Cold rolling refers to a material processing method in which the material is forged at normal temperature to make the thickness of the material gradually reduce. The raw material of cold rolling is generally steel coil after heat treatment of[SCALE STEEL] hot rolling. In the process of cold rolling, the metastable austenite structure will undergo strain-induced martensitic transformation, which makes the strength and hardness of the steel increase, and the plasticity decrease, resulting in obvious work hardening.
With the increase of forging passes, the total deformation rate of forging increases, the work hardening effect becomes more and more obvious, and the material becomes more and more hard. Under the conventional heat treatment, the strength and hardness of the nickel-based superalloy are lower, and the plasticity is better, which is [SCALE STEEL]good for forging. If the superalloy is cold-rolled directly without heat treatment, the cost of material production can be greatly reduced. The strength of the heat treated and hot rolled superalloys was analyzed, the test rolling process parameters were determined, and the mechanical properties of the test rolled products were compared.
Feasibility analysis of direct cold rolling of superalloy without heat treatment
1.1 Mechanical property analysis
Samples of Hastelloy alloy in hot rolled state and hot rolled state were taken in production site, and the mechanical properties were tested and the results were compared. Comparing the mechanical properties of the hot-rolled and hot-rolled nickel-based alloys, it can be seen that the average yield strength of the hot-rolled alloys [SCALE STEEL]is 80.9 MPa higher, the average tensile strength is 40.7 MPa higher and the elongation is 5.7% lower than that of the hot-rolled alloys.
From the point of view of mechanical properties, the strength of hot rolled nickel-based alloy plate has little difference before and after heat treatment, the hardening process of hot rolled material without heat treatment is a little faster [SCALE STEEL]than that of heat treatment, but it is not obvious, and the load of cold rolling equipment has little change.
Metallographic microstructure analysis The hot rolled and hot rolled nickel-based alloys were sampled, polished and corroded with HCl-FeCl3 solution. It can be seen from the figure that the superalloy grains have completely recovered to [SCALE STEEL]recrystallization after heat treatment. Partial recovery also occurred in untreated superalloys.
Hot rolled sheet technology of nickel-based alloy Hastelloy -1. PNG
The dynamic grain recovery and dynamic recrystallization of Hastelloy alloys occur during hot rolling process, which causes the work [SCALE STEEL]hardening to be released continuously.
After hot rolling, because the steel coil still has a high temperature and lasts for a certain period of time in the high temperature state, grain recovery and recrystallization will occur in the material in this state, and the elongated grain will nucleate into equiaxed grain, and part of work hardening can be eliminated by [SCALE STEEL]eliminating the microstructure and residual stress formed by the elongated grain. After hot rolling and air cooling, strip steel has similar characteristics to that after heat treatment.
Hot rolled sheet technology of nickel-based alloy Hastelloy -2. PNG
Based on the mechanical properties, work hardening and microstructure, it is considered that the current field Ni-base alloy [SCALE STEEL]Hastelloy superalloy can be cold-rolled directly without heat treatment.
Cold rolling test for heat treatment of nickel-based alloy high temperature alloy for cold rolling, cold rolling mill roll system, the rigidity of twenty more roller base mill rolling mill, the forging process by adjusting the supporting roller crown and a middle roller axial control plate shape, putting-in-service proactively ACG system control the thickness of the material, appropriate to increase the flow of forging[SCALE STEEL] lubricants at the same time, To improve the cooling effect of the material in the forging process.
Fearing **** passes, 6500 kN pressure, 300 kN higher than the pressure of ordinary heat treatment material, but the deformation rate is 2% lower than the ordinary heat treatment material, the subsequent passes, forging pressure is higher than the ordinary heat treatment material, but the deformation rate is low, the same forging total deformation rate, under the condition of the forging force is [SCALE STEEL]not greatly improved, The coil forged directly without heat treatment has one more forging pass than that of the heat-treated coil, which indicates that the deformation resistance of the hot rolled material without heat treatment is greater.
Hot rolled sheet technology of nickel-based alloy Hastelloy -3. PNG
The two cold-rolled materials were then treated by solution heat treatment at temperatures ranging from 1 050 ℃ to 1 150 ℃. [SCALE STEEL]The purpose of solid solution heat treatment is to dissolve the precipitated carbide into austenite again and restore the cold rolled strip structure to recrystallization.
