EP0808914A1 - Tauchteil für Schmelzbad aus Nichteisenmetallen - Google Patents

Tauchteil für Schmelzbad aus Nichteisenmetallen Download PDF

Info

Publication number
EP0808914A1
EP0808914A1 EP97108034A EP97108034A EP0808914A1 EP 0808914 A1 EP0808914 A1 EP 0808914A1 EP 97108034 A EP97108034 A EP 97108034A EP 97108034 A EP97108034 A EP 97108034A EP 0808914 A1 EP0808914 A1 EP 0808914A1
Authority
EP
European Patent Office
Prior art keywords
steam
atmosphere
oxynitriding
weight
oxide
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.)
Withdrawn
Application number
EP97108034A
Other languages
English (en)
French (fr)
Inventor
Kazuaki c/o Wakamatsu Netsuren Co. Ltd. Fukuba
Seiichiro Miyata
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wakamatsu Netsuren Co Ltd
Original Assignee
Wakamatsu Netsuren Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from JP16659296A external-priority patent/JPH09137265A/ja
Application filed by Wakamatsu Netsuren Co Ltd filed Critical Wakamatsu Netsuren Co Ltd
Publication of EP0808914A1 publication Critical patent/EP0808914A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/10—Oxidising
    • C23C8/16—Oxidising using oxygen-containing compounds, e.g. water, carbon dioxide
    • C23C8/18—Oxidising of ferrous surfaces

