Heat processing of refractory martensite steels. RU patent 2520286.
| Heat treatment method of 14x17h2 wrought corrosion-resistant steel / 2508410 Method involves heating of steel for hardening at the temperature of 1040-1050°C, oil cooling, double annealing with cooling in water after every annealing operation; besides, heating at the first annealing is performed at the temperature of 600-610°C. |
| Method for non-corrosive thermal treatment of parts and assembly units / 2456350 Method for thermal non-corrosive treatment, implemented in high tempering of parts and assembly units lies in the following: degreased parts are loaded into a furnace, a furnace is vacuum-treated. The mixture is heated to a temperature stage of 300-350°C, is kept at this temperature for 30-40 minutes, performing heating up to the temperature of high tempering, is kept at this temperature, the parts are cooled to the temperature of ≈100-150°C, the load is discharged from the furnace. |
 Procedure for thermal treatment of crank shafts dies out of martensite-ferrite steel of class 14x17h2 / 2453614They are subjected to hardening by heating to 970-1020 °C and cooling in oil, then to a double tempering at 620-670 C, with the first tempering carried out for 4.5-5 hours, and the second one for 3.5-4.5 hours, and cooled after each tempering in water or oil. |
 Procedure for thermal treatment of austenite precipitation-hardening alloy 68hxbktu-vi / 2434950Alloy 68HXBKTU-VI is heated for quenching to 1090±10°C, conditioned, cooled with furnace at rate 500-650°C per hour to 980±10°C, cured for 0.5 hour to separation of phase Ni3 (Al, Ti) in laminated form and cooled in water. |
 Procedure for thermal treatment of high durable corrosion resistant steel of martensite class / 2388833Here is disclosed design and industrial adoption of new process for thermal treatment of complex alloyed stainless steel. The procedure consists in homogenisation of steel at temperature 1150°C, in conditioning in terms of 3 min/mm of cross section, in cooling in air, in successive tempering at temperature 650°C, and in conditioning in terms of 6 min/mm of cross section. Further steel is heated for hardening to temperature 1050°C with holding in terms of 2 min per mm of cross section of an item, cooled in oil, successively tempered at 650°C, cured in terms of 6 min/mm of cross section and cooled in air. |
 Method of thermal processing of high-strength maraging steel articles / 2344182Invention concerns engineering industry and can be applied in various industry spheres for thermal processing of maraging steel articles, such as "08Х15Н5Д2Т", "06Х14Н6Д2МБТ", "10Х14Н4АМ3" and "07Х16Н6". To enhance resilience an article is annealed at 650-670°C for 6-10 hours, further is heated to 1000-1070°C for tempering in furnace, matured for 2-3 hours and cooled down in oven to 880- 900°C first, with maturing at that temperature for 2.5-3 hours, then cooled down in water, blazed off and aged. |
 Steels with pack-net martensite-austenite microstructure subjected to cold treatment / 2301838Steel rod whose microstructure has grains consisting of martensite plates alternating with thin films made from stabilized austenite is subjected to cold strain. Due to high density of dislocation in structure and tendency of strain stresses to move between martensite and austenite phases, cold strain imparts unique mechanical properties including tensile strength without intermediate heat treatment of steel between cogging procedure by cold treatment. |
 Method of heat treatment of martensitic precipitation-hardening steels / 2253684Proposed method may be used for production of parts working in acid media under load not below 0.8 of 517 Mpa in Northern regions. Proposed method enhances level of plastic characteristics and impact strength at negative temperatures. During heat treatment of martensitic precipitation-hardening steels, they are subjected to hardening at temperature of 900-1000 C continued during 1 h and two-stage double aging at temperature of from 650 C and not above 67520 C and at temperature of 620 C10 C; operation at each stage is continued for 4 h as minimum. |
 Method of thermomechanical treatment / 2519343Invention relates to thermomechanical process in production of thick sheet (1) from higher-viscosity initial material, particularly, low-temperature viscosity. Thick sheet (1) is heated and subjected to partial or final rolling and, then, to accelerated cooling. Thick sheet (1) heated for partial rolling above temperature Ac3 is subjected to accelerated cooling after final forming. Thick sheet (1) is subjected to accelerated cooling to below Ar3 between partial and final rolling and, then, to inductive heating to above Ac3. |
 Control over continuous heat treatment / 2518039Invention relates to machine building and metallurgy. It aims at preventing the rejects of continuously annealed metal blank and allowing the maximum metal yield. Continuous thermal processing is continuously controlled by NDT testing of mechanical properties after thermal processing. Electric power intensity is used as a control record. Current power consumption is compared with power inputs derived from preset regression dependence of mechanical properties on power costs per unit for required mechanical properties. Blank heat treatment conditions are adjusted to make the magnitude of power inputs fall in the range of tolerable magnitudes. |
