Inspection methods and standard specifications in welded workpieces

Date：2022-02-28 13:38:00Views：1404

The welding method is usually selected according to the following principles. The selected welding method must ensure the welding quality and meet the technical requirements of product design; At the same time, it can improve the welding production efficiency, reduce the manufacturing cost and improve the working conditions. According to the heating degree and process characteristics of the welding process, the welding methods can be divided into three categories.

(1) Fusion welding. The welded part of the workpiece is locally heated to the molten state to form a molten pool (usually filled with filler metal), the weld is formed after cooling and crystallization, and the welded workpiece is combined into an integral whole. Common fusion welding methods include gas welding, arc welding, electroslag welding, plasma arc welding, electron beam welding, laser welding, etc.

(2) Pressure welding. In the welding process, whether heated or not, pressure welding method is required. Ordinary pressure welding includes resistance welding, friction welding, cold pressing welding, diffusion welding, explosive welding, etc.

(3) Brazing. After melting with solder (filler metal) whose melting point is lower than that of the welded metal, the gap is filled and diffused with the welded metal to realize the connection. In the brazing process, the welded workpiece will not melt and usually plastic deformation will not occur.

Characteristics of welding production:

(1) Save metal materials and light structure.

(2) The combination from small to large can manufacture heavy and complex mechanical parts, simplify casting, forging and cutting processes, and obtain the best technical and economic results.

(3) The welded joint has good mechanical properties and air tightness.

(4) Bimetallic structures can be manufactured, so that the properties of materials can be fully utilized.

Testing methods: common NDT methods: ultrasonic testing (UT), magnetic particle testing (MT), liquid penetrant testing (PT) and X-ray testing (RT). There is no need to repeat here. Among them, X-ray detection technology is more recommended, which is also the development trend in the future. It is sensitive to the detection of volumetric defects, and it is easier to characterize the defects. It can visually display the shape and type of defects. The image processing technology is mature, the results can be saved and traced, and it can be supported online and offline.

From the selection of inspection methods of workpieces, precautions in the inspection process, to the final evaluation of workpieces and the issuance of report parameters, it is often necessary to follow certain standards and specifications recognized by both the supplier and the demander. Standards and specifications are shared for your reference only:

JB / t6062 penetrant inspection method for welds and classification of defective magnetic traces

Iso10675-2 nondestructive testing of welds - Part 2: evaluation and acceptance level of radiographic testing of aluminum alloy products

GB / t3323 radiography of metal fusion welded joints

ASTM E390 standard radiograph for fusion welding of steel

Iso5817 incomplete quality classification of weld steel, nickel, titanium and their respective alloy fusion welded joints (except beam welding)

GB / t11345 manual ultrasonic testing method for steel welds and classification of testing results

Jisz3081 ultrasonic bevel flaw detection method for aluminum pipe welds and classification method of inspection results

JB / t9212 ultrasonic flaw detection for welds of atmospheric steel oil tank

ISO 17636-1 non destructive testing of welds X-ray and gamma ray film technology

GB / t12605 radiographic technology and quality classification of circumferential fusion welded butt joints of steel pipes

JB / t6061 magnetic particle testing method for welds and classification of defective magnetic traces

Iso17638 non destructive testing of welding magnetic particle testing of welded joints

Nb / t47103 nondestructive testing of pressure equipment

GB / t14693 symbols for nondestructive testing of welds

ASTM e1032 radiographic testing method for weldments

GB / t15830 ultrasonic testing methods and classification of test results for butt circumferential welds of steel pipes

Iso11666 non destructive testing of welds acceptance level of ultrasonic testing of welded joints

TB / t1558 ultrasonic flaw detection for butt welds

Iso10042 quality classification of incomplete welded aluminum and its alloy arc welded joints

Iso10675-1 nondestructive testing of welds - Part 1: evaluation and acceptance level of radiographic testing of steel, nickel, titanium and their alloy products

Jisz3080 ultrasonic bevel flaw detection method for aluminum welds and classification method of inspection results

Iso17640 weld nondestructive testing ultrasonic testing technology, acceptance level and result evaluation

Iso17636-2 nondestructive testing of welds X-ray testing and gamma ray electronic imaging technology

Iso3452 nondestructive testing Penetrant testing

Iso23278 non destructive testing of welds magnetic particle testing acceptance level of welded joints

Jisz3105 radiographic inspection method and film rating method for aluminum welds

Astme1648 radiographic reference film for aluminum fusion welding inspection

Iso23277 nondestructive testing of welds acceptance level of penetrant testing of welds