JPS6261666B2 - - Google Patents
Info
- Publication number
- JPS6261666B2 JPS6261666B2 JP12495081A JP12495081A JPS6261666B2 JP S6261666 B2 JPS6261666 B2 JP S6261666B2 JP 12495081 A JP12495081 A JP 12495081A JP 12495081 A JP12495081 A JP 12495081A JP S6261666 B2 JPS6261666 B2 JP S6261666B2
- Authority
- JP
- Japan
- Prior art keywords
- heat
- resistant container
- recess
- heating
- surface treatment
- 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
Links
- 238000010438 heat treatment Methods 0.000 claims description 48
- 239000012756 surface treatment agent Substances 0.000 claims description 19
- 229910052751 metal Inorganic materials 0.000 claims description 13
- 239000002184 metal Substances 0.000 claims description 11
- 229910000831 Steel Inorganic materials 0.000 claims description 9
- 239000010959 steel Substances 0.000 claims description 9
- 238000004381 surface treatment Methods 0.000 claims description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 5
- 150000002739 metals Chemical class 0.000 claims description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 4
- 229910002804 graphite Inorganic materials 0.000 claims description 3
- 239000010439 graphite Substances 0.000 claims description 3
- 235000002639 sodium chloride Nutrition 0.000 description 14
- 150000003839 salts Chemical class 0.000 description 12
- 239000000463 material Substances 0.000 description 8
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 229910021538 borax Inorganic materials 0.000 description 6
- 229910052796 boron Inorganic materials 0.000 description 6
- 239000002075 main ingredient Substances 0.000 description 6
- 239000004328 sodium tetraborate Substances 0.000 description 6
- 235000010339 sodium tetraborate Nutrition 0.000 description 6
- 230000003014 reinforcing effect Effects 0.000 description 5
- 238000011282 treatment Methods 0.000 description 5
- 229910000628 Ferrovanadium Inorganic materials 0.000 description 4
- PNXOJQQRXBVKEX-UHFFFAOYSA-N iron vanadium Chemical compound [V].[Fe] PNXOJQQRXBVKEX-UHFFFAOYSA-N 0.000 description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000011819 refractory material Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- INZDTEICWPZYJM-UHFFFAOYSA-N 1-(chloromethyl)-4-[4-(chloromethyl)phenyl]benzene Chemical compound C1=CC(CCl)=CC=C1C1=CC=C(CCl)C=C1 INZDTEICWPZYJM-UHFFFAOYSA-N 0.000 description 1
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910052580 B4C Inorganic materials 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- WDIHJSXYQDMJHN-UHFFFAOYSA-L barium chloride Chemical compound [Cl-].[Cl-].[Ba+2] WDIHJSXYQDMJHN-UHFFFAOYSA-L 0.000 description 1
- 229910001626 barium chloride Inorganic materials 0.000 description 1
- 239000013040 bath agent Substances 0.000 description 1
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 239000012611 container material Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910001120 nichrome Inorganic materials 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/60—Heating arrangements wherein the heating current flows through granular powdered or fluid material, e.g. for salt-bath furnace, electrolytic heating
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/34—Methods of heating
- C21D1/44—Methods of heating in heat-treatment baths
- C21D1/46—Salt baths
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Furnace Details (AREA)
- Resistance Heating (AREA)
Description
【発明の詳細な説明】
本発明は硼砂等の硼化物を主剤とする塩浴を用
いる金属等の表面処理用加熱炉、特に1100℃以上
のような高温に塩浴を保持するのに適した加熱炉
を提供しようとするものである。[Detailed Description of the Invention] The present invention is a heating furnace for surface treatment of metals, etc. that uses a salt bath containing a boride such as borax as a main ingredient, and is particularly suitable for maintaining the salt bath at a high temperature of 1100°C or higher. The aim is to provide a heating furnace.
従来、塩浴を用いる鋼の焼入、焼もどしなどの
熱処理では、塩浴の入つた容器の外側に熱源が配
置された外熱炉とか、塩浴中に複数の電極を入れ
電極間に電流を流し浴の抵抗熱によつて加熱する
内熱炉等の直接加熱炉が用いられている。 Conventionally, heat treatments such as quenching and tempering of steel using a salt bath have been carried out using an external heat furnace where a heat source is placed outside a container containing a salt bath, or by placing multiple electrodes in a salt bath and applying an electric current between the electrodes. A direct heating furnace such as an internal heating furnace is used, which heats by the resistance heat of a flowing bath.
