1. Chemical Composition of
Seamless Steel Pipes: The chemical composition of steel is one of the most important factors affecting the performance of seamless steel pipes, and it is also the main basis for formulating rolling process parameters and heat treatment process parameters for steel pipes.
(1) Alloying Elements: Intentionally added, depending on the application;
(2) Residual Elements: Introduced during steelmaking, appropriately controlled;
(3) Harmful Elements: Strictly controlled (As, Sn, Sb, Bi, Pb), gases (N, H, O); Ladle refining or electroslag remelting: improve the uniformity of chemical composition and purity of steel, reduce non-metallic inclusions in the billet, and improve their distribution morphology.
2. Geometric Dimensional Accuracy and Shape of Seamless Steel Pipes
(1) Outer Diameter Accuracy of Seamless Steel Pipes: Depends on the sizing (reduction) method, equipment operation, process system, etc. (1) Allowable deviation of outer diameter δ = (D-Di)/Di ×100% D: or minimum outer diameter mm;
(2) Nominal outer diameter mm;
(3) Wall thickness accuracy of seamless steel pipe: related to the heating quality of the billet, the process design parameters and adjustment parameters of each deformation process, tool quality and its lubrication quality, etc.; Allowable deviation of wall thickness of seamless steel pipe: ρ = (S-Si)/Si ×100% S: minimum wall thickness on the cross section; Si: nominal wall thickness mm;
(4) Ellipticity of seamless steel pipe: indicates the degree of non-roundness of seamless steel pipe;
(5) Length of seamless steel pipe: normal length, fixed (multiple) length, allowable length deviation;
(6) Curvature of seamless steel pipe: indicates the curvature of the steel pipe: curvature per meter of seamless steel pipe length, curvature of the entire length of the steel pipe.
(7) Bevel angle of seamless steel pipe end face: indicates the degree of inclination between the end face of the seamless steel pipe and the cross section of the seamless steel pipe;
(8) Bevel angle and blunt edge of seamless steel pipe end face.
Threeway Steel is known as a professional supplier engaged in manufacturing and distributing a wide range of steel pipe, and our headquarter located the central part of China – Hunan and six associated factories throughout China.
Threeway Steel is known as a professional supplier engaged in designing, manufacturing and distribution of a wide range of steel products with the headquarter located the central part of China – Hunan and six associated factories throughout China.
Threeway Steel is known as a professional supplier engaged in designing, manufacturing and distribution of a wide range of steel products with the headquarter located the central part of China – Hunan and six associated factories throughout China.
Threeway Steel is known as a professional supplier engaged in designing, manufacturing and distribution of a wide range of steel products with the headquarter located the central part of China – Hunan and six associated factories throughout China.
Threeway Steel is known as a professional supplier engaged in designing, manufacturing and distribution of a wide range of steel products with the headquarter located the central part of China – Hunan and six associated factories throughout China.
