What are the physical properties of seamless tubes?

What are the physical properties of seamless tubes?

1. Chemical composition. Requirements are put forward for the content of harmful chemical elements As, Sn, Sb, Bi, Pb and gases N, H, O, etc. In order to improve the uniformity of chemical composition in steel and the purity of steel, reduce non-metallic inclusions in tube blanks and To improve its distribution, refining equipment outside the furnace is usually used to refine the molten steel, or even an electroslag furnace is used to remelt and refine the tube blanks.

2. Dimensional accuracy and appearance. The geometric dimensions of seamless tubes mainly include the outer diameter, wall thickness, ovality, length, curvature, pipe end slope, bevel angle and blunt edge of the steel pipe, the cross-sectional dimensions of the heterogeneous steel pipe, etc.

3. Surface quality. The standard stipulates the requirements for the smooth surface of seamless steel pipes. Common defects include cracks, hair lines, inward folds, outward folds, rolled breaks, inner straights, outer straights, separation layers, scars, pits, convex bumps, and hemp. Pits (pockmarks), scratches (abrasions), inner spiral path, outer spiral path, green line, correction of dents, roller marks, etc. Among them, cracks, inward folds, outward folds, rolled breaks, separation layers, scars, pits, convex bulges, etc. are dangerous defects; pitted surfaces, green lines, scratches, slight internal and external straight lines, slight internal and external spirals, straightening of steel pipes, etc. Concave and roller marks are general defects.

4.Physical and chemical properties. Including mechanical properties at room temperature and mechanical properties and corrosion resistance at a certain temperature. Generally speaking, it depends on the chemical composition, structural properties and purity of the steel, as well as the heat treatment method of the steel. In some cases, the rolling temperature and deformation degree of the steel pipe will also affect the performance of the steel pipe.

5. Process performance. Including the flaring, flattening, curling, bending, ring-drawing and welding properties of steel pipes.
6. Metallographic structure. Including low-magnification structure and high-magnification structure of steel pipe.
7. Special requirements. Requirements other than those proposed by standards when using steel pipes.

The thicker the wall thickness of the seamless tube, the more economical and practical it is. The thinner the wall thickness, its processing cost will increase significantly; secondly, the process of the product determines its partial performance, generally seamless The tube accuracy is low: the wall thickness is uneven, the inner surface of the tube is low in brightness, the cost of sizing is high, and there are pits and black spots on the inner surface that are difficult to remove; thirdly, its detection and shaping must be processed offline. Therefore, it shows its superiority in high pressure, high strength, and mechanical structural materials.

Tips: ASTM A106 seamless steel tube includes two processes: cold drawing and hot rolling. In addition to the different production processes, the two are different in precision, surface quality, minimum size, mechanical properties, and organizational structure. It is widely used in various industries such as petroleum, chemical industry, boilers, power stations, ships, machinery manufacturing, automobiles, aviation, aerospace, energy, geology, construction and military industry.