Classifications

• • 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
  • C21D7/00—Modifying the physical properties of iron or steel by deformation
  • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
  • C21D7/04—Modifying the physical properties of iron or steel by deformation by cold working of the surface
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C14/00—Alloys based on titanium
• • 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
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C38/00—Ferrous alloys, e.g. steel alloys
  • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
• • 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
  • C23C8/02—Pretreatment of the material to be coated
• • 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
  • C23C8/34—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 more than one step
• • 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
  • C23C8/40—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 liquids, e.g. salt baths, liquid suspensions
  • C23C8/58—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 liquids, e.g. salt baths, liquid suspensions more than one element being applied in more than one step
• • 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
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F17/00—Multi-step processes for surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by subclass C21D or C22F or class C25
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
  • F16C33/02—Parts of sliding-contact bearings
  • F16C33/04—Brasses; Bushes; Linings
  • F16C33/06—Sliding surface mainly made of metal
  • F16C33/12—Structural composition; Use of special materials or surface treatments, e.g. for rust-proofing
  • F16C33/121—Use of special materials
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
  • F16D69/02—Composition of linings ; Methods of manufacturing
  • F16D69/027—Compositions based on metals or inorganic oxides
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D2250/00—Manufacturing; Assembly
  • F16D2250/0038—Surface treatment

