Titanium and its alloy polishing methods

Titanium and its alloy have low density and excellent strength and weight ratio, good corrosion resistance and high mechanical strength, but expensive production cost. Titanium and titanium alloy grinding and polishing’s low efficiency make its microscopic structure change because the excessive severe cutting and polishing process will create a mechanical twin in the alpha phase.

At present, the methods of free abrasive grinding and chemical mechanical polishing are mainly used in the precision machining of titanium alloys. Grinding fluid is made by free silicon carbide or alumina abrasives, polishing fluid is a mainly strong acid, strong alkali or toxic chemical reagents, the free abrasives are difficult to control its movement trajectory, easy to leave deep scratches on the surface of the processing, reducing the processing accuracy. The handling of strong acids, strong bases and toxic chemicals is cumbersome, time-consuming and potentially hazardous to operators and the environment.

Early mechanical polishing processes were time-consuming, and almost all mechanical polishing methods used a polishing fluid containing an erosive agent in the final or two-step process. The electrolytic polishing methods can often get a better polishing surface, but the electrolyte brings a certain risk. This article here discusses the methods of grinding and chemical mechanical polishing to achieve super precision polishing of titanium alloys.

In the 1970s and 1980s, engineers Springer and Ahmed first published a paper on the polishing method of titanium and titanium alloys in 1984. This is the three-step sample polishing method. It is assumed that 320 grit paper is used to finish the sample grinding process, but this may not always be the case. If the sample is cut with an ultra-thin cutting piece or a grinding wheel cutting piece with appropriate bonding strength, the cutting surface is smooth and the damaged layer is minimal, 320grit is the ideal choice. If the cut surface is rough and the damaged layer is large, for example, if a band saw is used, then rougher sandpaper must be used and a certain amount of time must be spent to remove the damaged layer.

 

Springer, Ahmed titanium 3-steps polishing methods

  1. Grind, water cool with 320grit paper, grind for 2-3 minutes, remove the damage layer caused by cutting and make the surface of the sample flat. 320grit SiC sandpaper, water-cooled, rotate at 240 RPM, turn in the same direction, pressure: 27N (6lbs)/each sample until the sample is smooth. Note: removal of cut damage layer is the foundation of polishing, incomplete removal can directly affect the experimental results.
  2. Rough polishing, pre-apply 9 mm METADI® diamond polishing paste on TEXMET® polishing cloth with holes, use distilled water as cooling lubricant, and polish for 10~15 minutes. Rough polishing process: 9 mm METADI diamond polishing fluid + METADI polishing lubricant, polishing surface with ultra-pad ™, 120 RPM, reverse rotation, pressure: 27N (6lbs)/each sample, time: 10min.
  3. Finish polishing, using MICROCLOTH® or MASTERTEX® polishing cloth, adding MASTERMET® silica suspension polishing fluid and polishing for 10-15 minutes. Final polishing process: on the polished surface of MICROCLOTH, use MASTERMET silica polishing fluid, rotate at 120 RPM, reverse rotate, pressure: 27N (6lbs)/sample, time: 10min.

 

Müller titanium 3-steps polishing methods

  1. P500 sandpaper, water-cooled, rotating speed 300 RPM, pressure 16.7n (3.75lb) on each sample, preparation time until all samples are smooth.
  2. P1200 sandpaper was water-cooled at a speed of 300 RPM, a pressure of 16.7n (3.75lb) on each sample, and a 30S preparation time. Note: the specific time is determined according to the actual polishing situation, and the time parameters are only for reference. Usually, manual polishing is used for polishing, so the parameters may vary depending on the equipment.
  3. Synthetic non-pile polishing cloth + silica suspension polishing fluid containing chemical etchant, polishing machine speed is 150 RPM, polishing time: pressure on each sample is 33N (7.5lb) for 10 minutes, pressure on each sample is 16.7n (3.75lb) for 2 minutes, and pressure on each sample is 8N (2lb) for 1 minute.
  4. Polishing agent: 260ml SiO2+40ml H2O2 (concentration 30%),1mlHNO3 + 0.5ml HF.The P500 and P1200 grit sizes of FEPA correspond to ANSI/CAMI 320/360 and 600 grit, respectively.

