JPH04285113A - Hearth roll for thick steel plate heat treatment furnace - Google Patents
Hearth roll for thick steel plate heat treatment furnaceInfo
- Publication number
- JPH04285113A JPH04285113A JP3046415A JP4641591A JPH04285113A JP H04285113 A JPH04285113 A JP H04285113A JP 3046415 A JP3046415 A JP 3046415A JP 4641591 A JP4641591 A JP 4641591A JP H04285113 A JPH04285113 A JP H04285113A
- Authority
- JP
- Japan
- Prior art keywords
- steel plate
- hearth roll
- heat treatment
- thick steel
- treatment furnace
- 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 22
- 239000010959 steel Substances 0.000 title claims abstract description 22
- 238000010438 heat treatment Methods 0.000 title claims abstract description 16
- 230000003746 surface roughness Effects 0.000 claims abstract description 8
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000011195 cermet Substances 0.000 claims abstract description 6
- QDOXWKRWXJOMAK-UHFFFAOYSA-N dichromium trioxide Chemical compound O=[Cr]O[Cr]=O QDOXWKRWXJOMAK-UHFFFAOYSA-N 0.000 claims description 8
- 238000005507 spraying Methods 0.000 claims description 8
- 229910045601 alloy Inorganic materials 0.000 claims description 7
- 239000000956 alloy Substances 0.000 claims description 7
- 229910052593 corundum Inorganic materials 0.000 claims description 5
- 229910001845 yogo sapphire Inorganic materials 0.000 claims description 5
- 230000001105 regulatory effect Effects 0.000 abstract 2
- 238000012360 testing method Methods 0.000 description 10
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 8
- 239000012298 atmosphere Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 238000000576 coating method Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 3
- 238000007751 thermal spraying Methods 0.000 description 3
- 229910000975 Carbon steel Inorganic materials 0.000 description 2
- 229910019830 Cr2 O3 Inorganic materials 0.000 description 2
- 229910001208 Crucible steel Inorganic materials 0.000 description 2
- 239000010962 carbon steel Substances 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000010408 film Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000007373 indentation Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000007750 plasma spraying Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 229910018404 Al2 O3 Inorganic materials 0.000 description 1
- 229910000946 Y alloy Inorganic materials 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004453 electron probe microanalysis Methods 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Landscapes
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
- Tunnel Furnaces (AREA)
- Powder Metallurgy (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は産業用機械、造船等に用
いられ主として炭素鋼である厚鋼板の熱処理炉用ハース
ロールに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hearth roll for use in heat treatment furnaces for thick steel plates, mainly carbon steel, used in industrial machinery, shipbuilding, etc.
【０００２】0002
【従来の技術】一般に炭素鋼の厚鋼板の熱処理炉は炉内
で鋼板に酸化スケールが発生するのを防ぐため、Ｎ２
等の不活性ガス雰囲気とし、熱源としてラジアントチュ
ーブといわれる放射伝熱を利用した加熱装置を用いて間
接加熱を行っている。しかしながら該ラジアントチュー
ブの経年劣化による穴明きあるいは炉殻シール部劣化等
により炉内へ空気が侵入するトラブルが起るため被処理
材である鋼板が酸化され脱落した酸化スケールがハース
ロールに付着するいわゆるピックアップと呼ばれる現象
が発生する。このピックアップはロール表面から***し
、逆に鋼板への押し込み疵となるため製品の品質確保の
上で重大な問題となっていた。[Prior Art] Generally, heat treatment furnaces for thick carbon steel plates use N2
Indirect heating is performed using a heating device called a radiant tube that utilizes radiant heat transfer as a heat source. However, problems such as holes forming in the radiant tube due to aging or deterioration of the furnace shell seal may occur, causing air to enter the furnace, causing the steel plate to be oxidized and the oxidized scale that falls off to adhere to the hearth roll. A phenomenon called so-called pickup occurs. These pickups bulge out from the roll surface and conversely cause indentation flaws in the steel sheet, posing a serious problem in ensuring product quality.
