China Supplier Baotou Steel Large Diameter Seamless Pipe - A335 P11 A369 FP12 A213T11 alloy steel pipe – Weichuan

27SiMn seamless steel pipe, i.e. 27 silicon manganese seamless steel pipe, is one of the materials of seamless steel pipe, and the carbon content is between 0.24-0.32%. SIMN is listed separately because the content of silicon manganese in the five elements (carbon C, silicon Si, manganese Mn, phosphorus P, sulfur s) is about 1.10-1.40%. 27SiMn seamless pipe is suitable for power plant, boiler plant, chemical industry, vehicle and ship accessories, etc.

27SiMn, hydraulic strut pipe. Unified digital code: a10272

Standard: GB / t17396-2018

This kind of steel has better properties than 30Mn2 steel, high hardenability, critical hardenability diameter of 8 ~ 22mm in water, good machinability, medium cold deformation plasticity and weldability; In addition, the toughness of steel does not decrease much during heat treatment, but it has quite high strength and wear resistance, especially when water quenching; However, this steel is sensitive to white spot, temper brittleness and overheating sensitivity during heat treatment.

This kind of steel is mainly used in the quenched and tempered state to manufacture hot stamping parts requiring high toughness and wear resistance; It can also be used under normalized or hot rolling supply, such as tractor track pin, etc.

Application of 27 SIMN seamless pipe and ordinary steel pipe

27SiMn seamless steel pipe

27SiMn seamless steel pipe

1. Seamless steel pipe for fluid: GB / t8163-2018

2. Seamless steel pipe for boiler: GB / t3087-2018

3. High pressure seamless pipe for boiler: GB / t5310-2018 (ST45.8 – type III)

4. High pressure seamless steel pipe for chemical fertilizer equipment: GB / t6479-2018

5. Seamless steel pipe for geological drilling: yb235-70

6. Seamless steel pipe for oil drilling: yb528-65

7. Seamless steel pipe for petroleum cracking: GB / t9948-2018

8. Special seamless pipe for petroleum drill collar: yb691-70

9. Seamless steel pipe for automobile axle shaft: GB / t3088-2018

10. Seamless steel pipe for ships: GB / t5312-2018

11. Cold drawn cold rolled precision seamless steel pipe: GB / t3639-2018

12. Seamless steel pipe for hydraulic prop: GB / t17396-2018

Mechanical properties of 27SiMn seamless steel pipe

Tensile strength σ b (MPa): ≥980

yield strength σ s (MPa): ≥835

Elongation δ 5/(%): ≥12

Reduction of area ψ/(%): ≥40

Impact absorption energy (impact value) (aku2 / J): ≥ 39

All seamless steel pipes shall be tested for mechanical properties. The testing methods of mechanical properties are mainly divided into two categories: tensile test and hardness test.

Tensile test is to make seamless steel pipe into a sample, pull the sample to fracture on the tensile testing machine, and then measure one or several mechanical properties. Usually, only tensile strength, yield strength, elongation after fracture and reduction of area are measured.

Hardness test is to slowly press a hard indenter into the sample surface according to the specified conditions, and then test the indentation depth or size, so as to determine the hardness of the material.

Good machinability, medium cold deformation plasticity and weldability; In addition, the toughness of steel does not decrease much during heat treatment, but it has quite high strength and wear resistance, especially when water quenching; However, this steel is sensitive to white spot, temper brittleness and overheating sensitivity during heat treatment.

Precautions for high magnification inspection of seamless steel pipe

Precautions for high magnification inspection of seamless steel pipe mainly include the following points:

1. Depth and extent of surface decarburization.

2. Length and depth of surface rolling defects, shrinkage cavity, central segregation of carbon and sulfur.

3. Distribution of ferrite and pearlite in seamless steel pipe.

4. Other microstructure defects, as well as grain size, seamless pipe surface roughness and inclusion content.