JPH0346534B2 - - Google Patents

Description

[Detailed description of the invention]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to hard-facing metal parts, and in particular to homogeneous ductile materials used in hard-facing. Hardfacing is a method of depositing a wear- and corrosion-resistant layer by melting a suitable alloy in situ. Only the surface of the base metal to be hardfacing is brought to a melting point, and the hard facing rod, cotton material or powder is melted and applied to the surface of the base metal. Hardfacing is a quick and economical method used to repair or reinforce worn parts, thereby reducing overall operating and downtime costs. Using this method, composite parts can be made that combine strength, toughness, and corrosion resistance at low cost. Suitable wear and corrosion resistant surface layers can be applied to parts such as dies and tooling made of relatively inexpensive impact resistant alloys (eg, plain carbon steel or low alloy steel). Additionally, hard facings are employed in structures that use a flexible core to overcome stress and a hard casing to resist wear. Examples of this type of construction include injection screws and extrusion screws used in plastic processing and the like. Many parts that would otherwise be discarded are used again at below cost. It is understood that further savings can be made as the part can be remanufactured on site if necessary. Common hardfacing methods include oxyacetylene method, tungsten inert gas welding (TIG),
Metal inert gas welding (MIG), immersion electric arc welding,
This includes plasma transfer electric arc welding. The hardfacing alloys used in such processes contain substantial amounts (about 1-11% by weight) of metalloid elements such as boron, silicon or carbon.
As a result, these alloys are extremely brittle and can only be obtained in the form of rods or powders. One of the most difficult problems with common hardfacing methods and materials is the difficulty in controlling the thickness and homogeneity of the surface layer. The tough rod-like structures used to extrude hardfacing material into the heating zone cannot be economically advantageously applied to continuous surface treatment processes. Hardfacing bars are typically applied manually using tungsten inert gas or oxyacetylene methods. These are discontinuous and inherently slow. Continuous hardfacing can be achieved by automatic tungsten inert gas machines where individual bars are fed by gravity, or by plasma welding electric arc (PTA) welding methods where powdered hardfacing material is fed into the heating zone. achieved.
Such methods require relatively expensive equipment and materials. Furthermore, the excess heat generated by the plasma in the PTA welding process adversely affects the flowability of the hardfacing alloy, dilutes the alloy with material from the base metal, and changes the compositional homogeneity of the surface layer. Therefore, there remains a need in the art for an economical continuous hardfacing process. A ductile glassy alloy is shown in U.S. Pat. No. 3,856,513, issued to HS Chien et al. These alloys have the formula MaYbZc
Includes compositions with In the formula, M is a metal selected from the group consisting of iron, nickel, cobalt, vanadium and chromium, Y is an element selected from the group consisting of phosphorus, boron and carbon, Z
are aluminum, silicon, tin, germanium,
An element selected from the group consisting of indium, antimony, and beryllium, where "a" is approximately 60 to 90
%, with "b" ranging from about 10 to 30 atomic % and "c" ranging from about 0.1 to 15 atomic %. Also shown is a vitreous wire with the formula TiXj. In the formula, T is at least one transition metal, X is an element selected from the group consisting of phosphorus, boron, carbon, aluminum, silicon, tin, germanium, indium, beryllium and antimony, and "i" is about ~87 at.%.
Such materials are conveniently prepared by rapid cooling from the melt using processing methods that are now well known in the art. However, hardfacing compositions are not shown here. There remains a need in the industry for homogeneous hardfacing materials available in thin, ductile foil form. In accordance with the present invention, a homogeneous ductile hard facing foil is provided which is useful as a filler metal for hard faced metal articles. This hardfacing foil consists of a metastable material with at least 50% glassy structure and a thickness of
Not larger than 0.004 inch (10.16 x 10 ^-3 cm)
Especially 0.0005~0.04 inch (1.27× ^10-3 ~10.16×
10 ^-3 cm). It has been found that by using a flexible, thin, homogeneous hardfacing foil as described above, the hardfacing speed can be increased and the hardness of the deposited surface layer can be improved. More specifically, this hard facing foil has a thickness of approximately 0.0005 to 0.004 inches (1.27 x 10 ^-3 to 10.16 x
10 ^-3 cm). The foil of the present invention can be comprehensively expressed in the broadest concept as follows. That is, a homogeneous, ductile hardfacing foil for use as a surface layer of a hardfacing metal article having at least 50% glassy structure and containing from 2 to 25 atomic % boron; % or less silicon, 5 atom % or less carbon,
30 atom% or less of chromium, 16 atom% or less of tungsten, 5 atom% or less of molybdenum, 2 atom% or less of manganese, 25 atom% or less of cobalt, and
At least one element selected from the group consisting of nickel in an amount of 32 atomic percent or less, with the remainder being iron and incidental impurities, provided that the total of iron, cobalt, nickel, chromium, tungsten, molybdenum, and manganese is within the range of 70 to 88 atomic%,
