144 results about "Case hardening" patented technology

This bearing track component comprises a shaft member comprising a first portion and a second portion. The first portion is made of a first steel material containing a first alloy component, and the second portion is made of a second steel material containing a second alloy component. The first alloy component is different from the second alloy component. The first portion has a bearing part having a track, and the second portion has a power transmission part having teeth. The first portion has a first surface-hardened layer provided along the outer peripheral surface of the first portion, and a first inner part. The average hardness of the first surface-hardened layer is greater than the average hardness of the first inner part. The second portion has a second surface-hardened layer provided along the outer peripheral surface of the second portion, and a second inner part. The average hardness of the second surface-hardened layer is greater than the average hardness of the second inner part. The first surface-hardened layer and the second surface-hardened layer are both carburized layers or carbonitrided layers, and the first surface-hardened layer and the second surface-hardened layer are connected to each other.

The invention discloses a heat treatment process for improving the obdurability of die steel, and belongs to the technical field of metal heat treatment. The invention relates to a heat treatment process for improving the toughness of die steel, which adopts a die steel material with a specific component proportion, and the die steel material comprises carbon, chromium, molybdenum, vanadium, tungsten, nickel, niobium, niobium carbide and trace boron element. By sequentially implementing austenitizing, quenching, deformation heat treatment, multi-stage subzero treatment, pulsed magnetic field assisted tempering, gradient surface hardening and nano-precipitation regulation treatment, the hardness and toughness of the die steel are remarkably improved. Particularly, through the synergistic effect of multiple advanced heat treatment means, the martensite structure is effectively refined, carbide precipitation is strengthened, the surface hardness and the core toughness are improved, the comprehensive performance of toughness and toughness is achieved, and the method is suitable for the field of high-performance injection molds and hot-working molds.

The invention discloses a surface hardening method for a universal joint of a screw drill and the related universal joint. The method comprises the following steps: carrying out thermal refining and finish machining on a universal joint blank subjected to rough turning to obtain a universal joint body; after the universal joint body is preheated, spot welding is conducted on the tungsten-cobalt alloy block wrapped by the nickel-based brazing filler metal to the wear-resisting contact face at one end of the universal joint body; spraying and welding nickel tungsten carbide powder and nickel-coated boron carbide composite powder on the wear-resistant contact surface to form a hardened layer on the wear-resistant contact surface; after cooling, the spray welding working face is ground to the designed size; checking pores of the spray welding working surface after grinding, filling the pores with composite powder of nickel tungsten carbide powder and nickel-coated boron carbide, and heating and melting to seal and fill the pores; and after cooling, the universal joint is finely ground to the designed size. The wear resistance and the impact fracture resistance of the universal joint are greatly improved, so that the universal joint can be matched with other screw drilling tool parts resistant to the high temperature of 350 DEG C to jointly form a screw drilling tool resistant to the high temperature of 350 DEG C.

The present invention is a bearing track member that comprises a shaft section that comprises a first portion and a second portion. A first steel material is used as a material of the first portion, a second steel material is used as a material of the second portion, and the alloy composition of the first steel material differs from the alloy composition of the second steel material. The first portion has a bearing portion that has a track, and the second portion has a power transmission portion that has teeth. The first portion has a first surface hardened layer, disposed along an outer peripheral surface of the first portion, and a first inner section, and the average hardness of the first surface hardened layer is greater than the average hardness of the first inner section. The second portion has a second surface hardened layer, disposed along an outer peripheral surface of the second portion, and a second inner section, and the average hardness of the second surface hardened layer is greater than the average hardness of the second inner section. The first surface hardened layer and the second surface hardened layer are each a carburized layer or a carbonitrited layer, and the first surface hardened layer and the second surface hardened layer are connected. The combination of the first steel material and the second steel material is at least one of the following first through fourth combinations. The first combination is a combination in which the first steel material and the second steel material each include at least one of manganese, nickel, chromium, and molybdenum, the total manganese, nickel, chromium, and molybdenum content of the first steel material being greater than 1.5 times the total manganese, nickel, chromium, and molybdenum content of the second steel material. The second combination is a combination in which the first steel material and the second steel material each include silicon, the silicon content of the first steel material being less than the silicon content of the second steel material. The third combination is a combination in which the first steel material includes either no chromium or no more than 1.6% by mass of chromium and includes either no niobium or no more than 0.01% by mass of niobium, and the second steel material includes at least 1.0% by mass and no more than 2.5% by mass of chromium and includes at least 0.02% by mass and no more than 0.10% by mass of niobium. The fourth combination is a combination in which the first steel material includes at least 0.001% by mass and no more than 0.050% by mass of nitrogen, includes either no boron or no more than 0.001% by mass of boron, and includes either no titanium or 0.003% by mass of titanium, and the second steel material includes at least 0.001% by mass and no more than 0.050% by mass of nitrogen, includes at least 0.001% by mass and no more than 0.005% by mass of boron, and includes at least 0.01% by mass and no more than 0.08% by mass of titanium.

