1888 results about "Hot working" patented technology

There is provided an α-β type titanium alloy having a normal-temperature strength equivalent to, or exceeding that of a Ti-6Al-4V alloy generally used as a high-strength titanium alloy, and excellent in hot workability including hot forgeability and subsequent secondary workability, and capable of being hot-worked into a desired shape at a low cost efficiently. There is disclosed an α-β type titanium alloy having high strength and excellent hot workability wherein 0.08-0.25% C is contained, the tensile strength at room temperature (25° C.) after annealing at 700° C. is 895 MPa or more, the flow stress upon greeble test at 850° C. is 200 MPa or less, and the tensile strength / flow stress ratio is 9 or more. A particularly preferred α-β type titanium alloy comprises 3-7% Al and 0.08-025% C as α-stabilizers, and 2.0-6.0% Cr and 0.3-1.0% Fe as β-stabilizers.

Method and apparatus for storing heat in industrial systems where large sources of stored energy are called upon to meet a work load, storing the heat content of a hot working fluid by using the hot working fluid as a heat transfer fluid in vapor form and depositing its heat content on a heat storage medium and then removing the cooled and condensed liquid phase of that heat transfer fluid, and when hot working fluid again is needed, the liquid heat transfer fluid is returned to the heated storage medium and is reheated as it passes through the hot storage medium and then is returned to the working system to be used as a hot working fluid.

The invention belongs to the field of titanium-based alloys, and particularly relates to a novel heat-resisting titanium alloy and a processing and manufacturing method and application thereof. The processing and manufacturing method comprises the composition elements of alloy components, smelting, heat processing, heat treatment and the like, wherein the alloy components are as follows (in percentage by weight): 5.4%-6.3% of Al, 3.0%-5.0% of Sn, 2.5%-6.4% of Zr, 0.0%-0.96% of Mo, 0.25%-0.5% of Si, 0.2%-0.5% of Nb, 0.3%-3.4% of Ta, 0.2%-1.6% of W, 0.0%-0.07% of C, less than or equal to 0.17% of O, less than or equal to 0.03% of Fe and the balance of Ti and inevitable impurity elements. The novel heat-resisting titanium alloy disclosed by the invention can obtain different matching of tensile strength, plasticity, permanence, creep strength and heat stability through the combination of different heat processing process and heat treatment processes, can be used for manufacturing parts, namely blades, coil assemblies and the like which are positioned on the high-temperature parts of an advanced aircraft engine, is used for a long time within a range of 600-650 DEG C, can also be used for manufacturing high temperature-resistant structural members, namely aerospace craft skin and the like, is used for a short time at about 700 DEG C and can be used as a material and the like used for high temperature-resistant corrosion-resistant valves of an automobile and a boiler.

An easily cutted lead-free brass alloy is prepared from Cu (60-62 wt.%), Bi (0.5-2.2), Al (0.01-0.1), Sn (0.5-1.6), P (0.04-0.15) and Zn (rest) through heat treating at 460-600 deg.C for 30 min-4 hr, and slow cooling at speed lower than 70 deg.C / hr.

As a rawmaterial of a copper base alloy containing at least one of 0.2 to 12 wt% of tin and 8 to 45 wt% of zinc, at least one of a copper base alloy having a large surface area and containing carbon on the surface thereof, a copper base alloy having a liquidus line temperature of 1050 DEG C or less, a copper base alloy surface-treated with tin, and a copper base alloy containing 20 to 1000 ppm of carbon, is used for obtaining a copper base alloy having an excellent hot workability. If necessary, when the raw material of the copper base alloy is melted, the material of the copper base alloy may be coated with a solid material containing 70 wt% or more of carbon, or 0.005 to 0.5 wt% of a solid deoxidizer having a stronger affinity with O than C with respect to the weight of the molten metal may be added to the molten metal.

A method of making a steel composition includes the steps of: a. providing a steel composition that includes up to 15% Cr, up to 3% Mo, up to 4% W, 0.05-1% V, up to 2% Si, up to 3% Mn, up to 10% Co, up to 3% Cu, up to 5% Ni, up to 0.3% C, 0.02-0.3% N, balance iron, wherein the percentages are by total weight of the composition; b. austenitizing the composition at a temperature in the range of 1000° C. to 1400° C.; c. cooling the composition of steel to a selected hot-working temperature in the range 500° C. to 1000° C.; d. hot-working the composition at the selected hot-working temperature; e. annealing the composition for a time period of up to 10 hours at a temperature in the range of 500° C. to 1000° C.; and f. cooling the composition to ambient temperature to transform the steel composition to martensite, bainite, ferrite, or a combination of those microstructures.