and the total of boron, silicon and carbon is 12 to 30
Hardfacing foils consisting of metastable materials with compositions in the atomic percent range. Preferably the foil consists essentially of less than 25 atomic percent cobalt and nickel.
It has a composition consisting of 30 atomic% or less, chromium 30 atomic% or less, tungsten 5 atomic% or less, molybdenum 4 atomic% or less, boron 2-25 raw material, silicon 15 atomic% or less, and carbon 5 atomic% or less, with the remainder being iron. and accompanying impurities, except iron, cobalt,
The sum of nickel, chromium, tungsten and molybdenum ranges from 70 to 88 atomic percent, boron,
The sum of silicon and carbon ranges from 12 to 30 at.%. Other preferred hardfacing foil compositions include less than 25 atomic percent essential cobalt and less than 20 atomic percent iron;
Consisting of 15 at% or less chromium, 16 at% or less tungsten, 5 at% or less molybdenum, 2 to 20 at% boron, 10 at% or less silicon, and 5 at% or less carbon, the remainder being nickel and accompanying impurities, However, the total of iron, cobalt, nickel, chromium, tungsten and molybdenum is 70~
The total amount of boron, silicon and carbon is in the range of 12 to 30 atom %. Still other preferred hardfacing foil compositions are essentially less than 32 at.% nickel and 10 at.% iron.
Chromium: 30 at% or less, tungsten: 2 at% or less, molybdenum: 4 at% or less, boron: 2 to 25
atomic%, silicon 15 atomic% or less, manganese 2 atomic%
The remainder is essentially cobalt and accompanying impurities, with the exception that the total of iron, cobalt, nickel-trichromium, manganese, tungsten and molybdenum is 70 to
88 atom %, with the sum of boron, silicon and carbon ranging from 12 to 30 atom %. The reason why the hard facing foil alloy of the present invention requires each component element is as follows. Reason for needing the element Chromium To make the alloy resistant to corrosion and oxidation. Tungsten To improve thermal hardness and wear resistance. Molybdenum To improve corrosion and wear resistance and increase thermal hardness. Boron To lower the melting temperature. Silicon To lower the melting temperature. Carbon To improve wear resistance by forming carbides. Nickel and Cobalt to improve corrosion resistance. The reason for limiting the composition range for each element is that each such composition range maintains the liquidus and solidus temperatures under the necessary restrictions and maintains the desired mechanical and chemical properties of the alloy. This is because it is necessary to do so. The homogeneous hardfacing foils of the present invention are produced by preparing a melt of the composition described above and quenching the melt on a rotating quench wheel at a rate of at least about 10 ⁵ C/sec. This filled metal foil can be easily processed into a homogeneous ductile ribbon useful for hardfacing. Additionally, the homogeneous ductile hardfacing foil of the present invention allows for reduced deposit thicknesses, resulting in less dilution from the substrate and less expense in grinding the deposited layer. The invention will be better understood, and other advantages will become apparent, from the following detailed description of the preferred embodiments of the invention. The present invention provides a homogeneous ductile hardfacing material in foil form. This hardfacing foil is less than 0.004 inch (10.16 x 10 ^-3 cm) thick,
Preferably 0.004 to 0.002 inches (10.16 x 10 ^-3 to
5.08×10 ^-3 cm) and essentially has the following composition: 1 Cobalt 25 atomic% or less, Nickel 30 atomic% or less, chromium 30 atomic% or less, tungsten 5 atomic% or less, molybdenum 4 atomic% or less, boron 2~
25 atom%, less than 15 atom% silicon and less than 5 atom% carbon, the remainder being iron and accompanying impurities, except for iron, cobalt, nickel, chromium,
Total of tungsten and molybdenum is 70-88
The total amount of boron, silicon and carbon is in the range of 12 to 30 atomic %. 2 Cobalt 25 atom % or less, iron 20 atom % or less, chromium 15 atom % or less, tungsten 16 atom % or less, molybdenum 5 atom % or less, boron 2 to 20 atom %, silicon 10 atom % or less, and carbon 5 atom %
Below, the remainder is nickel and accompanying impurities, but the total of iron, cobalt, nickel, chromium, tungsten and molybdenum is 70
~88 at.%, with the sum of boron, silicon and carbon ranging from 12 to 30 at.%. 3 Nickel 32 atomic% or less, iron 10 atomic% or less, chromium 30 atomic% or less, tungsten 2 atomic% or less, molybdenum 4 atomic% or less, boron 2-25 atomic%, silicon 15 atomic% or less, manganese 2 atomic%
less than or equal to 5 atom % and carbon, the remainder being cobalt and incidental impurities, except for the sum of iron, cobalt, nickel, chromium, manganese, tungsten and molybdenum ranging from 70 to 88 atom %, boron, silicon and carbon. The sum is in the range of 12 to 30 at.%. These compositions are suitable for hardfacing low carbon and low alloy steels with relatively high wear and corrosion resistance. By homogeneous it is meant that the produced foil has a substantially uniform composition in all directions. Ductile means that the foil can be bent to a circular radius ten times the thickness of the foil without breaking. Examples of hard facing alloy compositions within the scope of this invention are shown in the table below. a/o and in the table
At% means atomic percent, w/o and wt% mean weight percent.

