiler steel pipe obtained in each of Examples and Comparative Examples was subjected to a color check. As a result, cracks were generated on the surface of the self-fluxing alloy film in each of Examples and Comparative Examples.
次に、これらの鋼管から亀裂部を含む試験片(長100m
m)を切出し、これを600℃のH2S:1%、COS:0.3%、H2:2
%、N2:残り(何れも容量%)のガス雰囲気中に300時
間曝露した後、皮膜の断面を光学顕微鏡により調査し、
結果を第2表に示した。Next, test specimens containing cracks (length 100 m)
m) was cut out, and this was heated at 600 ° C. in H 2 S: 1%, COS: 0.3%, H 2 : 2
%, N 2 : After exposure to the remaining (all by volume%) gas atmosphere for 300 hours, the cross section of the film was examined with an optical microscope,
The results are shown in Table 2.
比較例の自溶合金皮膜そのものには多少の硫化腐食の
発生は認められるものの、大きな変化はない。しかし、
皮膜の亀裂部を通って侵入したH2S,COSの腐食性により
ボイラ鋼管(母材)が激しく腐食され、皮膜の一部が基
底部(皮膜と鋼管との結合部)から、すでに剥離しつつ
ある状況が観察された。 Although some occurrence of sulfidation corrosion is observed in the self-fluxing alloy film itself of the comparative example, there is no significant change. But,
The boiler steel pipe (base metal) is severely corroded due to the corrosiveness of H 2 S, COS that has penetrated through the cracks in the coating, and part of the coating has already been peeled off from the base (the joint between the coating and the steel pipe). A rising situation was observed.
これに対し、実施例の鋼管は皮膜には比較例の皮膜同
様の亀裂が発生しているが、母材の鋼管上に溶射されて
いるAl層の存在により全く腐食されず、卓越した耐硫化
腐食性を発揮することが確認された。In contrast, the steel pipe of the example had cracks in the coating similar to the coating of the comparative example, but was not corroded at all by the presence of the Al layer sprayed on the base steel pipe, and had excellent sulfurization resistance. It was confirmed that it exhibited corrosiveness.
上記の実施例及び比較例の表面処理済みの鋼管を用い
て、高温環境下及び高温腐食環境下における耐ブラスト
エロージョン性(以下、エロージョン)を調査した。The blast erosion resistance (hereinafter referred to as erosion) in a high-temperature environment and a high-temperature corrosion environment was investigated using the surface-treated steel pipes of the above Examples and Comparative Examples.
図2は、エロージョン試験装置の概要を示したもので
ある。試験鋼管9を高温炉10の中に設置し、その前面に
設けられた噴射ノズル11から珪砂(平均粒径100μm)
を鋼管に向け、加温された圧縮空気(3kgf/cm2)により
鋼管表面へ噴射した。高温炉10へ導入する空気は予熱炉
12によってほぼ試験温度迄上昇させ、高温炉10から出た
空気サイクロン13を通して珪砂を分離した後、再循環さ
せている。腐食性のガスは、あらかじめ所定の組成に調
整済のボンベ14から流量計15によって流量を調整し、高
温炉中へ注入できるようになっている。FIG. 2 shows an outline of the erosion test apparatus. A test steel pipe 9 is set in a high-temperature furnace 10 and silica sand (average particle diameter 100 μm) is injected from an injection nozzle 11 provided in front of the test steel pipe 9.
Was directed toward the steel pipe, and injected to the surface of the steel pipe by heated compressed air (3 kgf / cm 2 ). The air introduced into the high-temperature furnace 10 is a preheating furnace
The temperature is raised to approximately the test temperature by 12, and the silica sand is separated through an air cyclone 13 discharged from the high-temperature furnace 10 and then recirculated. The flow rate of the corrosive gas is adjusted by a flow meter 15 from a cylinder 14 which has been adjusted to a predetermined composition in advance, and can be injected into a high-temperature furnace.
高温の空気環境下におけるエロージョン試験の評価
は、600℃の温度で10時間珪砂を吹付け、試験後の自溶
合金皮膜の減少程度を顕微鏡により観察することによっ
て実施した。第3表は、この結果を示したもので、実施
例の皮膜は比較例とほぼ同等の耐エロージョン性を有し
ていた。Evaluation of the erosion test in a high-temperature air environment was performed by spraying silica sand at a temperature of 600 ° C. for 10 hours and observing the degree of reduction of the self-fluxing alloy film after the test by a microscope. Table 3 shows the results. The coatings of the examples had almost the same erosion resistance as the comparative examples.