The invention relates to the technical field of steel for agricultural machinery, in particular to a manufacturing method of a surface hardening agricultural machinery tool. Comprising the steps of smelting, continuous casting, casting blank treatment, rolling, cooling, surface treatment, part forming, heat treatment and local surface hardening treatment. The obtained hot-rolled plate is free of surface scale, the hardness after heat treatment is 53 HRC or above, the surface hardness difference is + / -0.5 HRC, the tensile strength is 1800 MPa or above, the ductility is larger than or equal to 8%, the ballistic work Akv at the temperature of 20 DEG C is larger than or equal to 20 J, tempering treatment, sand blasting and tumbling are not needed, the hardness of an agricultural machine tool obtained after surface local hardening treatment is 60 HRC or above, and the wear resistance is obviously improved.

To provide improved surgical instruments. [Solution] Surface preparation of sliding surfaces can improve the wear performance of surgical instruments such as surgical staplers, which include a reusable mechanism that is used multiple times with a single-use reloadable cartridge. A combination of surface hardening, surface finishing, and surface coating can be applied to the metal components of surgical instruments to reduce the possibility of abrasive wear in metal-to-metal sliding engagements. Surface hardening technology can enable further manufacturing operations such as welding without compromising the strength of the underlying metal substrate. With stainless steel metal substrates, surface hardening or surface hardening technology may reduce corrosion resistance, so a surface coating can be added to suppress surface oxidation and to provide a barrier against metal-to-metal contact. Further lubricating coating layers, such as a brazing coating layer, can enhance abrasion resistance.

This invention discloses a hardening device and method for rolling bearing steel balls, relating to the field of surface hardening treatment technology. The hardening device includes a bath, an elastic base disposed below the bath, a working medium and steel balls inside the bath, the working medium comprising alloy element powder, abrasive powder, and a conductive solution, a pulsed plasma gun positioned above the bath, the outlet end of the pulsed plasma gun inserted into the bath with its axis intersecting the vertical axis of the bath at an acute angle, and an electromagnet for attracting steel balls mounted on the surface of the bath. A matching hardening method is also provided. The technical solution of this invention forms a high-hardness alloy layer on the surface of the steel ball, improving the hardening quality of the steel ball surface and enabling the steel ball to meet the performance requirements for use under high load and corrosive environments.

The invention relates to a method and a product for eliminating helium bubble defects in nuclear power steel, which comprises the following steps of: treating the nuclear power steel which is damaged by helium ion irradiation to generate helium bubble gathering and surface hardening by pulse current, eliminating the helium bubble defects, recovering the surface hardness of the nuclear power steel, and realizing dynamic self-repairing of irradiation damaged tissues of the nuclear power steel. The method is suitable for pulse current elimination of irradiation helium bubble defects of nuclear power steel such as austenitic stainless steel and austenite-ferrite duplex stainless steel, and is also suitable for pulse current elimination of irradiation helium bubble defects of any metal material. Experiments prove that helium bubbles induced by irradiation cause serious hardening of the surface of the material, and after the helium bubbles are eliminated through pulse current treatment, nanoindentation tests show that the hardness of the material is remarkably reduced and basically returns to the original level before irradiation. The method has the advantages of short treatment time and low energy consumption, and can effectively prolong the service life of key components such as nuclear-grade main pipelines.