It is a new preparation and production method of corrosion-resistant and anti-abrasive plastic die steel 4Cr16Mo and its big mirror module. The characteristic is about its chemical composition. There are 0.33-0.43%C, 0.30-1.00%Mn, 0.30-1.00%Si, less than 0.045%S, less than 0.045%P, 14-18%Cr, 0.10-1.00%Ni, 0.80-1.50%Mo besides Fe. The method includes double refinement consisting of the primer smelting in electric furnace and vacuum handling outside the furnace and electroslag remelting, and necessary stress relieving annealing static ingot and electroslag ingot to refine electroslag ingot of component-uniform. After that, it uses hot machining forging technology and necessary stress relieving annealing of module to make the electroslag ingot into big module (thickness: 500mm, width:1200mm, length: 2500mm). At last, special heat-treat module modified treatment technology is used to bring out big highly corrosion-resistant and highly anti-abrasive plastic die steel module. This kind of module has stable quality and the nature reaching the standard(dirty component A<=2.0, B<=2.0, C thinness<=2.0, C thickness<=1.5, D<=2.0). To sum up, it has significant economic and social efficiency.

The invention relates to an ultra pure electroslag remelting method for a high-performance corrosion resistant alloy, and the method comprises the following steps of: preparing the following ingredient components of a self-fluxing electrode bar in parts by weight: 25-34 parts of Ni, 25-29 parts of Cr, 2.5-4.5 parts of Mo and 30-45 parts of Fe, and carrying out vacuum induction melting, so as to obtain the self-fluxing electrode bar; slowly melting the self-fluxing electrode bar in melted electroslag remelting slag charge comprising the following components in parts by weight: 55-80 parts of CaF2, 5-25 parts of CaO, 5-15 parts of Al2O3 and 5-10 parts of MgO, purifying, and recrystallizing in a crystallizer, so as to obtain an electroslag ingot; and forging the electroslag ingot into a bar material at the temperature of 1130+ / -5 DEG C, and carrying out solution treatment, so that the high-performance corrosion resistant alloy is obtained. By utilizing the ultra pure electroslag remelting method provided by the invention, the content of harmful elements such as sulphur and phosphorus in the alloy can be reduced, the impurity distribution of the alloy is improved, fining of structure can be facilitated, and the hot workability and yield of the alloy can be improved.

A thermal collection system has a first tank for storing relatively hot working fluid and a second tank for storing relatively cold working fluid. A heat exchanger is connected for receiving the relatively hot working fluid from the first tank for providing heat to the heat exchanger. The heat exchanger discharges the working fluid at a lower temperature than a temperature of the relatively hot working fluid of the first tank. A solar panel collector is connected for receiving the lower temperature working fluid from the heat exchanger and for heating the lower temperature working fluid and feeding same to a first control valve. The first control valve is operative for feeding working fluid from the solar collector selectively to one of the first tank and the second tank. The second tank has a second control valve selectively operative for permitting working fluid from the second tank to flow to the solar collector. Improved collection efficiencies in the solar collector may be obtained using the two tank structure for passing working fluid through the solar collector.

The invention relates to a high-strength high-toughness anticorrosion high-temperature bearing / pinion steel and a preparation method thereof, belonging to the technical field of bearing / pinion steel. The bearing / pinion steel comprises the following chemical elements in percentage by weight: 0.10-0.22% of C, at most 0.5% of Mn, at most 0.5% of Si, 12.0-15.0% of Cr, 1.50-3.00% of Ni, 4.00-6.00% of Mo, 0.50-0.90% of V, 12.0-15.0% of Co, 0.30-2.00% of W, 0.02-0.08% of Nb and the balance of Fe and inevitable impurities, wherein the V / Nb ratio is 25-35, the Mo / W ratio is 6-12, the Co / Mo ratio is 2-3, Cr+6Si+4Mo+1.5W+11V+5Nb<=52%, 40C+2Mn+4Ni+30N+2Co>=42%, and [O]+[N]+[H]<=0.0040%. The preparation method comprises the following steps: proportioning and controlling the components; carrying out vacuum smelting; carrying out hot working on a steel ingot to obtain a steel product; carrying out surface carburized hardening treatment on the steel product; and carrying out heat treatment on the steel product. The invention can satisfy the requirements of new-generation bearing / pinion steel for bearing the actions of high temperature and corrosive environment in the service process, and implements good cooperation of high strength, high hardness, high toughness, high temperature properties and anticorrosion property.

