What Does a Welding Inspector Do?

Welding inspection is one of the welding disciplines based on modern chemical physics, chemistry, mechanics, electronics and materials science. It is a brand-new field in which comprehensive quality management science and non-destructive evaluation technology are closely combined. Its advanced testing methods and first-stage equipment, strict organizational management system and high-quality welding inspection personnel are important guarantees for achieving quality control and safe operation of modern welding industry products.

Welding inspection is one of the welding disciplines based on modern chemical physics, chemistry, mechanics, electronics and materials science. It is a brand-new field in which comprehensive quality management science and non-destructive evaluation technology are closely combined. Its advanced testing methods and first-stage equipment, strict organizational management system and high-quality welding inspection personnel are important guarantees for achieving quality control and safe operation of modern welding industry products.

With the development of boilers, pressure vessels, chemical machinery, marine structures, aerospace vehicles and atomic energy engineering towards high parameters and large-scale development, the work becomes increasingly demanding and complex. Obviously, these welded structural parts must be of high quality; otherwise, accidents in operation will cause heavy losses. The main role of welding inspection:

(1) Ensure the manufacturing quality of welded structural parts, improve product reliability, and ensure its safe operation.

(2) Improve welding technology and product quality.

(3) Reduce product cost and conduct safety assessment correctly.

(4) The reliable guarantee of welding inspection can promote the wider application of welding technology.

Welding inspection can be divided into three categories: destructive inspection, non-destructive inspection and acoustic emission inspection.

Welding production must be inspected in accordance with the drawings, technical standards and inspection documents.

(1) Construction drawings. Drawings are the most basic materials used in production, and processing should be carried out in accordance with the provisions of the drawings. The drawing specifies the raw materials, the position of the weld, the shape and size of the groove, and the inspection requirements for the weld.

(2) Technical standards. Including relevant technical documents, which stipulates the quality requirements and quality assessment methods of welding products, and is a guiding document for engaging in inspection work.

(3) Inspection documents. Including process rules, inspection rules, and inspection process lights, they specify inspection methods and inspection procedures, and know that on-site inspectors work. In addition, it also includes inspection documents collected during the inspection process: inspection reports, non-conforming product disposal orders, change notices, written notices used for pattern changes, process changes, material substitution, addition or change of inspection requirements, etc.

(4) Order contract. The user's requirements for the welding quality of the product are clearly marked in the contract, and can also be used as supplementary provisions for drawings and technical documents.

Extending the welding inspection work to the entire welding production and product use process can fully and effectively play the positive role of various inspection methods, and can prevent and even prevent waste and accidents caused by defects.

(1) Inspection before welding. The pre-weld inspection is mainly a pre-weld inspection. It is a proactive and effective measure to prevent or reduce the occurrence of welding defects and ensure the quality of welding.

(2) Inspection of welding process. Welding process not only refers to the process of forming welds, but also includes post-heat welding and post-heat treatment processes.

(3) Inspection after welding. Although the welding structure (piece) has been inspected before and during the welding process, welding defects may still occur due to changes in external factors or specifications during the manufacturing process, energy fluctuations, etc. After welding, visual inspection and non-destructive Inspection, mechanical property inspection, metallographic inspection, weld intergranular corrosion inspection, weld ferrite content inspection, compactness inspection, weld strength inspection and other post-weld inspections.

(4) Inspection of installation and commissioning quality. During the installation and commissioning process, the manufacturing quality of the welded product should be re-examined in order to find missing or incorrect inspections, as well as handle and eliminate hidden dangers to ensure the safe and reliable operation of welded structural parts.

(5) Inspection of product service quality. 1) Quality control during product operation; 2) Review of product maintenance quality; 3) On-site treatment of service product quality problems; 4) On-site investigation and analysis of welding structure damage accidents ^[1] .

There are generally defects in welded structures (parts). Defects will affect the quality of welded joints, and the quality of joints directly affects the safe use of welded structural parts.