Features And Causes Of Eight Defects Of Seamless Steel Pipe

Features and causes of 8 defects of seamless steel pipe:folding, crack, scratches, pit, pitted surface, spots, warped pores and skin, scar.

If there are some defects in the seamless steel pipe, it should undoubtedly have a fatal impact on the quality of our products. So easy methods to keep away from these defects? Then you definitely need to grasp the reasons for these defects. Permanent Steel Manufacturing Co.,Ltd will work with you to debate the particular reasons for the eight defects of seamless steel pipes:

1. Seamless steel pipe-folding

It’s a linear or spiral, steady or discontinuous state that exists on the outer or inside floor of seamless steel pipe. The main reason for the folding is poor quality of the pipe materials, folding itself, or inclusions, critical scratches and cracks on the surface, edges and corners in the grinding place, and folding after drawing. In order to keep away from folding, the quality of the pipe material must be improved and a focus ought to be paid to inspection and grinding.

2. Seamless steel pipe-crack

Refers to the small cracks on the inner and outer surfaces of the seamless steel pipe which are distributed in a straight line or a spiral, with a depth of 1 mm or extra, continuous and discontinuous. In accordance with the analysis of Permanent Steel Manufacturing Co., alloy sheet Ltd, the cause is: the new-rolled tube clean has subcutaneous bubbles and subcutaneous inclusions, and alloy bar sheet there are cracks or deep pits on the steel pipe earlier than drawing. During the new rolling or chilly drawing processes Longitudinal scratches or scratches occurred throughout the operation. If you beloved this information as well as you desire to be given more details relating to alloy sheet; simply click the following internet page, i implore you to check out our own webpage. Preventing the formation of cracks additionally lies in bettering the standard of the tube blank and strengthening the inspection and grinding of the tube materials. At the same time, pitting, scratches and scratches must be avoided in the course of the chilly drawing manufacturing course of.

3. Seamless steel pipe-scratches

The characteristic of the defect is that there are longitudinally linear scratches of varying lengths on the inner and outer surfaces of the seamless pipe. Most of them are groove-formed, however they could also be raised stripes. The main purpose for the scratches (reducing) is: there are inside markings on the pipe materials, which can’t be eliminated during drawing, the iron oxide film remains on the steel pipe and the mold sticks to the steel, and the strength and hardness of the mold are insufficient or uneven. Fragmentation and put on occur, the hammer head is defective, and the sharp edges and corners of the hammer head transition part injury the mold. In order to prevent scratches and scratches, the quality of every preparation course of before drawing must be improved, and molds with excessive power and hardness and good smoothness should be used.

4. Seamless steel pipe-pit

This is one in all the commonest floor defects of seamless pipes. Local depressions with different areas are distributed on the floor of the steel pipe. Some of them are periodic and a few are irregular. The pits are attributable to iron oxide scale or different hard dirt pressed into the floor of the steel pipe throughout the drawing or straightening course of, or the peeling of the unique peeling on the floor of the steel pipe. Shandong Jute Pipe Industry identified that the measures to prevent pits are to carefully examine the pipe materials and take away defects comparable to warping, keep the work site, instruments and lubricants clear, and prevent oxide scale and dirt from falling on the floor of the steel pipe.

When there are easy or sharp spiral marks on the outer floor of the seamless steel pipe, the straightening machine should be checked. Due to the incorrect place and angle of the straightening roller, the steel pipe rubbed the shoulders on the edge of the straightening roller throughout straightening. There are worn grooves on the straightening roller, and both ends of the steel pipe might seem on the outer floor of the steel pipe. Pits.

5. Seamless steel pipe-pitted floor

It’s characterized by small pits within the type of items and dots on the surface of the steel pipe. The principle motive for the pitting floor is pitting corrosion during pickling. After annealing, the oxide scale is just too thick and straightened and pressed into the floor of the steel pipe to type a pitted surface; the steel pipe is kept in a humid setting, and even pitted rust occurs after water enters. After removing the rust spots Form pitted floor.

6. Seamless steel pipe-spots

Since seamless steel pipes are involved with water (or water vapor) throughout processing or storage and are not treated in time (reminiscent of drying), the traces left by water evaporation are called water spots, akin to lengthy contact with water or corrosive water Rust spots are formed when the substance is Water spots usually have no depth, and rust spots often corrode the surface of the steel pipe, and there will nonetheless be pitted surfaces after elimination.

7. Seamless steel pipe-warped skin

It’s characterized in that the internal and outer surfaces of the seamless steel rod pipe are partially separated from the metal substrate, and the person pieces are lumpy, discontinuous, rooted or not rooted on the pipe wall, but cannot peel off naturally. The reasons are poor steel high quality, the existence of subcutaneous bubbles, that are uncovered after chilly drawing; the warping produced throughout scorching rolling isn’t removed on the tube billet to cold drawing; the original deep and angular transverse pits on the steel tube After drawing, it varieties a warped pores and skin.

8. Seamless steel pipe-scar

The inside and outer surfaces of the steel pipe weren’t eliminated in time attributable to defects corresponding to folding and warping. In the following processing, skinny slices that could not be separated from the metallic substrate had been formed. A few of them have been lumpy, discontinuous, and rooted or not rooted on the pipe wall, but they couldn’t peel off naturally. , Called scarring. Surface defects have to be checked and removed in time to remove scars.

Tips: ASTM A53 Grade B is more in style than different grades. These pipes could be bare pipes without any coating, or it could also be Hot-Dipped or Zinc-Coated and manufactured by Welding or by a Seamless manufacturing course of. In Oil and Gas, A53 grade pipes are used within the structural and non-essential applications.

In the appliance of submarine oil and gasoline pipeline engineering, ERW welded pipes are protected and economical.

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