The invention discloses a diphase stainless steel, which comprises the following components in percentage by weight: less than or equal to 0.05 percent of C, 0.2 to 1.0 percent of Si, 0 to 2.0 percent of Mn, 22 to 27 percent of Cr, 0 to 2.0 percent of W, less than or equal to 0.1 percent of S, less than or equal to 0.03 percent of P, 0 to 0.003 percent of B, more than 0 and less than or equal to 0.2 percent rare earth of which the Ce content is more than 50 percent, and the balance of Fe and inevitable impurities, wherein a casting blank of the diphase stainless steel comprises over 60 percent of isometric crystal. A method for manufacturing the diphase stainless steel comprises the following steps of: performing smelting, die casting or continuous casting to form the casting blank, wherein the thickness of a steel die is more than 30 mm during the die casting to ensure that the cooling velocity of the steel is more than 10 DEG C per minute, and in the process of the continuous casting, the degree of superheating of the casting is between 30 and 100 DEG C, and the casting speed is over 1.2 meters per minute; putting the casting blank into a heating furnace, heating the casting blank to the temperature of between 1,100 and 1,250 DEG C, performing heat preservation on the casting blank, and then forging or hot-rolling the casting blank to a required thickness; and annealing and pickling a steel plate or a plate coil after forging or hot-rolling, and controlling the annealing temperature to be between 1,000 and 1,100 DEG C. The diphase stainless steel has high corrosion resistance and high hot-working performance, and can be widely applied in the fields of petroleum, chemical industry, papermaking, marine engineering and the like in rigorous corrosion environments.

The invention relates to a high-toughness heat-resistant Mg-Al-RE-Mn wrought magnesium alloy and a preparation method of a plate made of the same. The high-toughness heat-resistant Mg-Al-RE-Mn wrought magnesium alloy comprises aluminum, rare earth, manganese, impurity elements (silicon, iron, nickel and copper) and magnesium. The preparation method comprises the following steps: proportionally preparing pure magnesium, pure aluminum cast ingots, magnesium-manganese (or aluminum-manganese) interalloy and magnesium-rear earth interalloy; smelting and refining by using a smelting furnace, and casting to obtain cast ingots; carrying out homogenizing treatment at 370-410 DEG C, and quenching with water; and before plastic deformation treatment, keeping the temperature at 280-400 DEG C for a period of time, and extruding and rolling, or extruding while rolling, thereby obtaining the high-toughness heat-resistant Mg-Al-RE-Mn wrought magnesium alloy. The high-toughness heat-resistant Mg-Al-RE-Mn wrought magnesium alloy and the plate made of the same provided by the invention have the advantages of high toughness, high heat resistance, high plasticity and favorable hot working properties; and the product can be used as a light-weight high-toughness heat-resistant structural material to satisfy the demands of aviation, spaceflight, civil vehicles and the like for the light-weight high-toughness heat-resistant wrought magnesium alloy material.

The invention discloses a smelting technique of a novel nickel-iron-base high-temperature alloy GH4169D, which aims to smelt the novel high-temperature alloy GH4169D consumable ingot which has the advantages of lower raw material cost and favorable hot working properties in industrial production as well as high stability at high temperature. The scheme of the smelting technique is as follows: on the basis of the GH4169 alloy composition, the Fe content is lowered, the sum and proportion of Al and Ti are adjusted, and proper P and B are added; and by adopting a triple (VIM+PESR+VAR) smelting technique, proper slag and technological parameters are selected, and the burning loss of Al and Ti in the protective-atmosphere electroslag smelting process is controlled to obtain the precise contents of Al and Ti. The technique enhances the metallurgical quality of the high-temperature alloy, and fills up the blank of the high-temperature alloy in the aspect of the application temperature between 650 DEG C and 750 DEG C; the GH4169D alloy has the high strength, favorable hot working property and weldability of the GH4169 alloy, and has the high application temperature and other comprehensive properties of the GH4738 alloy; and the GH4169D alloy has long-term stability at 700 DEG C.