Steel introduction: PM ASP® 2030 Steel

The ASP® is a range of powder metallurgy high-speed steel brands form Erasteel, a subsidiary of France Eichmann group. The ASP® steels are suitable for a wide range of tooling and component applications like cutting tools, cold work tools, saws & knives, automotive components and wear-resistant components. The steel mainly includes: ASP®2005, ASP®2017, ASP®2023, ASP®2030, ASP®2052 and ect, they can be good at different applications such as ASP®2055 with cobalt for gear cutting, ASP®2030 for taps and ASP®2005 for the cold work. Today we will introduce ASP® 2030 steel for you, if interested in, please read on.

 

Features

HSS ASP2030 is characterized by good high wear resistance, high compressive strength and high hardness, overall hardening and heat treatment dimensional stability and resistance to reignition, especially suitable for use in high load forming dies and multi-blade tools.

 

Standards and Equivalent Brands

AISIENW.Nr.
M3:2+CoHS 6-5-3-81.3244
ErasteelASP®2030
ASSABVANADIS 30
BöhlerS590
CrucibleCPM Rex 45
HitachiHAP40
DAIDODAP 540,DEX40
SanyoSPM30

 

Chemical Composition

CCrMoWCoV
1.284.25.06.48.53.1

 

Hardness of delivery

DeliverySoft annealingCold drawCold rolled
Hardness, HB≤300≤320≤320

 

Physical property

Temperature20℃400℃600℃
Density, g/cm3  [1]8.17.97.9
Elasticity modulus, kN/mm2  [2]240214192
Thermal expansivity, per℃ [2]11.8×10-612.3×10-6
Thermal conductivity, W/m℃ [2]242827
Specific heat, J/kg℃ [2]420510600

Note: [1]: Soft annealing; [2]: Quenching at 1180℃, tempering at 560℃, 3×1H

 

Heat treatment

  • Soft annealing in shield gas in the temperature of 850 ~ 900℃ for 3 hours, then slow cooling 10℃ to 700℃ per hour, followed by air cooling.
  • De-stress is between 600℃ and 700℃ for about 2 hours, then slowly cool to 500℃.
  • Quenching in the shielding gas, preheating at 450 ~ 500℃ and 850 ~ 900℃ respectively, austenitizing at the required hardness suitable temperature, slow cooling to 40 ~ 50℃.
  • It is recommended to temper 3 times at 560℃ for at least 1 hour each time, cool to room temperature (25℃) in the process of tempering.

 

Surface treatment

ASP2030 is a good substrate material for PVD (physical coating) and CVD (chemical coating). If nitriding is required, 2 to 15 m thick permeable layer or steam tempering is recommended.

 

S7 High toughness shock-resisting tool steel

AISI S7 steel was originally derived from the United States commercial brand Finkl DRX, is a kind of medium carbon chromium molybdenum alloy shock resisting tool steel. It’s characterized by a good comprehensive property like hardenability, high strength, toughness, tempering stability and oxidation resistance of temperature, is suitable for load tools or dies working under high temperature and high impact and hammer forging die manufacturing. This steel has a high hardness after forging, so it needs softening and annealing to reduce the hardness and facilitate cutting. The available forms of S7 steel including round bar, drill rod, rectangular bar, ground flat bar, square bar and plate

 

Equivalent Material

USAGERMANCHINA
ASTM A681 T41907DIN 1.2357GB/T 1299 5Cr3MnSiMo1

 

S7 Chemical Composition

CSiMnPSCrMoV
0.45~0.550.20~1.000.20~0.90≤0.030≤0.0303.00~3.501.30~1.80≤0.35

 

S7 Mechanical Property

Density0.283 lb/in3 (7833 kg/m3)
Modulus of Elasticity30 x 106 psi (207GPa)
Thermal Conductivity16.5 BTU/hr-ft-°F (28.5 W/m/°K)
Machinability70-75% of a 1% carbon steel

 

Comparison with  A2 and H13

According to the analysis of hardness, wear-resistance and toughness (see the figure below), the performance of S7 is between A2 and H13, which can make up for the deficiency of both.

Hardness

The applied hardness of S7 is between 52~58HRC. Another 1~2HRC can be raised if proper heat treatment is applied.

 

Applications

S7 has high strength, toughness and wear resistance, making it a tool steel used for pneumatic tools and cutting tools such as punch, forging die, hammer, chisel, jig die, cutting tool and various cold and hot dies that require high hardness.

 

For more information about the S7 tool steel, contact us now!

What is the use of vanadium in steel?