Hot rolled sheet technology of nickel-based alloy Hastelloy alloy -4. PNG
The elongation, yield strength and tensile strength of the cold rolled products in the hot rolled and hot rolled heat treatment state [SCALE STEEL]are all up to the standard, but the elongation and strength of the cold rolled products in the hot rolled state are slightly lower and slightly higher.
After cold rolling and solid solution treatment, the elongated fibrous structures in cold rolling process are nucleated and[SCALE STEEL] recrystallized, and the grains are completely recovered. However, the grains of hot rolling untreated materials are finer.
Hot rolled sheet technology of nickel-based alloy Hastelloy alloy -5. PNG
Deposition process of the two solid solution and precipitation process is the same, but not direct cold rolling, heat treatment conditions hot rolling state of isometric into rectangular fibrous tissue, part of the deformation work at the same time in the form of lattice distortion and residual stress are preserved, form the recrystallization driving force, so the hot rolling without heat treatment after cold rolled steel coil easier to solid solution heat treatment; On the other hand, the grain of hot rolled steel coil will grow up further during solution heat treatment. Therefore, hot rolled materials without heat treatment are more likely to occur in the solution heat treatment after cold rolling, and the second is that the grain is more refined after heat treatment.
1) Ni-base alloy hot-rolled unheat-treated steel coil can be cold-rolled directly, but the forging resistance is larger than that of hot-treated material.
2) After cold rolling, the grain of untreated hot rolled nickel-based alloy coils can be completely recovered by solution heat treatment, and the grain size is relatively fine.
Under the same conditions, the silicon consumption and lime consumption are almost the same, which can be used as a substitute for the steel and chromium scrap.
3) Red mud ball. The use of red clay balls in AOD furnace is essentially the same as that in electric furnace. Both of them use Si elements in pig iron and ferrochrome to reduce valuable metals such as Fe, Cr and Ni. At present, the benefit estimated by AOD small batch test is 1 000 yuan /t. If the furnace entry condition can be optimized and the usage amount can be increased under the condition of excess temperature in the smelting process, the benefit will be further expanded.
4) High nickel steel. The experimental results and theoretical calculation of using high nickel steel in AOD furnace have a certain influence on silicon consumption and lime consumption. When 3 tons of high nickel steel is used in each furnace, the silicon consumption increases by 0.2 kg/t and the lime consumption increases by 1.0 kg/t, and the total impact cost is 377 yuan/furnace. The profit is better when the difference between scrap steel and slag steel is converted.
5) high chromium steel. It can completely replace the use of chromium scrap steel, has no obvious effect on the index, and the benefit is significant.
Hard alloy is a kind of or several refractory carbide (tungsten carbide, titanium carbide, etc.) powder as the main component, adding as an adhesive metal powder (cobalt, nickel, etc.), by powder metallurgy method and made of alloy. It is mainly used in the manufacture of high-speed cutting tools and hard and tough material cutting tools, as well as the production of cold work die, measuring tools and high [SCALE STEEL]wear-resistant parts that are not affected by impact and vibration. The hardness, wear resistance and red hardness of high cemented carbides at room temperature hardness up to 86 ~ 93HRA, equivalent to 69 ~ 81HRC. It can maintain high hardness at 900 ~ 1000℃ and has excellent wear resistance. Compared with high speed tool steels, the cutting speed can be 4 ~ 7 times higher, the life can be 5 ~ 80 times longer, and the hardness can be cut up to 50HRC hard materials.
When manufacturing cemented carbide, the raw material powder particle size is between 1 to 2 microns, and the purity is very high. Raw materials according to the provisions of the composition of the proportion of the ingredients, add alcohol or other media in the wet ball mill wet grinding, so that they are fully mixed, crushed, after drying and screening to add wax or glue and other forming agents, and then [SCALE STEEL]after drying, sieving the mixture. Then, the mixture is granulated, pressed, heated to close to the melting point of the bonding metal (1300 ~ 1500℃), the hardening phase and the bonding metal will form eutectic alloy.
Cemented carbide is also long used in the production of cold drawing die, cold punching die, cold extrusion die, cold pier die and other cold [SCALE STEEL]die. Moulds made of cemented carbide can better withstand impact and have better impact toughness, fracture toughness, fatigue strength, bending strength and wear resistance. Usually, the cemented carbides used in the production of molds are medium and high cobalt and medium and coarse grain grades, such as YG15C, etc.
