1612 results about "High-speed steel" patented technology

The invention relates to a tool, especially a cutting insert for cutting metallic materials, which consist of a hard metal, cermet ceramics or steel base, especially of a high speed steel base, and at least one layer deposited thereon. The single layer, or in the case of several layers the outer layer or the layer underneath the outer layer, contains molybdenum sulfide. The aim of the invention is to improve the resistance to wear of the friction-reducing, molybdenum sulfide containing layer even at high pressures. To this end, the molybdenum sulfide containing layer consists of an alternating sequence of two layer that are different from one another. The first layer contains 51 to 100% by weight of metallic molybdenum and the second layer contains 21 to 100% by weight of MoS2 which substantially consists of hexagonal crystals that are at least substantially oriented in a plane parallel to the tool surface.

The invention relates to a centrifugal casting high-speed steel composite roll and a manufacture method thereof and belongs to the field of casting. The composite roll is composed of outer layer high-speed steel, middle layer graphitic steel and core high-strength nodular cast iron by centrifugal compounding. The centrifugal casting high-speed steel composite roll is based on the conventional high-carbon high-vanadium high-speed steel roll, the content of vanadium is appropriately reduced, niobium is added at the same time, and the Nb / V is controlled to be 0.3 to 0.5 so that Nb and V form complex carbide (V, Nb) C so as to avoid forming segregation under the action of centrifugal force. A roll core of the high-speed steel composite roll adopts high-strength nodular cast iron, and a multivariate graphite steel middle layer is poured between an outer layer and the roll core for preventing interfusing elements of Cr, B, and the like which cause embrittlement when the nodular cast iron is poured to be fused with the outer layer high-speed steel. Microalloying processing for refining the organization is carried out on a roll surface high-speed steel material and the middle layer graphitic steel so as to achieve the purpose of improving the thermal cracking capacity of the roll material. The centrifugal casting high-speed steel composite roll has high overall performance, long service life and good economic benefits.

The invention discloses a high-carbon high-vanadium high-speed-steel complex roll. The outer layer of the high-carbon high-vanadium high-speed-steel complex roll comprises, based on weight percent, C: 1.8%-3.0%, V: 3.0%-6.0%, Cr: 4.0%-6.0%, Mo: 3.0%-6.0%, W: 1.0%-3.0%, Nb: 1.0%-5.0%, Co: 1.0%-5.0%, Si: <1.0%, Mn: <1.5%, P: <0.04%, S: <0.04%; Y: 0.05%-0.20%, Ti: 08%-0.25%, Mg: 0.03%-0.12%, Zr: 0.04%-0.18%, Te: 0.02%-0.12%, the residuel of Fe, the total of 100%. The roll is produced by smelting using electric furnace, casting and forming using centrifugal casting, heat treatment comprising quenching and tempering treatment. The high-speed-steel roll has high rigidity and strength, good toughness and wear resistance, and good anti-thermal fatigue, without roll breakage and desquamation in use. The application of the inventive roll can reduce the consumption of roll, improve the work rates of roll, prolong roll changing cycle, improve the surface quality of roll, with good economic and social effect.

The invention discloses a resource-saving type high-boron high-speed steel composite roll and a manufacturing method of the resource-saving type high-boron high-speed steel composite roll, and belongs to the technical field of rolls. The composite roll is composed of outer-layer high-boron high-speed steel, middle transition-layer graphitic steel and roll core hot rolling medium-carbon round steel, the outer-layer high-boron high-speed steel and the middle transition-layer graphitic steel are formed in a centrifugal combination mode, and the transition-layer graphitic steel and the roll core hot rolling medium-carbon round steel are formed in a hot charging combination mode. The composite roll is high in roll face rigidity and good in rigidity uniformity, and it is guaranteed that the composite roll is excellent in abrasive resistance. A roll core is formed by machining the hot rolling medium-carbon round steel and is good in obdurability, the roll breakage accident cannot happen in the roll using process, and good economic benefits and social benefits are achieved through popularization and application.