次に、高温炉中にH2S:1%、COS:0.5%、H2:2%、残:
N2の腐食性ガスを2.5時間通した後、2.5時間珪砂を吹付
ける試験を2回繰返した。 Then, in a high-temperature furnace, H 2 S: 1%, COS: 0.5%, H 2 : 2%, remaining:
After passing a corrosive gas of N 2 for 2.5 hours, a test in which silica sand was blown for 2.5 hours was repeated twice.
第4表は、この結果を示したもので、腐食作用とエロ
ージョン作用が繰返される環境では、実施例の自溶合金
皮膜の損耗率は50%であったが、母材の鋼管は健在であ
った。比較例の皮膜は、腐食性のガスにより浸食され、
その表面に多孔質で、密着性に乏しい腐食生成物(硫化
物)が形成された後、珪砂の吹付けによりこの腐食生成
物が除去され、母材の鋼管にも損傷が認められた。Table 4 shows the results. In an environment where the corrosive action and the erosion action were repeated, the wear rate of the self-fluxing alloy film of the example was 50%, but the steel pipe of the base metal was in good condition. Was. The coating of the comparative example is eroded by corrosive gas,
After a porous, poorly adhered corrosion product (sulfide) was formed on the surface, the corrosion product was removed by spraying silica sand, and damage was also observed on the base steel pipe.
〔発明の効果〕 本発明は、上記の構成を採用し、ボイラ用鋼管表面に
Alを溶射した後、自溶合金皮膜を形成させることによ
り、自溶合金皮膜に亀裂が発生しても、鋼管の硫化腐食
を防止することが可能になった。 [Effects of the Invention] The present invention adopts the above-described configuration and applies
By forming a self-fluxing alloy film after spraying Al, even if a crack occurs in the self-fluxing alloy film, it has become possible to prevent sulfuration corrosion of the steel pipe.
第1図は一般的な石炭流動床のボイラの例の断面図を示
し、第2図は本発明の実施例としてのボイラ用鋼管の耐
ブラストエロージョン性を試験するための腐食エロージ
ョン用試験装置の概略図である。FIG. 1 is a sectional view of an example of a general coal fluidized bed boiler, and FIG. 2 is a corrosion erosion test apparatus for testing the blast erosion resistance of a steel pipe for a boiler as an embodiment of the present invention. It is a schematic diagram.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭56−9361(JP,A) 特開 昭51−126937(JP,A) 特開 昭61−41756(JP,A) 特開 昭60−142103(JP,A) 特開 昭63−162836(JP,A) 特開 昭63−140056(JP,A) 特開 昭54−115624(JP,A) 特公 昭49−11294(JP,B2) ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-9361 (JP, A) JP-A-51-126937 (JP, A) JP-A-61-41756 (JP, A) JP-A Sho 60- 142103 (JP, A) JP-A-63-162836 (JP, A) JP-A-63-140056 (JP, A) JP-A-54-115624 (JP, A) JP-B-49-11294 (JP, B2)
Claims (1)
-Cr-B-Si-C-Fe-Coからなる自溶合金、又は、Ni-Cr-B-Si
-C-Fe-Co-Cuからなる自溶合金、又は、Ni-Cr-B-Si-C-Fe
-Co-Mo-Cuからなる自溶合金、又は、Ni-Cr-B-Si-C-Fe-C
o-Mo-Wからなる自溶合金を溶射し、フュージング処理を
施してなることを特徴とする耐硫化腐食性・耐エロージ
ョン性ボイラ鋼管。1. After spraying Al on the outer surface of a steel pipe, Ni
-Cr-B-Si-C-Fe-Co self-fluxing alloy or Ni-Cr-B-Si
-C-Fe-Co-Cu self-fluxing alloy or Ni-Cr-B-Si-C-Fe
-Co-Mo-Cu self-fluxing alloy or Ni-Cr-B-Si-C-Fe-C
A boiler steel tube resistant to sulfidation corrosion and erosion, characterized by spraying a self-fluxing alloy consisting of o-Mo-W and subjecting it to fusing treatment.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1004605A JP2718734B2 (en) | 1989-01-13 | 1989-01-13 | Steel pipe for boiler which is resistant to sulfidation corrosion and erosion |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1004605A JP2718734B2 (en) | 1989-01-13 | 1989-01-13 | Steel pipe for boiler which is resistant to sulfidation corrosion and erosion |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP24532497A Division JPH10168554A (en) | 1997-09-10 | 1997-09-10 | Method for treating surface of steel tube for sulfodation corrosion resistant and erosion-resistant boiler |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH02185961A JPH02185961A (en) | 1990-07-20 |
