The processing method of high speed steel
The invention relates to the field of instrumental promyshlennosti, in particular to the processing of metals by pressure. The technical result of the invention is to increase the utilization of metal, increase the wear resistance of the tool, providing the width of the temperature range of superplasticity, the lower energy process, achieving the desired hardness of the workpiece. To achieve a technical result of the procurement of high-speed steel is heated to a temperature deformation 760-770oC and at this temperature, hold the plastic deformation in the isothermal mode at a rate of 10-4-10-1with-1in the process of metastable phase transition with the utmost degree of deformation of 92%. table 1. The invention relates to thermo-mechanical processing of metals, in particular to the processing of metals by pressure, and can be used in the tool industry to get pieces of tools made of high speed steels and other steels in this group (R6M5, RMF, RM, RM-MP, RMC, RAM, RAMP).A method of processing high-speed steel, including annealing, heating to a temperature of deformation and plastic deformations mode when the temperature 880-920oWith the degree of 40-50% and a rate of 10-4-10-1with-1(and.with. 1502636, IPC3C 21 D 9/22, 1987).The disadvantage of this method is the high energy intensity of the process, the presence of subsequent softening annealing of workpieces, the low resistance of the deforming tool, oxidation and loss of metal at high tolerances, reducing the utilization of metal.The closest (prototype) to the proposed invention the technical essence is a method of processing high-speed steel comprising heating to a temperature of deformation and plastic deformation in isothermal mode at a rate of 10-4-10-1with-1that is carried out at a temperature of 5-40obelow the point Ac1in the process of metastable phase transition.with. 2002822, IPC521 D 9/22, 41 BI, 1993).The disadvantage of the invention is not high enough utilization of metal, the low wear resistance of the tool is obtained in this way, the narrow temperature region of superplasticity, high energy consumption of the process, lack of hardness of the workpiece.The objective of the proposed invention is to increase the utilization of metallogenia energy process, achieving the desired hardness of the workpiece.The problem is solved in such a way that in the proposed method of processing high-speed steel comprising heating to a temperature of deformation and plastic deformation in isothermal mode at a rate of 10-4-10-1with-1in the process of metastable phase transition is carried out at a temperature of 760-770owith the utmost degree of 92%.The drawing shows lines of equal values of relative elongation of steel R6M5 during tensile tests at different temperatures and strain rates. Analysis of mathematical models has allowed to identify the patterns of the investigated processes. In all the investigated strain rates the resistance to deformation of steel R6M5 when the temperature decreases and reaches a minimum near the phase transition temperature, and then increases. From the analysis carried out after research it is clear that in steel R6M5 revealed a clear field of plasticity. So, at a temperature of 760-770osteel exhibits plasticity, measured elongation does not exceed 90% at strain rates l0-3c-1. Surface plasticity is limited to lines of equal values of relative UD is the durability of the samples at 30-40% below the maximum, which limits their practical application, because the reduced resource, the deformation capacity of steel, and it is not possible to produce blanks of complex shape for a small number of transitions. Similar surface plasticity obtained tensile steel R6M5 shown in the drawing, in the temperature region 820-840oC and strain rates of 10-4-10-3with-1. At temperatures 835oC and strain rates of 10-4with-1is a narrow area of maximum effect of superplastic steel, bounded by lines of equal plasticity= 107%. The results of the studies presented in the drawing, obtained experimentally using the optimum planning, statistical processing of experimental data and mathematical modeling of the isothermal processes of deformation and superplasticity.For synthesized exact D-optimal design of experiments in each study point in the factor space temperature and velocity fields shown in the drawing, held on 3-4 experiment tensile and compression specimens of steel R6M5 at different speeds and temperatures. Then experimental data processing is in process factors. Conducted control experiments. Built graphics based on the analyzed criteria. Established laws of their changes in temperature and velocity fields and determined the conditions of the manifestation of the effect of superplasticity.The data is shown in the drawing, are of great practical importance as they define the boundaries of the effect of increased plasticity and superplasticity and are the basis for creation of database changes plasticity in the paired temperature and velocity fields.The method of processing high-speed steel is the following. First, the workpiece is heated to a temperature of 765oWith