一方、硼砂等の硼化物を主剤とする塩浴は、硼
化物と特定の添加物（例えばフエロボロン、フエ
ロバナジウム）からなる浴で、この浴に被処理金
属を浸漬保持し、あるいは浸漬しつつ電解処理を
施すことにより、被処理金属の表面に硼素、バナ
ジウム等が拡散浸透し、硼化物あるいは炭化物の
層が形成される。 On the other hand, a salt bath whose main ingredient is a boride such as borax is a bath consisting of a boride and specific additives (e.g. feroboron, ferrovanadium), and the metal to be treated is immersed in this bath or held while being immersed. By performing electrolytic treatment, boron, vanadium, etc. diffuse into the surface of the metal to be treated, and a layer of boride or carbide is formed.
この硼化物を主剤とする浴に対しては一般に外
熱炉が使用される。これは硼化物が耐火物や電極
を浸食する作用が強いため、内燃炉の寿命が短か
いことに起因する。 An external heating furnace is generally used for this boride-based bath. This is because borides have a strong effect of corroding refractories and electrodes, so the lifespan of internal combustion furnaces is short.
一方、外熱炉には内熱炉にみられる欠点は見ら
れないが、昇温に長時間を要するとか、塩浴容器
には外壁が空気あるいは燃焼ガス雰囲気中で長時
間加熱されるために高度の耐酸化性、耐高温腐食
性が要求され、かつ同時に容器自身および塩浴の
重量に耐えるための高温強度が要求される。特に
塩浴温度が1100℃あるいはそれ以上のような高温
であると、上記した塩浴容器の特性は高度に要求
され、これを工業的に満し得る容器材料はきわめ
て限られると同時に著しく高価である。その上さ
らに大きな問題は昇温速度の小さい外熱式の欠点
が、熱源温度と加熱温度との差が小さい高温では
さらに助長されて、塩浴の寿命時間に対して昇温
所要時間が工業的に無視できない大きさになるこ
とである。硼化物を主剤とする塩浴の寿命は使用
浴温度が上昇するにつれて急激に短かくなるのが
一般であつて、浴組成によつて著しく異なるが、
例へば硼砂にフエロバナジウム粉末を添加したバ
ナジウム炭化物被覆浴の1200℃使用における浴寿
命は10〜20時間以下であつて数時間の昇温時間は
工業上無視できない。 On the other hand, external heat furnaces do not have the disadvantages of internal heat furnaces, but they do require a long time to heat up, and salt bath vessels have outer walls that are heated for long periods of time in an air or combustion gas atmosphere. A high degree of oxidation resistance, high temperature corrosion resistance, and at the same time high temperature strength to withstand the weight of the container itself and the salt bath are required. In particular, when the salt bath temperature is at a high temperature of 1100°C or higher, the above-mentioned characteristics of the salt bath container are highly required, and the container materials that can industrially meet these requirements are extremely limited and at the same time extremely expensive. be. An even bigger problem is that the shortcoming of the external heating method, which has a low heating rate, is exacerbated at high temperatures where the difference between the heat source temperature and the heating temperature is small, and the time required to raise the temperature compared to the life of the salt bath becomes industrially low. The problem is that it becomes too large to be ignored. Generally, the life of a salt bath containing boride as the main ingredient rapidly shortens as the bath temperature increases, and it varies markedly depending on the bath composition.
For example, the bath life of a vanadium carbide coating bath made by adding ferrovanadium powder to borax when used at 1200°C is 10 to 20 hours or less, and a heating time of several hours cannot be ignored in industry.