The invention relates to high-boron low-alloy high-speed steel roll and a preparation method thereof. The roll comprises two parts, namely a roll barrel (1) and a roll core (2), wherein the roll barrel comprises the following chemical components by weight percent: 0.32-0.55% of C, 1.42-2.13% of B, 5.2-6.5% of Cr, 2.5-4.5% of W, 1.6-1.8% of V, 0.5-1.0% of Nb, 0.3-1.0% of Si, 0.3-1.0% of Mn, 0.10-0.20% of Ti, 0.05-0.12% of N, 0.04-0.12% of Y, 0.08-0.15% of Mg, less than 0.04% of P, less than 0.04% of S and the balance Fe. The roll prepared by the method of the invention is characterized by high hardness, deep quenched depth and good wear resistance and thermal fatigue resistance, and has good use effect in the production of hot rolled steel.

To provide alloy tool steel having a quenching temperature lower than that of conventional matrix high speed steel and also having the same characteristics such as hardness and toughness after heat treatment, as those of conventional alloy tool steel, and to provide its manufacturing method and a die using it. The alloy tool steel has a composition which contains prescribed amounts of C, Si, Mn, P, S, Cu, Ni, Cr, Mo or / and W, V, Al, O and N and further contains prescribed amounts of one or more elements among Co, Nb, Ti, B, Ta, Zr, Pb, Bi, Ca, Te, Se, REM and Mg and has the balance Fe with inevitable impurities and in which inequality -0.2<[Delta]C<0.2 (where [Delta]C=C-(0.06*Cr+0.063*Mo+0.033*W+0.2*V+0.1*Nb)) is satisfied and the value of Lc defined by equation Lc=(8.8*Mo+5.9*W+50*V+40*Nb) / (6*Cr) is made to 1.0 to 2. (C)2004,JPO.

The invention discloses a casting high-boron high-speed steel for manufacturing a composite roll ring roller and hot processing method thereof. The steel is a wear-resistant material having superior thermal-shock resistance, and can be applied to other suitable working conditions. The chemical compositions of the steel are (weight%): 0.20 to 1.10 of C, 1.0 to 2.5 of B, 3.0 to 5.0 of Cr, 0.5 to 0.9 of Si, 0.6 to 1.3 of Mn, 2.0 to 10.0 of V, 0.5 to 1.5 of Ni, 1.0 to 4.0 of Mo, 0.2 to 4.0 of W, 0.1 to 2.0 of Nb, less than 0.04 of S, less than 0.04 of P and residue of Fe. The hot processing method includes annealing, quenching and 2 to 3 times of temper. The annealing heating temperature is 800 to 860 DEG C, furnace cooling or air cooling is carried out after furnace cooling to less than 500 DEG C; the quenching heating temperature is 1020 to 1150 DEG C, wind cooling or air cooling is carried out thereafter; 2 to 3 times of temper are carried out, the heating temperature is 500 to 550 DEG C, furnace cooling or air cooling is carried out thereafter. Compared with traditional high-nickle-chrome-molybdenum roller, the roller of the invention greatly improves alloy wearing resistance, heat resistance and thermal-shock resistance, and reduces thermal endurance crack phenomena appearing during use, as well as pits and crack arising therefrom, embodying good organic combination of safety and wearing resistance.

The present invention discloses compound high speed steel roll and its making process. The compound high speed steel roll consists of roll body and roll core compounded through central casting. The roll body is made of high speed steel comprising chemically C 1.8-2.8 (in wt%, same as below), Mo 4.0-8.0, V 3.0-7.0, Nb 1.5-4.0, Cr 6.0-12.0, RE 0.1-0.25, Ti 0.15-0.40, N 0.08-0.20, K 0.06-0.18, Si<2.0, Mn<2.0, S<0.05 and P<0.05, except Fe and inevitable impurity. The roll core is made of high strength nodular cast iron comprising chemically C 3.2-3.6 (in wt%, same as below), Si 1.8-2.4, Mn 0.4-0.8, Ni 0.3-1.2, Cr 0.3-0.8, Mo 0.2-0.5, Mg 0.03-0.08, RE 0.05-0.14, P<0.08 and S<0.03, except Fe and inevitable impurity. The compound high speed steel roll has high wear resistance, simple making process and high production efficiency.

