Seamless steel pipe quality requirementsQuality requirements ①Chemical composition of steel: The chemical composition of steel is one of the most important factors affecting the performance of seamless steel pipes. It is also the main basis for formulating pipe rolling process parameters and steel pipe heat treatment process parameters. a. Alloying elements: intentionally added, according to purpose b. Residual elements: brought in from steelmaking, properly controlled c. Harmful elements: strictly controlled (As, Sn, Sb, Bi, Pb), gases (N, H, O) Out-of-furnace refining or electroslag remelting: improve the uniformity of the chemical composition of the steel and the purity of the steel, reduce non-metallic inclusions in the tube blank and improve its distribution pattern. ②Steel pipe geometric dimension accuracy and shape a. Steel pipe outer diameter accuracy: depends on the method of determining (reducing) diameter, equipment operation conditions, process system, etc. Allowable devi…