stand until warm billet, then perform the plastic deformation in the isothermal mode at a rate of 10-3with-1at a temperature of 765oWith deformation rate up to 92%. For the procurement of steel R6M5 before heat is applied protective and lubricating coating of stilografica mixture to protect against decarburization, oxidation and lubrication during plastic deformation in the heated condition.The table presents General information, i.e., received data, and displays the data of the prototype.Example 1.Conducted manufacturing disk �32D/chr/963.gif">in= 770 MPa and elongation=15%.Billets with a diameter of 16 mm and a height of 22 mm with a protective and lubricating coating on them and subjected to drying, was heated in a chamber of an electric furnace to 750oC. Then heated workpiece carried in insulated stamp with temperature 750oWith and deformed in isothermal conditions at a rate of 10-3with-1and with deformation rate of 75% in the die block, which is made of heat-resistant Nickel alloy LGL-6K and installed on a hydraulic press, a force of 400 kN. When the degree of deformation<75% on the side of the sample surface cracks and there is a discontinuity of the material and the destruction of the sample.Example 2.Spent the manufacture of disk cutters of steel R6M5 GOST 19265-73 in the state after annealing with the original hardness HB 250, tensile strengthin= 770 MPa and elongation=15%.Billets with a diameter of 16 mm and a height of 22 mm with a protective and lubricating coating on them and subjected to drying, was heated in an electric chamber furnace up to 765oC. Then heated workpiece bore isotherms in the>1with deformation rate up to 92% in the die block, made of heat-resistant Nickel alloy LGL-6K installed on a hydraulic press, a force of 400 kN. There is no destruction of the sample and the formation of cracks on the side surface of the workpiece disk cutters of steel R6M5. After deformation, the workpiece has a hardness of HB 247, not to exceed the original.Example 3.Spent the manufacture of disk cutters of steel R6M5 GOST 19265-73 constant after annealing with the original hardness HB 250 tensile strengthin= 770 MPa and elongation=15%.Billets with a diameter of 16 mm and a height of 22 mm with a protective and lubricating coating on them and subjected to drying, was heated in an electric chamber furnace up to 790oC. Then heated workpiece carried in insulated stamp with a temperature of 780oWith and deformed in isothermal conditions at a rate of 10-3with-1in the die block, made of heat-resistant Nickel alloy LGL-6K and mounted on a hydraulic press, a force of 400 kN. The degree of deformation may not exceed 70-75% due to the discontinuity of the sample material and its destruction.P is blast superplasticity, than 835oWith that does not require expensive high-precision regulating pyrometers.2. Lower process temperature, 70oWith lower than the current that reduces energy consumption and speed scaling.3. The practical absence of decarburization of the resulting preform.4. After forming the workpiece has a hardness of 240 HB, i.e., it is in the annealed condition and does not require training patterns before quenching and well processed by cutting.5. Lower the yield stress of steel (deformation force).6. The use of technology isothermal and superplastic deformation can reduce the harmful impact on the natural environment by reducing emissions that accompany technological processes.7. The increase in cost of expensive high-speed steels and scarce alloying elements: vanadium, molybdenum, chromium, and especially the strategic element of tungsten can be attributed to the forming processes using the effect of superplastic to the process of rational nature management.
ClaimsThe method of processing high-speed steel, including load, iswith-1in the process of metastable phase transition, characterized in that the plastic deformation is carried out at a temperature 760-770With the utmost degree of deformation of 92%.
FIELD: mechanical engineering; welding production.
SUBSTANCE: the invention is pertaining to the field of mechanical engineering, in particular, to the welding production, mainly to manufacture and repair of the executive devices of agricultural machines. The technical effect of the invention is the increased service life of the executive devices of agricultural machines due to improvement of their strength characteristics and a wear-resistance to an abrasive wear. At short-time action on a component of a high intensity current - up to 16 kA in the welding machine MT-1614, as a result of a high heating appear the structural alterations caused by formation of quenching structures. Therefore the strength of the contact patch i.e. the heat-affected zone becomes considerably higher, then the strength of the parent metal. New in the given method is that for strengthening and as a consequence of it for increasing the agricultural machines executive devices components wear-resistance to the abrasive wear was usage of the electric welder МТ-1614. As a result of application of this method there is no need in the further machining or buying the dear alloying materials.