Definitions

• austenitic stainless steels such as for example the common stainless steels comprising substantial proportions of addition elements such as chromium and nickel, and on the hypereutectoid alloy steels containing by weight 11 to 14% of magnanese, l to 1.3% of carbon, not more than 0.6% of silicon, impurities in the usual proportions, the remainder being constituted by iron.
• titanium and its alloys exhibit similar properties together with the drawbacks which result from them.
• All the metals and alloys enumerated above have the common property of hardening by cold-hammering, subsequently showing a great density of planes of slip in their superficial crystalline structure.
• the object of the present invention is to obtain parts which present immediately, as soon as they are put to use, a good resistance to seizure and to wear.
• parts made of a metallic material capable of hardening by cold-hammering or coldrolling and having in its superficial crystalline structure a high density of plane of slip to a deep cold-hammer- 3,321,338 Patented May 23, 1967 ing carried out in such manner that it produces on the surface of the parts striations which are substantially perpendicular to the direction of application of the friction.
• the cold-hammering can be carried out either by knurling or by hammering.
• knurling which is preferably used when the parts to be cold-hammered are flat or round surfaces
• the rollers must be cut so that the striations which they impress by forging on the surface of the part are arranged in a direction substantially perpendicular to the direction of application of the friction.
• a hammer with a striated striking face In the case where the parts to be cold-hardened are neither flat nor round, it is preferable to employ a hammer with a striated striking face.
• the thermal treatment or treatments are carried out in such manner that there is obtained a superficial incorporation of one or of two metalloids, or of a transition metal capable either of depositing on the surface of the part an ionic compound by reaction with the underlying metal, or of inserting its atoms into the" structure of the underlying metal while forming a solid insertion solution.
• transition metals or these metalloids may be, for example, nitrogen, sulphur, selenium, 'telluriu-m, amongst others.
• the introduction of a metalloid or of a transition metal as defined above, into the cold-hardened layer is obtained by a heat treatment of the knurled part in a salt bath or in gaseous atmosphere for a period of time anywhere from one hour to as long as six hours at a temperature between 400 C. and 590 C.
• the coldhardened part is treated with a bath of sulphur salts or a gaseous sulphur atmosphere for a period of time of at least two hours and at a temperature higher than 500 C.
• a treatment of this kind can for example be ap lied by means of a process known in France under the commercial name of Sulfinuz.
• all the identical or similar processes using salt baths or a gaseous medium producing superficial structure layers of compositions similar or identical with those which are obtained by the Sulfinuz process may be employed.
• the parts are preheated to about 300 to 350 C. and are then immersed for a period of 2 to 6 hours in a salt bath maintained at an approximate temperature of 570 C. and are composed of an inactive base such as the alkali and alkaline earth chlorides and carbonates, permitting a melting point to be obtained of less than 500 C. of sulphur compounds, the action of which is preponderant and buffer cyanides or cyanates which protect the sulphur compounds by keeping the bath in a reducing medium.
• a salt bath maintained at an approximate temperature of 570 C. and are composed of an inactive base such as the alkali and alkaline earth chlorides and carbonates, permitting a melting point to be obtained of less than 500 C. of sulphur compounds, the action of which is preponderant and buffer cyanides or cyanates which protect the sulphur compounds by keeping the bath in a reducing medium.
• the treatment temperature in salt baths or in a gaseous atmosphere may, depending on the composition of the bath, for example when it contains a sulphide and a ferro-cy-anide, be less than 570 C., the sulphuretting action being then capable of taking place from 400 C.
• the incorporation of nitrogen can be effected by means of any nitriding process which is effective below a maximum temperature of 580 C., beyond which temperature the decomposition of the austenite is too great and introduces excessive brittleness.
• Tufftride also known in the anglo-saxon countries by the name of Tufftride is a process of mild nitridation which makes it possible to obtain on the steel parts, an outer layer comprising iron carbide and iron nitride covering a ditfusionlayer of nitrogen in the steel.
• This result can be obtained for example by immersing the part for a sufficient pre-determined period, for example for two hours, in a salt bath heated to a temperature comprised between 550 and 580 C., for erample 565 C., comprising about 32 to 35% of alkali cyanates, for example 45 of potassium cyanate, and 50 to 55% approx. of alkali cyanides, for example 55 of potassium cyanide, the bath being stirred by blowing-in air.
• results obtained are substantially identical with those which are recorded after a sulphurizing treatment, such as the Sulfinuz process.
• the cold-hardened parts can advantageously be successively subjected to a nitridation such as the Tenifer treatment and then to a sulphurizing treatment, for example according to the Sulfinuz process.
• a nitridation such as the Tenifer treatment
• a sulphurizing treatment for example according to the Sulfinuz process.
• Example 1 A shaft and rings of 15 40 mm. were machined from a steel in the super-tempered state containing, by weight, 1.2% of carbon and 14.5% of manganese. Immediately after the lathe operation, the bearing surfaces of the shaft and the corresponding surfaces of the rings were knurled with a tool which pressed two rollers of 20 mm. against the parts with a force of 400 kg., giving two families of striations of 0.15 mm. in depth and 1 mm. apart, respectively inclined by -15 to the direction of the gen erator lines.