A high-speed steel roller ring for rolling wire or rod material contains C, W, Mo, V, Cr, Al, Ni, Co, Nb, Ti, Ce, Na, Mg, Si, Mn, S, P and Fe proportionally. It is prepared through smelting in electric furnace, centrifugal casting, and annealing, high-temp quenching and tempering twice. Its advantages are high hardness, tension strength and toughness for breaking, smooth surface and high size stability.

The invention belongs to the field of steel rolling manufacture, specifically is a high-speed steel composite roll for strip mill in steel rolling industry and casting method thereof. The outer layer of the composite roll is made of high-speed steel, the middle layer is made of ductile cast iron base iron or graphite semisteel, the core is made of ductile cast iron. The invention employs centrifugal compound foundry technique, the roll is moulded by three times of casting. Constant centrifugal rotating speed is kept in centrifuge, the metal material of the outer layer and the middle layer are mould cast, and then the metal of the roll core is statically cast to form the final product. Compared with former dual-layer or other three-layer composite high-speed steel rolling rolls, the three layers of metal of the high-speed steel composite roll of the invention are well combined and have high strength; the optimal selection of the material of the middle layer improves the strength of the bonding layer, the carbide affecting the binding performance in the middle layer is reduced, the spreading of alloy element in the outer layer high-speed steel to the core, which affects the core material performance, is also effectively avoided by the middle layer, cracking and dropping off of the working layer in hot processing and rolling process are prevented as well.

The invention relates to the technical field of cryogenic processes, in particular to a cryogenic process for prolonging the service life of a jet-moulded high-speed steel milling cutter. The cryogenic process for prolonging the service life of the jet-moulded high-speed steel milling cutter is characterized by comprising the following specific steps: preheating; quenching in vacuum; cooling; tempering primarily; performing cryogenic treatment; and tempering secondarily. Compared with the prior art, a new technology for combining vacuum quenching, tempering and cryogenic treatment is performed on a material of the jet-moulded high-speed steel milling cutter, so that after treatment of the cryogenic process, the wear resistance and the hardness of the material of the jet-moulded high-speed steel milling cutter are obviously improved, the comprehensive mechanical property of the milling cutter is improved and the service life of the milling cutter is prolonged.

The invention relates to a forging method, in particular to a multidirectional forging method for obtaining a high-alloyed high-temperature alloy sheared billet / biscuit with the uniform and fine structure. The multidirectional forging method includes the following steps that (1) high-temperature homogenizing treatment is conducted on a low-segregation and high-purity controlled directional solidification ingot blank; (2) the controlled directional solidification ingot blank is subjected to upsetting and cogging; (3) the upset blank is forged into a cuboid blank; (4) multidirectional forging is conducted on the cuboid blank; (5) the blank subjected to multidirectional forging for multiple cycles is subjected to finishing, so that a shear billet / biscuit of the required size is obtained; and (6) the obtained shear billet / biscuit is subjected to physical and chemical testing. The multidirectional forging method is not only suitable for preparation of uniform and ultra-fine-grain high-alloyed nickel-based high-temperature alloy sheared billets for aviation, spaceflight and vessels, but also can be popularized to a steel mill to product high-speed steel and hot-working die steel, and the prepared ultra-fine-grain shear billets have the characteristic of uniform structure.

A kind of low alloy high speed steel roller material and the method to produce it. The chemical components of it is( weight percent): C: 1.2-1.8%, Cr: 4.5-6.5%, W: 1.0-3.0%, Mo: 1.0- 3.0%, V: 3.0-5.0%, Al: 0.6-1.2%, Si: 0.8-1.2%, N: 0.05-0.15 %, B: 0.04-0.12%, Nb: 0.05-0.20%, Ti: 0.06-0.18%, Y: 0.04- 0.15%, Mn<0.5%, P<0.04%, S<0.04%, the other is Fe, and the actual content of carbon of it is: 0.033W+0.063Mo+0.060Cr+0.200V+(0.08-0.20). It is made by smelting with electric cooker, the roller is molded by centrifugal complex cast or continuous complex cast, the roller will be quenched and tempered after it has been processed rudely, and the regulated size and accuracy will fulfilled after a fine machining at last. Less Tungsten and Molybdenum element are contained in the low alloy high speed steel roller material, and it does not contain the expensive Cobalt, the production cost of it is lower, and it own high red-hardness, obdurability and abrasion resistance. This patent can improve the productivity of the rolling mill, and prolong the life of roller, and decrease the cost of rolled metal.