Definitions

  • the present invention relates to a member for use in contact with molten nonferrous metals, particularly to a member which is highly resistant to dissolution loss by molten nonferrous metals such as aluminum, zinc, copper, brass, etc.
  • thermocouple protection tubes immersed in molten nonferrous metals, dies into which molten nonferrous metals are injected, etc.
  • thermocouple protection tubes immersed in molten nonferrous metals, dies into which molten nonferrous metals are injected, etc.
  • ceramics or nitrided steel in general.
  • most immersion members are made of ceramics
  • most contact members are made of nitrided steel.
  • the ceramics are disadvantageous in their high cost and vulnerability to cracking and breakage, and the nitrided steel is disadvantageous in its small resistance to dissolution loss by molten nonferrous metals.
  • an object of the present invention is to provide a member for use in contact with molten nonferrous metals, which has a substrate made of iron or its alloy and is highly resistant to dissolution loss by molten nonferrous metals such as aluminum, zinc, copper, brass, etc.
  • the member for use in contact with molten nonferrous metals comprises a substrate made of an Fe-base alloy and a dense surface layer composed of an oxide or oxynitride formed in the presence of steam.
  • the dense surface layer is formed by preheating the member substrate in a non-oxidizing atmosphere and then heat-treating it in an oxidizing or oxynitriding atmosphere containing steam or in an atmosphere generating oxygen and steam.
  • Fig. 1 is a graph showing the relations between the Cr content (weight %) and crack resistance and peel resistance (expressed by the number of repetition) in the members for use in contact with molten nonferrous metals according to the present invention.
  • the members for use in contact with molten nonferrous metals include members such as thermocouple protection tubes, heater tubes and slag filters which are directly immersed in molten nonferrous metals, and members such as die-casting cylinders, plunger heads, die-casting molds, melt supply tubes, inner walls of melt pumps and melt kilns which are brought into contact with molten nonferrous metals, etc.
  • the members for use in contact with molten nonferrous metals are sometimes simply called "melt-contacting members" herein.
  • the melt-contacting member of the present invention comprises a substrate made of an Fe-base alloy and a surface layer composed of an oxide or oxynitride formed in the presence of steam.
  • the substrate of the melt-contacting member of the present invention may generally be made of Fe-base alloys ranging from usual carbon steel to cast iron to alloyed steel and to alloyed cast iron.
  • the alloying elements for the Fe-base alloys are preferably Cr, Si and Al, which are effective for enhancing denseness, adhesion, crack resistance, etc. of the oxide or oxynitride surface layers formed on the member substrates.
  • the Cr content is preferably 40 weight % or less based on the total weight (100 weight %) of the member substrate. Even if the Cr content exceeds 40 weight %, the further growth of an oxide or oxynitride layer is not expected, only deteriorating the denseness, adhesion, crack resistance, etc. of the resultant layer and making the melt-contacting member expensive. For better effects, the Cr content is preferably 5 weight % or more.
  • Si and/or Al When Si and/or Al is added to the member substrate, remarkable effects of improving denseness, adhesion, crack resistance, etc. of the oxide or oxynitride surface layers formed on the member substrates can be achieved as long as the amount of Si and/or Al added is 4 weight % or less. When both Si and Al are added together, their total amount is 4 weight % or less.
  • the lower limit of the amount of Si and/or Al added is preferably 1 weight %.
  • rare earth elements such as yttrium, etc.
  • the rare earth elements such as yttrium, cerium, dysprosium, lanthanum, etc., are effective for improving the adhesion of the oxide or oxynitride surface layer to the melt-contacting member substrate.
  • the substrate structure of the melt-contacting member may be austenite, ferrite, martensite or mixtures thereof, depending on the uses of the melt-contacting members.
  • the substrate structure can metallurgically be controlled by adjusting heat treatment conditions or by adding alloying elements.
  • the members with oxide or oxynitride layers formed in the presence of steam exhibit excellent resistance to dissolution loss by molten nonferrous metals.
  • the oxide or oxynitride layer is obtained by an oxidation or oxynitriding treatment in an oxidizing or oxynitriding atmosphere containing steam or in an atmosphere generating oxygen and steam.
  • an oxidizing or oxynitriding atmosphere containing steam or in an atmosphere generating oxygen and steam The detailed descriptions of such atmospheres will be given in [3] (2) below.
  • the composition of the oxide or oxynitride layer directly formed on the melt-contacting member appears to be an MO-type oxide such as FeO or an M(ON)-type oxynitride such as Fe(ON). Further formed thereon may be an M 3 O 4 -type oxide such as Fe 3 O 4 or an M 2 O 3 -type oxide such as Fe 2 O 3 .
  • the MO-type oxide or M(ON)-type oxynitride layer has a high resistance to peeling from the melt-contacting member as well as an excellent crack resistance.
  • the thickness of the oxide or oxynitride layer is preferably 10-500 ⁇ m. When the oxide or oxynitride layer is thicker than 500 ⁇ m, it easily peels off from the melt-contacting member substrate. On the other hand, when the oxide or oxynitride layer is thinner than 10 ⁇ m, it fails to have a sufficient resistance to dissolution loss by molten nonferrous metals. The more preferable thickness of the oxide or oxynitride layer is 20-100 ⁇ m.
  • the important feature of the present invention is that in the temperature elevation process to a temperature T 1 which is preferably between [an oxidizing or oxynitriding temperature T 2 - 100°C] and [an oxidizing or oxynitriding temperature T 2 + 0°C], the member substrate is placed in a non-oxidizing atmosphere in a furnace to prevent premature oxidation or oxynitriding. If the temperature T 1 is lower than an oxidizing or oxynitriding temperature T 2 by more than 100°C, a dense oxide or oxynitride layer cannot be obtained.
  • the temperature T 1 is higher than an oxidizing or oxynitriding temperature T 2 , the oxide or oxynitride layer is likely to peel off from the melt-contacting member substrate.
  • the more preferred temperature T 1 is between [an oxidizing or oxynitriding temperature T 2 - 50°C] and [an oxidizing or oxynitriding temperature T 2 + 0°C]. Specifically, the temperature T 1 is 650-1100°C.
  • the non-oxidizing atmosphere means an atmosphere which does not contain oxygen and steam. It naturally does not contain a nitriding gas such as ammonia.
  • the preferred non-oxidizing atmosphere is an inert gas such as a nitrogen gas, an argon gas, etc.
  • the heating of the Fe-base alloy substrate to the temperature T 1 in the non-oxidizing atmosphere makes it possible to form a dense oxide or oxynitride layer on the Fe-base alloy substrate in the subsequent oxidizing or oxynitriding step.
  • An oxidizing or oxynitriding gas containing steam or an atmosphere generating oxygen and steam is supplied to a furnace in which the Fe-base alloy substrate is preheated.
  • the addition of steam to these atmospheres turns them to slightly oxidizing, suitable for forming an oxide or oxynitride layer on the melt-contacting member substrate.