発明者は、この対策として腐食性の少い塩化物
浴の内燃炉の中に硼化物を主剤とする容器を入
れ、塩化物浴の持つ熱によつて硼化物を主剤とす
る浴剤を加熱溶融し、一定温度に維持する間接加
熱炉に想達し、種々研究を重ねて本発明の間接加
熱炉を完成したものである。すなわち、本発明の
硼化物浴を用いる金属等の表面処理用間接加熱炉
は、その断面図を第１図に示すように、非導電性
耐火物で形成され上端開口の凹部１１を有する加
熱部１と、上記炉体１の凹部１１に保持される塩
化物を主成分とする熱媒体２と、上記炉体１の凹
部１１の上方に着脱自在に保持される耐熱性容器
３と、上記耐熱性容器３内に保持される、金属等
の表面処理剤４とよりなり、上記表面処理剤４は
硼化物を主剤とするものであり、上記炉体１の凹
部１１を形成する内部には少なくとも１対の加熱
用電極１２が保持され、該電極１２の位置は内壁
面を形成する各電極１２の最上部を結ぶ線ｌが上
記耐熱性容器３の下方にあり、かつ該各電極１２
の最上部を結ぶ線ｌと上記耐熱性容器３との最も
短かい間隔Ｍが該電極１２間の距離Ｌの少なくと
も1/4以上としたことを特徴とするものである。 As a countermeasure to this problem, the inventor placed a container containing boride as the main ingredient in an internal combustion furnace containing a less corrosive chloride bath, and used the heat of the chloride bath to heat the bath agent containing boron as the main ingredient. We conceived of an indirect heating furnace that melts and maintains it at a constant temperature, and after conducting various studies, we completed the indirect heating furnace of the present invention. That is, the indirect heating furnace for surface treatment of metals and the like using the boride bath of the present invention has a heating section made of a non-conductive refractory and having a recess 11 with an opening at the top, as shown in a cross-sectional view in FIG. 1, a heat medium 2 mainly composed of chloride held in the recess 11 of the furnace body 1, a heat-resistant container 3 detachably held above the recess 11 of the furnace body 1, and a heat-resistant container 3 held detachably above the recess 11 of the furnace body 1; The surface treatment agent 4 is made of metal or the like and is held in the reaction container 3, and the surface treatment agent 4 is mainly composed of boride. A pair of heating electrodes 12 are held, and the positions of the electrodes 12 are such that a line l connecting the tops of the electrodes 12 forming the inner wall surface is below the heat-resistant container 3, and each electrode 12
The shortest distance M between the line 1 connecting the tops of the electrodes 1 and the heat-resistant container 3 is at least 1/4 of the distance L between the electrodes 12.
本発明の加熱炉を構成する炉体１は基本的には
従来の内熱炉と同様のもので、アルミナ等の耐火
物で製作される。炉体１の中央には凹部１１が形
成れている。この凹部は熱媒体２を保持するため
のものである。第１図に示す加熱炉においては、
凹部１１は底の深い四角状となつている。また凹
部１１の下方側壁部に１対の電極１２が埋めこま
れている。これら電極１２はSUS３１０やSCH
１３等の耐熱鋼製で外部電源（図示せず）に接続
されている。また凹部１１の上端には耐熱性鋼製
の補強リング１３が組みこまれている。 The furnace body 1 constituting the heating furnace of the present invention is basically the same as a conventional internal heating furnace, and is made of a refractory material such as alumina. A recess 11 is formed in the center of the furnace body 1. This recess is for holding the heat medium 2. In the heating furnace shown in Figure 1,
The recess 11 has a square shape with a deep bottom. Further, a pair of electrodes 12 are embedded in the lower side wall portion of the recess 11 . These electrodes 12 are SUS310 or SCH
It is made of heat-resistant steel such as No. 13 and is connected to an external power source (not shown). Further, a reinforcing ring 13 made of heat-resistant steel is incorporated into the upper end of the recess 11.
炉体１の凹部１１には熱媒体２が保持される。
熱媒体２としては食塩（NaCl）、塩化バリウム
（BaCl2）等の塩化物が利用できる。これらの熱媒
体は800℃以上で十分な流動性をもつ。なお、熱
媒体２が固体状の場合には電気抵抗発熱体として
の十分な導電性をもたないため、予めニクロム線
などの発熱体を凹部１１の底に設けておき、この
発熱体により熱媒体２を加熱溶融させる。熱媒体
２が溶融したのち電極１２間に電圧を印加し、熱
媒体２自体の電気抵抗による発熱で熱媒体２を加
熱する。なお、熱媒体２が溶融状態になつた時発
熱体は凹部１１より取り除く。また熱媒体２を放
冷する場合には凝固する前に発熱体を再び凹部１
１に挿入するようにする。 The heat medium 2 is held in the recess 11 of the furnace body 1 .
