What Are The Quality Requirements For Seamless Steel Pipe?
What are the quality requirements for Seamless Steel Pipe?
1. The first is the chemical composition of steel in seamless steel pipe: the chemical composition of steel is one of the most important factors affecting the performance of seamless steel pipe, but also to develop the rolling process parameters and the main basis for heat treatment process parameters.
A. Alloying elements: intentionally added, depending on the application
B. Residual elements: steel into, appropriate control
C. Harmful elements: strict control (As, Sn, Sb, Bi, Pb), gas (N, H, O)
Furnace refining or electroslag remelting: Seamless Steel Pipe improve the uniformity of chemical composition in steel and steel purity, reduce the non-metallic inclusions in the tube and improve its distribution.
2. followed by the seamless steel pipe geometry accuracy and shape
A. Pipe diameter accuracy: depends on the fixed (minus) diameter method, equipment operation, process system.
Outside diameter allowable deviation δ = (D-Di) / Di × 100% D: Maximum or minimum outside diameter mm
Di: nominal outside diameter mm
B. Thickness of steel pipe wall thickness: the quality of heating with the tube, the process design parameters and adjustment parameters, Seamless Steel Pipe tool quality and lubrication quality and so on
Wall thickness Allowable deviation: ρ = (S-Si) / Si × 100% S: maximum or minimum wall thickness in cross section
Si: nominal wall thickness mm