Detecting whether the quality of fluid seamless pipes (eg: ASTM A106 GR.B) meets the standard mainly includes the following methods.

1. Detect the chemical composition of fluid seamless pipes

Detect the content of harmful chemical elements As Sn Sb Bi Pb and gas N,H,O. In order to improve the uniformity of the chemical composition in the steel and the purity of the steel, reduce the non-metallic inclusions in the tube billet and improve its distribution, often use outside the furnace The refining equipment refines molten steel, and even uses an electroslag furnace to remelt and refine the tube billet.

2. Detect the dimensional accuracy and shape of fluid seamless pipes

The geometric dimensions of seamless pipes mainly include the outer diameter, wall thickness, ellipticity, length, curvature of the pipe, pipe end face cut, bevel angle and blunt edges, and cross-sectional dimensions of the heterogeneous steel pipe.

3. Detect the surface quality of fluid seamless pipes

The standard stipulates the requirement of "smooth surface" of seamless steel pipe. Common defects are: cracks, hair lines, internal folds, external folds, punctures, internal straights, external straights, separation, scars, pits, convex hulls, pits, scratches (scratches), internal spirals , Outer spiral track, blue line, concave correction, roll printing, etc. Among them, cracks, internal folds, external folds, rolling, delamination, scars, pits, convex hulls and other dangerous defects; pitted surface, blue line, scratches, slight internal and external straightness, slight internal and external spiral, correction Concave and roll marks are general defects.

4. Detect the physical and chemical properties of fluid seamless pipes

Including the mechanical properties at room temperature and the mechanical properties at a certain temperature (thermal strength and low temperature properties) and corrosion resistance (such as oxidation resistance, water corrosion resistance, acid and alkali resistance, etc.) generally depend on the chemical composition and structure of the steel Performance and purity of steel and heat treatment methods of steel. In some cases, the rolling temperature and degree of deformation of the steel pipe will also affect the performance of the steel pipe.

5. Detect process performance of fluid seamless pipe

Including the flaring, flattening, crimping, bending, ring drawing and welding performance of seamless steel pipes.

6. Detect metallographic structure of fluid seamless pipe

Including the low-magnification and high-magnification of the steel pipe

7. Special requirements for testing fluid seamless pipes

Requirements other than the standards put forward when users use seamless steel pipes.