Cemented carbide has good corrosion resistance, oxidation resistance and high temperature resistance. Cutting tools made of [SCALE STEEL]cemented carbide usually have good resistance to corrosion caused by atmosphere, acid, alkali, etc., are not prone to oxidation, and can remain hard at temperatures of 900 to 1000 degrees.
The linear expansion coefficient of [SCALE STEEL]cemented carbide is very small, which leads to its stable shape and size during machining.
Based on Inconel718 alloy, GH4169 nickel-based superalloy was designed in China. GH4169 alloy properties **** The temperature range of GH4169 is -253 °C~650 °C. At this time, not only the strength and plasticity [SCALE STEEL]are very high, but also the yield strength and durability are very high. At the same time, the radiation resistance, corrosion resistance and welding performance are also very good. This makes this alloy since the launch of the beginning, by the attention of all walks of life, its current output can reach the total output of nickel-based high temperature alloy about 50%.
In the application of GH4169 alloy, the application of key components of aeroengine is the main driving force for the development[SCALE STEEL] of GH4169 alloy, and the alloy also ensures the stable operation of aeroengine.
An alloy with good properties must be inseparable from its chemical composition and structure, GH4169 alloy is no exception. Its chemical composition is shown in Table 1. The strengthening phase is mainly γ 'phase and γ "phase, which are Ni3(Al,Ti,Nb) and Ni3Nb phase respectively. GH4169 alloy generally contains [SCALE STEEL]more than a dozen chemical elements, which are located in different positions in the crystal structure of the alloy. Based on these elements, they can be divided into the following three categories:
The **** type of elements are solid solution strengthening elements, including nickel, iron, chromium, cobalt, tungsten and[SCALE STEEL] molybdenum from groups V, VI and VII, which are selected to form the austenite matrix (γ ').
The second type of elements are precipitation-strengthening elements, including niobium, aluminum, titanium, hafnium and[SCALE STEEL] molybdenum from groups III, V, VI, etc., which are distributed into the formation of γ "precipitate phase.
The third type of elements is interstitial elements, including boron, zirconium and carbon from groups II, III and IV, which tend [SCALE STEEL]to segregate at grain boundaries.
For 3D printing and laser cladding processes, the sphericity, oxygen content, fluidity and hollow sphere ratio of the powder have a decisive effect on the performance of the final molded parts. The spherical degree of GH4169 superalloy powder for 3D printing produced by Guanda Technology is more than 90%, the oxygen content can be kept within 100ppm, and the Hall flow rate is 15.6s, which [SCALE STEEL]can meet the requirements of 3D printing process.
GH4169 Powder Particle Size Distribution for 3D Printing
The microstructure of GH4169 alloy is particularly sensitive to the hot working process. The processor needs to master the phase precipitation and melting law in the alloy and the relationship between the[SCALE STEEL] microstructure and the process and the properties, so as to develop a feasible process, so as to produce parts that meet different strength levels and use requirements. The disk, ring, blade, shaft and shell parts of GH4169 are used in the next generation rocket engine components.
GH4169 nickel-based deformed superalloy
Chinese brand number: GH4169/GH169, GH169 (GH4169)
U.S. brand: INCONEL 718/UNS NO7718
French brand number: NC19FENB
The GH4169 alloy is a nickel-based superalloy precipitated by γ" phase with a body center square and γ" phase with a face center cubic. It has good comprehensive properties in the temperature range [SCALE STEEL]of -253 ~ 700℃, and the yield strength below 650℃ ranks first in the deformation superalloy, and has good fatigue resistance, radiation resistance, oxidation resistance, corrosion resistance, as well as good processing performance, welding performance and long-term organizational stability. It can manufacture various complex shapes of parts. It is widely used in aerospace, nuclear energy and petroleum industries in the above temperature range.
Another characteristic of the alloy is that the alloy structure is particularly sensitive to the hot working process, grasp the alloy phase precipitation and dissolution law and the relationship between the structure and process, performance, can be used for different requirements to develop a reasonable and feasible process rules, can be obtained to meet the different strength levels and use [SCALE STEEL]requirements of various parts. The products we supply are forgings, forging bars, rolling bars, cold rolling bars, round cakes, ring pieces, plates, belts, wires, pipes and so on. It can be made into disk, ring, blade, shaft, fastener, elastic element, plate structure, casing and other parts and components for long-term use in aviation.