 Increasing physical-mechanical properties of tool and structural steels by volumetric pulsed laser hardening / 2517632Article is processed by pulse laser with efficient pulse energy of 60-500 J, pulse power density of 1.2·1010-4.3·1011 W/m2, wavelength of 1.064·10-6 m, pulse duration of 0.8·10-3 s, beam diameter of 1.2·10-3-2.5·10-3 m and distance fro irradiated point to surface being hardened of 12-30 mm. |
 Production of cold-rolled strip from low-carbon steel for coil blanking / 2516358Invention relates to rolling and can be used for production of cold-rolled strip from low-carbon steel used for cold blanking. Proposed method comprises steel smelting at the following ratio of components in wt %: carbon - 0.003-0.007, manganese - 0.10-0.25, silicon - not over 0.03, sulphur - not over 0.025, phosphorus - not over 0.020, nickel - not over 0.10, chromium - not over 0.05, copper - not over 0.10, aluminium - 0.02-0.07, niobium - 0.020-0.050, titanium - 0.015-0.035, vanadium - not over 0.05, iron making the rest. Slab is subjected to hot rolling at coiling temperature of 700-750°C followed by cold rolling. Then, recrystallisation stepwise annealing with specified curing is performed at temperatures depending upon hardness of hot-rolled semi-finished stock calculated by empirical formula. Finally, temper rolling is carried out with reduction ε=0.8÷1.6%. |
 Method to produce metal product with specified structural condition / 2516213Stock is made of steel containing wt %: C 0.05-0.18, Si 0.05-0.6, Mn 1.30-2.05, S not more than 0.015, P not more than 0.020, Cr 0.02-0.35, Ni 0.02-0.45, Cu 0.05-0.30, Ti not more than 0.050, Nb 0.010-0.100, V not more than 0.120, N not more than 0.012, Al not more than 0.050, Mo not more than 0.45, iron and unavoidable admixtures - balance. The stock is heated, and rough rolling is carried out under temperatures exceeding temperature of austenite recrystallisation, with a deformation-to-deformation pause, providing for required reduction of metal temperature, then finishing rolling is carried out, straightening and accelerated cooling of rolled metal, at the same time heating temperature for rolling T is set to ensure required solubility of carbides and nitrides of microalloying elements, and using the following dependence: t+280°C<T<t+310°C, where t=883-313.95C+37.88Si-9.58Mn-2.79Cr-15.99Ni-2.55Cu+110.18Ti+5.5Nb+76.74V-142.53N+71.45Al+23.67Mo, °C, and heat removal from the rolled metal surface in process of accelerated cooling is sent to ensure formation of the required volume share of bainite in the cross section of the metal product. |
| Production of anisotropic stalloy and finished stalloy / 2514559 Proposed method comprises smelting of stalloy, continuous casting, hot rolling, cold rolling, decarburising annealing, second cold rolling to produce final thickness sheet, laser processing, application of protective coating, high-temperature annealing, application of insulating coating and straightening annealing. Laser processing is performed with the help of continuous laser beam and pulses laser beam source. Pulsed laser beam has diameter of projection on sheet surface smaller than that of continuous laser beam and higher energy density of radiation in projection on steel strip surface than that of continuous laser beam. Every linear trace of laser effects is formed by synchronised displacement of continuous and pulsed laser beams over sheet surface, pulse laser beam lagging behind the continuous laser beam. Continuous laser beam is used to form axial area of laser linear trace with cast structure and peripheral area of structure of partial recrystallisation. Pulsed laser beam is used to form groove of cast structure in axial area. Laser effects traces arranged in parallel are located at the angle to rolling direction on sheet surface. Every linear trace has axial area with cast structure in width of 0.2-0.35 of sheet depth and in depth of 0.15-0.2 of sheet depth and groove in width of 0.05-0.1 of sheet depth and in depth of 0.05-0.1 of sheet depth there along. |
| Method of pipe rolling mill mandrel heat treatment / 2511452 Invention relates to machine building. Mandrel 15 meters in length and 137-200 mm in diameter is made from alloyed tool steel that contains chromium in amount of over 4 wt %, every other carbide-forming element and silicon in amount of 1 wt % and carbon in amount of 0.44 wt %. It is subjected to quenching by induction heating at current frequency of 50-1000 Hz to 1040°C-1080°C, cooled by sprayer, tempered at 705°C-725°C and air cooled. Note here that mandrel is displaced in quenching at the rate of 70-180 mm/min while in tempering at 70-180 mm/min. |
| Heat treatment method of hard-magnetic alloys based on iron-chrome-cobalt system / 2511136 Invention relates to metallurgy, and namely to production of hard-magnetic alloys based on Fe-Cr-Co system, which are used in instrument-making industry, relay engineering, electric machine engineering, medicine and automobile industry. In order to increase residual induction, alloy is subject to homogenisation, hardening, thermomagnetic treatment and multistage annealing; with that, heating of alloy to thermomagnetic treatment temperature is performed in a magnetic field. |