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.

The invention relates to a Mn-containing creep-resisting rolled zinc alloy belt material. The material comprises the following components in percentage by weight: 0.5 to 3.0 percent of copper, 0.01 to 2.0 percent of manganese, 0.05 to 0.3 percent of titanium and the balance of zinc and less than 0.05 percent of impurities. An alloy component can also contain the following component in percentage by mass: 0.01 to 0.5 percent of X, wherein the X is at least one of aluminum and rare earth elements (Ce+La). A method for preparing the material comprises the following steps of: smelting by a protective covering method and adding alloy elements in the forms of pure zinc, Zn-Cu, Zn-Ti, Cu-Mn, pure aluminum and Ce+La composite rare earth, wherein a smelting temperature is between 650 and 740 DEG C; pouring at the temperature of between 420 and 480 DEG C; uniformly annealing cast ingots at the temperature of between 350 and 380 DEG C for 6 to 10 hours; performing hot rolling for multiple times at the temperature of between 220 and 280 DEG C, wherein total deformation is between 60 and 95 percent; performing cold rolling, wherein the total deformation is between 50 and 80 percent; and after rolling, annealing at the temperature of between 180 and 200 DEG C for 2 to 3 hours. The alloy of the invention has high creep resistance, hot processing performance and mechanical property and is suitable for the fields of building decoration, transportation, instruments, meters and the like.

The invention discloses an aluminum bronze. The aluminum bronze comprises the following components in percentage by weight: 9.0-18.0% of aluminum, 2.0-7.0% of iron, 1-5% of manganese, 0.01-1% of zinc and the balance of copper and inevitable impurities. The aluminum bronze has the following advantages that through utilizing specific element ratio, specific processing mode and composition, the tensile strength of the aluminum bronze can reach above 700 MPa, the Brinell hardness (HB) of the aluminum bronze is 300-400, and the compressive strength of the aluminum bronze is above 1000MPa; the aluminum bronze has high wear resistance; the friction coefficient of the aluminum bronze is less than 0.15, so that scratched products and adhered products cannot be caused; the alloy has good hot working character; the alloy has high anti-softening temperature; and the aluminum bronze is not added with noble elements such as Ag and Ni, does not need to be thermally treated, and the raw material and production costs are lowered.

Described herein are methods for forming titanium alloy tubes having an α-β grain structure. The methods include the steps of hot-working a titanium alloy workpiece at a temperature below the β-transus temperature of the workpiece and above the recrystallization temperature of the workpiece to produce an α-β titanium alloy preform hollow. Subsequently, the α-β titanium alloy preform hollow is flowformed, thereby forming a α-β titanium alloy tube.

The invention relates to a novel lead-free environment-friendly high-strength wear-resistant copper-base alloy bar which is prepared from the following components in percentage by weight: 1-3% of manganese, 2-4% of tin, 0.01-0.5% of phosphorus, 1.5-4.5% of zinc and the balance of copper. The metallic element manganese is used instead of lead; the manganese, zinc, tin, phosphorus and copper are mixed proportionally, extruded by an extruding machine at proper temperature, and drawn by a drawing machine to obtain the alloy bar; the alloy bar has wear resistance in the traditional copper-lead-bronze alloy, can be used for hot working, and has better workability than the copper-lead-bronze alloy; the alloy bar provided by the invention is free of lead, thereby avoiding the environmental pollution caused by the use of lead and being beneficial to environmental protection; and thus, the novel lead-free environment-friendly high-strength wear-resistant copper-base alloy bar provided by the invention can completely substitute the traditional copper-lead-bronze alloy.

