|Name||Water Tube ss400|
|Length||as customer's requirement|
|Surface Treatment||Pre-galvanized/Hot Dip Galvanized|
|Material||Q 195 Q235 Q345 SS400 or as customer's requirement|
|Ends||Plain or Threaded with coupling|
|MOQ||common size 1tons,special size 10-20tons|
|Delivery time||in 20-40days|
|Payment terms||T/T LC|
Mill Test for Water Tube
The technical requirements
1. Brand and chemical composition.
The steel plate and chemical composition of galvanized steel tube shall conform to the brand and chemical composition of the black pipe used in GB/T3092.
2. Manufacturing method
The manufacturing method of black pipe (furnace welding or welding) is selected by the manufacturer. Hot dip galvanizing method is adopted.
3. Thread and pipe joint.
(a) galvanized steel pipe with thread, thread should be made after galvanized. Thread should comply with YB 822.
(b) steel pipe joints shall conform to the provisions of YB 238; The joint of malleable cast iron pipe shall conform to the provisions of YB 230.
4. Mechanical properties of steel tube before galvanization should comply with GB 3092.
5. The uniform galvanized steel pipe shall be tested for the uniformity of galvanized layer. The steel tube samples were impregnated 5 times in the copper sulfate solution without turning red (copper plating).
6. Cold bending test nominal diameter of no more than 50mm galvanized steel pipe shall be subjected to cold bending test. Bending Angle is 90 °, bending radius to diameter 8 times. When the test is not filled with filler, the weld should be placed on the outside or upper part of the bending direction. After the test, there should be no crack and zinc peeling.
7. Water pressure test should be carried out in black pipe, and eddy current test should be used instead of water pressure test. Test pressure or eddy current testing should be in accordance with GB 3092. The mechanical property of steel is an important index to ensure the final performance of steel.
Mechanical properties of
1) tensile strength (sigma b) : in the process of drawing, sample in the snap of the most strongly (Fb), divided by the sample of the original cross-sectional area (So) stress (sigma), referred to as tensile strength (sigma b), units of N/was (MPa). It indicates the maximum resistance of metal materials to damage under tensile force. In the formula: Fb-- the most powerful force when the sample is pulled and broken, N (Newton); So-- the original cross-sectional area of the sample, mm2.
Yield point (s) : a metal material with a yield phenomenon that does not increase in the tensile process (remains constant) and can continue to extend the stress at the point of yield. If the force decreases, the upper and lower yield points should be distinguished. The yield point is N/mm2 (MPa). Upper yield point (su) : the maximum stress before the first descending force of the specimen; Lower yield point (s) : the minimum stress in the yield phase when the initial transient effect is not considered. In the formula: Fs-- the yield force (constant), N (Newton) So-- the original cross-sectional area of the sample, mm2.
Hardness index: the ability of a metal material to resist a hard surface, called hardness. According to the test method and applicable range, hardness can be divided into brinell hardness, rockwell hardness, vickers hardness, scleroscope hardness, microhardness and high temperature hardness. There are three kinds of tubes commonly used for pipe, such as bushi, Lowell and vickers.
Brinell hardness (HB) : with a certain diameter of steel ball or cemented carbide balls, with provisions of the surface of the test force (F) into the style, after keep stipulated time unloading test, measuring indentation on the surface of the specimen (L) in diameter. The brinell hardness is the quotient of the test force divided by the spherical surface area of the indentation. In the case of HBS, the unit is N/mm2(MPa).
Contact Person: Ann Jia
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