Material grade GH4169(GH169)
1.2 GH4169 was investigated similar brand Inconel 718 (USA), NC19FeNb (France)
Technical standard for 1.3GH4169 material
The chemical composition of the alloy can be classified into three categories: standard composition, high quality composition, and high purity composition, as shown in Table 1-1. High quality components on the basis of standard components to reduce the amount of niobium carbide, reduce the number of fatigue sources and increase the number of strengthening phase, improve the fatigue [SCALE STEEL]resistance and material strength. At the same time reduce harmful impurities and gas content. High purity components are based on high quality standards to reduce the content of sulfur and harmful impurities, improve the purity and comprehensive properties of materials.
For the GH4169 alloy used in nuclear energy, the boron content shall be controlled (other elements shall remain[SCALE STEEL] the same), and the specific content shall be determined by the supply and demand parties through negotiation. When ω (B) ≤0.002%, to distinguish with the aerospace industry GH4169 alloy, alloy grade for GH4169A.
4Cr3Mo2NiVNB steel code name is HD steel, is a kind of air-cooled hardening martensitic hot work die steel, is based on Sweden Udholm QRO-80 steel, by the Huazhong University of Science and Technology and other units[SCALE STEEL] independently developed new hot work die steel.
C 0.35～0.45 Cr 2.50～3.00
Si ≤0.35 Mo 1.80～2.20
Mn ≤0.40 Ni 0.80～1.20
P ≤0.030 V 1.00～1.40
S ≤0.030 Nb 0.10～0.25
AC1 =789℃, AC3 =910℃, MS =363℃
➣ HD Steel Forging Process Specification
ITEMS STEEL INGOT BILLET
HEATING TEM℃ 1140～1180 1120～1160
FORGING TEM(BEGINNING)℃ 1080～1140 1060～1120
FORGING TEM(END)℃ ≥900 ≥850
COOLING METHOD[SCALE STEEL] SAND OR PIT SLOW COOLING SAND OR PIT SLOW COOLING
Preliminary Heat Treatment
Isothermal annealing of forging material: < 500℃ into furnace with furnace temperature rise, heating temperature 830 ~ 850℃, holding time (H) 1+1min/mm, isothermal temperature 730±10℃, holding time (H) 2+1min/mm, with furnace [SCALE STEEL]cold to < 500℃ air cooling (HB≤250).
Quenching temperature is 1130±10℃, oil cold.
➣ The Relationship Between Quenching Temperature And Hardness And Grain Size Of Hd Steel
QUCHENING TEM/℃ HARDNESSHRC GRAIN SIZE/CLASS
1050 50.5 --
1100 53.5 11
1130 53.5 10
1160 56.0 8～9
1180 56.0 7～8
1200 56.5 7～8
➣ HD Stee’s Hardness Levels on Different Tempered Tem:
Tempered Tem/℃ HRC
HD Steel 3Cr2W8VSteel
300 52.5 51.0
400 52.0 51.0
500 52.5 51.4
530 53.5 52.3
560 54.0 51.5
590 53.8 51.8
620[SCALE STEEL] 51.2 50.0
650 47.0 46.0
700 41.0 34.0
Mechanical Properties（Comparing with 3Cr2W8V Steel）
➣ HD Steel’s Mechanical Property under Different Room Tem:
Heat Treatments 1130℃ Quenching
650℃ Tempering 1130℃ Quenching
HD 3Cr2W8V HD 3Cr2W8V
σ0.2/MPa 1633 1463 1165 952
ψ（%） 32.4 41.8 45.7 41.9
αk/(J/cm2) 38.8 -- 48.8 --
➣ HD Steel’s Mechanical Property under Different Tem:
Test Tem 650℃ 700℃
HD 3Cr2W8V HD 3Cr2W8V
σ0.2/MPa[SCALE STEEL] 536.9 414 405.3 235
ψ（%） 66.1 49.1 69.3 85.4
αk/(J/cm2) 56/54 -- 75/40 62/38
Note: The denominator in αk value is hardness value (HRC).