 Heating device, heat treatment device and heating method / 2510996Group of inventions relates to a heating device, a heat treatment device and a heating method for induction heating of an annular workpiece. The heating device includes a support intended for installation of the annular workpiece, a rotation drive assembly and a heater intended for heating of the workpiece. The workpiece support includes several rollers installed so that they can be rotated and located in a circumferential direction. The rotation drive assembly has the possibility of transferring rotation to the above rollers to provide rotation of the workpiece arranged on the support in the direction of the annular shape of the workpiece. The heater includes a heating coil intended for induction heating of the workpiece in its location place on the workpiece support, and a support box supporting the heating coil. The heating device is equipped with an actuator intended for movement of the heating coil relative to the workpiece with possibility of adjusting the distance between the workpiece and the heating coil and including a vertical movement section, intended for vertical movement of the support box, and a horizontal movement section of the support box in a radial direction from the workpiece rotation centre. The heat treatment device includes the above heating device and a cooling unit intended for cooling of the workpiece heated by the heater, which is characterised by the fact that the drive unit is located above the workpiece. |
 Method of making wearproof coating / 2510319Invention relates to machine building and can be used for making wearproof coatings on part surface with feed of reconditioning compositions on part surface and plastic deformation by nonabrasive ultrasound finishing. Revitalisant layer is applied on metal part surface to perform nonabrasive ultrasound finishing with transverse working head feed relative to part surface at 0.26-0.08 mm/rev to surface roughness Rα=0.3-0.125 mcm. |
 Installation used for rolled metal cooling / 2244022The invention presents an installation for rolled metal cooling and is dealt with metal rolling, in particular with cooling of rolled metal. The installation for rolled metal cooling contains a body with an inlet branch-pipe and two rows of outlet branch-pipes displaced from each other by a half step. Value of a step of the outlet branch pipes in each row does not exceed four internal diameters of the branch-pipes. Across the body opposite to an entry of the inlet branch-pipe a dissector is installed. Along the body opposite to the outlet branch-pipes there are two entire central plates and two fragmentary lateral plates forming two longitudinal funnel-shaped cavities, turned by their narrow parts to each row of outlet branch-pipes. Fragmentariness of the lateral plates is created at the expense at least of one cutout in the base of each plate, at the longitudinal butts of which there are two perpendicularly fixed damping plates facing inside the funnel-shaped cavities. The invention allows to increase evenness, flexibility and efficiency of the rolling metal cooling process and ensures reliable operation of the installation. |
 Method providing an increase of wear resistance of metal-cutting tools made out of tool steels by magnetic-pulse treatment with a preheating and an installation for its realization / 2244023The invention presents a method providing an increase of wear-resistance of the metal-cutting tools made out of tool steels by magnetic-pulse treatment with a preheating and an installation for its realization. The invention is dealt with the field of mechanical engineering, in particular with production of metal-cutting tools made out of tool steels by preheating and magnetic-pulse treatment. The technical result is increased wear-resistance of the metal-cutting tools made out of tool steels due to removal of internal stresses, increase of thermal conductivity, ordering of magnetic structure of a material. For achievement of the technical result conduct a preheating of the tools by high-frequency currents (HFC) with consequent action by a pulse of a magnetic field of high magnetic intensity. The method is realized by an installation containing a combined inductor with windings. At that a winding of the inductor, powered by high-frequency currents, is placed inside the winding powered by a magnetic-pulse device. |
 Bibrostabilization unit / 2244755Proposed device is used for excitation of torsional and longitudinal vibrations and treatment of parts in resonance mode irrespective of level of natural vibrations of parts, thus ensuring smooth distribution of varying stresses over entire surface pf part. Vibrostabilization process includes securing one end of part and applying force to free end in form of torque and longitudinal exciting force; frequency of excited vibration is equal to natural frequency of vibrations of part. Proposed device includes vibration unit with vibrator and fasteners; one fasteners has plates for transmission of exciting force to free end of part at wide range of frequency change, resonance mode inclusive, when excitation frequency coincides with natural frequency of vibrations or resonance frequency of device. Device is provided with inertial mass in form of massive ring which is engageable with vibrator; flexible plates are secured to ring. |
FIELD: metallurgy.