The invention relates to niobium microalloyed high-strength hot working die steel, belonging to the alloy steel manufacturing process technical field. The compositions by weight percentage of the steel are: 0.3 to 0.6 percent of C, 0.1 to 0.5 percent of Si, 0.1 to 0.5 percent of Mn, 4.0 to 6.5 percent of Cr, 1.0 to 3.5 percent of Mo, 0.4 to 1.4 percent of V, 0.02 to 0.10 percent of Nb, less than 0.03 percent of P, less than 0.03 percent of S, and the balance being Fe. The process for preparing the hot working die steel comprises the following steps of: batching, smelting, secondary refining and electroslag remelting; homogenizing the mixture for 5 to 10 hours at a temperature of between 1210 and 1300 DEG C, and forging, annealing, quenching and tempering the mixture; heating up the mixture to a temperature of between 1000 and 1100 DEG C for austenization, after performing 'step heating' at a temperature of 650 DEG C and at a temperature of 800 DEG C, then performing secondary tempering to the processed mixture, and finally acquiring the hot working die steel. The die steel has the advantages of good thermal resistance, good thermal stability and good thermal fatigue performance.

The invention discloses a manufacturing process of phi 300 mm-phi 700 mm high-carbon high-chromium cold-working die steel forged round steel, and the purpose is to solve the problems of quite severe ununiformity of large-section forging material eutectic carbides and the increase of defects of internal cracks and surface cracks during the forging process caused by segregation deterioration of cast structure carbides of large steel ingots. By using steel-making technical measures such as LF refining, VD degassing, aluminium wire feeding, and the like, the invention improves the molten steel cleanliness, the control of electroslag remelting output power, and the homogenization treatment before forging, and improves the segregation of eutectic carbides and the hot-working plasticity of steel; by controlling the forging heating numbers and various deformation amounts of large high-carbon high-chromium steel ingots, large granular carbides are crushed; the ununiformity of eutectic carbides is improved; crack defects during the forging process are prevented; and the produced high-carbon high-chromium steel large-section forging materials has ununiformity of eutectic carbides of up to grade 4-grade 6; the results of ultrasonic inspection are at good levels of E / e grade, D / d grade.

Metastable beta titanium alloys and methods of processing metastable β-titanium alloys are disclosed. For example, certain non-limiting embodiments relate to metastable β-titanium alloys, such as binary β-titanium alloys comprising greater than 10 weight percent molybdenum, having tensile strengths of at least 150 ksi and elongations of at least 12 percent. Other non-limiting embodiments relate to methods of processing metastable β-titanium alloys, and more specifically, methods of processing binary β-titanium alloys comprising greater than 10 weight percent molybdenum, wherein the method comprises hot working and direct aging the metastable β-titanium alloy at a temperature below the β-transus temperature of the metastable β-titanium alloy for a time sufficient to form α-phase precipitates in the metastable β-titanium alloy. Articles of manufacture comprising binary β-titanium alloys according to various non-limiting embodiments disclosed herein are also disclosed.

The invention discloses a method for establishing a constitutive model for aluminum alloy thermal elastoplastic deformation simulation. The method comprises the following steps: (1) selecting the constitutive model; (2) determining model parameters; and (3) substituting the parameters into a constitutive model equation, and determining the constitutive model equation. The method has the advantages that the establishment of the constitutive model fills up the blank of simulating a relationship between the mechanical performance and temperature of a material used in machining of a 7A52 aluminum alloy heat machine with a numerical simulation method all the time, improves the accuracy of 7A52 aluminum alloy thermal elastoplastic deformation simulation, lays an important basis for confirming a 7A52 aluminum alloy hot working process and studying a metal plastic deformation theory, and has an important significance for practical application of 7A52 aluminum alloy.

The present invention relates to one kind of Fe-base RE-adding high performance anticorrosive high strength two phase stainless steel and its smelting process. The stainless steel has proper amount of RE added for modifying and micro alloying, N to replace Ni, properly regulated Cr, Ni, Cu, Mo, Si, Mn and other alloy elements, and added W to raise performance. During smelting, composite active metal elements Re, Mg and Ca are used in treating molten steel; and in electroslag remelting, the RE steel electrode is remelted in a five-component slag system comprising ReO2, MgO, CaO, CaF2 and Al2O3 in the weight ratio of 10 to 10 to 10 to 50 to 20 to result in new material with obviously raised mechanical strength, and improved heat working performance, heat resisting performance and hydrochloric acid corrosion resisting performance. The present invention is suitable for making anticorrosive apparatus for petrochemical, papermaking and other industry.

