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4140 Alloy Structural Steel

ASTM 4140 Steel is a Alloy Structural Steel. AISI 4140  is a chromium molybdenum alloy steel, widely used in Oil and Gas industry and Large Machinery Strutural. Also used for  components like axles, shafts, bolts, gears and other applications. 4140 Steel Plate China Supplier and factory Otai Special Steel Supply ASTM 4140 steel in Round bar, Plate, Flat bar, Square, Forging Ring and others any shape. And provide cutting, sawing, milled, machining processing.

4140 Steel sheet equivalent standards:

4140 steel Mechanical Properties:

Tensile strength:655 MPa

Yield strength:415 MPa

Elongation at break (in 50 mm):25.70%

Poisson’s ratio:0.27-0.30

1.5217 alloy steel

1.5217 belongs to alloy steel, otai manufacture 1.5217 alloy steel. 1.5217 supplier.

1.5217 Steel equivalent standards:

1.5217 steel mechanical properties:

Yield strength [MPa]:410-450

Tensile strength[MPa]:550-750

Elongation A [%]:20

Reductionof area Z [%]:40

Hardness:< 220 HB

1.5217 alloy steel application

Tubular parts for the automotive, oil and gas, construction, general engineering and agricultural industry, such as bushes, hydraulic cylinders, hollow shafts, rings, hollow rolls for conveyors, nuts, gear wheels, shafts, axles, stuffing boxes, spindles, drill jigs, rolls etc.

3 steel grades suitable for making gear

Gear steel is the general name of steel used in gear manufacturing. Gear is one of the most widely used mechanical components, and is widely used in mechanical transmission. There are many types of gears, such as spur gear, chain gear, synchronous pulley, helical gear, internal gear, rack, straight bevel gear, arc bevel gear, zero bevel gear, staggered spiral gear, worm gear, etc.

Gear steel is a key material with high requirements for special alloy steel used in automobile, railway, ship and engineering machinery. Gear material needs strong bending fatigue strength and contact fatigue strength, and the tooth surface should have enough hardness and wear resistance, and the tooth core should have certain strength and toughness. Gears are usually made of forged steel, except for foundry plants with too large size (Dia > 400-600mm) or suitable for complex structures and shapes.
Carbon steel or alloy steel with carbon content of 0.15-0.6% is usually used in gear applications. The Microalloy Elements in gear steel can improve the toughness, impact resistance, wear resistance and adhesion of the material, and the mechanical properties of the material can also be improved by heat treatment or chemical heat treatment. Alloy gear steel usually does not include low carbon alloy steel, such as 15CrMo, 20Cr, etc. and medium carbon alloy steel: 40Cr, 42CrMo, 35CrMo, etc.

15CrMo
Carburizing surface quenching treatment is generally used to pay attention to the strength or toughness of parts or parts that need to bear a lot of friction, such as cylinder piston, spindle, gear, bolt, shaft, etc. It is used to make profile less than 30mm under high speed, medium load or heavy load, impact and friction of important parts; for example, crosshead of gear, ring gear and gear shaft.
In the automotive industry, the cross-section used is less than 30mm; important carburizing parts bear high speed or heavy load and impact; for example, gears, shaft gear rings, gear shafts, sliding bearing spindles, crossheads, claw clutches, worm, etc

25CrMo4
The alloy structural steel 25crmo4 (ASTM 4118) has high hardenability, no temper brittleness, good weldability, little cold crack tendency, good machinability and cold strain plasticity.
25CrMo4 gear steel is used in general conditions or under carburizing quenching conditions, which is used for manufacturing corrosive medium with working temperature lower than 250 ℃, high pressure pipe and various fasteners working with medium containing hydrogen nitrogen mixture, higher carburizing parts and automobile gears, various special wear-resistant parts, such as aircraft, shaft, high pressure pipe and various fasteners.

42CrMo4
42CrMo4 (ASTM 4140) is a medium carbon chromium molybdenum alloy steel. Chromium content provides good hardness permeability, molybdenum element provides hardness uniformity and high strength. The alloy well balances strength, toughness and wear resistance. It has the following advantages: stable composition, less harmful elements, high purity of steel, small decarbonization layer, less surface defects, etc., and easy to process under heat treatment conditions, with good ductility and high temperature stress resistance. This material is widely used in the production of high-strength steel fasteners, such as engine, mould, motor, gear, transmission parts, shaft, gear, arm, cold forging, screw products.