Vanadium(V) has been widely used in metallurgy, chemistry, aerospace industry, agriculture, medicine and other fields due to its characteristics of vanadium added in steel can improve the strength, toughness and plasticity of steel, improve the hardness,  abrasion resistance in steel products, among which the metallurgical industry accounts for almost one third of its consumption. At present, V has been added in high-strength hot-rolled ribbed steel, high-carbon low-alloy steel, spring steel, bearing steel, mold steel, high-speed steel, Martensite heat-resistant steel and other steel as an important alloying element to improve the performance of steel. In the last article, we introduce the effect of V in steel, here we will continue the use of vanadium in steel, if interested, please read on!

For high carbon and low alloy, V is mainly used to refine grain, improve the strength, yield ratio and low-temperature toughness after normalizing, and improve the welding performance of steel. V will reduce the hardenability of steel in general heat treatment conditions, usually added with one or two kinds of alloy elements like manganese, chromium, molybdenum and tungsten. High strength low alloy steel contains 0.04% ~ 0.12% V, and special steel can up to 0.16% ~ 0.25%.

Vanadium is an indispensable alloy element in high-speed tool steel(HSS). It can prevent grain growth, improve red hardness and cutting ability of steel, increase wear resistance and prolong service life in high-speed tool steel containing tungsten. Almost all-alloy mold steel like cold work tool steel, hot work tool steel, plastic mold steel contains 1% ~ 3% vanadium, a few special requirements can be up to 5%. Vanadium is the main secondary hardening element that is commonly used hot mold steel (H13) and cold mold steel (D2). The content of V in mold steel is usually 0.1% ~ 5%, the United States developed A11 cold tool steel of which vanadium content up to 9.75%. In Germany, V consumption in tool steel and high-speed steel accounts for about 1/3 of the total V consumption. These steel products made by HSS can reach to 60HRC hardness, has been widely used surgical instruments and tools and various cutting tools: drills, taps, milling cutters, tool bits, gear cutters, saw blades, planer and jointer blades, router bits; sharp tools like files, chisels, hand plane blades, knives

In addition, V has a place in heat resistant steel, stainless steel, bearing steel and spring steel, Nickel-based alloys. Vanadium addition of 0.15% ~ 0.40% can form highly dispersed carbide and nitrite particles in heat-resistant steel, which polymerizes and grows very slowly at a high temperature, which can improve the thermal strength and creep resistance of heat-resistant steel and be applied in power station systems such as T91 and P92 steel.

For spring steel and bearing steel, V can improve the elastic limit, strength and yield ratio, reduce the decarburization sensitivity of the steel during heat treatment, thereby improving the metallurgical and surface quality of the steel. Vanadium has also been used in Hastelloy corrosion-resistant alloy, for example, Hastelloy B alloy contains V≤0.60%, Hastelloy C22, Hastelloy C 276 alloy ≤0.35%, Hastelloy N ≤0.50% V, Hastelloy W ≤0.60% V.

What is the effect of vanadium in steel?

Vanadium is a common rare metal used to refine grain size, improve the strength, toughness and plasticity of steel, and improve the service performance of vanadium steel products. Steel contains a certain amount of carbon and nitrogen, which can be precipitated with vanadium in the form of carbide, nitride, or carbonitride in the steel, affecting the microstructure evolution. Vanadium content in steel is generally no more than 0.5% (except high-speed tool steel), which is widely used in alloy structural steel, spring steel, bearing steel, alloy tool steel, high-speed tool steel, heat resistant steel, hydrogen resistant steel and low-temperature steel.

The features of Vanadium in steel

(1) Refine the structure and grain size of the steel, improve the grain coarsening temperature, thereby reducing the sensitivity of overheating and improving the strength and toughness of the steel.

(2) When dissolved into austenite at high temperature, the hardenability of steel can be increased; In contrast, the presence of carbides will reduce the hardenability of steel.

(3) Increase the hardenability and tempering stability of hardened steel, refine grain and produce secondary hardening effect.

(4) The solid solubility of vanadium carbide and vanadium nitride in austenite is high, so it is not easy to produce the crack caused by precipitation. At high temperature, the tendency of cracks in steel billet during solidification is small.

(5) The low precipitation temperature of carbon/vanadium nitride, leading the low drag force of solid solution migration in grain boundary in austenite, which is favorable for austenite recrystallization and crystallization controlled rolling. Uniform recrystallized grains can be obtained over a wide temperature range. Compared with other microalloy steel and alloy steel, vanadium steel has less rolling resistance, which is roughly equivalent to carbon manganese steel.