  • the oxidizing gas may be the air, and the oxynitriding gas may be the air to which a nitriding gas such as ammonia is added.
  • Typical examples of the steam-containing oxidizing gas are (i) a mixture of the air and an overheated steam, (ii) an exhausted gas generated by burning oil or natural gas, etc.
  • the percentage of steam may be 12-35 volume %, and the percentage of oxygen may be 88-65 volume %. If the percentage of steam is less than 12 volume % or more than 35 volume %, a sufficiently dense oxide layer cannot be formed on the Fe-base alloy substrate. Preferably, the percentage of steam is 15-30volume %, and the percentage of oxygen is 85-70 volume %.
  • the percentage of steam may be 14-35 volume %
  • the percentage of oxygen may be 57-81 volume %
  • the percentage of the nitriding gas may be 5-8 volume %. If the percentage of steam is less than 14 volume % or more than 35 volume %, a sufficiently dense oxide layer cannot be formed on the Fe-base alloy substrate.
  • the percentage of steam is 18-25 volume %
  • the percentage of oxygen is 67-77 volume %
  • the percentage of the nitriding gas is 5-8 volume %.
  • the atmosphere generating oxygen and steam is an atmosphere capable of generating oxygen and steam at the oxidizing or oxynitriding temperature T 2 , for instance, a mixture of hydrogen gas and a carbon dioxide gas, etc.
  • the percentage of the hydrogen gas may be 20-55 volume %, and the percentage of the carbon dioxide gas may be 80-45 volume %. If the percentage of a hydrogen gas is less than 20 volume % or more than 55 volume %, a sufficiently dense oxide layer cannot be formed on the Fe-base alloy substrate.
  • the percentage of a hydrogen gas is 30-45 volume %, and the percentage of a carbon dioxide gas is 70-55 volume %.
  • the mixture of a hydrogen gas and a carbon dioxide gas may further contain up to about 100 volume % of the air per 100 volume % of a hydrogen gas + a carbon dioxide gas.
  • the oxidizing or oxynitriding temperature T 2 is preferably between 400°C and 1250°C. If the oxidizing or oxynitriding temperature T 2 is lower than 400°C, a dense oxide or oxynitride layer cannot be formed on the Fe-base alloy substrate. On the other hand, if the oxidizing or oxynitriding temperature T 2 is higher than 1250°C, the oxide or oxynitride layer is likely to peel off from the melt-contacting member substrate The more preferred oxidizing or oxynitriding temperature T 2 is between 700°C and 1200°C.
  • the oxidizing or oxynitriding time may vary depending on the oxidizing or oxynitriding temperature T 2 , but it may generally be 15-45 minutes. If the oxidizing or oxynitriding time is shorter than 15 minutes, a sufficient surface layer cannot be formed. On the other hand, even if the oxidizing or oxynitriding time is longer than 45 minutes, further improvements cannot be obtained.
  • the heat-treated member may be left to cool in the air, or forced to cool by air blow, water spray, etc. Since the oxide or oxynitride layer thus formed is extremely dense and has strong adhesion the member substrate, it has an excellent resistance to dissolution loss by molten nonferrous metals such as aluminum, zinc, copper, brass, etc.
  • Table 1 No. Composition of Sample (weight %) 1 SS41 (Soft Steel) 2 SUS304 (Austenite Stainless Steel) 3 SUS310S (Austenite Stainless Steel) 4 SUS410 (Martensite Stainless Steel) 5 SUH1 (Heat-Resistant, Si-Cr Stainless Steel) 6 Fe-25%Cr-2%Al Steel (Heat-Resistant, High-Cr, Al, Steel) 7 Fe-3%C-25%Cr Cast Iron
  • Each sample was in the shape of a round rod of 200 mm in length and 20 mm in diameter.
  • each sample was placed in a furnace at room temperature, which was evacuated and filled with a dry nitrogen gas at atmospheric pressure. Each sample was heated to about 850°C (Sample Nos. 1-3, 6 and 7) and about 950°C (Sample Nos. 4 and 5) in the dry nitrogen gas. After reaching the above temperature, a mixture of the air and an overheated steam (volume ratio: 20/1) at 850°C was introduced into the furnace while heating each sample, to carry out an oxidation treatment at 900°C (Sample Nos. 1-3, 6 and 7) and at 1000°C (Sample Nos. 4 and 5) for 1 hour. After the completion of the heat treatment, each sample was cooled in the furnace. Incidentally, Sample Nos. 4 and 5 were annealed at 750°C.
  • Each sample was immersed in molten aluminum kept at 750°C for 10 hours to measure its loss by dissolution into the molten aluminum.
  • the oxide layer of the present invention is remarkably effective for improving a resistance to dissolution loss by molten aluminum.
  • Each sample was in the shape of a round rod of 200 mm in length and 20 mm in diameter.
  • Each sample was placed in a furnace at room temperature, which was evacuated and filled with a dry nitrogen gas at atmospheric pressure. Each sample was heated to about 850°C in the dry nitrogen gas. After reaching the above temperature, a mixture of hydrogen and carbon dioxide (volume ratio: 2/3) at 850°C was introduced into the furnace while heating each sample, to carry out an oxidation treatment at 900°C for 1 hour. An excess hydrogen gas was burned outside the furnace. After the completion of the heat treatment, each sample was cooled in the furnace.
  • Each sample was immersed in molten aluminum kept at 750°C for 10 hours to measure its loss by dissolution into the molten aluminum.
  • the oxide layer of the present invention is remarkably effective for improving a resistance to dissolution loss by molten aluminum.
  • Samples having various Cr contents were measured with respect to crack resistance and peel resistance of their surface oxide layers.
  • Each sample was made of an Fe-Cr-base alloy having a Cr content of 0 weight %, 5 weight %, 10 weight %, 20 weight %, 30 weight %, 40 weight % and 50 weight %, respectively.
  • the total amount of other elements was less than 1 weight %.
  • 0.1 weight % of Y was added to the first group of samples, and no Y was added to the second group of samples.
  • Each sample was in the shape of a round rod of 200 mm in length and 20 mm in diameter.
  • each sample was placed in a furnace at room temperature, which was evacuated and filled with a dry nitrogen gas at atmospheric pressure. Each sample was heated to 950°C (Sample Nos. 1-3, 6-10) and 1000°C (Sample Nos. 4 and 5) in the dry nitrogen gas. After reaching the above temperature, a mixture of the air, an overheated steam and an ammonia gas (volume ratio: 11/3/1) at 950°C was introduced into the furnace while heating each sample, to carry out an oxidation treatment at 1000°C (Sample Nos. 1-3, 6-10) and 1050°C (Sample Nos. 4 and 5) for 1 hour. After the completion of the heat treatment, each sample was cooled in the furnace. Incidentally, Sample Nos. 4 and 5 were annealed at 650°C.
  • Each sample was immersed in molten zinc kept at 650°C for 20 hours to measure its loss by dissolution into the molten zinc.
  • the melt-contacting member of the present invention has an excellent resistance to dissolution loss by nonferrous molten metals such as aluminum, zinc, copper, brass, etc.
  • the melt-contacting members of the present invention such as thermocouple protection tubes, heater tubes, die-casting cylinders, plunger heads, die-casting molds, melt supply tubes, inner walls of melt pumps and melt kilns, etc., are useful in the field of casting of molten nonferrous metals.
EP97108034A 1996-05-22 1997-05-16 Tauchteil für Schmelzbad aus Nichteisenmetallen Withdrawn EP0808914A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP166592/96 1996-05-22
JP16659296A JPH09137265A (ja) 1995-09-06 1996-05-22 非鉄金属溶湯部材