As the heat medium 2, chlorides such as common salt (NaCl) and barium chloride (BaCl 2 ) can be used. These heat carriers have sufficient fluidity at temperatures above 800°C. In addition, if the heat medium 2 is solid, it does not have sufficient conductivity as an electric resistance heating element, so a heating element such as a nichrome wire is provided in advance at the bottom of the recess 11, and this heating element generates heat. The medium 2 is heated and melted. After the heat medium 2 is melted, a voltage is applied between the electrodes 12, and the heat medium 2 is heated by heat generated by the electric resistance of the heat medium 2 itself. Note that the heating element is removed from the recess 11 when the heat medium 2 becomes molten. In addition, when cooling the heating medium 2, the heating element is placed in the recess 1 again before it solidifies.
1.
耐熱性容器３は耐熱鋼製であり、炉体１の凹部
１１内の溶融した熱媒体２中に入れられる。第１
図に示す加熱炉においては、耐熱性容器３は上部
にフランジ３１をもつ円筒状のものとし、凹部１
１の補強リング１３に挿入されて保持されるもの
とした。なお、耐熱性容器３と電極１２の相対位
置は、耐熱性容器３の最下部が凹部１１の内壁面
を形成する各電極１２の最上部を結ぶ線ｌより上
方にあり、かつ、該各電極１２の最上部を結ぶ線
ｌと耐熱性容器３との最も短かい間隔Ｍが電極１
２間の距離の少なくとも1/4以上であるようにし
てある。また、炉体１の凹部１１の内壁面と耐熱
性容器３の外側面との距離を50mm以上とした。さ
らに、炉体１の凹部１１の開口は補強リング１３
と耐熱性容器３のフランジ３１で密封する構造と
した。なお、凹部１１の上部に不活性ガスを導入
する配管を設けることもできる。 The heat-resistant container 3 is made of heat-resistant steel and is placed in the molten heat medium 2 in the recess 11 of the furnace body 1 . 1st
In the heating furnace shown in the figure, the heat-resistant container 3 has a cylindrical shape with a flange 31 at the top, and a recess 1
It is assumed that the reinforcing ring 13 of No. 1 is inserted into and held. Note that the relative position of the heat-resistant container 3 and the electrode 12 is such that the lowest part of the heat-resistant container 3 is above the line l connecting the highest part of each electrode 12 forming the inner wall surface of the recess 11, and The shortest distance M between the line l connecting the top of the electrode 12 and the heat-resistant container 3 is the electrode 1.
The distance is at least 1/4 of the distance between the two. Further, the distance between the inner wall surface of the recess 11 of the furnace body 1 and the outer surface of the heat-resistant container 3 was set to be 50 mm or more. Furthermore, the opening of the recess 11 of the furnace body 1 is formed by a reinforcing ring 13.
and a flange 31 of the heat-resistant container 3 for sealing. Note that a pipe for introducing an inert gas can also be provided above the recess 11.
電極１２は、第２図の上面図、第３図の正面図
（図中、後述する蓋５は示していない。）に示すよ
うに、角柱状であり、凹部１１の内面に面してい
る。また、電極１２は炉体１の外側に設置してな
る電源１２１と電線１２２により接続されてな
る。 The electrode 12 has a prismatic shape and faces the inner surface of the recess 11, as shown in the top view of FIG. 2 and the front view of FIG. 3 (the lid 5 described later is not shown in the figure). . Further, the electrode 12 is connected to a power source 121 installed outside the furnace body 1 by an electric wire 122.
耐熱性容器３には硼化物を主剤とする表面処理
剤４が保持される。最も実用性の高い硼化物とし
ては硼砂をあげることができる。表面処理剤４は
これらの硼化物に炭化硼素、フエロボロン等の硼
素源、フエロニオブ、クロム、フエロバナジウ
ム、チタニウム等の周期律表第ａ，ａ，ａ
族元素等の金属元素源を配合したものである。表
面処理剤４は加熱されることにより硼砂等の硼化
物が溶融する。この溶融した硼化物に硼素源、金
属元素源が溶解する。 The heat-resistant container 3 holds a surface treatment agent 4 containing boride as a main ingredient. The most practical boride is borax. The surface treatment agent 4 includes these borides, boron sources such as boron carbide and ferroboron, and boron sources such as ferronniobium, chromium, ferrovanadium, and titanium of periodic table a, a, and a.