(6) Vanadium is precipitated and strengthened in Ferrite or Martensite, generally at 50MPa ~ 100MPa. The precipitation of vanadium can be promoted by increasing the nitrogen content in steel, and the precipitation strengthening effect can be obtained. The use of vanadium can be saved in the production of high strength hot rolled steel bar.

(7) The strong binding force between vanadium and nitrogen can form vanadium nitride, which is conducive to reducing the strain aging of steel, which is very important in the service process of steel bar that has experienced cold deformation.

(8) Vanadium addition in Martensitic steel can increase the tempering and softening properties of the steel, so that the steel can maintain the shape of Martensitic slab in the tempering process, or release vanadium carbide in the tempering process, resulting in secondary hardening effect.

The heat treatment of H13 hot steel

H13 is the most commonly used hot work steel, it has higher thermal strength and hardness, wear resistance and toughness, better heat resistance fatigue performance, has been widely used in the manufacture of various forging die, hot extrusion die and aluminum, copper and its alloy casting mold. Hot-working tool steel undertakes a lot of impact load, friction, intense cold and heat cycle caused by thermal stress and high-temperature oxidation, often produce a series of failure forms such as crack, collapse, wear and so on.

H13 steel is a type of hypereutectoid alloy steel, and its metallographic structure has many defects such as non-metallic inclusions, carbide segregation, loose center and white spots, which can reduce the strength, toughness and thermal fatigue resistance of die steel. Heat treatment technology has a great influence on the structure and performance of the H13 steel mold.

Forging process
H13 steel contains quite high alloy elements, offering poor thermal conductivity and low eutectic temperature, easy to cause overburning. For the blank with Ø 70 mm H13 steel block in diameter, it should be preheated within the range of 800 ~ 900 ℃, at first, then in the forging heating temperature 1065 ~ 1175 ℃, repeatedly pulling long upsetting forging, be noted that the forging ratio should be greater than 4.

Spheroidization annealing process
The purpose of spheroidization annealing is to uniform structure, reduce hardness, improve cutting performance and prepare the structure for quenching and tempering. The annealing process is insulated at 845 ~ 900℃ (1h+1min) /mm, then cooled to 720 ~ 740℃ isothermal (2h+1min) /mm, and finally cooled to 500℃ and out of the furnace, spheroidization annealing structure is pellet pearlite and hardness less than 229HBS.

Quenching and tempering process
The best heat treatment process of H13 steel is that the oil cold quenched or fractional quenched after heating at 1020 ~ 1080℃, and then it is tempered at 560 ~ 600℃ twice. The microstructure is tempered torstenite + tempered sostenite + residual carbide, and the microhardness is 48 ~ 52HRC. For high thermal hardness requirements of the mold (die casting die) can be taken upper limit heating temperature quenching. The lower limit heating temperature can be used to quench the mold (hot forging mold).

 

In addition, the manufacture of H13 steel mold has to go through a series of processes such as forging, annealing and machining. Improper operation in each process will cause premature failure of the mold and reduce its service life. Therefore, attention must be paid to the influence of preheating, cooling and lubrication of the mold, forging, cutting, grinding and EDM on H13.

The welding of stainless steel-carbon steel clad plate

The clad plate is produced by bonding two or more metals together into a single steel sheet or plate. Stainless steel-Carbon steel clad plates combined the stainless steel and carbon steel material through the explosion and rolling process, which make the metal plate more corrosion resistant, abrasive resistance and high temperature and pressure resistance. But the welder will face the new problem that is the welding, everyone knows that the two different material welding will be more complex and difficult.

Generally speaking, The welding sequence of the stainless steel cladding steel plate is generally as follows: first weld the inside of the base layer, then weld the outside of the base layer after root removal on the back and finally weld the transition layer and cladding layer (groove diagram). However, for the welding of the longitudinal girth weld of the small-diameter cylinder (diameter below 500), the outer groove shall be selected. Therefore today let’s learn the welding process of a pressure vessel made by small diameter stainless steel cladding plate.

Hydrogen sulfide tower bottom reboiler (or U-tube heat exchanger). The medium containing ammonia, the container is made of Q245R + S31603 stainless steel clad steel plate, the design pressure of 1.18 MPa, the design temperature of 189 ℃, Φ 600 mm in diameter.

Groove design

Due to the small diameter of the shell body, it can only be welded from the outside, so the outer groove – single side welding type is adopted. This groove adopts GTAW+SMAW welding on the outside of the barrel, and the welding sequence is as follows: cladding welding, transition welding and base welding. Different from the previous welding sequence, this welding sequence brings about the selection of welding materials.