【０００３】0003
【発明が解決しようとする課題】これを解決する手段と
して、特公昭５２−１３４８６号公報に提示されたロー
ル表面改質によるピックアップ付着を防止する方法があ
る。これはハースロール表面にＡｌ２ Ｏ３ ，ＳｉＯ
２ 等の結晶性ガラス層を形成するものであるが、以下
の理由から実用化は難しい。即ち結晶性ガラス層では皮
膜が脆く剥落し易いため、厚みが数１００ｍｍにも及ぶ
大重量の厚鋼板熱処理炉では衝撃が大きいため短期間の
うちに剥離摩滅してしまう。As a means to solve this problem, there is a method of preventing pickup adhesion by modifying the roll surface, as proposed in Japanese Patent Publication No. 52-13486. This is because Al2O3 and SiO are on the surface of the hearth roll.
Although this method forms a crystalline glass layer such as No. 2, it is difficult to put it into practical use for the following reasons. That is, the crystalline glass layer is brittle and easily peels off, so in a heat treatment furnace for a heavy steel plate with a thickness of several 100 mm, the impact is large and the layer peels off and wears out in a short period of time.
【０００４】0004
【課題を解決する為の手段】本発明は上記欠点を解消す
ることを目的として提案するもので、厚鋼板を熱処理す
る模型炉内で該厚鋼板を搬送するハースロールにおいて
、その表面に成分がＡｌ２ Ｏ３ ，Ｃｒ２ Ｏ３ の
うちの１種又は２種を含み残部耐熱合金からなるサーメ
ットで、常温表面ショア硬度Ｈｓ＝４５〜７０、表面粗
さＲａ≧４μｍ、Ｈｓ≧７０−（５／２）×Ｒａを満足
する溶射皮膜を形成したことを特徴とする厚鋼板熱処理
炉用ハースロールである。[Means for Solving the Problems] The present invention is proposed for the purpose of eliminating the above-mentioned drawbacks, and is aimed at solving the above-mentioned drawbacks. A cermet containing one or two of Al2O3 and Cr2O3 and the remainder being a heat-resistant alloy, with normal temperature surface Shore hardness Hs=45-70, surface roughness Ra≧4μm, Hs≧70-(5/2)× This is a hearth roll for a thick steel plate heat treatment furnace, characterized by forming a thermal spray coating that satisfies Ra.
【０００５】以下図面に基づいて本発明を詳細に説明す
る。本発明者らは、まず厚鋼板熱処理炉におけるハース
ロールピックアップの主原因を確認するため図２に示す
ラボ実験を行った。ハースロール本体材料として一般に
広く使われるＳＣＨ２２耐熱鋳鋼材１を１０ｍｍ立方体
に加工し、この立方体を上下２ケ重ね合せその間に炉内
で発生する酸化スケールと同等の精製酸化鉄粉（Ｆｅ３
Ｏ４ ）２をはさんで電気炉３内で実炉温度レベルの
９００℃にて１時間保持し加圧接合させた後、常温で当
該接合面の剪断試験を行い、この剪断強さが小さい程結
合力が小さくピックアップが付着し難いと判断するもの
である。実験は加圧力を３水準に振り、雰囲気を厚鋼板
熱処理炉の正常時の雰囲気であるＮ２ １００％雰囲気
及び侵入空気が多量に存在し、部分空間として高酸素濃
度になった場合を想定した大気雰囲気条件及び、比較例
として連続薄鋼板熱処理炉で採用される還元雰囲気（９
５％Ｎ２ −５％Ｈ２ ）の３条件で実験した。The present invention will be explained in detail below based on the drawings. The present inventors first conducted a laboratory experiment shown in FIG. 2 in order to confirm the main cause of hearth roll pickup in a steel plate heat treatment furnace. SCH22 heat-resistant cast steel material 1, which is generally widely used as the material for the hearth roll body, is processed into 10 mm cubes, two cubes are stacked on top of each other, and refined iron oxide powder (Fe3), which is equivalent to the oxide scale generated in the furnace, is
After holding O4)2 in an electric furnace 3 for 1 hour at 900°C, which is the actual furnace temperature, and bonding under pressure, a shear test was conducted on the bonded surface at room temperature. It is determined that the bonding force is small and the pickup is difficult to adhere to. In the experiment, the pressurizing force was varied to three levels, and the atmosphere was a 100% N2 atmosphere, which is the normal atmosphere of a steel plate heat treatment furnace, and an atmosphere that assumed a case where there was a large amount of intruding air and a high oxygen concentration in the partial space. Atmospheric conditions and reducing atmosphere (9) adopted in a continuous thin steel plate heat treatment furnace as a comparative example
The experiment was conducted under three conditions: 5% N2 - 5% H2).