It contains metal element sources such as group elements. When the surface treatment agent 4 is heated, borides such as borax are melted. A boron source and a metal element source are dissolved in this molten boride.
表面処理すべき金属等の被処理材は、この溶融
した表面処理剤４中に浸漬保持される。なお、被
処理材が表面処理剤中に浸漬保持されている間に
被処理材を陰極として電解処理を実施することも
できる。被処理材としては鉄、鉄鋼、合金鋼、黒
鉛等である。被処理材中に炭素が含まれており表
面処理剤４に周期律表第ａ，ａ，ａ族の金
属元素源が含まれている場合には、被処理材の表
面にそれら金属元素の炭化物層が被覆される。ま
た、表面処理剤４中に硼素が溶解している場合、
および、電解処理を実施する場合には被処理材表
面に主として硼化物層が被覆される。 A material to be surface treated, such as a metal, is immersed and held in this molten surface treatment agent 4. Note that electrolytic treatment can also be performed using the treated material as a cathode while the treated material is immersed and held in the surface treatment agent. The materials to be treated include iron, steel, alloy steel, graphite, etc. When the material to be treated contains carbon and the surface treatment agent 4 contains a source of metal elements in groups a, a, and a of the periodic table, carbides of those metal elements may be formed on the surface of the material to be treated. A layer is coated. In addition, if boron is dissolved in the surface treatment agent 4,
When electrolytic treatment is performed, the surface of the material to be treated is mainly coated with a boride layer.
表面処理を実施している間よび熱媒体２を加熱
しいる間、炉体１の凹部１１には蓋５がかぶせら
れる。この蓋５により、熱媒体２とか表面処理剤
４から発生するガスの飛散がある程度防止でき、
かつ、放熱をおさえる。蓋５は耐火物又は鉄鋼等
で作られる。 During surface treatment and while heating the heat medium 2, the recess 11 of the furnace body 1 is covered with a lid 5. This lid 5 can prevent the scattering of gases generated from the heat medium 2 and the surface treatment agent 4 to some extent.
And suppresses heat radiation. The lid 5 is made of refractory material, steel, or the like.
次に、本発明の具体的な実施例を説明する。 Next, specific examples of the present invention will be described.
第１図ないし第３図に示すように、炉体１は鉄
枠で囲まれた耐火レンガ製であり、幅130cm×奥
行130cm×高さ120cmの長方体である。炉体１の中
央には、幅23cm×幅23cm×深さ63cmの四角状の凹
部１１が形成されている。凹部１１の下方側壁部
に埋めこまれた１対の電極１２は、24％のクロム
を含む耐熱鋼製であり、幅11.4cm×高さ6.4×長
さ94cmである（高さ6.4cmは凹部１１の内面に面
している箇所の値である。）。また、これらの電極
１２は、炉外部（水冷されている）で外部電源１
２１と電線１２２により接続されている。 As shown in FIGS. 1 to 3, the furnace body 1 is made of firebrick and surrounded by an iron frame, and has a rectangular shape of 130 cm wide x 130 cm deep x 120 cm high. A rectangular recess 11 measuring 23 cm wide x 23 cm wide x 63 cm deep is formed in the center of the furnace body 1 . A pair of electrodes 12 embedded in the lower side walls of the recess 11 are made of heat-resistant steel containing 24% chromium, and measure 11.4 cm wide x 6.4 cm high x 94 cm long (the height 6.4 cm is 11). In addition, these electrodes 12 are connected to an external power source 1 outside the furnace (which is water-cooled).
21 and is connected by an electric wire 122.
また、凹部１１の上端にはSUS３１０製の補強
リング１３が組み込まれている。 Furthermore, a reinforcing ring 13 made of SUS310 is incorporated into the upper end of the recess 11.
炉体１の凹部１１には塩化物からなる溶融した
熱媒体２が保持されている。 A recess 11 of the furnace body 1 holds a molten heat medium 2 made of chloride.