On the basis of 4Cr3Mo3V steel, the toughness and thermal stability of 4Cr3Mo2NiVNb (HD) steel at room temperature and high temperature were improved by reducing the content of Mo and V and adding[SCALE STEEL] the mass fraction of 1%Ni and 0.15%Nb. The hardness of 4Cr3Mo3V steel at 700℃ could still maintain 40HRC. Under the same conditions of hardness, HD steel has 50% higher fracture toughness than 3Cr2W8V steel, 70% higher tensile strength at 700℃, 1 times higher cold and hot fatigue resistance and 50% higher hot wear resistance, respectively.
HD steel comprehensive performance is good, suitable for making heating temperature about 700 ℃, using strict hot-work mold, such as ferrous and non-ferrous materials of hot extrusion die, such as hot fine[SCALE STEEL] forging die, in the steel tube hot extrusion convex die, the bottom of the copper alloy tube extrusion die and punch needle, hot extrusion convex die and concave die bearing ring, valve end of extrusion die and mold USES, The service life of 3Cr2W8V steel is significantly improved.
34CrNiMo6 is German standard low alloy high strength[SCALE STEEL] steel, German projects are more used, the same steel number in China is 34Cr2Ni2Mo.
CHINA GB/T 3077-2015
JB/T 6396-2006 34Cr2Ni2Mo
GERMANY DIN EN 10083-3:2007[SCALE STEEL]
DIN 17200:1987 34CrNiMo6
MATERIAL 34Cr2Ni2Mo 34CrNiMo6
C 0.30~0.38 0.30~0.38
Si 0.17~0.37 ≤0.40
Mn 0.50~0.80 0.50~0.80
P ≤0.030[SCALE STEEL] ≤0.025
S ≤0.030 ≤0.035
Cr 1.30~1.70 1.30~1.70
Ni 1.30~1.70 1.30~1.70
Mo 0.15~0.30 0.15~0.30
Mechanical Property（GB/T 3077-2015）
Sample Size（mm） Ø25
Heat Treatment（℃） Quenched(Oil Cooling) 850
Tempered(Water,Oil Cooling) 540
Mechanical Property TSMPa[SCALE STEEL] ≥1080
HardnessHBW Annealed or Tempered in High Temperature ≤269
34CrNiMo6 is similar to 42CrMo in performance and has high strength and good toughness. It is used to manufacture important structural [SCALE STEEL]parts for high load work, such as wind turbine spindles, high-speed train axles, torsion shafts of armored vehicles, crankshafts and connecting rods for heavy diesel engines, and gears for other heavy duty parts.
20Cr1Mo1VNbTiB China's self-developed low alloy high strength steel, also [SCALE STEEL]known as Zhengqi No.1 steel.
GB/T 20410-2006 "high temperature bolts for turbine steel"
DL/T 439-2018 "Technical guidelines for high-temperature fasteners in thermal power plants"
DL/T 715-2015 "Guidelines for Selection [SCALE STEEL]of Metal Materials in Thermal Power Plants"
Chemical Composition（%）（GB/T 20410-2006）
C 0.17~0.23 Cr 0.90~1.30
Si 0.40~0.60 Mo 0.75~1.00
Mn 0.40~0.65 V 0.50~0.70
P ≤0.025 Nb 0.11~0.22
S ≤0.025 Ti 0.05~0.14
Ni ≤0.30[SCALE STEEL] B 0.001~0.004
1020~1040℃ Oil Cooling，700~720℃ Tempering for 6h and then air cooling.
Mechanical Property（GB/T 20410-2006）
Sample Size（mm） Ø25
Heat Treatment Quenched（Oil,Water Cooling/℃ 1020~1040
Tempered（Air Cooling）/℃ 690~730
Mechanical Property TS Rm/MPa[SCALE STEEL] ≥785
YS Rp0.2/MPa ≥670
Hardness HBW 10/3000 255~305
1.Good high temperature performance, high durable strength and plasticity, good anti-relaxation performance, small thermal brittle tendency, low notch sensitivity.
2.Heat treatment is more [SCALE STEEL]sensitive, such as improper thermal processing control, easy to appear naked eye coarse grain, so there are strict grain size acceptance standards for different design grades.
The highest operating temperature is 570℃.
20Cr1Mo1VNbTiB bainite [SCALE STEEL]heat resistant steel has excellent comprehensive properties and is mainly used as high temperature bolts in thermal power plants below 570℃. It is widely used in large and medium-sized units in thermal power plants.