EFFECT: the invention ensures an increased wear-resistance of the agricultural machines executive devices components to the abrasive wear due to usage of the electric welder МТ-1614.
FIELD: agriculture engineering; mechanical engineering.
SUBSTANCE: invention relates to heat treatment of duckfoot shovels. To increase wear resistance, tillage member, after heating to austenite state, is subjected to thermocyclic machining and at last cycle it is heated to austenite state with size of grain of 0.011-0.045 mm and is hardened to bainite structure, with heater enclosing working member over entire contour from side of blade, and after thermal treatment it is subjected to surface plastic deformation at angle of α=5÷65° to blade.
EFFECT: increased wear resistance of tillage members by 50%.
SUBSTANCE: tool is made from alloyed tool steel containing the following components in wt %: carbon - 2.00-2.20; chromium - 11.0-12.0; tungsten - 0.50-0.80; vanadium - 0.15-0.30; molybdenum - 0.60- 0.90. Stepped flat knife from alloyed tool steel is arranged on working face of cylindrical male mould along its lengthwise axis and features straight and skewed inward cutting edges. Distance between cutting edges and cylindrical male mould length exceeds maximum weld trimmer crosswise thickness. Cylindrical male mould and flat knife share outer surface with its diametre not exceeding minimum inner diametre of the tube with due allowance for tolerable height of nearby weld trimmer. Flat knife step height equal half the diametre of cylindrical male mould. Trimmer thermal processing includes hardening made in steps by preheating to 200-300°C and subsequent heating to 1020-1050°C salt bath, and one-run tempering at 400-500°C for at least 3 hours along with cooling in air.
EFFECT: tool higher life and reduced wear in producing drill pipe with welded locks.
2 cl, 2 dwg
FIELD: machine building.
SUBSTANCE: surface of back side of edge is heated with electric arc of reverse polarity by means of carbon electrode and successively cooled. Also, the electrode is transferred along a curvilinear trajectory formed with linear transfer along a sharp edge and with a rotation around vertical axis. Angular speed of electrode rotation is determined from the ratio: 3 V/R < w < 9 V/R, where w is angular rate of electrode rotation, rad/s; V is velocity of linear transfer, m/s, R is radius of electrode rotation, m. Arcing is carried out under a pulse mode. Duration and amplitude of current pulses per one revolution of the electrode is increased at moving away from the sharp edge and is decreased at approach to it.
EFFECT: obtaining strengthened layer with alternate cross section facilitating edge self-sharpening.
SUBSTANCE: during electromechanical processing on ploughshare surface there formed are parallel strengthening zones with hardening structures of high hardness level. Strengthening zones with depth of up to 3 mm and width of 3.5÷7 mm are located at an angle of 40÷55° to ploughshare blade at the distance between them of 10÷30 mm. As a result of the above method the additional materials are not consumed and further mechanical processing is not required.
EFFECT: increasing lifetime of ploughshares due to improving their strength characteristics and wear resistance to abrasive wear.
SUBSTANCE: plough surface is subjected to electromechanical treatment at current density of up to 109 A/m2 to make hardened zones deep to 3 mm shaped to continuous lines. Front and bottom blades are hardened as well as plough tip at 20-40 mm from front blade with hardened zone width of 10-20 mm.
EFFECT: longer life owing to higher strength, wear resistance and self-sharpening.
FIELD: process engineering.
SUBSTANCE: invention relates to blades for thermoplastic polymer pelletising and to method of their sharpening. Said blade is made from tool steel for cold machining with hardness making at least 65 units in Rockwell C-scale. Prior to fitting in pelletiser, said blade is heated treated at 500-700°C for over 5 minutes at the rate equal to or lower than 15°C/min. Blades are sharpened by abrasion against extrusion head plate surface. Force acting on blade at pressing it against plate surface does not exceed 0.5 N. Simultaneously, cooling is performed by circulating thermostatic fluid at variable flow rate.
EFFECT: higher quality of cutting, lower wear rate.
10 cl, 4 dwg, 2 tbl, 6 ex