SUS３１０製の耐熱性容器３は、直径12cm×深
さ30cmの円筒状であり、上部にフランジ３１を有
する。該耐熱性容器３は、補強リング１３に挿入
されて熱媒体２中に保持される。耐熱性容器３と
電極１２との相対位置は、第１図におけるＭ＝25
cmであり、Ｍ＝25／23Lとなるようにしてある
（Ｌ＝23cm）。また、凹部１１の内壁面と耐熱性容
器３の外側面との距離は55mmとした。この耐熱性
容器３には硼砂とフエロバナジウムとからなる表
面処理剤４の溶融したものが保持されている。 The heat-resistant container 3 made of SUS310 has a cylindrical shape with a diameter of 12 cm and a depth of 30 cm, and has a flange 31 at the top. The heat-resistant container 3 is inserted into the reinforcing ring 13 and held in the heat medium 2. The relative position of the heat-resistant container 3 and the electrode 12 is M=25 in FIG.
cm, and M=25/23L (L=23cm). Further, the distance between the inner wall surface of the recess 11 and the outer surface of the heat-resistant container 3 was 55 mm. This heat-resistant container 3 holds a molten surface treatment agent 4 made of borax and ferrovanadium.
被処理剤を表面処理剤４中に吊り下げ、電極間
の電流を加減することで熱媒体２の温度を調節
し、表面処理剤４の温度を所定の処理温度に保持
し、硼化処理を行う。本実施例では、熱媒体２を
1200℃、表面処理剤４を1180℃とした。 The agent to be treated is suspended in the surface treatment agent 4, the temperature of the heating medium 2 is adjusted by adjusting the current between the electrodes, the temperature of the surface treatment agent 4 is maintained at a predetermined treatment temperature, and the boriding treatment is carried out. conduct. In this embodiment, the heat medium 2 is
The temperature was 1200°C, and the temperature of surface treatment agent 4 was 1180°C.
表面処理を実施している間および熱媒体２を加
熱している間、炉体１の凹部１１には、耐火綿を
つめた鉄枠製の蓋５をかぶせる。 During surface treatment and while heating the heat medium 2, the recess 11 of the furnace body 1 is covered with a lid 5 made of an iron frame filled with refractory cotton.
本発明の加熱炉においては、熱媒体２を十分高
温度に加熱した後に耐熱性容器３を熱媒体２に浸
すことができる。このため耐熱性容器３内の表面
処理剤４は高温の熱媒体２により急速に加熱され
る。また、表面処理が終つた後は、耐熱性容器３
を熱媒体２より引き上げ炉体１と分離して放冷す
ることができる。このため、表面処理剤４の加熱
および冷却に要する時間を極めて短かくできる。
この時間的短縮により、耐熱性容器３の実質的使
用可能時間が大巾に向上する。 In the heating furnace of the present invention, the heat-resistant container 3 can be immersed in the heat medium 2 after the heat medium 2 is heated to a sufficiently high temperature. Therefore, the surface treatment agent 4 inside the heat-resistant container 3 is rapidly heated by the high-temperature heat medium 2. In addition, after the surface treatment is completed, the heat-resistant container 3
can be pulled up from the heating medium 2, separated from the furnace body 1, and left to cool. Therefore, the time required for heating and cooling the surface treatment agent 4 can be extremely shortened.
This time reduction greatly improves the usable time of the heat-resistant container 3.
さらに、本発明の加熱炉において加熱のための
電極１２と耐熱性容器３の相対位置を、内壁面を
形成する各電極１２の最上部を結ぶ線ｌが上記耐
熱性容器３の下方にあり、かつ、該各電極１２の
最上部を結ぶ線ｌと上記耐熱性容器３との最も短
かい間隔Ｍが該電極１２間の距離Ｌの少なくとも
1/4以上、としたため、すなわち、電極１２を耐
熱性容器３の十分に下方に設けたため、電極１２
間に電圧を印加した場合に、耐熱性容器３自体に
電流が流れることがない。このため耐熱性容器３
自体が局部的に過熱されることはなく、局部過熱
による耐熱性容器３の劣化は生じない。また、加
熱は耐熱性容器３の下方でなされ、かつ、加熱部
１の凹部１１の内壁面と耐熱性容器３の外側面と
の距離を50mm以上としているため熱媒体２の自燃
対流により耐熱性容器３の周囲の熱媒体３の温度
は比較的均一に保たれる。 Furthermore, in the heating furnace of the present invention, the relative position of the electrode 12 for heating and the heat-resistant container 3 is such that a line l connecting the top of each electrode 12 forming the inner wall surface is located below the heat-resistant container 3; And, the shortest distance M between the line l connecting the tops of the electrodes 12 and the heat-resistant container 3 is at least the distance L between the electrodes 12.