【０００６】この結果を表１に示す。[0006] The results are shown in Table 1.
【０００７】[0007]
【表１】[Table 1]
【０００８】以上の結果から酸化鉄は非還元雰囲気下で
はロールに付着し難く面圧が大きな場合にのみ接合する
が接合強さは小さいことが分かった。接合した試験片の
界面をＥＰＭＡで線分析した結果、還元雰囲気の場合は
何れも酸化鉄粉側のＦｅと耐熱鋼側のＣｒの相互拡散が
見られたが非還元雰囲気で接合された試験片界面には殆
ど拡散層が確認できなかった。一方、実炉ハースロール
の鋼板との接触面圧は酸化スケールはさみ込みによる局
部面圧上昇を考えない平均値でも３００ｋｇｆ／ｃｍ２
にも及び試験Ｎｏ３の面圧レベル以上であるので酸化
鉄の結合は起り得ると言える。[0008] From the above results, it was found that iron oxide is difficult to adhere to the roll in a non-reducing atmosphere and is bonded only when the surface pressure is large, but the bonding strength is low. As a result of line analysis using EPMA of the interface of the joined specimens, it was found that in both cases of reducing atmosphere, interdiffusion of Fe on the iron oxide powder side and Cr on the heat-resistant steel side was observed, but in the specimens joined in a non-reducing atmosphere. Almost no diffusion layer was observed at the interface. On the other hand, the contact pressure between the actual furnace hearth roll and the steel plate is 300 kgf/cm2 even on average without considering the increase in local contact pressure due to oxidized scale entrapment.
It can be said that bonding of iron oxide can occur since the surface pressure is higher than the surface pressure level of Test No. 3.
【０００９】以上の知見から当該厚鋼板熱処理炉におけ
るピックアップは酸化スケールの拡散反応等の化学的結
合力ではなく、酸化スケール付着部の局部高面圧により
ロールが塑性変形し、押し込まれたためのもの、即ちメ
カニカルな結合が主要因であることが分かった。[0009] From the above findings, the pick-up in the steel plate heat treatment furnace is not due to chemical bonding force such as the diffusion reaction of oxide scale, but is due to plastic deformation of the roll due to local high surface pressure at the area where the oxide scale is attached, and the roll is pushed in. In other words, it was found that mechanical coupling was the main cause.
【００１０】そこでロール表面の塑性変形抵抗を高める
べく、高温でも硬度が高く、且つ酸化雰囲気下でも安定
な酸化物であるＡｌ２ Ｏ３ ，Ｃｒ２ Ｏ３ に着目
し、これらを主成分として残部をＣｏ系或いはＮｉ系の
耐熱合金としたサーメットを溶射被覆することを想到し
、実材テストを行った。溶射はロールの１ｍ長さの範囲
に部分的に施工することにし、各種仕様の皮膜をプラズ
マ溶射で形成させ約１．５年間テストを行った。テスト
に供したロールの状況図を図３に示す。テストは酸化物
としてＡｌ２ Ｏ３ 及び５０ｗｔ％Ａｌ２ Ｏ３ −
５０ｗｔ％Ｃｒ２ Ｏ３ 混合粉及びＣｒ２ Ｏ３ を
用い、耐熱合金としては重量％で５０％Ｃｏ−２５％Ｎ
ｉ−１８％Ｃｒ−６％Ａｌ−０．８％Ｙ合金を用いてサ
ーメットとし酸化物と耐熱合金の配合割合及び皮膜厚み
をコントロールして皮膜表面硬度を変化させた。ここで
酸化物の量が多い程、硬度が高くなることは言うまでも
ない。Therefore, in order to increase the plastic deformation resistance of the roll surface, we focused on Al2 O3 and Cr2 O3, which are oxides that have high hardness even at high temperatures and are stable even in an oxidizing atmosphere. We came up with the idea of thermal spray coating cermet, which is a Ni-based heat-resistant alloy, and conducted an actual material test. Thermal spraying was carried out partially over a 1m length of the roll, and coatings with various specifications were formed by plasma spraying, and tests were conducted for about 1.5 years. Figure 3 shows a diagram of the rolls used in the test. The test was carried out using Al2O3 and 50 wt% Al2O3 − as oxides.