The hardfacing foils of the present invention can be prepared by melting a melt of the desired composition at a rate of at least about 10 ⁵ °C/sec using alloy quenching techniques well known in the glassy metal alloy art (e.g., U.S. Pat. No. 3,856,513 and U.S. Pat. 4148973
(see each specification). The purity of all compositions is that found in normal commercial practice. Various techniques are used to process continuous ribbons, cotton stock, sheets, etc. Typically, a specific composition is selected, powders or granules of the required elements in the desired proportions are melted and homogenized, and the molten alloy is quenched on a cooling surface, for example on a rapidly rotating metal cylinder. . Under this quenching condition, a metastable homogeneous ductile material is obtained. The metastable material may be glassy, in which case there is no extensive alignment. The X-ray diffraction diagram of glassy alloys shows only diffuse halos similar to those of inorganic oxide glasses. Glassy alloys of this type must be at least 50% vitreous in order to be sufficiently ductile that they can be subsequently handled (for example, stamping complex shapes from alloy ribbons). In order to obtain excellent ductility,
The vitreous alloy should preferably be at least 80% vitreous, most preferably substantially (or entirely) vitreous. The metastable phase may be a solid solution of the constituent elements.
In the case of the alloys of the present invention, metastable solid solution phases of this type are not normally produced by conventional processing techniques used in the art of crystalline alloy processing. The X-ray diffraction diagram of the solid solution alloy shows sharp diffraction peaks typical of crystalline alloys, with some broadening of the peaks due to the desired fine-grained crystallites. Metastable materials of this type are also ductile when produced under the conditions mentioned above. In accordance with the present invention, hardfacing of metal substrates is facilitated by feeding a continuous filament from a spool or other similar coiled source to the heating zone. The filament thus provided is homogeneous and ductile, consists of a metastable material with at least 50% glassy structure, and has a composition consisting essentially of: 1 Cobalt 25 atomic% or less, Nickel 30 atomic% or less, chromium 30 atomic% or less, tungsten 5 atomic% or less, molybdenum 4 atomic% or less, boron 2~
25 atom%, silicon 15 atom% or less, and carbon 5
At % or less, the remainder is iron and accompanying impurities, except that the total of iron, cobalt, nickel, chromium, tungsten and molybdenum is 70
~88 at.%, with the sum of boron, silicon and carbon ranging from 12 to 30 at.%. 2 Cobalt 25 atomic % or less, iron 20 atomic % or less, chromium 15 atomic % or less, tungsten 16 atomic % or less, molybdenum 5 atomic % or less, boron 2 to 20 atomic %, silicon 10 atomic % or less, and carbon 5 atomic % or less , the remainder is nickel and associated impurities, except for a total of 70 iron, cobalt, nickel, chromium, tungsten and molybdenum.
~88 at.%, with the sum of boron, silicon and carbon ranging from 12 to 30 at.%. 3 Nickel 32 atomic% or less, iron 10 atomic% or less, chromium 30 atomic% or less, tungsten 2 atomic% or less, molybdenum 4 atomic% or less, boron 2-25 atomic%, silicon 15 atomic% or less, manganese 2 atomic%
less than or equal to 5 atomic percent of carbon, the remainder being cobalt and associated impurities, with the sum of iron, cobalt, nickel, chromium, tungsten and molybdenum ranging from 70 to 88 atomic percent, and the sum of boron, silicon and carbon. is 12-30
in the atomic percent range. Heat is applied to the filament in the heating zone to melt the filament and deposit it on the workpiece surface in close proximity to it. The workpiece surface is then allowed to cool and the deposited filament forms a hard adhesive coating on this surface. The following examples are presented in order to more fully understand the invention. The specific techniques, conditions, materials, proportions, and reported data presented to illustrate the principles and practice of the invention are illustrative only and should not be construed as limitations on the scope of the invention. EXAMPLE 1 A melt of a specific composition was injected onto a rapidly rotating copper cooling wheel (surface velocity 3000-6000 ft/min, i.e. 914.4-1828.8 m/min) under heavy pressure of argon to form a 2.5 mm width. ~25.4mm
(0.10 to 1.00 inch) and thickness 13 to 60 μm (approx.
0.0005 to 0.0025 inch) ribbon was created. A metastable homogeneous ribbon of a substantially glassy alloy was obtained having the following composition (wt % and atomic %): The composition of the ribbon is shown in the table below.