1/4 or more, that is, because the electrode 12 was provided sufficiently below the heat-resistant container 3, the electrode 12
When a voltage is applied between them, no current flows through the heat-resistant container 3 itself. For this reason, heat-resistant container 3
The container itself is not locally overheated, and the heat-resistant container 3 does not deteriorate due to local overheating. In addition, since the heating is performed below the heat-resistant container 3 and the distance between the inner wall surface of the recess 11 of the heating part 1 and the outer surface of the heat-resistant container 3 is 50 mm or more, heat-resistant convection of the heat medium 2 is achieved. The temperature of the heat medium 3 around the container 3 is kept relatively uniform.
電極１２を耐熱性容器３の下方に配置したので
加熱炉の設置面積を小さくできる。また図に示す
加熱炉においては凹部１１の開口端を耐熱性容器
３のフランジ部３１で密閉する構造としているた
め、熱媒体２の蒸散とか熱媒体２が熱処理剤４中
に混入する等の不都合はない。また、フランジ部
３１による密閉を利用し、凹部１１の空間をアル
ゴンガス等の保護ガスで満たすこともできる。 Since the electrode 12 is placed below the heat-resistant container 3, the installation area of the heating furnace can be reduced. Furthermore, in the heating furnace shown in the figure, the open end of the recess 11 is sealed with the flange 31 of the heat-resistant container 3, so there are problems such as evaporation of the heat medium 2 or mixing of the heat medium 2 into the heat treatment agent 4. There isn't. Further, the space of the recess 11 can be filled with a protective gas such as argon gas by utilizing the sealing provided by the flange portion 31.
このように本発明の加熱炉は、1100℃以上の高
温での使用においても、耐熱性容器３の寿命延長
あるいは低級材料化が可能となり、熱媒体２の消
費量減および作業環境の改善に貢献する。 In this way, the heating furnace of the present invention can extend the life of the heat-resistant container 3 or use lower grade materials even when used at high temperatures of 1100°C or higher, contributing to a reduction in the consumption of the heat medium 2 and an improvement in the working environment. do.
第１図は本発明の加熱炉の断面図、第２図はそ
の上面図、第３図はその正面図である。図中符号
１は炉体、１２は電極、２は熱媒体、３は耐熱性
容器、４は表面処理剤を示す。
FIG. 1 is a sectional view of the heating furnace of the present invention, FIG. 2 is a top view thereof, and FIG. 3 is a front view thereof. In the figure, reference numeral 1 indicates a furnace body, 12 an electrode, 2 a heat medium, 3 a heat-resistant container, and 4 a surface treatment agent.
Claims (1)
有する炉体と、 上記炉体の凹部に保持される塩化物を主成分と
する熱媒体と、 上記炉体の凹部の上方に着脱自在に保持される
耐熱性容器と、 上記耐熱性容器内に保持される、金属等の表面
処理剤とよりなる金属の表面処理用間接加熱炉に
おいて、 上記表面処理剤は硼化物を主剤とするものであ
り、 上記炉体の凹部を形成する内壁部には少なくと
も１対の加熱用電極が保持され、該電極の位置
は、内壁面を形成する各電極の最上部を結ぶ線が
上記耐熱性容器の下方にあり、かつ該各電極の最
上部を結ぶ線と上記耐熱性容器との最も短かい間
隔が該電極間の距離の少なくとも1/4以上である
ことを特徴とする金属等の表面処理用間接加熱
炉。 ２ 加熱部の凹部の内壁面と耐熱性容器の外側面
との距離は50mm以上である特許請求の範囲第１項
記載の加熱炉。 ３ 耐熱性容器は耐熱鋼または黒鉛製である特許
請求の範囲第１項記載の加熱炉。 ４ 電極は耐熱鋼または黒鉛製である特許請求の
範囲第１項記載の加熱炉。 ５ 耐熱性容器の上端にはフランジ部が形成され
該フランジ部で炉体の凹部の開口をふさぐ特許請
求の範囲第１項記載の加熱炉。[Scope of Claims] 1. A furnace body made of a non-conductive refractory and having a recess with an opening at the top; a heat medium containing chloride as a main component held in the recess of the furnace body; and a recess of the furnace body. In an indirect heating furnace for surface treatment of metals, the furnace comprises a heat-resistant container detachably held above and a surface treatment agent for metals, etc. held in the heat-resistant container, the surface treatment agent being a boride. At least one pair of heating electrodes is held on the inner wall forming the recess of the furnace body, and the position of the electrode is determined by a line connecting the top of each electrode forming the inner wall surface. is located below the heat-resistant container, and the shortest distance between the line connecting the tops of the electrodes and the heat-resistant container is at least 1/4 of the distance between the electrodes. Indirect heating furnace for surface treatment of metals, etc. 2. The heating furnace according to claim 1, wherein the distance between the inner wall surface of the recess of the heating section and the outer surface of the heat-resistant container is 50 mm or more. 3. The heating furnace according to claim 1, wherein the heat-resistant container is made of heat-resistant steel or graphite. 