• the knurled wheels made 14 to-and-fro passages under these conditions.
• the part is easily brought back to its initial dimension by a light polishing with emery cloth.
• the parts, shaft and rings, cold-hardened in this way have in section under metallographic examination, extremely dense networks of lines of shear, this is to say having for example four lines of shear per square of 0.01 mm. sides, and penetrating to a depth of more than 0.3 mm.
• the micro-hardness indicates that in the zone of shear, the initial hardness of 70 kg./sq. mm. has increased to 190 kg./sq. mm., the hardness of the core not being modified.
• the whole was assembled without lubrication and immersed in water.
• the amplitude of the oscillations was 90 and their frequency was 2 cycles/sec.
• the load was 2,000 kp.
• Example 2 A part of Hadfield steel, cold-hardened and knurled, was plunged into a bath of molten salts at 560 C., containing cyanides and unstable isomers of potassium cyanate. After immersion in this bath, of which one of the types is known by the commercial name of Tenifer, the same precipitates are found along the planes of shear, without increase in the micro-hardness, over the first four-tenths of a millimeter of the surface of the part, as those which were observed on the cold-hardened parts subjected to a sulphurizing treatment.
• Example 3 A shaft and rings of the same dimensions as those of Example 1 were machined from a standard stainless steel containing, by weight, 18% of chromium, 8% of nickel and 3% of molybdenum. Tested under the treatments according to the invention, substantially under the same conditions of tests as the parts of Example 1, that is to say with an amplitude of oscillations of a frequency of one cycle per sec. and a load of 2,000 kp., the whole immersed in water at 20 C., seizure inevitably occurs in less than a few minutes. On the other hand, when knurled and subjected to the sulphurizing treatment, an identical shaft can oscillate for more than 50 hours while retaining a satisfactory surface condition. The same advantage was obtained by means of nitridation.
• Example 4 Parts of titanium or of titanium alloy were subjected to cold-hardening followed in some cases by a sulphurizing thermal treatment and in the other cases by a nitriding treatment. After these applications of the process according to the invention, they all showed equally as soon as they were put into use, a good resistance to seizure and to wear.
• Example 5 A piece of Hadfield steel, after the cold-hardening operation, is immersed for two hours in a bath of nitriding salts at 560 C., the bath being constituted by a mixture of alkali cyanates and cyanides following the Tenifer process. After this mild nitridation, the part is subjected to the sulphurizing action of a bath such as that of the process known "by the commercial name of Sulfinuz, this process comprising a treatment of at least two hours in a sulphurizing 'bath or a sulphurizing atmosphere at a temperature exceeding 500 C. The results obtained are superior to those which are recorded on cold-hardened parts subjected only either to a sulphurizing treatment or to a nitriding treatment.
• a method for producing metallic parts having a high resistance to seizure and to wear by friction wherein parts made from a metallic material chosen from the group of metals capable of hardening by cold-hammering While exhibiting in its superficial crystalline structure a high density of planes of shear, and consisting of austenitic stainless steels, hyper-eutectoid alloy steels containing at least 11% by weight of manganese, titanium, and titanium alloys containing a major part of titanium, are subjected to a deep cold-hardening executed in such manner that it produces, on the surface of the part, striations substantially perpendicular to the direction of the friction, following which the part is subjected to the superficial incorporation of at least one element chosen from the group of the metalloids and transition metals, which metalloids and transition metals possess one of the two properties consisting firstly in the capacity of depositing at the surface of the parts an ionic compound by reaction with the underlying metal, and secondly of the capacity of inserting its atoms into the structure
• a method for producing metallic parts having a high resistance to seizure and to wear by friction which comprises forming a metallic part of a metal capable of hardening by cold-hammering while exhibiting in its superficial crystalline structure a high density of planes of shear and selected from the group consisting of austenitic stainless steels, hyper-eutectoid alloy steels containing at least 11% by weight manganese, titanium, and titanium alloys containing a major part of titanium; subjecting the part to a deep cold-hardening executed in such a manner that it produces on the surface of the part striations substantially perpendicular to the direction of frictional wear; subjecting the striated part to superficial incorporation of at least one element selected from the group consisting of nitrogen, carbon, sulfur, selenium, and tellurium, by maintaining contact between said metal part and a fluid containing such element for a period of time between one and six hours at a temperature of about 400 to 590 C.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• General Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
• Heat Treatment Of Articles (AREA)

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Cited By (14)

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Citations (5)

• 1964
  • 1964-06-23 FR FR979316A patent/FR86012E/fr not_active Expired
  • 1964-12-03 BE BE656607D patent/BE656607A/xx unknown
  • 1964-12-04 LU LU47522A patent/LU47522A1/xx unknown
  • 1964-12-09 GB GB50082/64A patent/GB1088122A/en not_active Expired
  • 1964-12-10 US US417495A patent/US3321338A/en not_active Expired - Lifetime
  • 1964-12-10 SE SE14926/64A patent/SE321396B/xx unknown
  • 1964-12-10 DE DE19641521660 patent/DE1521660A1/de not_active Withdrawn
  • 1964-12-11 OA OA50796A patent/OA00716A/fr unknown

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