Publications (1)

Publication Number Publication Date
EP0808914A1 true EP0808914A1 (de) 1997-11-26

Family

ID=15834147

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97108034A Withdrawn EP0808914A1 (de) 1996-05-22 1997-05-16 Tauchteil für Schmelzbad aus Nichteisenmetallen

Country Status (1)

Country Link
EP (1) EP0808914A1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002068708A1 (de) * 2001-02-27 2002-09-06 Thyssenkrupp Vdm Gmbh Verfahren zur erhöhung der härte und verschleissfestigkeit von bauteilen, insbesondere aus austenitische nickellegierungen
US20150104333A1 (en) * 2012-04-13 2015-04-16 ArcelorMittal Investigación y Desarrollo, S.L. Bubble pump resistant to attack by molten aluminum

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2236728A (en) * 1940-05-01 1941-04-01 Perfect Circle Co Process of treating bearing members
US2727842A (en) * 1950-06-21 1955-12-20 Tno Process for the conversion of at least the surface layer of an iron article into magnetite and thus prepared articles
US3611530A (en) * 1970-03-19 1971-10-12 John T Mayhew Antipickup roll construction and utilization for plating lines
GB2092621A (en) * 1981-02-06 1982-08-18 Maschf Augsburg Nuernberg Ag Forming oxide layer on alloy steels
JPS6277451A (ja) * 1985-09-30 1987-04-09 Toshiba Corp 電導性耐食材料の製造方法
JPH03264658A (ja) * 1990-02-07 1991-11-25 Kayaba Ind Co Ltd 部材の表面及び色度処理法
JPH0754127A (ja) * 1993-08-09 1995-02-28 Shinto Kogyo Kk 溶融亜鉛めっき装置材料