The invention belongs to the field of hardened layer depth detection, and relates to a metal surface hardened layer depth standard test block. The whole standard test block is half-ship-shaped, and a stepped hardened layer area is arranged at the upper end of the standard test block and used for detecting the depth of a hardened layer of a plane component. A small-curvature outer cambered surface hardened layer area is arranged at the left end and is used for detecting the depth of a hardened layer on the outer surface of a thin shaft type component and a special-shaped component; a small-curvature inner cambered surface hardened layer area is arranged at the lower end and is used for detecting the hardened layer depth of the inner surfaces of the pipes and the special-shaped components; a large-curvature outer cambered surface hardened layer area is arranged at the lower part of the right end, namely the bow position, and is used for detecting the depths of hardened layers on the outer surfaces of column, shaft, pipe and disc components; a large-curvature inner cambered surface hardened layer area is arranged at the upper part of the right end and is used for detecting the hardened layer depth of the inner surfaces of the pipe and disc components. The test block provided by the invention simultaneously meets the requirements of hardened layer depth detection equipment calibration and hardened layer depth verification of various components.

The invention provides a high-precision rapid positioning countersunk head screw for sheet metal connection and a processing method thereof, which can solve the problems of low positioning precision and unstable connection of the existing countersunk head screw, the high-precision rapid positioning countersunk head screw is integrally formed by a screw head and a screw rod, the screw head is provided with a double-taper-angle structure and a reverse radial insection, and the screw rod is internally provided with a screw rod channel. The detachable positioning cone is inserted into the screw channel, the slot of the screw is in sliding connection with the insertion block of the positioning cone, and the threaded part of the screw is provided with a spiral glue overflow groove which is matched with the threaded part to realize double threads and bonding sealing; multi-station cold heading is adopted for one-time forming of screw head double taper angles, thread rolling, whirlwind milling of glue overflowing grooves and laser cutting of inserting grooves, then the positioning cone is assembled, surface hardening treatment is carried out, the process is short, precision is high, cost is low, and the method is suitable for high-strength, anti-loosening and sealing connection of sheet metal parts and has high positioning precision, connection reliability and loosening resistance.

A surface of a tool or other object may have a hardfacing deposit thereon that comprises a hardfacing alloy. Said hardfacing alloy may include: about 0.9 wt%to about 1.5 wt%carbon, about 1.5 wt%to about 2.5 wt%boron, about 0.5 wt%to about 1 wt%manganese, about 0.7 wt%to about 2.2 wt%silicon, about 5.5 wt%to about 8 wt%chromium, about 7 wt%to about 10 wt%niobium, about 0.2 wt%to about 0.7 wt%titanium, about 0.4 wt%to about 0.8 wt%vanadium, 0 wt%to about 0.2 wt%aluminum, 0 wt%to about 0.1 wt%total impurities, and a balance iron, wherein each wt%is based on a total weight of the hardfacing alloy. Examples of tools may include pipe joints, center wear pada, tubing connections, tube bodies, drill collars, stabilizers, earthmoving equipment, and dredging equipment.

The invention provides a ball joint capable of improving rigidity of a columnar part and a method for manufacturing the ball joint. A ball joint (100) is provided with a columnar section (110) and a housing (120). The columnar section (110) is provided with: a connection section (111) that is connected to an object to be connected (10); a flange-shaped receiving part 115 on which the object 10 to be connected is placed; and a ball part 114 having a spherical surface. A male thread part 112 for fastening the mounting nut 12 is formed on the connecting part 111. The flange-shaped receiving section (115) is formed so as to protrude radially outward from the connecting section (111) in a flange-shaped manner. A surface hardening layer 118 for hardening the surface layer is formed at a boundary portion 117 between the connecting portion 111 and the flange-shaped receiving portion 115.