SUBSTANCE: proposed method comprises holding in austenite region at 1060°C for 30-40 min with subsequent air cooling two-step tempering. At first step, low-temperature tempering is performed at 200-350°C while at second step it is performed at 760°C. Every tempering takes 3 hours.
EFFECT: higher long-term strength and creep limit.
4 tbl, 1 ex
The invention relates to the field of metallurgy, in particular to a method of heat treatment heat-resistant steels of martensitic class. The method can be used to produce steel with high heat resistance, for the manufacture of elements of thermal power plants with a working steam temperature of up to 650 C.
Currently, heat treatment heat-resistant steels of martensitic class is usually a restraint in austenitic area when 1040-1100°C with the subsequent cooling on air, tempering temperatures 750-780 C. Various ways of heat treatment heat-resistant steels, which include steels of martensitic class with the chemical composition (wt.%): carbon 0,01-0,2, silicon does not exceed 0.2, manganese 0,01-0,6, chrome 9,0-13,0, Nickel not more than 0.2, tungsten 0,5-2, molybdenum 0,5-1,0, cobalt 0.1 to 5.0, vanadium of 0.18-0.25, niobium 0,05-0,1, nitrogen 0.04 to 0.1, the Bor 0,0005-0,005, sulfur, not more than 0.01, phosphorus not more than 0.01, aluminium is not more than 0.02, copper, not more than 0.05, iron - other, presented in table 1.
Table 1 PatentThermal treatment modes
Operating temperature steel, C
EN 2237102
The exposure 1050°C+vacation when 550-570°C
≤500US 20080241583
The exposure 1060°C with the subsequent cooling on air+vacation at 760°C
≤620US 4762577
The exposure 1038-1093°C with the subsequent cooling on air+vacation when 690-704°C
≤590US 4857120
The exposure 1050-1150°C with subsequent cooling in water+vacation at 500-600°C+vacation at 600-700°C
600-650US 5560788
The exposure 1050°C and then cooled in oil+air vacation at 570°C+vacation at 700°C
600-650In the process of aging at temperatures 1040 - 1150°With almost complete dissolution of carbides and carbonitrides present in steels, and upon further cooling in air or in water in steel structure batch of martensite. Next vacation at temperatures of 650 -780°leads to the separation of carbides and carbonitrides type MSSB (size 50 - 170 nm), and MX (size 14 - 30 nm) [Macuata K. Strengthening mechanisms of creep resistant tempered martensitic steel / K. Maruyama, K. Sawada, J. Koike engineering Germany // ISIJ Int. - 2001. - Vol.41. - P. 641-653; Ennis, P. J. Recent advances in creep resistant steels for power plant applications / P. J. Ennis, A. Czyrska-Filemonowicz // Operat. Maint. Mater. - 2002. - Vol.1. - P. 1-28]. Stability formed after the holidays patterns at creep determined by the specific volume, distribution and size of carbonitrides and carbides. The dispersed particles constrain the movement of dislocations. As a result, the border reek of treestatenode keep the structure in the process of creep at elevated temperatures. It is the combination of dislocation structure of treestatenode with nanoparticles secondary phases provides a unique heat-resistant characteristics of steels of martensitic class.