 

Welding material

Considering the dilution effect of the base material, the welding material with higher chrome-nickel content should be selected. The welding material of the base layer is generally stainless steel, the covering layer is generally ER316L (H03Cr19Ni12Mo2Si) welding wire, and then the welding electrode A042 (e309mol-16) is used to weld the transition layer and the base layer.

 

Welding test

ProcessLayer NoMaterialSize(mm)ElectrodeElectricity(A)Arc voltage(V)Speed(cm/min)Heat input(kJ/cm)
CTAW1ER316L2.0DCEN100-40011-1414-16≤8.4
SMAW2A0423.2DCEP90-11021-2314-16≤10.8
SMAW3-4A0424.0DCEP140-16023-2616-18≤15.6

After passing NDT, the samples were tested for mechanical properties and intergranular corrosion. It can be seen from the test results that the tensile strength, bending performance, impact performance and intergranular corrosion of the welded joint meet the standard requirements, which proves the welding process and welding material w.

 

The experiment shows that the stainless steel clad plate can be welded in this order: cladding weld – welding transition weld – base weld. After welding the overlaying seam, the welding material of the base should be stainless steel. Adopting the process of  GTAW+SMAW to weld the stainless steel cladding plate of small diameter barrel on the outside side with the correct welding material, which can completely meet the standard requirements.

3 tips for Ni-based high temp alloy cutting

In the last article we discussed what’s the high temp alloy, we know nickel-based alloy is the most commonly used high temperature alloy used in aerospace, aviation and other fields at about or above 1000℃. Because it contains many high-melting-point alloy elements such as Fe, Ti, Cr, Ni, V, W, Mo, etc., which forms austenitic alloy with high purity and dense structure, and some elements from metal and non-metallic compounds with high hardness, small specific gravity and high melting point with non-metallic elements such as C, B, N, making its poor machinability. Its relative machinability is only 5 ~ 20% of that of plain carbon steel. The superalloys are characterized by difficulty cutting, do you know why they are difficult to cut? There are some features you should know before answer the question.

  • High content of fortified elements

In the process of cutting, a large number of abrasive metal carbide, intermetallic compound and other hardpoints are formed, which has a strong scratch on the knife, and is easy to produce deposition and clipping, affecting the quality of the processed surface.

  • High temp strength and work hardening tendency

The cutting process produces great plastic deformation resistance and cutting load, and the cutting temperature is high. The unit cutting force of nickel-based superalloy is 50% higher than that of medium carbon steel. The working hardening and residual stress of the surface layer after processing are large, and the hardening degree can reach 200% ~ 500%, leading to serious edge and edge wear, groove wear is also easy to occur.

Now that we know that Nickel-based high temp alloys are difficult to cut, here we will discuss 3 tips should pay attention to in cutting.

  • Metal Cutting Tools

Superalloys must have special tool materials for cutting. The most commonly used are carbide cutters, or high speed steel for machining complex surfaces with very low cutting speed. Hot-working grades with better performance are most commonly used in practice. In addition, Si3N4 ceramics tools are the best option for high temp alloy due to its higher resistance to adhesion, heat resistance and hardness than cemented carbides and are also suitable for semi-finishing and finishing of superalloy.

  • Tool Feeds and Speeds

The cutting of superalloy materials also requires the geometric parameters of cutting tools, such as forging, hot rolling and cold drawing. The rake angle of the tool (γ0) is about 10 degrees while the casting superalloy is about 0 degrees. The cutter’s back angle (a) = 10 ~15. The cutter inclination angle (λs) is – 5 10 in rough machining and lambda s = O 3 in finish machining. The main deviation angle (κr) is 45 ~75. The arc radius (r) of the tool tip is 0.5-2 mm, which is large in rough machining.

  •  Cutting Parameters and Conditions

The choice of cutting amount is basically the same as stainless steel, the most important is the cutting speed. For carbide tools, cutting speed (Vc) =20 ~ 50m/min; Feed quantity (f) should be small, generally f=0.1 ~ 0.5mm/r, the large value should be taken for coarse turning, the small value should be taken for fine turning. Backdraft (ap) should not be too small. For coarse turning, ap=2 ~ 4mm, and for fine turning, ap=0.2 ~ 0.5mm.Vc=5 ~ 10m/min for high temperature alloy machining with HSS endmill; Fn =0.05 ~ 0.12mm/r, ap+1 ~ 3mm.The carbide face milling cutter is Vc=20 ~ 45m/min. Fn =0.05 ~ 0.1mm/r, ap=1 ~ 4mm.