The invention relates to a steel material for a piston shaft of a large-scale breaker hammer and a manufacturing method thereof. The steel material is based on iron and contains the following chemical components by mass percentage: C: 0.85-1.10%, Si: 0.15-0.70%, Mn: 0.25-1.20%, Cr: 1.05-1.60%, S≤0.020%, P≤0.020%, Ni≤0.30%, Cu≤0.25%, Mo≤0.10%, Al: 0.015-0.050%, Ca≤0.0010%, Ti≤0.0030%, O≤0.0010%, As≤0.04%, Sn≤0.03%, Sb≤0.005%, Pb≤0.002%; the piston shaft meets the following requirements: O≤6ppm, Ti≤15ppm, and large-particle non-deformable inclusions are in accordance with ISO 4967-2013 rating ≤ 1.0, product surface hardness ≥ 61HRC, core hardness ≥ 40HRC, surface hardened layer thickness not less than 10mm, hardness within the surface hardened layer thickness not less than 58HRC. Piston shaft masterbatch manufacturing (continuous casting and rolling + structural pretreatment) - piston shaft processing - heat treatment (turning + quenching, tempering + grinding).

The invention provides a furnace building method for building a furnace through double melting channels. The problems that in the prior art, positioning is not accurate, fixing is not firm, grooving is not precise, and procedures are scattered are solved. The method comprises the following steps of: filling a base layer at the bottom of a furnace in advance, scraping a melting channel groove, accurately positioning the melting channel, sealing a water jacket opening by using a baffle plate, continuously filling a hearth, removing the baffle plate, cleaning redundant ramming materials between the two melting channels, mounting the water jacket at a preset position, and sealing the edge. And after secondary filling and surface hardening are completed, coil-iron core assembling is conducted, and furnace building is completed.

The utility model discloses a turning blade for heavy-load rough machining of high-temperature alloy and stainless steel, the upper end part and the lower end part of a blade main body are both polygonal structures, main cutting edges or auxiliary cutting edges are formed at the joints of the upper end part and the lower end part and each side wall connected with the upper end part and the lower end part, and the main cutting edges and the auxiliary cutting edges are arranged at intervals; polygonal chip breaking tables are formed in the middle of the upper end face and the middle of the lower end face respectively, and the number of the side edges of the chip breaking tables is the same as that of the upper side edges of the blade body. A sharp cutting edge can be formed, the deformation degree of cuttings can be increased, the cuttings can be guided to flow out smoothly, meanwhile, the strength of the cutting edge is increased, the service life is prolonged, cutting force can be reduced, the deformation degree of material grains is reduced, the surface hardening degree of a workpiece is reduced, built-up edges are avoided, cutting heat is controlled, and the service life of the cutting edge is prolonged. The utility model particularly relates to heavy and rough cutting machining of high-temperature alloys such as GH4169 and Inconel 718 and difficult-to-machine materials such as stainless steel.

The invention discloses a surface hardening steel with uniformly distributed hardness of a hardening layer, which contains Fe and inevitable impurities, and further contains the following chemical elements in percentage by mass: 0.34 to 0.42 percent of C, 0.1 to 0.4 percent of Si, 0.7 to 1.4 percent of Mn, 0.02 to 0.25 percent of Cr, 0.02 to 0.15 percent of Mo, 0.015 to 0.05 percent of Al, 0.001 to 0.0035 percent of B, 0.02 to 0.06 percent of Ti, 0.01 to 0.035 percent of S, 0.003 to 0.008 percent of N and the balance of Fe. And no Cu element is contained. The invention further discloses a manufacturing method of the steel. The manufacturing method comprises the following steps: smelting and casting; heating and rolling; normalizing after rolling; surface quenching and low-temperature tempering are carried out, wherein the surface quenching temperature is 830-950 DEG C; and the low-temperature tempering temperature is 150-250 DEG C, and the heat preservation time is 1-3 h.