[Table] Hard facing layers were formed using ribbons of various alloy compositions according to the following procedure. Ribbon thickness ranges from 0.001 to 0.0025 inches (2.54 x 10 ^-3 to 6.35 x
10 ^-3 cm). The ribbon is made of AISI340 stainless steel sheet (0.0625 inch thick [1.59 x 10 ^-1
cm] and the composites were individually heated in a vacuum oven to a temperature of 1900-2300㎓ (1038-1260° C.) depending on each alloy for 15 minutes. The samples were then removed from the oven, cut, mounted, and polished for microhardness measurements of the hard facing layer. The composition and Knoop hardness (load: 100 g, indentation time: 15 seconds) of each tested ribbon alloy are shown in the table.

[Table] Although the present invention has been described in more detail below, it is not necessary to adhere strictly to these detailed descriptions, and those skilled in the art will be able to make various changes and modifications, all of which are within the scope of the claims. It will be understood that the invention falls within the scope of the invention.

Claims (1)

Claims: 1. A homogeneous, ductile hardfacing foil for use as a surface layer of a hardfacing metal article, the foil having at least 50% glassy structure and containing from 2 to 25 at. Boron; 15 atomic % or less silicon, 5 atomic % or less carbon,
Chromium up to 30 atomic %, tungsten up to 16 atomic %, molybdenum up to 5 atomic %, manganese up to 2 atomic %, cobalt up to 25 atomic %, and 32
At least one element selected from the group consisting of nickel and the remainder being iron and incidental impurities, provided that the total of iron, cobalt, nickel, chromium, tungsten, molybdenum and manganese is 70% or less. A hardfacing foil characterized in that it consists of a metastable material having a composition in the range of ~88 at.% and the sum of boron, silicon and carbon in the range of 12 to 30 at.%. 2 The tungsten content is 5 at% or less,
The hard facing foil according to claim 1, having a molybdenum content of 4 at % or less. 3. A hard facing foil according to claim 2, wherein said material is at least 80% vitreous. 4. A hard facing foil according to claim 2, wherein said material is 100% vitreous. 5 (a) Homogeneous and ductile, at least 50%
has a glassy structure, and contains 2 to 25 at.% of boron; up to 15 at.% of silicon, up to 5 at.% of carbon, up to 30 at.% of chromium, up to 16 at.% of tungsten, up to 5 at.% of boron; Contains at least one element selected from the group consisting of molybdenum, manganese at 2 atomic % or less, cobalt at 25 atomic % or less, and nickel at 32 atomic % or less, with the remainder being iron and incidental impurities, provided that ,iron,
cobalt, nickel, chromium, tungsten,
Spool a continuous foil of metastable material having a composition in which the sum of molybdenum and manganese is in the range 70 to 88 atom % and the sum of boron, silicon and carbon is in the range 12 to 30 atom %. (b) positioning the continuous foil in close proximity to the surface of the workpiece prior to applying heat to the continuous foil; (c) applying heat to the foil within the heating zone to heat the foil; (d) cooling the workpiece surface so that the deposited foil forms a hard adherent film on the workpiece surface; Hard facing method of base material. 6. The hard facing method for a metal substrate according to claim 5, wherein the foil has a tungsten content of 5 at % or less and a molybdenum content of 4 at % or less.