SCM440 is a kind of steel commonly used in the production of high strength fasteners. The product has the advantages of stable composition, low harmful elements, high purity of steel, small decarburization layer, [SCALE STEEL]few surface defects and so on. It is easy to make spidizing annealing, low cold heading cracking rate, stable heat treatment quality and uniform hardness, and is widely used in engine, mold and other industries.
Material Name: Alloy Structural Steel
Brand number: SCM440(Japanese brand, see standard JIS G4053-2008
It belongs to medium hardenability steel. After heat treatment, it has good strength, good comprehensive [SCALE STEEL]mechanical properties, good technability and high yield of finished products.The highest operating temperature is 427℃.Can be used as steam turbine fasteners.
Characteristics and application
1.Good quenching [SCALE STEEL]property, can be deep quenching, rather than the market anti-saw lock surface quenching
2.Less tendency to temper brittleness
3.Good high temperature processing, beautiful after processing
5.The absorption performance of the impact is good, the hammer hit it will have a sense of rebound, unable to carry out violent destruction advantages:
(1) Good processability
(2). Good shock [SCALE STEEL]absorption performance
(3). Welding is easy
C: 0.38 to 0.43
Si: 0.15 to 0.35
Mn: 0.60 to 0.85
P: 0.03 or less
S: 0.03 or less
Cu: 0.30 or less
Ni: 0.25 or less
Cr: 0.90 to 1.20
Mo: 0.15 to 0.30
Ni: 0.25 or less
Cu: 0.30 or less
Mechanical Properties of SCM440:
Tensile strength [SCALE STEEL]σb (MPa) : ≥1080(110) Yield strength σs (MPa) : ≥930(95)
Elongation Δ5 (%) : ≥12
Section shrinkage ψ(%) : ≥45
Impact work AKV (J) : ≥63
Impact toughness value α kV (J/ Cm&SUP 2;)A: 78 (8) or
Hardness: 217 HB or less
SCM420 alloy structure steel has high hardenability, no tempering brittleness, good weldability, little tendency to form cold[SCALE STEEL] crack, good machinability and cold strain plasticity.
Corresponding to Domestic Grade Name: 20CrMo
Corresponding to Germany Grade Name: 25 crmo4 (1.7218)
Executive Standard:[SCALE STEEL] JIS G4053-2003
Features and Scope of Application:
SCM420 is generally used under the condition of quenching and tempering or carburizing. It is used to manufacture high-pressure pipes and various fasteners and advanced carburizing parts, such as gears and shafts, which work in non-corrosive media and medium with nitrogen and hydrogen mixture at [SCALE STEEL]working temperature below 250℃.
SCM420 Alloy Structural Steel
Chemical Composition (unit %) :
C: 0.18 ~ 0.23
Si: 0.15 ~ 0.35
Mn: 0.60 ~ 0.90
S: allowable residual content ≤0.030
P: allowable residual content ≤0.030
Cr: 0.90 ~ 1.20
Ni: allowable residual content ≤0.25
Cu: allowable residual content ≤0.30
Mo: 0.15 ~ 0.25
Mechanical Properties (Tempering and Tempering State) :
Tensile Strength σb (MPa) : ≥885(90)
Yield Strength σs (MPa) : ≥685(70)
Elongation Δ5 (%) : ≥12
Section [SCALE STEEL]Shrinkage ψ(%) : ≥50
Impact Work AKV (J) : ≥78
Impact Toughness Value α kV (J/ Cm&SUP 2;)A: 98 (10) or
Hardness: 197 hb or less
Heat Treatment Specification and Metallographic Structure:
Heat Treatment [SCALE STEEL]Specification: Quenching 880℃, water cooling, oil cooling;Tempering 500℃, water cooling, oil cooling.
Delivery Status: Delivered under heat treatment (normalizing, annealing or high temperature tempering) or without heat treatment. The delivery status shall be specified in the contract.
40CrNi2Mo, also known as 4340 steel, is a kind of low alloy ultra-high strength steel.Only steels with tensile strength greater than [SCALE STEEL]1400MPa and yield strength greater than 1200MPa at room temperature are termed "ultra-high strength steels".4340 steel is a typical ultra high strength steel, which is obtained by heat treatment.
