Product introduction

GB 20Cr alloy Steel is a high quality Quenched and Tempered Alloy Structural steel, It belong to the high quality low carbon,Low alloy chromium, molybdenum, nickel case hardening steel. Oil Quenched & Tempered Hardness is 28-34 HRc. GB 20Cr steel Annealing delivery hardenss less than 250HB.20Cr With a lower carbon content range, So GB 20Cr alloy steel have good weldability.

GB 20Cr alloy steel equivalent specification: ASTM A29/A29M, DIN EN 10083/3, JIS G4053 and GB/T 3077. GB 20Cr equivalent steel round bar and flat bars can be cut to your required sizes. China steel 20Cr hot rolled and forged steel bar can also be supplied, providing a high quality tool steel precision ground tool steel bar to your required tolerances. GB 20Cr steel equivalent material bars are supplied in round, square and flat shapes.
GB 20Cr alloy Steel is a high quality Quenched and Tempered Alloy Structural steel. It belongs to the high quality low carbon,Low alloy chromium, molybdenum, nickel case hardening steel. Oil Quenched & Tempered GB 20Cr Steel Hardness is 28-34 HRc. GB 20Cr steel Annealing delivery hardenss less than 250HB. With a lower carbon content range, GB 20Cr alloy steel equivalents have good weldability.
GB 20Cr forged steel bar and hot rolled steel bar is widely used for a variety of applications in the used in the automotive and engineering industries for toolholders and other such components. Mostly used in the manufacture of the demand is higher, intensity of heart surface wear, under section under 30 mm or small carburized parts of complex shape and load (oil quenching), such as: transmission gear, gear shaft, CAM, worm, piston pin, claw clutch, etc

Compared with 15Cr steel, it has higher strength and hardenability. The critical hardening diameter in oil reaches 4-22mm, and the critical hardening diameter in water reaches 11-40mm, but its toughness is poor. There is a tendency for grains to grow, and direct quenching at cooling has a greater impact on impact toughness. Therefore, after carburizing, secondary quenching is required to improve the toughness of the part core without temper brittleness; steel has high cold strain plasticity and can be drawn in cold conditions. ; Machinability is good under high temperature normalizing or quenching and tempering state, but poor after annealing; 20Cr is pearlite, with good weldability, generally does not need heat treatment after welding, but parts with a thickness greater than 15mm need to be preheated before welding When it reaches 100～150℃, tempering heat treatment is not required after welding.

Product parameters

Technical data

20Cr hot rolled steel sheet Chemical Composition

Mechanical properties
 

Equivalent Of 20Cr alloy Structure Steel

Heat treatment Related

• Annealing of 20Cr Alloy structural steel

Slowly heated to 850 ℃ and allow enough times, let the steel to be thoroughly heated, Then cool slowly in the furnace. The 20Cr alloy steel will get MAX 250 HB （Brinell hardness）.

• Hardening of GB Alloy structural steel 20Cr

First quenching heated slowly to 880°C, Then after adequate soaking at this temperature quench in oil or water. Temper as soon as tools reach room temperature. Second quenching heat to 780-820°C， then quenching in oil or water.

• Tempering of 20Cr Alloy structural steel

Heat to 20°C, then cool in water or oil.normal delivery hardness 179HB Min.

 

Applications

GB 20Cr steel is widely used for a variety of applications in the used in the automotive and engineering industries for toolholders and other such components. Mostly used in the manufacture of the demand is higher, intensity of heart surface wear, under section under 30 mm or small carburized parts of complex shape and load (oil quenching), such as: transmission gear, gear shaft, CAM, worm, piston pin, claw clutch, etc.; For the heat treatment deformation and high abrasion resistance parts, should be high frequency surface quenching after carburizing, such as modulus is less than 3 of the gear, shaft, spline shaft, etc. This steel can be used in the quenched and tempered state and used in the manufacture of large and medium under impact load in her work parts, this kind of steel also can be used as a low carbon martensite steel quenching, further increasing steel yield strength and tensile strength increased (about 1.5 ~ 1.7 times). Typical applications such as valve bodies, pumps and fittings, Shaft, the high load of wheel, bolts, double-headed bolts, gears, etc
 

Regular size and Tolerance

Steel round bar: Diameter Ø 5mm – 3000mm

Steel plate: Thickness 5mm – 3000mm x Width 100mm – 3500mm

Steel Hexagonal bar: Hex 5mm – 105mm

Others 20Cr have not specified size, pls contact our experienced sales team.
 

Processing

GB 20Cr alloy steel round bar and flat sections can be cut to your required sizes. 20Cr alloy steel ground bar can also be supplied, providing a high quality tool steel precision ground tool steel bar to your required tolerances. GB 20Cr steel is also available as Ground Flat Stock / Gauge Plate, in standard and nonstandard sizes.