Primary flaw detection standard

Level 1 flaw detection standards are as follows:

First-class flaw detection: conduct preliminary surface inspection and acoustic flaw detection on the weld, mainly to detect the appearance and acoustic echo of the weld.

Secondary flaw detection: on the basis of primary flaw detection, magnetic particle flaw detection and penetrant flaw detection are added to detect tiny cracks, defects and blowholes.

Three-level flaw detection: On the basis of two-level flaw detection, ultrasonic flaw detection and radiographic flaw detection are added to detect deeper defects and cracks.

Four-level flaw detection: On the basis of three-level flaw detection, eddy current flaw detection and thermal infrared flaw detection are added to detect more subtle defects and cracks.

According to different welding materials, structures and requirements, different levels of flaw detection methods and technologies will be selected and applied to achieve more accurate and comprehensive nondestructive testing results.

Expand:

Inspection standard of secondary weld: the secondary weld must be inspected by flaw detection, which should meet the design requirements and the provisions of construction and acceptance specifications, and the weld flaw detection report should be checked; The secondary weld shall be free of defects such as cracks, flash, burn-through and arc pits. Grade Ⅱ weld shall be free of defects such as surface porosity, slag inclusion, arc pit, crack and arc abrasion, and Grade Ⅰ weld shall be free of defects such as undercut and incomplete penetration. Weld quality: no surface porosity, slag inclusion, crack, arc scratch and other defects.

Proportional requirements for weld grade inspection:

1, the first-class weld needs 100% weld flaw detection, that is, all welds are inspected.

2. No less than 20% of secondary welds shall be inspected by weld flaw detection, and random witness sampling shall be conducted.

Therefore, both primary and secondary welds need to be inspected, but the inspection ratio is different! Please contact us if you still want to know about the inspection of steel structure welds. Zhongze Testing provides one-stop nondestructive testing service.