The welding inspection includes the inspection of materials, tools, equipment, process and finished product quality from the design of the drawings to the production of the product. It is divided into three stages: pre-weld inspection, inspection during welding, and post-weld inspection. Inspection of finished products. The inspection method can be divided into two types: destructive inspection and non-destructive inspection according to whether the product is damaged. (3) Strength test of pressurized containers (4) Inspection of physical methods 1 ray inspection 2 Ultrasonic flaw detection 3 magnetic test 4 penetration test Polyester Ratchet Tie Down,Ratchet Tie Down,Custom Ratchet Tie Down,Good Strength Ratchet Tie Down SHAOXING GULI BELTING CO., LTD , https://www.gulilifting.com
1) Pre-weld inspection
Pre-weld inspection includes inspection of raw materials (such as base metal, welding rods, flux, etc.) and inspection of welding structure design.
2) Inspection during welding
Including inspection of welding procedure specifications, inspection of weld size, fixture conditions and inspection of structural assembly quality.
3) Inspection of finished products after welding
There are many methods for inspection of finished products after welding. The following are commonly used:
(1) Appearance inspection
The appearance inspection of welded joints is a simple and widely used inspection method. It is an important part of the inspection of finished products, mainly to find defects and dimensional deviations on the surface of the weld. It is generally inspected by the naked eye and by means of tools such as standard templates, gauges and magnifiers. If there is a defect on the surface of the weld, there is a possibility of defects inside the weld.
(2) Compactness test
Welding containers for storing liquids or gases whose weld seams are not dense, such as penetrating cracks, pores, slag inclusions, incomplete penetration and loose structures, can be found by compactness tests. The methods of compactness test include: kerosene test, water carrying test, water flushing test, etc.
In addition to the sealing test, the pressure vessel is subjected to a strength test. There are two types of hydraulic tests and air pressure tests. They both verify the weld density of containers and pipes that work under pressure. The air pressure test is more sensitive and rapid than the water pressure test, and the tested product does not need to be drained, which is especially suitable for products with difficult drainage. However, the risk of the test is greater than the hydrostatic test. When conducting tests, the corresponding safety technical measures must be observed to prevent accidents during the test.
The physical test method is a method of measuring or testing using some physical phenomena. Inspection of the internal defects of materials or workpieces is generally carried out by means of non-destructive testing. At present, non-destructive testing includes ultrasonic flaw detection, radiographic inspection, penetrant inspection, magnetic flaw detection, etc. To view multiple videos in wmv format, hover your mouse over the desired video.
Radiographic inspection is a method of detecting defects by using radiolucent materials and attenuating properties in the material. According to the different rays used in flaw detection, it can be divided into three types: X-ray inspection, γ-ray inspection and high-energy radiation inspection. Because of the different methods of displaying defects, each type of radiographic inspection is divided into ionization method, screen observation method, photographic method and industrial television method. The ray inspection is mainly used to inspect cracks, incomplete penetration, pores, slag inclusions, etc. inside the weld.
Ultrasonic waves can be used for the inspection of internal defects due to reflections at the interface of different media in the propagation of metals and other homogeneous media. Ultrasonic can inspect any weldment material, any part of the defect, and can detect the location of the defect more sensitively, but it is difficult to determine the nature, shape and size of the defect. Therefore, ultrasonic flaw detection is often used in conjunction with radiographic inspection.
Magnetic testing is the use of magnetic fields to magnetize the magnetic flux generated by ferromagnetic metal parts to find defects. According to the method of measuring magnetic flux leakage, it can be divided into magnetic powder method, magnetic induction method and magnetic recording method, among which magnetic powder method is the most widely used.
Magnetic flaw detection can only find defects on the surface of magnetic metal and near surface, and can only quantitatively analyze defects. The nature and depth of defects can only be estimated based on experience.
Penetration testing uses physical properties such as permeability of certain liquids to detect and display defects, including both coloring and fluorescence detection, and can be used to examine defects on the surface of ferromagnetic and non-ferromagnetic materials.
Welding inspection