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2236728A (en) * 1940-05-01 1941-04-01 Perfect Circle Co Process of treating bearing members
US2727842A (en) * 1950-06-21 1955-12-20 Tno Process for the conversion of at least the surface layer of an iron article into magnetite and thus prepared articles
US3611530A (en) * 1970-03-19 1971-10-12 John T Mayhew Antipickup roll construction and utilization for plating lines
GB2092621A (en) * 1981-02-06 1982-08-18 Maschf Augsburg Nuernberg Ag Forming oxide layer on alloy steels
JPS6277451A (ja) * 1985-09-30 1987-04-09 Toshiba Corp 電導性耐食材料の製造方法
JPH03264658A (ja) * 1990-02-07 1991-11-25 Kayaba Ind Co Ltd 部材の表面及び色度処理法
JPH0754127A (ja) * 1993-08-09 1995-02-28 Shinto Kogyo Kk 溶融亜鉛めっき装置材料

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 011, no. 273 (C - 445) 4 September 1987 (1987-09-04) *
PATENT ABSTRACTS OF JAPAN vol. 016, no. 071 (C - 0913) 21 February 1992 (1992-02-21) *
PATENT ABSTRACTS OF JAPAN vol. 095, no. 005 30 June 1995 (1995-06-30) *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002068708A1 (de) * 2001-02-27 2002-09-06 Thyssenkrupp Vdm Gmbh Verfahren zur erhöhung der härte und verschleissfestigkeit von bauteilen, insbesondere aus austenitische nickellegierungen
US20150104333A1 (en) * 2012-04-13 2015-04-16 ArcelorMittal Investigación y Desarrollo, S.L. Bubble pump resistant to attack by molten aluminum
US10711335B2 (en) 2012-04-13 2020-07-14 ArcelorMittal Investigación y Desarrollo, S.L. Bubble pump resistant to attack by molten aluminum

Similar Documents

Publication Publication Date Title
US10724121B2 (en) Thermostable and corrosion-resistant cast nickel-chromium alloy
US4439248A (en) Method of heat treating NICRALY alloys for use as ceramic kiln and furnace hardware
US3989514A (en) Heat-resisting austenitic stainless steel
US4881983A (en) Manufacture of corrosion resistant components
KR100503838B1 (ko) 가스침탄로용부품및지그
CN108642373A (zh) 一种高温抗氧化奥氏体耐热钢及其制备工艺
US4150978A (en) High performance bearing steels
JPH0548293B2 (de)
EP0808914A1 (de) Tauchteil für Schmelzbad aus Nichteisenmetallen
JP3410303B2 (ja) 耐溶融金属溶損性および耐摩耗性に優れたＦｅ−Ｎｉ−Ｃｒ−Ａｌ系フェライト合金およびその製造方法
US3868277A (en) Method of producing a steel product having an oxidation-resistant coating
EP0030699B1 (de) Verfahren zum Herstellen von Walzdraht zum Kaltumformen
JP2003154437A (ja) 鋳造用金型およびその製造方法
JPH0280512A (ja) 高度合金クロム鋼の熱処理方法
JPH0343338B2 (de)
EP0454680A1 (de) Auf eisen, nickel und chrom basierende legierung.
JPH06122957A (ja) フェライト系ステンレス材の表面処理方法
JPS56150155A (en) Preparation of ferrous sintered material
US3926688A (en) Method of manufacturing a flat steel product having an oxidation-resistant coating
FR2642438A1 (fr) Procede pour former une couche d'oxyde de fer sur un objet en acier exempt de decarburation peripherique et application de ce procede
KR100321047B1 (ko) 페라이트계 스테인레스 열연강대의 표면경화 소둔열처리방법
RU2090647C1 (ru) Способ диффузионного хромирования прокатных валков из отбеленного чугуна
RU2024622C1 (ru) Способ производства электротехнической анизотропной стали
SU1747535A1 (ru) Способ азотировани молибдена
SU1595926A1 (ru) Способ химико-термической обработки низкоуглеродистых легированных сталей

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19980527