The invention discloses a steel-based composite material grinding ball hard outside and tough inside and a preparation method and application thereof.The diameter of the steel-based composite material grinding ball is 100-150 mm, the steel-based composite material grinding ball sequentially comprises a surface hardening layer and a core area from outside to inside, the average Rockwell hardness of the surface hardening layer is 58-63 HRC, and the average Rockwell hardness of the core area is 60-80 HRC. The average Rockwell hardness of the core area is 50 to 53 HRC, and the unnotched impact toughness of the core area is 10 to 14.5 J / cm < 2 >; according to the method, through component design and reasonable control over the cooling path and the heat treatment process, gradient distribution of the organization structure and the mechanical property is achieved, and the fracture resistance and the service stability of the large-size grinding ball are fundamentally improved.

The invention discloses a rapid manufacturing process of a 3D printing sand mold outer mold for a static pressure molding line, and relates to the technical field of casting. The process is different from conventional metal mold and wood mold manufacturing processes, an outer mold body blank is rapidly manufactured through the 3D printing technology, and then hardening and surface smoothing treatment are conducted through hardening liquid. Through hardening of the hardening liquid, the surface strength and hardness of the outer mold body can be greatly improved, the outer mold body can completely bear the molding pressure (1.2 Mpa) of a static pressure molding line, the hardened sand mold can pass through at least 300 molds without deformation, and the dimensional tolerance stability is good. The surface of the outer mold body is smooth through surface smoothing treatment, and the sand scrabbling defect is avoided. Surface treatment is matched with surface hardening, the manufacturing period of the outer mold can be shortened, the manufacturing cost of the outer mold can be reduced, and meanwhile the use requirement of a static pressure molding line can be met.

The invention relates to the technical field of mixing and preparation of surface hardening agents, and discloses a premixing device for stirring a concrete surface hardening agent and a preparation process thereof.The premixing device comprises a stirring cabin arranged on a structural frame of the premixing device and used for containing a solution solute for preparing the concrete surface hardening agent; a hollow and one-way through sealing shaft is fixedly arranged in the stirring cabin, at least two bearings are arranged outside the sealing shaft, and the stirrer is rotationally arranged outside the sealing shaft in a sleeving manner; and the stirrer comprises a magnetic induction rotating shaft sleeved on the bearing, a supporting rod fixed outside the magnetic induction rotating shaft and an outer ring spiral stirring blade welded and fixed on the supporting rod. Silicate is added into a stirring cabin through a solid material feeding hopper, an emulsifying agent and a penetrating agent are added into the stirring cabin through a liquid material feeding hopper, and water is added into the stirring cabin before the silicate, the emulsifying agent and the penetrating agent are added.

This invention discloses a surface hardening method for universal joints in screw drills and related universal joints. The method includes: performing heat treatment and finishing on a rough-machined universal joint blank to obtain the universal joint body; after preheating the universal joint body, spot welding a tungsten-cobalt alloy block wrapped with nickel-based brazing filler metal to the wear-resistant contact surface at one end of the universal joint body; spraying nickel-tungsten carbide powder and nickel-coated boron carbide composite powder onto the wear-resistant contact surface to form a hardened layer on the wear-resistant contact surface; after cooling, grinding the sprayed surface to the design dimensions; inspecting the porosity of the ground sprayed surface, filling the porosity with nickel-tungsten carbide powder and nickel-coated boron carbide composite powder, heating and melting to seal the porosity; and after cooling, precision grinding the universal joint to the design dimensions. This invention greatly improves the wear resistance and impact fracture resistance of the universal joint, enabling it to be used in conjunction with other screw drill components resistant to 350℃ high temperatures to form screw drills resistant to 350℃ high temperatures.

