Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/24—Selection of soldering or welding materials proper
  • B23K35/32—Selection of soldering or welding materials proper with the principal constituent melting at more than 1550°C
  • B23K35/325—Ti as the principal constituent
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C16/00—Alloys based on zirconium
• • 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
  • C23C26/00—Coating not provided for in groups C23C2/00 - C23C24/00
  • C23C26/02—Coating not provided for in groups C23C2/00 - C23C24/00 applying molten material to the substrate
• • 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
• • 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
  • C23C8/24—Nitriding
• • 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
  • C23C8/28—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 more than one element being applied in one step
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T70/00—Locks
  • Y10T70/70—Operating mechanism
  • Y10T70/7441—Key
  • Y10T70/7486—Single key
  • Y10T70/7508—Tumbler type
  • Y10T70/7559—Cylinder type
  • Y10T70/7588—Rotary plug
  • Y10T70/7593—Sliding tumblers
  • Y10T70/7599—Transverse of plug
  • Y10T70/7605—Pin tumblers

Definitions

• the present invention relates to surface hardened metal bodies or articles consisting of or containing titanium or zirconium, and also to a process for surface hardening metal bodies or articlesconsisting of or containing titanium or zirconium.
• the metals belonging to the titanium group of the periodic system particularly titanium, zirconium and alloys containing the same have relatively low specific gravities and are excellent in tensile strength and anticorrosive properties, and therefore have extensively been used as materials for various articles, structures, apparatus, etc. including chemical apparatus and appliances.
• titanium and zirconium are low in hardness and are poor in wear resistance and furthermore have rawbacks that they are damaged particularly when applied to those which are subjected to friction. For these reasons, these materials are not fully satisfactory in spite of their various excellent properties.
• an improved metal body or article consists of a base metal consisting of or containing titanium or zirconium and a surface hardened coating or layer which consists of the nitride and/ or oxide of the metal or alloy of the said base, or consists of a dispersed layer of the nitride and/ or oxide.
• the hardened surface coating or layer is formed by reacting the surface layer of the base metal or alloy with oxygen and/ or nitrogen. It is preferable to use gaseous oxygen and gaseous nitrogen as oxidizing and nitridation agents respectively. More particularly, according to the present invention, the nitride and/ or oxide are formed by utilizing the so-called inert gas shielded arc welding arrangement with or without a filler metal rod consisting of the same material as the base metal or alloy. Oxygen and/ or nitrogen gas are mixed with the inert gas so that the nitridation and/or oxidation occur While the surface is being covered by the inert gas.
• the surface of the base is reacted with oxygen and/or nitrogen to integrally form the oxide and/ or nitride thereon, while when the filler metal is used the molten filler metal itself forms the oxide and/or nitride layer or coating on the base.
• Titanium is chemically stable below 500 C. but becomes very active at higher temperatures and reacts with oxygen at temperatures higher than the red heat (500 C.) to form titanium oxide as a solid solution or dispersion layer consisting mainly of titanium dioxide, and reacts with nitrogen at temperatures higher than 800 C. to form a solid solution or dispersion layer of titanium nitride.
• solubility of oxygen and nitrogen in titanium is appreciably higher than in other practical metals.
• zirconium reacts with oxygen and nitrogen at elevated temperatures (500 C.). The same is true in respect to titanium or zirconium base alloys. In any case, the oxide and/ or nitride forms very hard surface layer or coating on the base metal or alloy.
• the formation of the desired oxide and/or nitride is effected by shielding the surface of the base metal body or article with an inert gas such as argon or helium and the surface is are molten or coated with additional molten metal (by using a filler metal rod) while introducing a predetermined amount of oxygen and/or nitrogen in the inert gas.
• an inert gas such as argon or helium
• the amount and proportions of oxygen and/or nitrogen can be controlled quite easily as desired to stabilize the oxidation and/or nitridation reaction and form the desired and uniform hardened surface.
• an inert gas shielded arc welding arrangement which, so well known to those skilled in the art as requiring no detailed explanation, is a shield arc welding carried out in an inert gaseous atmosphere.
• an electrode of material having a high melting point such as tungsten is employed.
• the hardened layer to be formed is relatively thin A mm. or less
• no filler metal rod is used and the surface to be hardened is are molten and reacted with oxygen and/or nitrogen While shielded with the inert gas to form the hard oxide and/or nitride.
• the hardened layer to be formed is relatively thick (up to 5 mm. or thicker), it is preferable to use a filler metal in the usual manner.