What are high temp alloys?

High temp alloy is the alloy based on the element of Fe, Ni and Co, a kind of metal material that can work for a long time under the action of high temperature above 600℃ and certain stress; It has good high-temperature strength, oxidation resistance, corrosion resistance, fatigue performance, fracture toughness and other comprehensive properties. High-temperature alloy is single Austenite structure and has good stability and reliability at various temperatures. Based on the above performance characteristics and the high content alloy, also known as “superalloy”, widely used in aviation, aerospace, petroleum, chemical, an important material for ships.

Classification of high temp alloys

Superalloy materials can be classified according to the following three ways: matrix element type, alloy strengthening type, material forming mode.

According to the matrix element, it is divided into Fe-based, Ni-based, Co-based superalloys. The service temperature of Fe-base superalloy can only reach 750~780℃ generally. For the heat-resistant parts used at a higher temperature, nickel-based and refractory metal-based alloys are adopted. Ni-based high temp alloy occupies a special important position in the whole superalloy field. It is widely used in the manufacture of aviation jet engines and the hottest end parts of various industrial gas turbines.

 

By matrix element type

  • Fe-Ni-Cr/ Fe-Cr-Mn high temp alloy

Iron-based superalloy can also be called heat-resistant alloy steel, that adding a small amount of Ni Cr and other alloy elements on the basis of Fe. Heat-resisting alloy steel can be divided into Martensite, Austenite, Pearlite and Ferrite heat-resisting steel according to its normalizing requirements.

  • Nickel-based high temp alloy

The nickel-based superalloy contains 50% or more nickel, and the solid solution and aging treatment can greatly increase the creep resistance and compressive and yield strength. At present, the application range of nickel-based superalloy is far more than that of iron base and cobalt based superalloy. The turbine blades and combustion Chambers of many turbine engines and even turbochargers are made of nickel-based alloys.

  • Co-based high temp alloy

A cobalt-based superalloy is about 60% cobalt-based alloy, and the addition of Cr, Ni and other elements improves its heat resistance. Although this kind of superalloy has better heat resistance, the cobalt production ratio is less, so it is difficult to process. It is usually used for parts under high-temperature conditions (600 ~ 1 000℃) and high temperature under extreme complex stress for a long time, such as the working blade of aero engine, turbine disc, hot end parts of the combustor and aero engine. In order to obtain better heat resistance, elements such as W, Mo, Ti, Al and Co should be added in preparation under general conditions to ensure their superior thermal and fatigue resistance.

 

By alloy reinforced type

According to the type of alloy strengthening, superalloy can be divided into solid solution strengthening superalloy and aging precipitation strengthening the alloy.

  • Solid solution enhanced superalloy

Solid solution enhanced superalloy means that some alloy elements are added to iron, nickel or cobalt-based superalloy to form single-phase austenite structure. Solute atoms distort the matrix lattice of the solid solution, increasing the slip resistance in the solid solution and strengthening it. Some solute atoms can reduce the delamination energy of the alloy system and increase the dislocations’ decomposition tendency, leading to the difficulty of cross slip.

  • Aging precipitation strengthened superalloy

The so-called aging precipitation strengthening is the alloy workpiece after solid solution treatment, cold plastic deformation, in higher temperature or room temperature to maintain its performance of a heat-treatment process. For example, Inconel 718 alloy has a maximum yield strength of 1 000 MPa at 650℃, and the alloy can be made at 950℃.

 

By material forming method

According to the material forming method, it is divided into casting superalloy (including common casting alloy, single crystal alloy, directional alloy, etc.), deformed superalloy, powder metallurgy superalloy (including common powder metallurgy and oxide dispersion strengthened superalloy).

 

High temp alloy has been widely used in aerospace and energy fields due to its excellent comprehensive performance and has become an irreplaceable key material for hot end components of aero engine, even its consumption accounts for 40%~60% of the total amount of engines. Take Inconel 718 alloy as an example, it is the most widely used brand mainly used in the bolts, compressors, wheels and oil spinner of turbo-shaft engines as the main parts. In addition, it is also used in casing, ring, afterburner and nozzle. Superheater and resuperheater use high-temperature alloy tubes with good creep resistance and excellent corrosion resistance in the ultra-supercritical power boiler with high parameters for coal electricity. Turbine blades and guide blades for gas plants, steam generators for heat pipes for nuclear power, etc.