Described herein are methods for forming titanium alloy tubes having an α-β grain structure. The methods include the steps of hot-working a titanium alloy workpiece at a temperature below the β-transus temperature of the workpiece and above the recrystallization temperature of the workpiece to produce an α-β titanium alloy preform hollow. Subsequently, the α-β titanium alloy preform hollow is flowformed, thereby forming a α-β titanium alloy tube.

The invention provides a low-expansion antioxidative Ni-Fe-Cr-based high temperature alloy and a preparation method thereof. The alloy comprises 20 to 25% of Fe, 14 to 18% of Cr, 1.5 to 2.0% of Al, 1.5 to 2.5% of Ti, 0.5 to 2.0% of Nb, 0.3 to 2.0% of Mo, 0.5 to 2.0% of W, no more than 1.0% of Si, no more than 1.0% of Mn, no more than 0.5% of Cu, no more than 0.1% of C, no more than 0.01% of B, no more than 0.05% of Zr, no more than 0.05% of P and no more than 0.20% of a rare earth element, with the balance being Ni. The alloy is of a double-phase structure, wherein a substrate is an austenite (gamma) phase with a disordered face-centered structure, and a gamma' [Ni3(Al,Ti)] phase with an ordered structure is dispersed in the austenite. According to the invention, on the basis that structural stability, corrosion resistance and high temperature strength of the alloy are not influenced, the content of Fe is increased as much as possible to improve hot workability of the alloy and reduce cost. Compared with the prior art, the alloy provided by the invention has the advantages of low material cost, a low thermal expansion coefficient, excellent high temperature strength, hot-working performance and anti-oxidation corrosion and in particular, better cost performance when used under the conditions of high temperature, high pressure and supercritical water vapor.

There are provided a steel for warm working, to be subjected to warm working as various structures, components of cars, and the like, a warm working method thereof, and a steel material and a steel component obtainable from the warm working method.[Solving Means] A steel is to have a particle dispersion type fiber structure formed in the matrix by warm working. The steel is characterized in that the total amount of the dispersed second-phase particles at room temperature is 7×10−3 or more in terms of volume fraction, and the Vickers hardness (HV) is equal to or larger than the hardness H of the following equation (2):H=(5.2−1.2×10−4λ)×102  (2)when the steel is subjected to any of annealing, tempering, and aging treatments in the as-unworked state under conditions such that a parameter λ expressed by the following equation (1):λ=T(log t+20)(T; temperature(K), t; time(hr))  (1)is 1.4×104 or more in a prescribed temperature range of 350° C. or more and Ac1 point or less. This steel is taken as the steel for warm working.

The invention relates to a high-hardness high-polishing pre-hardening plastic die steel and a manufacture technology thereof, which belongs to the technical field of alloy steel manufacture technology. The steel is characterized in that the alloy chemical component comprises the following alloy elements by mass percentages: 0.25-0.40% of C, 0.10-0.30% of Si, 1.50-2.00% of Mn, 1.50-2.50% of Cr, 0.50-1.00% of Mo, 0.10-0.30% of V, less than or equal to 0.025% of P, less than or equal to 0.005% of S, 0.60-1.50% of Ni, less than or equal to 0.15% of Nb, and the balance of Fe. The manufacture method comprises the following steps: burdening, smelting, pouring, performing hot delivery; performing high-temperature diffusing heat treatment, then performing multi-directional forging and hot processing, normalizing on fine grains and dehydrogenizing and annealing; and finally quenching and performing temper heat treatment to obtain the tempered structure with hardness of 38-42HRC. The steel of the invention has the advantages of low cost, high hardenability, high hardness, high polishing performance and dermatoglyph etching performance.

The invention relates to a super-plastic forming / diffusion bonding forming method for a large-curvature complex surface titanium alloy part and belongs to the field of metal plates and hot working. Through reasonably and accurately calculating the unfold size of a part, residual materials on the wrinkled region of the part are removed through cutting in advance, after pre-forming is completed, overall welding and hot shape correction are performed, and the pre-formed and welded part is placed in the same tool so that super-plastic forming / diffusion bonding forming can be performed on the part. Without the help of blank holder force, pre-forming and super-plastic forming / diffusion bonding forming are completed through the same tool, one-time hot forming of the large-curvature complex surface part is completed, the defect that the part is wrinkled and loses stability is overcome, and technology difficulty and tool structure complexity are lowered. The part formed through the method has advantages.