Closest to the claimed is a method of thermal processing of heat-resistant steels of martensitic class E, which was chosen as the prototype described in the article [Qin, G. THE studies of microstructural evolution in creep exposed E911 / G. Qin, S.V.Hainsworth, A. Strang, P.F.Morris, P.D.Clarke, A.P.Backhouse // Creep & fracture in high temperature components. - DEStech Publications, 2009. - P.889-899]. Thermal treatment method includes:
- ageing of austenitic area at a temperature of 1100 & deg C for 1 hour with the subsequent cooling on air;
- leave at the temperature 760'c 2 hours to highlight carbides and carbonitrides.
The disadvantage of this method is the relatively large allocation of carbonitrides, which leads to low heat resistance characteristics.
The objective of the invention is development of the method of heat treatment heat-resistant steels of martensitic class to increase their heat resistance.
The technical result consists in allocation of dispersed carbonitrides Nb(C,N) of about 5 nm due to the introduction of additional low-temperature tempering in the temperature 200-350°C for 3 hours.
The problem is solved by the proposed method of heat treatment heat-resistant steels of martensitic class that includes an extract austenitic steel in the area with the subsequent cooling on air, tempering at a temperature of 760 degrees C and in which introduced the following new features: ageing of austenitic region carried out at a temperature 1060'c for 30-40 minutes, before holiday at 760°C conducted additionally low-temperature tempering in the temperature 200-350°C, the duration of leave is 3 hours.
Novelty confirmed by the fact that in the prior art technical solutions are not found with the proposed set of features.
Inventive step is confirmed by the fact that for the first time detected the allocation of carbonitrides Nb(C,N) of about 5 nm at low temperatures vacation 200-350 C. the Presence of carbonitrides Nb(C,N) of about 5 nm promotes heat-resistant characteristics of steels.
The example implementation.
Was cast steel chemical composition, similar in composition to become A described in the prototype (table 2).
Table 2Chemical composition (% by weight) steel
Fe C Si Mn P S Cu Ni Cr OSN. 0,12 0,06 0,36 0,010 0,008 0,02 0,2 9,8 With Mo W V Nb N In A1 0,1 1,01 0,93 0,2 0,05 0,05 0,003 0,015Steel is thermally treated in two different ways: the first is traditional, the second - according to the alleged invention.
1) holding at 1060'c for 30-40 minutes with the subsequent cooling on air and leave at a temperature of 760'c for 3 hours.
2) holding at 1060'c for 30-40 minutes with the subsequent cooling on air and two holidays: 1st level at a temperature of 300 C for 3 hours and 2nd level at a temperature of 760'c for 3 hours.
Test results of long-term strength and creep at a temperature of 650 degrees C and voltage 100 MPa, which were conducted according to ASTM E-06 and GOST 10145-81, respectively, are given in table 3.
Table 3Thermal treatment method
Time to failure, hours
The time to reach deformation equal to 1%, h
Traditional
1820 224According to the alleged invention
4983 463From table 3 it can be seen that the heat-resistant characteristics are processed by the proposed method is considerably superior to the corresponding characteristics of the steel treated in the traditional way.
The prototype test on durability at a temperature of 650 degrees C and different voltages are listed in table 4.
Table 4Time to failure, hours
Tension, MPa
849 124 2232 108 3454* 100 4530 93 14319 77*the estimated value
As seen from table 4, time to failure at the test temperature 650C and voltage 100 MPa almost 1.5 times longer than the sample annealed under the proposed method than that of the prototype.
Thus, these examples suggest that the task of devising the method of heat treatment heat-resistant steels of martensitic class with high heat resistance, such as long-term strength and creep strength, solved thanks to achieve the proposed technical result - selection at the first stage vacation dispersed carbonitrides Nb(C,N) of about 5 nm.
Method of heat treatment heat-resistant steels of martensitic class that includes exposure austenitic steel in the area with the subsequent cooling on air and leave, characterized in that the extract is carried out at a temperature 1060'c for 30-40 minutes, and leave carried out in two stages, with the first stage of conduct low-temperature tempering in the temperature 200-350°C, and the second stage vacationing at 760°C, and the duration of leave is 3 hours.