CHINA GB/T 3077-2015 40CrNi2Mo，A50400
GB/T 34484.2-2018 40CrNi2Mo
GB/T 38809-2020 40CrNi2MoA
GB/T 5216-2014 40CrNi2MoH
USA ASTM A29-2005[SCALE STEEL]
ASTM A322-2007 4340，G43400
JAPAN JIS G4053-2003 SNCM439
GERMANY DIN EN 10263-4:2002 41NiCrMo7-3-2，1.6563
Grade A50400 4340 SNCM439 1.6563
C 0.38~0.43 0.38~0.43 0.36~0.43 0.38~0.44
Si 0.17~0.37 0.15~0.35 0.15~0.35 ≤0.30
Mn 0.60~0.80 0.60~0.80 0.60~0.90 0.60~0.90
P ≤0.030 ≤0.035 ≤0.030 ≤0.025
S ≤0.030 ≤0.040 ≤0.030 ≤0.025
Cr 0.70~0.90[SCALE STEEL] 0.70~0.90 0.60~1.00 0.70~0.90
Ni 1.65~2.00 1.65~2.00 1.60~2.00 1.65~2.00
Mo 0.20~0.30 0.20~0.30 0.15~0.30 0.15~0.30
Cu ≤0.30 ≤0.35 ≤0.30 ≤0.25
QUENCHED FIRST TIME NORMALIZED AT 890℃，OIL QUENCHING
SECOND TIME 850℃，OIL QUENCHING
TEMPERED(AIR COOLING) 560~580℃ 220℃ TWICE OIL QUENCHING
TENSILE STRENGTH MPa ≥1050 ≥1790
YIELD STRENGTH MPa ≥980 ≥1500
ELONGATION % ≥12 ≥6
REDUCTION OF AREA %[SCALE STEEL] ≥45 ≥25
IMPACT TESTJ ≥48 --
TEMPERED HARDNESS ≤269HBW
4340 steel after heat treatment, not only obtain ultra-high strength, but also have good plastic toughness, excellent fatigue performance, fracture toughness and stress corrosion resistance, good comprehensive mechanical [SCALE STEEL]properties, so that it is often used in the industry as a tempering steel to manufacture bearings, gears and crankshafts, and in the aircraft structure has been widely used.Such as aircraft landing gear, helicopter rotor shaft and turbojet turbine shaft and other moving parts.
9Cr18Mo, also known as the American standard 440C martensitic stainless steel, is added to Mo on the basis of 9Cr18 steel, steel composition [SCALE STEEL]is characterized by high carbon and high chromium.
CHINA GB/T 1220-1992 9Cr18Mo
GB/T 1220-2007 102Cr17Mo，S45990
USA ASTM A276-2006 440C，S44004
JAPAN JIS G4303:2005[SCALE STEEL] SUS 440C
GERMANY DIN EN 10088-1:2005 X105CrMo17，1.4125
GRADE 9Cr18Mo 440C SUS 440C 1.4125
C 0.95~1.10 0.95~1.20 0.95~1.20 0.95~1.20
Si ≤0.80 ≤1.00 ≤1.00 ≤1.00
Mn ≤0.80 ≤1.00 ≤1.00 ≤1.00
P ≤0.035 ≤0.040 ≤0.040 ≤0.040
S ≤0.030 ≤0.030 ≤0.030 ≤0.030
Cr 16.0~18.0 16.0~18.0 16.0~18.0 16.0~18.0
Ni （≤0.60）[SCALE STEEL] -- （≤0.60） --
Mo 0.40~0.70 ≤0.75 (≤0.75) 0.40~0.80
➣ Annealing: Heating to 850~870℃, holding 4~6h, 30℃/h cooling to 600℃, air cooling, hardness ≤255HBS;
➣ recrystallization annealing: heating to 730~750℃, air cooling;
➣ Quenching: Heating to 1050~1100℃, oil cooling;
➣ Tempering: Heating to 150~160℃, [SCALE STEEL]holding for 2~5h, air cooling, hardness ≥58HRC.
The quenching has high hardness and high wear resistance;
② It has excellent corrosion resistance in the atmosphere, water and some acid and salt aqueous solutions;
(3) Good high temperature [SCALE STEEL]dimensional stability, the use of temperature does not exceed 250℃;
(4) tempering: heating to 150~160℃, heat preservation 2~5h, air cooling, hardness ≥58HRC.
9Cr18Mo is suitable for the manufacture of bearings, bushings, and other parts or die parts that are both wear-resistant and [SCALE STEEL]corrosion-resistant in corrosive environment and non-lubricating strong oxidation atmosphere.