Inspection of geometric dimensions and shape of steel pipes:
1. Steel pipe wall thickness inspection: micrometer, ultrasonic thickness gauge, no less than 8 points on both ends and record.
2. Inspection of the outer diameter and ellipticity of the steel pipe: caliper gauge, vernier caliper ring gauge, and the maximum and minimum points are measured.
3. Steel tube length check: steel tape measure, manual and automatic length measurement.
4. Checking the bend of steel pipe: ruler, horizontal ruler (1m), ruler and thin line measure the bend of every meter and bend of every meter.
5. Check the angle and blunt edge of the end face of the steel pipe: square ruler, card board.
Steel pipe surface quality inspection:
1. Artificial visual inspection: lighting conditions, standards, experience, logo, steel pipe rotation.
2. Non-destructive flaw detection: ultrasonic flaw detection UT, eddy current flaw detection ET, magnetic particle MT and magnetic flux leakage flaw detection, electromagnetic ultrasonic flaw detection, penetration flaw detection.
Special-shaped seamless steel pipes
play a vital role in urban construction. Its quality directly affects the solidity and quality of living buildings. Inferior special-shaped seamless steel tubes have the following characteristics:
1. Whether the surface is smooth
Due to the raw materials used, poor steel rolling equipment, unprofessional technical methods, and low cost, inferior shaped seamless steel pipes will have surface folding, pitting, scarring, cracks, and easy scratches.Generally, this situation can be passed Visual inspection revealed.
Therefore, it is recommended that when consumers encounter the above situations, they must be treated rationally, and do not purchase inferior square tubes for the sake of cheapness. The strength and hardness of these special-shaped seamless steel tubes do not reach the standard, which will affect their future use.
2. Whether the surface has metallic luster
Some inferior special-shaped seamless steel tubes use adobe, and the temperature is not standard.The steel temperature is grasped by visual inspection, so that the rolled steel will show the color of red or pig iron, and there is no metal gloss and performance of genuine special-shaped seamless steel tubes. Not to mention the above.
3. Whether the cross section and the cutting head are smooth
In order to save raw materials, the quality of the special-shaped seamless steel pipe is reduced in the first two passes of the finished roll, resulting in an oval cross-section, and the cut section of the inferior square tube
often has a flaking situation, that is, unevenness. Therefore, once you find that the cross section of the square tube is elliptical, and the cut head is uneven, everyone should be alert. This is a poor quality square tube.
4. Whether the size and weight are qualified
Generally, the size of low-quality special-shaped seamless steel tubes fluctuates greatly, and it helps to save raw materials.Most of them are not enough in weight, so you can look at the national standards and sizes in advance when purchasing square tubes, and you can ask for accuracy when checking samples. The size and weight of the square tube.