4. The heating furnace according to claim 1, wherein the electrode is made of heat-resistant steel or graphite. 5. The heating furnace according to claim 1, wherein a flange portion is formed at the upper end of the heat-resistant container, and the flange portion closes the opening of the recessed portion of the furnace body.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12495081A JPS5825470A (en) | 1981-08-10 | 1981-08-10 | Indirect heating furnace for surface treatment of metal or the like using boride bath |
| AU86769/82A AU545039B2 (en) | 1981-08-10 | 1982-08-05 | Indirect salt bath furnace for boronisins high speed steels |
| EP82107252A EP0072525A1 (en) | 1981-08-10 | 1982-08-10 | Indirect heating furnace for the surface treatment of a metal or the like employing a salt bath |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12495081A JPS5825470A (en) | 1981-08-10 | 1981-08-10 | Indirect heating furnace for surface treatment of metal or the like using boride bath |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5825470A JPS5825470A (en) | 1983-02-15 |
| JPS6261666B2 true JPS6261666B2 (en) | 1987-12-22 |
Family
ID=14898216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12495081A Granted JPS5825470A (en) | 1981-08-10 | 1981-08-10 | Indirect heating furnace for surface treatment of metal or the like using boride bath |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0072525A1 (en) |
| JP (1) | JPS5825470A (en) |
| AU (1) | AU545039B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0381059U (en) * | 1989-12-04 | 1991-08-20 |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4789410A (en) * | 1987-03-03 | 1988-12-06 | United Technologies Corporation | Method for heat treating and quenching complex metal components using salt baths |
| JP2000328225A (en) * | 1999-05-17 | 2000-11-28 | Dowa Mining Co Ltd | Surface treatment and treating vessel used for the method |
| CN113073290B (en) * | 2021-03-26 | 2021-11-02 | 长沙特耐金属材料科技有限公司 | Preparation method of metal-based material coated with multi-component composite coating |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB191110884A (en) * | 1911-05-05 | 1912-02-01 | Fletcher Russell & Co Ltd | Improvements in or applicable to Lead and Salt Bath Furnaces Employed for Hardening or Melting Metal. |
| US1736457A (en) * | 1925-10-10 | 1929-11-19 | Westinghouse Electric & Mfg Co | Composition of matter for and method of purifying fused salt baths |
| US1776128A (en) * | 1927-03-05 | 1930-09-16 | Gen Electric | Melting pot |
| FR701149A (en) * | 1929-08-24 | 1931-03-12 | Siemens Ag | Electrode oven for salts that attack masonry coverings |
| US2231010A (en) * | 1938-02-24 | 1941-02-11 | Du Pont | Heat treating process |
| FR913062A (en) * | 1944-08-03 | 1946-08-28 | Ici Ltd | Heat treatment of steels |
-
1981
- 1981-08-10 JP JP12495081A patent/JPS5825470A/en active Granted
-
1982
- 1982-08-05 AU AU86769/82A patent/AU545039B2/en not_active Ceased
- 1982-08-10 EP EP82107252A patent/EP0072525A1/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0381059U (en) * | 1989-12-04 | 1991-08-20 |
Also Published As
| Publication number | Publication date |
|---|---|
| AU545039B2 (en) | 1985-06-27 |
| AU8676982A (en) | 1983-02-17 |
| EP0072525A1 (en) | 1983-02-23 |
| JPS5825470A (en) | 1983-02-15 |
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