The invention discloses an AlTiN-AlCrN super hard nano multilayer composite coating hob and a preparation method thereof. The hob is provided with a nano composite coating consisting of Cr, CrN, AlTiN / CrhN and AlTiN / AlCr in sequence and generated by adopting an arc ion plating technology. The coating is reasonable in structural design and has gradually changed components and gradient hardness at the same time; and the prepared AlTiN / AlCr coating has good bonding force with the high-speed steel or hard alloy hob, high hardness and excellent temperature resistance. The problems of insufficient temperature resistance and abrasion resistance of the hob are well solved, the machining performance of the hob is greatly improved, and the hob has a good industrial application prospect.

The invention offers the high V super-speed steel complex roller and its producing craft. The roller includes roller heart and roller shell, the roller heart uses low metal alloy steel or middle carbon steel to produce, the shell uses high V super-speed steel, whose main element is : C: 1.8--3.5A%, V: 7--12%, Cr: 4--5%, Mo: 2--4%, Ni: 0.5--1.5%, other is Fe. The producing craft is: melt and cast the heart and shell by responding heat way. The roller in the invention has good whet feature, high rate of feature and price, using safely. Fine roller, high strength of combination, no crush in use; it can reduce the stop times. It efficiently increase the roller tenacity and whet feature, solve the problems in the heart leaving foundry, and solve the problems of complicated craft and high cost.

The invention discloses a boron-contained centrifugal composite high-speed steel roller, which comprises an outer layer of the high-speed steel roller, a middle layer of the high-speed steel roller and a core of the high-speed steel roller. The manufacturing method includes steps of smelting, interrupted front treatment, roller pouring, annealing, rough machining, double tempering, finish machining and testing. By the method, three-layer composite roller technology is adopted in the boron-contained centrifugal composite high-speed steel roller, composite ability of the outer layer of the high-speed steel roller and the core of the high-speed steel roller is increased, the roller is less prone to spalling, high in rigidity and accident resistant ability, fine in abrasion resistance, safe in use, low in energy consumption and short in cycle in heat treatment, oxidation and decarburization of the roller and roller breakage in use are avoided. The manufacturing method is simple and hot quenching process is omitted.

A manufacturing method for centrifugally casting high-boron high-speed steel composite roller belongs to the technical field of rolled steel. The invention aims to provide the manufacturing method for centrifugally casting the high boron high-speed steel composite roller without element segregation. The manufacturing method comprises the following steps: injecting high-seed steel liquid into a metal casting mould rotating at high speed on a centrifugal machine after the high-seed steel liquid is cooled by an inclined cooling plate; spaying, cooling and casting the high-seed steel liquid during a pouring process; and then centrifugally pouring an intermediate layer; finally pouring cast steel or alloyed ductile cast iron in a rolling core in a static state; and then obtaining the high-boron high-speed steel composite roller. The high-boron high-speed steel composite roller has the advantages of fine tissues on an external layer, compactness and no element segregation; and a boron element on the external layer cannot be mixed into a rolling core.

The invention provides a manufacturing method of high-vanadium high-cobalt high-speed steel, wherein, the composition weight percent of the high-speed steel is as follows: 1.1 percent to 2.18 percent of C, 5.0 percent to 8.0 percent of W, 4.0 percent to 6.0 percent of Mo, 3.0 percent to 5.0 percent of Cr, 1.2 percent to 8.3 percent of V, 6.5 percent to 11.5 percent of Co and the rest, Fe; the process steps of the high-speed steel includes master alloy preparation, spray forming, hot forging, quench tempering treatment, turning, milling and grinding or TiN / AlTiN coating treatment. The invention omits working procedures such as powder sieving, blending, encapsulation and cold and hot isostatic pressing, etc. and does not need costly equipment investment; moreover, the performance of the invention reaches to or even exceeds that of powder high-speed steel, thereby saving process cost and reducing the applied cost of the high-speed steel. The invention can be widely used in various cutters such as cutting tools for making difficult-to-machining material, and is particularly suitable to make cutters with quick-cutting, high hot hardness and long service life such as large-size broaching tool, gear shaver, hob and gear shaping tool for machining gear and various milling cutters used in digital control machine tool, etc.; moreover, the invention also can be used in making mould, etc.