JP2718734B2 true JP2718734B2 (en) | 1998-02-25 |
Family
ID=11588674
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1004605A Expired - Fee Related JP2718734B2 (en) | 1989-01-13 | 1989-01-13 | Steel pipe for boiler which is resistant to sulfidation corrosion and erosion |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2718734B2 (en) |
Cited By (1)
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CN111763902A (en) * | 2020-07-13 | 2020-10-13 | 中国人民解放军陆军装甲兵学院 | Powder core wire and preparation method thereof, and anti-corrosion wear-resistant composite coating and preparation method thereof |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FI96541C (en) * | 1994-10-03 | 1996-07-10 | Ahlstroem Oy | Device on a wall and method for coating the wall |
DE19607979A1 (en) * | 1996-03-01 | 1997-09-04 | Asea Brown Boveri | Waste gas path of combustion apparatus for burning heavy oil |
DE19646086A1 (en) * | 1996-11-08 | 1998-05-14 | Castolin Sa | Process for producing superheater needles, pipe bends or the like and their use |
JP2981184B2 (en) * | 1997-02-21 | 1999-11-22 | トーカロ株式会社 | Boiler heat transfer tube and method for producing boiler heat transfer tube with excellent effect of suppressing deposit adhesion on inner surface of tube |
US8568901B2 (en) | 2006-11-21 | 2013-10-29 | Huntington Alloys Corporation | Filler metal composition and method for overlaying low NOx power boiler tubes |
JP5794537B2 (en) * | 2012-05-11 | 2015-10-14 | 株式会社ディ・ビー・シー・システム研究所 | Heat-resistant alloy member and method for producing the same, alloy film and method for producing the same |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4911294A (en) * | 1972-05-27 | 1974-01-31 | ||
JPS51126937A (en) * | 1975-04-30 | 1976-11-05 | Taihei Kinzoku Kougiyou Kk | Heattresistant and abrasionnresistant metal spraying material |
US4099992A (en) * | 1977-04-11 | 1978-07-11 | Latrobe Steel Company | Tubular products and methods of making the same |
JPS569361A (en) * | 1979-06-30 | 1981-01-30 | Taihei Kinzoku Kogyo Kk | Heat/wear resistant spray coating material |
JPS60142103A (en) * | 1983-12-29 | 1985-07-27 | 新日本製鐵株式会社 | Manufacture of heat transfer pipe for boiler |
JPS6141756A (en) * | 1984-07-31 | 1986-02-28 | Fujiki Kosan Kk | Heat and wear resistant fluidized bed boiler tube |
JPS63140056A (en) * | 1986-12-03 | 1988-06-11 | Sumitomo Metal Ind Ltd | Highly corrosion resistant precipitation hardening-type ni-base alloy |
US4711763A (en) * | 1986-12-16 | 1987-12-08 | Cabot Corporation | Sulfidation-resistant Co-Cr-Ni alloy with critical contents of silicon and cobalt |
-
1989
- 1989-01-13 JP JP1004605A patent/JP2718734B2/en not_active Expired - Fee Related
Cited By (2)
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CN111763902A (en) * | 2020-07-13 | 2020-10-13 | 中国人民解放军陆军装甲兵学院 | Powder core wire and preparation method thereof, and anti-corrosion wear-resistant composite coating and preparation method thereof |
CN111763902B (en) * | 2020-07-13 | 2021-03-16 | 中国人民解放军陆军装甲兵学院 | Powder core wire and preparation method thereof, and anti-corrosion wear-resistant composite coating and preparation method thereof |
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