Using 50wt% Cr2O3 mixed powder and Cr2O3, the heat-resistant alloy was 50%Co-25%N by weight.
An i-18%Cr-6%Al-0.8%Y alloy was used as a cermet, and the coating surface hardness was changed by controlling the blending ratio of oxide and heat-resistant alloy and coating thickness. Needless to say, the larger the amount of oxide, the higher the hardness.
【００１１】一方、皮膜厚みは厚い方が硬度が高くなる
。何故なら溶射皮膜は一般に１ｍｍ以下程度の薄膜であ
るため、この部分だけで局部高面圧を支えることはでき
ず母材を含めた全体硬度で押し込みに対する抵抗力が決
まるからである。On the other hand, the thicker the coating, the higher the hardness. This is because thermal spray coatings are generally thin films of about 1 mm or less, so this portion alone cannot support the local high surface pressure, and the resistance to indentation is determined by the overall hardness including the base material.
【００１２】従ってハースロール４の母材を含めた全体
硬度を高くするためには、溶射皮膜５の厚みを靭性、耐
熱衝撃性を損わない範囲でできる限り厚くした方が有利
である。そのためには下盛層を施こしこの成分系及び上
盛と合せた肉盛厚みに工夫を加えることも良い方法であ
る。Therefore, in order to increase the overall hardness of the hearth roll 4 including the base material, it is advantageous to make the thermal spray coating 5 as thick as possible without impairing toughness and thermal shock resistance. For this purpose, it is a good method to apply an underlay layer and add some ideas to the composition of this layer and the thickness of the overlay combined with the overlay layer.
【００１３】本テストでは皮膜硬度をショア硬度計で計
っているが、当該測定法は皮膜厚みの影響も含んだ全体
硬度が分かるので上記の意味からも理にかなった判定方
法といえる。[0013] In this test, the hardness of the coating was measured using a Shore hardness meter, and this measuring method can be said to be a reasonable determination method from the above point of view, since it allows the determination of the overall hardness including the influence of the coating thickness.
【００１４】またピックアップの付着にはロール表面の
粗度も影響すると考えられたので、溶射条件をコントロ
ールすることにより粗度も変化させてテストした。テス
トの結果を図１に示す。この図から硬度についてはピッ
クアップを防止するためには最低Ｈｓ４５必要であるが
、Ｈｓ７０を超える高硬度になると皮膜の靭性、耐熱衝
撃性が確保できず剥離が発生することが分かった。表面
の粗度を荒くすることもピックアップ防止に効果がある
ことが分かり、中心線平均粗さＲａで最低４μｍあった
方が良いことが分かった。[0014] Since it was thought that the roughness of the roll surface also affected the adhesion of the pickup, tests were conducted by varying the roughness by controlling the thermal spraying conditions. The test results are shown in Figure 1. This figure shows that a minimum hardness of Hs45 is required to prevent pickup, but when the hardness exceeds Hs70, the toughness and thermal shock resistance of the film cannot be ensured and peeling occurs. It has been found that increasing the surface roughness is also effective in preventing pickup, and it has been found that it is better to have a center line average roughness Ra of at least 4 μm.
【００１５】また粗度Ｒａ４〜１０程度の領域ではＨｓ
≧７０−（５／２）×Ｒａで表わされるラインがピック
アップ発生有無の境界になっていることが分かった。以
上から溶射皮膜として表面ショア硬度でＨｓ≧４５〜７
０、かつ表面粗さＲａ≧４μｍ、かつＨｓ≧７０−（５
／２）×Ｒａを満足する領域が良好な結果が得られるこ
とが分かった。[0015] In addition, in the area of roughness Ra 4 to 10, Hs
It has been found that the line expressed by ≧70-(5/2)×Ra is the boundary between the occurrence and non-occurrence of pickup. From the above, as a thermal spray coating, the surface Shore hardness is Hs≧45~7
0, and surface roughness Ra≧4μm, and Hs≧70−(5
It was found that good results could be obtained in the region satisfying /2)×Ra.