The invention discloses high speed steel and a productive technology thereof. The high speed steel comprises the following chemical components by weight percent: 1.0 to 1.4 percent of C, 3.8 to 4.2 percent of Cr, 4.8 to 5.2 percent of Mo, 6.3 to 6.5 percent of W, 8.2 to 8.4 percent of Co, 2.2 to 3.0 percent of V, 0.4 to 1.5 percent of Nb and 0.2 to 0.4 percent Si, less than or equal to 0.03 percent of S, less than or equal to 0.03 percent of P, less than or equal to 0.4 percent of Mn, and the balance of Fe and inevitable impurities. The invention creatively introduces atomization deposition technology into the high speed steel preparation process, overcomes the defects of coarse crystalline grains and severe segregation of the traditional casted blank, abandons the disadvantages of various work procedures and high energy consumption of powder metallurgy technology, has the advantage of the powder metallurgy technology and consequently improves the various performances of metal material greatly. The advantage of the invention is obvious and outstanding.

The invention relates to a superfast heat treatment method of high-speed steel. The problems that high-strength steel is low in heat treatment efficiency, wastes energy and pollutes the environment are solved. According to the method, a heating device is adopted to heat the high-strength steel to the peak temperature Tp from the room temperature within 30 s, heat preservation is carried out for 5to 10 s, a cooling device is used for cooling the high-strength steel to the room temperature within 5 to 10 s, and the whole process is finished within 60 s; the high-strength steel is a steel wire or steel strip with the carton content ranging from 0.16 to 0.55% and the diameter or thickness being 5 mm or below; Tp exceeds the austenite transformation temperature Ac3 by more than 50 DEG C, Tp isequal to 1000 to 1200 DEG C, the maximum heating speed exceeds 400 DEG C / s, the maximum cooling speed exceeds 3000 DEG C / s, and 50cm / min continuous work is achieved. The method is novel and unique, scientific and reasonable, easy to operate, convenient to use, high in work efficiency, energy-saving, environment-friendly and capable of being widely applied to heat treatment strengthening of thin-specification steel strips and small-specification wire rods, and the method is creation of the high-strength steel heat treatment.

A coated body having a multi-layer of kappa-Al2O3 and or gamma-Al2O3 or TiN applied by MTCVD (Medium Temperature Chemical Vapor Deposition) is disclosed. The multi-layers can be interspersed with layers of Ti(C,N) which can also be applied by MTCVD. The body which is coated is preferably a cemented carbide, cermet, ceramic and / or high speed steel and may be used as a metal cutting insert.

The invention belongs to the technical field of rolled steel, and in particular relates to a manufacturing method of a spray formed high-vanadium high-speed steel composite roller. The high-vanadium high-speed steel comprises the following chemical components in percentage by mass: 1.7 to 1.8 percent of C, 1.2 to 1.6 percent of Si, 5.0 to 6.0 percent of Cr, 1.2 to 1.4 percent of Mo, 0.5 to 0.6 percent of Mn, 8.0 to 10.0 percent of V, and the balance of Fe; and the roller core is made of ball milling cast iron. The invention also discloses a preparation method of the radiation roller. The preparation method comprises the following steps of: preheating the roller core to a certain temperature by using an induction coil, simultaneously smelting the high-speed steel of the outer layer in a vacuum induction furnace, atomizing the high-speed steel molten metal flow by adopting a spray forming method and using nitrogen, and depositing the molten metal on the rotary roller core for compounding. The outer texture of the compound roller is uniform, rough eutectic carbides and texture segregation are eliminated, and good metallurgical combination is formed between the roller core and a spraylayer; and the spray formed compound roller has high hardness on the surface, good abrasion resistance, improved fatigue performance and longer service life, and has higher and better economic benefits as equipment is mature.