In addition, ASTM 4320, 4340, 8615, 8617, 8620, 8622, 9840 (https://otaialloysteel.com/products/alloy-steel/)and so on can also be used for gear purposes. As common alloy carburizing and bearing steel, they are mainly used as materials for automobile bearings, transmission shafts, gears, screws, tool parts and other impact resistant and wear-resistant parts. The surface after carburization has high hardness, wear resistance and contact fatigue strength, while the core still maintains good toughness and can bear high impact load.

46Mn7 alloy structural steel

46Mn7 is a kind of moderate strength alloy structural steel, as a carbon quenched and tempered steel, its strength, abrasion resistance and hardenability are high. After quenching and has good mechanical properties, machinability is still good.

46Mn7 equivalent steel grades:

46Mn7 Mechanical Properties:

Tensile strength σb (MPa): ≥885

Yield strength σs (MPa): ≥735

Elongation δ5 (%): ≥10

Impact energy Akv (J): ≥47

32NiCrMo14-5 Alloy steel

32NiCrMo14-5 has good corrosion resistance and high strength. It is often used as thin plate and has good welding performance.

32NiCrMo14-5  Equivalent Steel Grades:

32NiCrMo14-5 Mechanical property:

Yield Strength R_p0.2 (MPa):649

Tensile Strength R_m (MPa):814

Impact KV/Ku (J):13

Elongation A (%):32

Reduction Z (%):11

25Cr2MoV Alloy steel

25Cr2MoV steel has good intergranular corrosion resistance, excellent corrosion resistance and cold working stamping performance. It has strong corrosion resistance to oxidizing acid (such as nitric acid), alkali solution and most organic and inorganic acids.

Due to its proper hardenability, the microstructure of the alloy is homogeneous sorbite, bainite or very fine pearlite after proper metal heat treatment. Therefore, 25Cr2MoV has higher tensile strength and yield ratio, higher toughness and fatigue strength, and lower toughness and brittle transition temperature.
Generally, the steel material can be used in the state of quenching and tempering, and can also be used after normalizing and high temperature tempering.

25Cr2MoV  steel mechanical properties:

Tensile strength σ B (MPA): 1090
Yield strength σ s (MPA): 1042
Elongation δ 5 (%): 18
Reduction of area ψ (%): 63
Impact toughness value α Ku (J / cm2): 213
Hardness: 308HB

36CrNiMo4 alloy structural steel

36CrNiMo4 is an alloy structural steel. As a property of 36CrNiMo4 steel, density is closely related to the composition of 36CrNiMo4 steel.

36CrNiMo4 steel equivalent grade:

36CrNiMo4 mechanical properties:

Tensile strength σ B (MPA): ≥ 980 (100)
Yield strength σ s (MPA): ≥ 835 (85)
Elongation δ 5 (%): ≥ 12
Impact energy Akv (J): ≥ 78
Impact toughness value α kV (J / cm2): ≥ 98 (10)
Hardness: ≤ 269HB

18NiCrMo5 construction steel

18NiCrMo5 steel is a leading construction steel in circulation.
It is a type of steel supplied in the delivery condition “annealed”.

18NiCrMo5  equivalent steel grades:

Mechanical Properties:

Tensile Strength: ≥900

Yield Strength: ≥635

Elongation  (%): ≥10

Impact Value Kv (J): ≥35

Hardness (HB): ≥271

Thousand tons 30CrNiMo8 stocking

30CrNiMo8 steel is German DIN standard in Q+T (quenched and tempered steel), equivalent to 30cr2ni2mo in China.

30crnimo8 material has high yield strength, tensile strength and fatigue strength, and sufficient plasticity and toughness.

Generally, EAF and BOF are used for smelting, and secondary refining, electroslag remelting or vacuum treatment, vacuum induction furnace smelting or double vacuum smelting and appropriate heat treatment are adopted for those with high requirements.

The material 30CrNiMo8 is difficult to machine. 30CrNiMo8 to achieve hrb80 below is very difficult, generally do about hrb85 can.

 30crnimo8 equivalent grade

30crnimo8 steel properties

30CrNiMo8 steel belongs to DIN alloy structure tempered steel, which has high yield strength, tensile strength, and enough plasticity and toughness. The critical temperature of Ac3 in 30crnimo8 heat treatment is 800℃, and the quenching temperature is Ac3+(30 ~ 70)℃. After comprehensive consideration, the process was determined as follows: normalizing 880℃, holding heat for 5h; The quenching temperature is 840 ~ 860℃, and the holding time is 4 ~ 4.5h. Water quenching oil is used for quenching and tempering temperature is 570 ~ 620℃. The tempering time should not only ensure that the tissue transformation can be fully carried out through through burning, but also try to eliminate the residual stress.