• the filler metal which is the same material as the base metal to be coated is similarly arc molten and reacted with oxygen and/ or nitrogen while shielded with the inert gas to form the hard oxide and/ or nitride which are deposited on the said surface.
• the amount of oxygen and/ or nitrogen to be supplied in the inert gas will largely control the hardness of the formed layer or coating.
• the amount of the reactive gas is less than that required no sufiicient hardness would be obtained, while if the amount of the reactive gas is excessive fragility of the oxide and/ or nitride is unduly increased so that the surface would become brittle.
• the amount of the reactive gas is selected depending upon the desired hardness to be accomplished, the particular metal or alloy from which the body or article is formed, and the thickness of the hardened layer or coating. This amount can be selected easily by those skilled in the art by means of a small scale pretesting.
• the amount of the reactive gas (oxygen and/ or nitrogen) is determined by the proportion occupying in the inert gas. Generally, when the metal surface itself is molten and hardened without using a metal deposition from the filler met-a1 rod it has been found that the amount of the reactive gas is preferable to be selected less than 15% by volume of the inert gas, while when the metal deposition is used the amount of the reactive gas is preferable to be less than 10% by volume of the inert gas. In the latter case the said less amount is caused by the use of 45 cording to gas analysis. In any case, the Welding conditions were equally' as follows:
• the Weld or are current is f bl to be
• the depositioncoa-tlng or layer was formed controlled within the range from 60 to 130 amp., alh thickness of 5 and lts hardhes rt*Thhrkahly though not absolutely necessary to be limited to this parhlghef than that of the base mhtal tltahlu'mticul ar range.
• the arc length usually is about 2-10 mm.
• Example 2 7 l 0 I v 2 3 .5; z 3 2 2 3 dhehum s f:
• bodies of titan um, trtanlum base ale 1 6 gas a or e aroun e loys, zirconium, and zirconium base alloys were surface portion to be wgelded or molten may, 1n most cases, be hardened by amploying an oxygen and/o1.
• g ifii i coatmg zf 0n results were as indicated in the fol-lowing table.
• the surface hardness was measured by Vickers hardhas hardness of from 250 to 550 as measured by V1cxers t k 1 n ness meter (load 30 gs.). hardness meter (load 30 rigs).
• the reactive gas (oxy- W 1d A A a R W m gen and/ or nitrogen) is introduced in the inert gas which Body g @33 gg f Speeed su face creates an inert gas shield the stability and uniformity of ng (mm) (In /hr.) percent g'liglj/ hardness the reaction are assured, the control of the reaction is (a easy so that there 1s obtained a umform hard layer or Ti H50 H0 1O 30 (02) 10mm 2504300 coating.
• the filler metal rod for deposiuon a Ti al10y 00-150 2-10 10-g0 30 282) 100-150 25 -200 r .1 t z.
• Zr 00-180 2-10 10- 0 0 00-150 25 00 tlnch coatmg, if desired, can be obta ned.
• Zr H80 H0 10 30 g 100450 25mm controlling the amount of the deposition, the thickness of the hard coating may be varied as desired.
• Example 3 since the definite or calculated amount of oxygen and/ or T I d an b a nitrogen can be introduced, and undesired intrusion of b a 15 i fi g i i atmospheric air (which would cause nonuniformity of the 165 ace ar e e y W 051.1 g a 1 minim formed 1a er or 60min is v revented b the inert as oxide and n1tr1de layer thereon.
• a usual mert gw shieldd th a n 35 ed arc Welding apparatus with tungsten elec rode was S 1 Z e ayel or coa Hg mime 18 i an y employed together with a filler metal rod as indicated for form in hardness and structure or composruon.
• the Tesuh was as follows:
• a method of surface-hardening a metal body selected from the group consisting of titanium and zirconium which comprises the steps of: forming a layer on the surface of the body by reacting said body with a reactive gaseous element in an inert gas-shielded arc welding arrangement by heating the body surface to a temperate at which it is molten, and introducing in the inert gas the reactive gaseous element so that said surface of the body while being arc-welded and shielded by the inert gas, is reacted with said reactive gaseous element to form the layer.
• a method of surface hardening a metal body selected from the group consisting of titanium, zirconium, and titanium base alloys comprising the steps of: shielding the body with an inert gas having mixed therewith a measured amount of reactive gas for reacting with the body and simultaneously arc welding the body in the gas shield at a temperature which provides a molten surface on said body so that the molten portion of the body reacts with the reactive gas to form a hard layer on the surface of said body.
• a method as defined in claim 3 comprising depositing metal from a filler metal rod onto the body during arc welding.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
• Arc Welding In General (AREA)
• Nonmetallic Welding Materials (AREA)

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Citations (4)

• 0
  • CA CA713159A patent/CA713159A/en not_active Expired
• 1960
  • 1960-08-01 US US4635160 patent/US3111434A/en not_active Expired - Lifetime
  • 1960-10-04 FR FR840300A patent/FR1271837A/fr not_active Expired
  • 1960-10-08 DE DEK41851A patent/DE1182016B/de active Pending
  • 1960-10-25 GB GB3655660A patent/GB906895A/en not_active Expired
• 1961
  • 1961-02-06 CH CH134961A patent/CH414302A/de unknown

Patent Citations (4)

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