【００１６】[0016]
【作用】本発明の溶射皮膜の作用を図４，５により説明
する。先ず表面の硬度を適正レベル以上に高くすること
により、図４（ａ）の様にハースロール４の塑性変形抵
抗を大きくして、図４（ｂ）のような酸化スケール（ピ
ックアップ）６のハースロール４への押し込みを大幅に
軽減する。また表面粗度を荒くすることにより、図５（
ａ）の様に酸化スケール６〜ハースロール４間の真実接
触面積を減らして結合しにくくする。同図（ｂ）は表面
が平滑なために該接触面積が大きい場合を示している。[Function] The function of the thermal spray coating of the present invention will be explained with reference to FIGS. 4 and 5. First, by increasing the surface hardness to an appropriate level or higher, the plastic deformation resistance of the hearth roll 4 is increased as shown in FIG. Pushing into the roll 4 is significantly reduced. In addition, by roughening the surface roughness, the
As in a), the actual contact area between the oxide scale 6 and the hearth roll 4 is reduced to make it difficult for them to bond. Figure (b) shows a case where the contact area is large because the surface is smooth.
【００１７】[0017]
【実施例】従来ピックアップが問題となっていたＳＣＨ
２２耐熱鋳鋼製のハースロール９０本に対し全長をプラ
ズマ溶射法にて重量％で下盛として耐熱合金５０％Ｃｏ
−２５％Ｎｉ−１８％Ｃｒ−６％−Ａｌ−０．８％Ｙを
０．３ｍｍ被覆し上盛としてサーメット１０％Ａｌ２
Ｏ３ −１０％Ｃｒ２ Ｏ３ −８０％耐熱合金（下盛
に同じ）を０．２ｍｍ被覆して常温表面硬度をＨｓ５８
とし、表面粗度をＲａ１４μｍとして実用に供した。[Example] SCH where conventional pickup was a problem
22 90 hearth rolls made of heat-resistant cast steel were coated with 50% Co heat-resistant alloy as underlay by plasma spraying method in weight%.
-25%Ni-18%Cr-6%-Al-0.8%Y coated with 0.3mm and cermet 10%Al2 as overlay
O3 -10% Cr2 O3 -80% Covered with 0.2 mm of heat-resistant alloy (same as the bottom layer) to make the surface hardness at room temperature Hs58
The surface roughness was set to Ra 14 μm and used for practical use.
【００１８】従来の母材のままではロール手入立上後１
〜２ケ月でピックアップが顕著化し製品である厚鋼板の
表面疵も頻発していたが、本発明によるハースロールを
採用することにより、１年間の使用後もピックアップは
見られず、また皮膜剥離トラブルもない。磨耗は初期に
おいて１０μｍ程度の減肉があったがその後は磨耗の進
行はなく、耐久性としても良好であった。[0018] If the conventional base material is used, it will be difficult to
Pick-up became noticeable after ~2 months, and surface flaws were frequently occurring on the thick steel plates used as products. However, by adopting the hearth roll of the present invention, no pick-up was observed even after one year of use, and there was no problem with film peeling. Nor. As for wear, there was a thinning of about 10 μm in the initial stage, but the wear did not progress after that, and the durability was good.
【００１９】[0019]
【発明の効果】本発明の厚鋼板熱処理炉用ハースロール
によれば、以下の効果が得られる。[Effects of the Invention] According to the hearth roll for a thick steel plate heat treatment furnace of the present invention, the following effects can be obtained.
【００２０】（１）ハースロールに付着するピックアッ
プがなくなることにより、鋼板側へ転写される疵がなく
なり、熱処理後の鋼板疵手入が不要となる。その結果鋼
板疵手入工費が削減でき、かつ手入跡の無い美麗な鋼板
の製造が可能となる。(1) Since there is no pickup attached to the hearth roll, there are no flaws transferred to the steel plate side, and there is no need to clean the steel plate flaws after heat treatment. As a result, the cost of repairing steel plate defects can be reduced, and it is possible to manufacture beautiful steel plates without any traces of maintenance.
【００２１】（２）従来ピックアップが激しくなったと
き、それ以上に悪化しない様に炉内に存在する空気を少
しでも減らすため、炉内に吹き込むＮ２ 流量を大幅に
増やす操業をしており、このためＮ２ の消費コストが
多額であったが、これを削減できる。(2) Conventionally, when pick-up becomes severe, the flow rate of N2 blown into the furnace is greatly increased in order to reduce the amount of air present in the furnace to prevent further deterioration. Therefore, the consumption cost of N2 was large, but this can be reduced.