The present invention relates to a system and method for the non-destructive measurement of distance to the hardened area (Dh) where the end of a hardened area (1) of a part to be measured is located. Said invention comprises: a) scanning a measurement area of a part by applying a variable magnetic field to the part and measuring an MBN signal by means of a sensor (3); b) processing the MBN signal obtained; and i) training a regression model by using reference parts, which comprises carrying out the previous steps a) and b) on reference parts with a known distance to the hardened area (Dh', Dh"); ii) measuring the part to be measured, which comprises carrying out the previous steps a) and b) on the part to be measured with an unknown distance to the hardened area (Dh); and iii) calculating the distance to the hardened area (Dh) of the part to be measured.

The present invention addresses the problem of providing a surface-hardened steel that has excellent cold-forgeability and can sufficiently suppress variations in deformation resistance during cold forging. Provided is a surface-hardened steel that has a prescribed chemical composition and has a structure that comprises ferrite and spheroidized carbides. A dispersion index Vθ that represents the dispersibility of the spheroidized carbides satisfies Vθ≤0.80, and, for test pieces taken at 10 arbitrary locations in the rolling direction of a steel material that comprises the surface-hardened steel, the coefficient of variation CV of the Rockwell hardness at a cross-section that is orthogonal to the rolling direction satisfies CV×100≤0.65.

The present invention relates to the technical field of brake pad production, and discloses a production process for wear-resistant and heat-insulating brake pads, comprising the following steps: Step 1, powdering, subjecting the friction layer raw material and the heat-insulating layer raw material of the brake pad to powdering, and pre-storing the obtained friction layer powder and heat-insulating layer powder separately. Step 2, introducing the friction layer powder into a mold for hot pressing and forming, and after cooling, evenly arranging the heat-insulating layer powder on the friction layer in the mold, and then hot-pressing a second time to form the friction pad. Step 3, steel back glue coating, placing the steel back after surface hardening treatment on a glue coating machine for glue coating. The present invention not only enhances the heat-insulating effect by improving the purity of the heat-insulating layer, but also performs multiple hot pressing on the friction layer, thereby improving the wear resistance of the friction layer. By improving the steel back glue coating process and equipment, a uniform glue layer can be formed on the steel back, providing good preparation for the bonding of the heat-insulating layer and the steel back in rough blank forming.

This application discloses a method for preparing a surface-hardened layer on a nickel alloy. The method includes using a nickel alloy as a substrate, firstly cleaning and drying the substrate sequentially, followed by ultrasonic rolling; then covering the ultrasonically rolled substrate with a boronizing agent, heating and boronizing at 600-800℃ and holding at that temperature for 3-6 hours; next, under inert gas conditions with a purity greater than 99.5%, subjecting the boronized substrate to solution treatment at 1040-1140℃ and aging heat treatment at 700-850℃; finally, grinding the heat-treated substrate to obtain the target nickel alloy substrate containing the surface-hardened layer. The synergistic combination of ultrasonic rolling and boronizing processes refines the surface microstructure of the nickel alloy, improves the bonding strength between the boronized layer and the substrate, and prevents the formation of microcracks; while ensuring the performance of the surface-hardened layer, it does not damage the original corrosion resistance of the substrate, significantly improving the service life of the nickel alloy under high temperature, high pressure, and strong erosion wear conditions, demonstrating strong process stability and practicality.

An efficient cutting tool structure of an automatic oil pressure raw rubber cutting machine comprises a blade assembly, a tool handle assembly and a connecting piece. The blade assembly is made of high-strength alloy steel, the surface of the blade assembly is hardened to HRC58-62, reinforcing ribs are arranged to improve bending rigidity and reduce cutting deformation, protective edges on the arc-shaped side edges of the blade assembly can prevent raw rubber fragments from splashing, a front-end guide part guides smooth cutting-in, and impact force is reduced. The cutter handle assembly is also made of high-strength alloy steel, the surface is subjected to rust-proof treatment, a conical connecting part at one end can be quickly positioned and fixed, and lightening holes in the cutter handle assembly reduce weight and improve dynamic response. The connecting piece is used for fixedly connecting the blade and the handle. The structure is convenient to replace and maintain through modular design, all parts are optimized according to the characteristics of raw rubber, efficient, accurate and safe cutting is achieved, the problem of a traditional cutter in raw rubber cutting is effectively solved, the production efficiency and the cutting quality are improved, and good engineering feasibility and economical efficiency are achieved.