The invention relates to a high-speed steel roll and a preparation method thereof by centrifugal compounding in an electromagnetic field, belonging to the technical field of preparation of the high-speed steel roll. The components of a working layer material of the high-speed steel roll are as follows (in weight percent): 1.5 to 2.5 percent of C, 4.0 to 6.0 percent of V, 4.0 to 6.0 percent of W, 1.5 to 4.5 percent of Mo, 2.0 to 4.0 percent of Cr, 0.04 to 0.18 percent of Zr, 0.001 to 0.003 percent of B, less than or equal to 0.5 percent of Si, less than or equal to 0.5 percent of Mn, and the balance of Fe and impurity elements; and in the impurity elements, the required contents of S, P and O are respectively less than 0.01 percent, less than 0.01 percent and less than 0.0010 percent. The roll is cast by adopting a centrifugal compounding method in a pulse electromagnetic field, the frequency of the pulse magnetic field is 0.1 to 10Hz, and the peak strength of a central magnetic field of a cast mold is 1 to 10T. The roll has a plurality of precipitation strengthening phases, and the applied pulse magnetic field leads the strengthening phases and matrix crystal grains to be refined effectively and leads the strengthening phases to be distributed in a dispersed manner, thus overcoming the segregation of alloy elements and greatly improving the performance of the roll.

The invention relates to a tool comprising a substrate that consists of hard metal, cermet, ceramic, steel or high speed steel, and a multiple-ply coating that is applied using the PVD method and has a total thickness of 1 (mu)m to 20 (mu)m, said multiple-ply coating comprising a connecting layer and a wear-resistant layer deposited directly onto said connecting layer, characterised in that the connecting layer has a multiple-ply design and is deposited by means of cathodic vacuum arc vapour deposition (arc PVD), plies of said connecting layer which lie one immediately over the other having different compositions, and each of the multiple plies of said connecting layer being formed from carbides, nitrides, oxides, carbonitrides, oxycarbides, carboxy nitrides of at least two different metals selected from Ti, V, Cr, Zr, Nb, Mo, Ru, Hf, Ta, W, Al, Si, Y, Li and B, and solid solutions thereof; and said wear-resistant layer having a single or multiple-ply design and being deposited by means of high-power impulse magnetron sputtering (HIPIMS), each of said one or more plies of the wear-resistant layer being formed from carbides, nitrides, oxides, carbonitrides, oxycarbides, carboxy nitrides of at least two different metals selected from Ti, V, Cr, Zr, Nb, Mo, Ru, Hf, Ta, W, Al, Si, Y, Li and B and solid solutions thereof.

The invention discloses a method and a device for preparing a working layer of a metallurgical hot roll by laser direct deposition, which belong to the field of the application of laser technology. The method is characterized in that high speed steel-like powder and Co-based alloy composite powder are used as the materials for the working layer of the roll. Concretely, the method comprises: filling high speed steel-like powder or mechanically mixed powder which uses Co-based alloy and the like as a substrate material and is added with reinforcing and toughening submicron grains with different amounts into a powder supply system; and performing laser-assisted direct metal deposition on the surface of a roll core, of which the travel is controlled by a worktable, with synchronous powder supply to manufacture the working layer of the roll. A deposition method adopts an alternate deposition mode. The corresponding deposition thickness is determined according to the requirements on the thickness of the working layer. The hard phase content of the powder, in which the Co-based alloy is added as a hard phase, is increased layer by layer so as to form a gradient deposited layer. In the method, the reinforced, toughened and wear-resistance working layer is prepared on the surface of a cheap hot roll core part material by laser-assisted metal direct deposition technology under specific process conditions.

