Thursday, December 4, 2014

The testing standards and inner plate scanning method for welded steel pipe

The testing standards and inner plate scanning method of the welded steel pipe
During ultrasonic testing of the welded steel pipe, such as LSAW steel pipe and SSAW steel pipe, the relative motion between the detection probe and the specimen surface is called scanning. Scanning generally takes two principles into consideration, one is to ensure that the entire inspection of the pipe to be covered with enough acoustic beam to avoid missed; the second is to make sure the acoustic beam direction is always in line with the requirements of the standards required in the process of scanning .

Testing standards

a. ASTM A578-92
Scanning method:
1. Continuous scanning along the orthogonal grid line centers, grid line spacing of 9 inches (225mm) or according to the manufacturer's choice.
2. Continuous scanning along center perpendicular to the plate rolling direction of parallel lines, scanning spaced of 4 inches (100mm) or 3 inches (75mm).
3. Continuous scanning along the main plate rolling direction of the center line of parallel lines, scanning space of 3 inches (75mm) or less.

Surrounding Scanning method: 
2 inches (50mm) 100% scanning

b. GB/T 2790-91
Scanning method:
probe perpendicular to the plate rolling direction, scanning along with parallel lines spaced not more than 100mm.

Surrounding Scanning method:
50mm 100% scanning

c. SY/T 6243.5-1999
Scanning method:
1. Along with the scanning lines parallel or perpendicular to the pitch of the steel sheet rolling direction; scanning pitch
respectively 100,150 and 200mm.
2. The corresponding minimum coverage is 20%, 10% and 5%.
3. When probe swing scanning, the minimum coverage should be  half the corresponding given values.

Surrounding Scanning method:
≥15mm 100% scanning

d. ZB J74 003-88
Scanning method: probe direction perpendicular to the steel sheet rolling direction and scanning along with a pitch of parallel lines space of 100mm .

Surrounding Scanning method:
50mm 100% scanning

No comments:

Post a Comment