The invention discloses a surface ion nitriding TiAl alloy and a preparation method thereof, and belongs to the field of metal material surface hardening treatment.The preparation method comprises the steps that the TiAl alloy is polished and cleaned; the cleaned TiAl alloy is subjected to ion bombardment in the hydrogen atmosphere; the TiAl alloy subjected to ion bombardment is subjected to ion nitriding in the nitrogen atmosphere; and the TiAl alloy subjected to ion nitriding is cooled to 100 DEG C or below along with the furnace and discharged out of the furnace, and the TiAl alloy subjected to surface ion nitriding is obtained. According to the method, the surface of the TiAl alloy is bombarded by adopting high-energy ions before nitriding, impurities such as an oxidation film and oil dirt on the surface of a workpiece can be removed at the same time, the problem that the oxidation film hinders nitrogen permeation in the nitriding process is avoided, additional pretreatment is not needed, and the overall period is shortened; by optimizing the process parameters of ion nitriding, the time-consuming steps of slowly decomposing nitrogen atoms by depending on gases such as ammonia gas in atmosphere nitriding and then passively diffusing the nitrogen atoms are omitted, and the nitriding efficiency is greatly improved.

To propose a case-hardening steel with the ability to inhibit crystal grain coarsening during carburization.SOLUTION: A case-hardening steel contains C: 0.10-0.35 mass%, Si: 0.01-2.00 mass%, Mn: 0.20-1.90 mass%, P: 0.1 mass% or less, S: 0.5 mass% or less, Cr: 0.20-2.00 mass%, Al: 0.010-0.090 mass%, N: 0.0010-0.0250 mass% and Ti: 0.010-0.100 mass%, with the balance being Fe and inevitable impurities, where the standard deviation σTi of the Ti segregation degree (CTi / C0Ti) fulfills σTi≤72.SELECTED DRAWING: None

A method for producing a water-hydraulic machine having a first member (1) and a second member (2) in sliding contact with a contact surface (3) of the first member (1), wherein the second member (2) comprises a surface made of a friction reducing plastic material and the contact surface (3) is a metallic surface, is disclosed. The machine should have a low risk of damages. To this end, the method includes the steps of using a first member (1) comprising a first part (4) having the contact surface (3) and a second part (5), using a high temperature hardening process at a temperature of at least 1000° C. to give a deep surface hardening of the contact surface (3) of the first part (4), machining of the first part (4) to the desired geometry, assembling the first part (4) and the second part (5) to form the first member.

A prealloy powder for powder metallurgy, a sintered part using the same, and a manufacturing method thereof, which is configured to prevent deterioration of core hardness along with surface hardening while maintaining excellent tensile strength by adjusting an alloy composition so that a bainite phase is formed. The sintered part, which is manufactured by powder metallurgy, includes 1.05 to 1.55 wt % of Cr, 0.3 to 0.5 wt % of Mo, 0.5 to 0.7 wt % of C, and a remaining of Fe and other unavoidable impurities.

An anti-tamper component 50a 50b, to retain a panel of a window or door in its frame, comprises a base (52 Fig 5) for location on an edge surface of one of the panel or frame, and a retaining edge (60 Fig 5) for engaging a structure on the respective other of the panel or frame, wherein the retaining edge is carried on a return structure (62 Fig 5) of the anti-tamper component. The retaining edge 60 is provided by an edge structure of a sheet structure that is configured to yield by plastic deformation when exposed to a break-in force, thus allowing the component to take up stresses under load by deformation or stretching. The retaining edge may be a hook. The component may be a metal, for example hot rolled steel or case hardened steel, various case hardness values are disclosed. The component may have a specific elongation at faction value of 15%, 17.5%, 20% or 22.5%.