The invention discloses an abrasion-resistance high-speed steel composite roller and a preparation method thereof, and belongs to the technical field of rollers. The composite roller forms a whole through roller body high-speed steel and roller core nodular cast iron by means of centrifuge composite casting. The roller body molten steel is controlled to comprise, by mass, 1.5%-2.4% of C, 3.5%-6.0% of Cr, 3.5%-6.0% of Mo, 3.5%-6.0% of V, 1.5%-3.5% of W, 0.6%-1.2% of Nb, 0.5%-1.2% of Ni, 0.3%-0.8% of Si, 0.3%-0.8% of Mn, 0-0.04% of S, 0-0.04% of P and the balance Fe. The roller body molten steel is deoxidized, external-furnace modification treatment is conducted on the molten steel through multi-element micro-alloy wires, and then pouring is conducted on a centrifugal machine to form the roller; the roller core is made of nodular cast iron, tempering is conducted on the roller after quenching, and therefore the characteristics of being high in hardness, high in toughness, good in abrasive resistance and the like are realized, and an excellent using effect is achieved.

A coated body having a multi-layer of kappa-Al2O3 and or gamma-Al2O3 or TiN applied by MTCVD (Medium Temperature Chemical Vapor Deposition) is disclosed. The multi-layers can be interspersed with layers of Ti(C,N) which can also be applied by MTCVD. The body which is coated is preferably a cemented carbide, cermet, ceramic and / or high speed steel and may be used as a metal cutting insert.

A method for depositing refractory alumina (A2O3) thin layers on cutting tools made of cemented carbide, cermet, ceramics or high speed steel is disclosed. The present method is a Plasma Activated Chemical Vapor Deposition (PACVD) process in which the plasma is produced by applying a bipolar pulsed DC voltage across two electrodes to which the tool substrates to be coated are fixtured and electrically connected. In contrast to prior art methods, built-up electrical charge on non-conducting surfaces is suppressed and hence, no arcing occurs on said surfaces. This will permit stable, long-term processing, With the present method, high-quality coatings of either single phase gamma-Al2O3 or of a mixture of gamma- and alpha-Al2O3 phases can be deposited on cutting tools at deposition temperatures as low as 500 DEG C. When coated cemented carbide tools according to the invention are used in the machining of steel or cast iron, several important improvements to prior art produced Al2O3-coated tools have been observed.

The invention is a high speed steel roll collar applied to a high speed wire rolling mill and a manufacture method thereof. The chemical compositions thereof by mass percent is as follows; C 3.0-3.5, V 5.0-7.0, Cr 4.2-4.5, Mo 9.0-10.0, Co 5.5-8.0, Al 0.4-1.0, Nb 1.5-4.0, Ti 0.10-0.25, B 0.003-0.006, RE 0.08-0.25, Zr 0.06-0.12, Mn more than 0.8 and less than or equal to 1.0, and the remainder being Fe and unavoidable trace impurities. The roll collar of the invention is treated by smelting and deteriorating followed by casting on a centrifugal casting machine. The roll collar is annealed for crude processing, quenched and back fired for fine process. The roll collar of the invention has the characteristics of high hardness, good red hardness and the like, can be applied to high speed wire rolling mill, has good abrasion resistance and equivalent to hard alloy roll collar in terms of use effect, and obviously reduced manufacture cost.

The invention provides a high-boron high-speed steel roller material and a smelting process thereof. The smelting process of the high-boron high-speed steel roller material comprises the following steps: firstly, adopting Q235 waste steel, ferrotungsten, ferromolybdenum, ferrovanadium, high carbon ferro-chrome, metal copper, metal aluminum, calcium-silicon alloy, rare earth ferrosilicon magnesium alloy, ferrocolumbium, ferroboron, ferrosilicon, vanadium-nitrogen alloy, zirconium ferrosilicon and ferrotitanium as materials for smelting low-alloy high-speed molten steel in an electric furnace; then, adding the ferrovanadium and part of ferroboron to carry out alloying in a discharging process; finally, adding part of ferroboron and composite modificator in a casting ladle, adding the vanadium-nitrogen alloy, the zirconium ferrosilicon, the ferrosilicon and part of ferroboron in the casting process. The obtained casting piece has a little alloy elements, excellent abrasive resistance and good thermal fatigue resistance. When the high-boron high-speed steel roller material is used as a roller, the service life is prolonged by more than six times relative to a high nickel-chrome infinite cast-iron roller, and prolonged by 20% relative to a high-vanadium high-speed steel roller. Moreover, the roller is safe to use and reliable.