The testing standards for forgings mainly include two methods: ultrasonic testing and radiographic testing. The specific standards are as follows:
Ultrasonic Testing Standards
1. Equipment requirements: Use A-type pulse reflection ultrasonic flaw detector, with a probe frequency generally ranging from 2.5MHz to 5MHz. For forgings with a thickness of less than or equal to 50mm, use a straight probe to perform flaw detection from two mutually perpendicular directions; For forgings with a thickness greater than 50mm, in addition to using a straight probe for flaw detection, an oblique probe is also required to perform flaw detection on the circumferential surface.
2. Defect assessment: When the echo height of a single defect is 3dB higher than the distance amplitude curve (DAC), it is recorded as a defect; When the percentage of defects in the dense area to the total detection area is less than 10%, it can be rated as qualified.
Radiographic Testing Standards
1. Equipment requirements: Radiographic testing uses X-rays or gamma rays to penetrate forgings and detect internal defects through the attenuation law of the radiation in the material. Common standards include ISO 17636, ASME Section V, GB/T 3323, etc.
2. Defect assessment: Defects such as cracks, lack of fusion, and lack of penetration are not allowed; Circular defects are evaluated based on the number and size of defects within the evaluation area. For example, when the thickness of the base material is 10-25mm, the maximum allowable number of defect points is 12; The length and width of strip-shaped slag inclusions are also strictly limited.
The specific application of flaw detection methods and standards
1. Ultrasonic testing: Utilizing the propagation characteristics of ultrasonic waves in materials, defects are detected by detecting the reflection, scattering, and other phenomena of ultrasonic waves when encountering defects inside forgings. The main standards include ISO 11699, EN 583, GB/T 11345, ASTM E1901, etc.
2. Radiographic inspection: Using radiation to penetrate forgings and detect internal defects through the attenuation law of radiation in the material. The main standards include ISO 17636, ASME Section V, GB/T 3323, etc.
Qualification requirements for flaw detection personnel
Flaw detection personnel should have certain basic knowledge and experience in smelting, forging, heat treatment, etc., and pass the assessment of relevant departments to obtain the corresponding level of qualification certificate.
Grace Ma
Post time: Mar-14-2025
