Analysis of properties and chemical composition of 20CrMnTi cold-drawn seamless steel pipe

20CrMnTi steel is called gear steel, and many parts use 20CrMnTi.

20CrMnTi seamless steel pipe can be divided into three types: cold-drawn, hot-rolled and cold-rolled bright seamless steel pipe, with different requirements and different processes. However, some units use round steel to produce parts without considering the replacement of steel pipes. Replacing 20CrMnTi cold-drawn seamless steel pipe with 20CrMbTi round steel not only saves raw materials and labor hours, but also reduces costs and increases market competitiveness. 20CrMnTi and 30CrMnSiA cold-drawn seamless steel pipes are carburized steels with good performance, high hardenability, hard and wear-resistant surface and tough core after carburizing and quenching, high low-temperature impact toughness, medium weldability, and good machinability after normalizing. 20CrMnTi cold-drawn seamless steel pipe is usually low carbon steel with a carbon content of 0.17% - 0.24%. It is widely used in automobiles to manufacture transmission gears. It is medium hardenable carburized carbon steel, medium CrMnTi steel, with high hardenability. Under the condition of ensuring the hardenability, it has high strength and toughness, especially high low temperature impact toughness. 20CrMnTi surface carburized and hardened steel. Good machinability, small deformation in special processing, and good fatigue resistance. Purpose: for gears, shafts, Piston parts, etc. are used for various special parts of automobiles and airplanes

20CrMnTi standard: GB/T 3077-1988

Characteristics and scope of application of 20CrMnTi cold-drawn seamless steel pipe:

It is used to manufacture important parts with a section less than 30mm that bear high speed, medium or heavy load, impact and friction, such as gears, gear rings, gear shaft crossheads, etc.

Chemical composition of 20CrMnTi cold-drawn seamless steel pipe (points):

Carbon C: 0.17 ～ 0.23

Silicon Si: 0.17 ～ 0.37

Manganese Mn: 0.80 ～ 1.10

Sulfur S: allowable residual content ≤ 0.035

Phosphorus P: allowable residual content ≤ 0.035

Chromium Cr: 1.00 ～ 1.3020CrMnTi cold-drawn seamless steel pipe

Nickel Ni: allowable residual content ≤ 0.030

Copper Cu: allowable residual content ≤ 0.030

Titanium Ti: 0.04-0.10

Mechanical properties of 20CrMnTi cold-drawn seamless steel pipe:

tensile strength σ b (MPa)：≥1080(110)

yield strength σ s (MPa)：≥835(85)

elongation δ 5 (％)：≥10

Reduction of area ψ (％)：≥45

Impact energy Akv (J): ≥ 55

Impact toughness value α kv (J/cm2)：≥69(7)

Hardness: ≤ 217HB

Sample size: sample blank size is 15mm

Heat treatment specification and metallographic structure of 20CrMnTi cold-drawn seamless steel pipe:

Heat treatment specification: quenching: 880 ℃ for the first time, 870 ℃ for the second time, oil cooling; Temper 200 ℃, water cooling and air cooling.

20crmnti steel pipe is a medium hardenability steel, which has good hardenability due to the multiple alloying of Cr, Mn and Ti. The critical diameter of oil quenching is about 40mm; After carburizing and quenching, it has high wear resistance and high toughness, especially low temperature impact toughness; The steel has good carburizing process, small grain growth trend, direct quenching and small deformation. 20CrMnTi steel can basically be used to produce heavy duty carburized parts with section less than 30 ℃, and can withstand high speed, medium load or heavy load, impact and friction, such as gears, gear shafts, gear rings, cross rings, claw clutches, worms, etc.

The chemical composition of 20crmnti steel pipe includes carbon C, silicon Si, manganese Mn, sulfur S, phosphorus P and chromium Cr. 20crmnti steel pipe production process: carbon steel, finish rolling, non-oxidation bright heat treatment (NBK state), nondestructive testing, steel pipe inner wall is brushed with special equipment and washed under high pressure, anti-rust oil on the steel pipe is treated for rust prevention, and the covers at both ends are treated for dust prevention. 20crmnti steel pipe features: the internal and external walls of the steel pipe have high precision and high finish, the steel pipe has no oxide layer after heat treatment, the internal wall has high cleanliness, the steel pipe bears high pressure, cold bending does not deform, and the expansion and flattening do not have cracks.

Shandong Haihui Steel Co., Ltd. produces cold rolled precision bright seamless steel pipes of GB 10 #, GB20 #, GB35 #, GB45 #, 20Cr, 40Cr, 16Mn, 35CrMo, 20CrMoTi, Gcr15.