【００２２】（３）またピックアップが余りに激しくな
ったときは炉は消火して炉内でハースロール表面の手入
を実施していた。一般に厚鋼板熱処理炉の内部は狭あい
で極めて作業環境が悪く、安全上、衛生上問題が多いが
、この作業を解消できる。(3) When the pickup became too intense, the furnace was extinguished and the surface of the hearth roll was cleaned inside the furnace. Generally, the inside of a thick steel plate heat treatment furnace is narrow and the working environment is extremely poor, causing many safety and hygiene problems, but this work can be solved.
【００２３】（４）本発明の溶射を施工することにより
従来ロール表面に発生していた肌荒れ、アバタがなくな
り、ロール本体寿命も延びるためトータル整備コスト削
減にもつながる。(4) By applying the thermal spraying method of the present invention, the rough skin and abrasions that conventionally occur on the roll surface are eliminated, and the life of the roll body is extended, leading to a reduction in total maintenance costs.
【図１】本発明の実施例でハースロールの表面粗度と表
面硬度との関係を示す図。FIG. 1 is a diagram showing the relationship between surface roughness and surface hardness of a hearth roll in an example of the present invention.
【図２】（ａ）、（ｂ）は本発明に係る実験方法を示す
模式図。FIGS. 2(a) and 2(b) are schematic diagrams showing the experimental method according to the present invention.
【図３】本発明の実機試験に供した溶射皮膜の施工範囲
を示すハースロールの正面図。FIG. 3 is a front view of a hearth roll showing the application range of the thermal spray coating used in the actual machine test of the present invention.
【図４】（ａ）、（ｂ）は本発明の作用を説明する模式
図。FIGS. 4(a) and 4(b) are schematic diagrams illustrating the action of the present invention.
【図５】（ａ）、（ｂ）は本発明の作用を説明する模式
図。FIGS. 5(a) and 5(b) are schematic diagrams illustrating the action of the present invention.
Claims (1)
板を搬送するハースロールにおいて、その表面に成分が
Ａｌ２ Ｏ３ ，Ｃｒ２ Ｏ３ ，のうちの１種又は２
種を含み残部耐熱合金からなるサーメットで、常温表面
ショア硬度Ｈｓ＝４５〜７０、表面粗さＲａ≧４μｍ、
Ｈｓ≧７０−（５／２）×Ｒａを満足する溶射皮膜を形
成したことを特徴とする厚鋼板熱処理炉用ハースロール
。Claim 1: A hearth roll for transporting a thick steel plate in a model furnace for heat-treating the plate, the surface of which contains one or two of the following components: Al2O3, Cr2O3.
A cermet containing seeds and the rest being a heat-resistant alloy, with a surface hardness at room temperature Hs = 45 to 70, and a surface roughness Ra≧4 μm.
A hearth roll for a thick steel plate heat treatment furnace, characterized in that a thermal spray coating satisfying Hs≧70−(5/2)×Ra is formed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3046415A JPH04285113A (en) | 1991-03-12 | 1991-03-12 | Hearth roll for thick steel plate heat treatment furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3046415A JPH04285113A (en) | 1991-03-12 | 1991-03-12 | Hearth roll for thick steel plate heat treatment furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04285113A true JPH04285113A (en) | 1992-10-09 |
Family
ID=12746522
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3046415A Pending JPH04285113A (en) | 1991-03-12 | 1991-03-12 | Hearth roll for thick steel plate heat treatment furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04285113A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6386856A (en) * | 1986-09-29 | 1988-04-18 | Nippon Steel Corp | Thermally sprayed roll for treating hot steel slab |
| JPH02194118A (en) * | 1989-01-23 | 1990-07-31 | Sumitomo Metal Ind Ltd | Roll for heat treatment furnace and its production |
| JPH02270955A (en) * | 1989-04-12 | 1990-11-06 | Kobe Steel Ltd | Hearth roller for high-temperature heat treatment furnace |
-
1991
- 1991-03-12 JP JP3046415A patent/JPH04285113A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6386856A (en) * | 1986-09-29 | 1988-04-18 | Nippon Steel Corp | Thermally sprayed roll for treating hot steel slab |
| JPH02194118A (en) * | 1989-01-23 | 1990-07-31 | Sumitomo Metal Ind Ltd | Roll for heat treatment furnace and its production |
| JPH02270955A (en) * | 1989-04-12 | 1990-11-06 | Kobe Steel Ltd | Hearth roller for high-temperature heat treatment furnace |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 19961015 |