A Brief Discussion on Welding Processes

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I. General Terms 1. Welding is a method of joining workpieces by heating or applying pressure, or both, with or without the use of filler material. 2. Welding methods refer to specific welding techniques such as submerged arc welding and gas shielded welding; their definition includes the metallurgical, electrical, physical, chemical, and mechanical principles involved in those methods. It is mainly divided into brazing, welding, and pressure welding. 3. All the processing methods and implementation requirements for manufacturing welded parts through welding processes, including welding preparation, material selection, determination of welding methods, and requirements for operating welding parameters. 4. Welding procedure specifications (rules) are detailed documents that outline all the processing and practical requirements related to the fabrication of welded parts, ensuring reproducibility of quality when operated by skilled welders or operators. 5. A groove of a specific geometric shape, which is created at the part of the weldment to be welded according to design or process requirements, and then assembled there. 6. The process of preparing a groove using machinery, flame, or arc welding. 7. A double-sided groove forms a double-sided weld groove. 8. The groove surface on the part to be welded at the groove edge. 9. Bevel angle: the angle between the two bevel surfaces. 10. Groove face angle: the angle between the end face of the groove to be processed and the groove face. 11. Joint root: the part where the two components forming the joint are closest to each other. 12. The gap reserved between the roots of the joints prior to root gap welding. 13. The root radius is the fillet radius at the bottom of J-shaped and U-shaped grooves. 14. When beveling a weldment with blunt edges, it refers to the straight edge portion along the root of the groove at the joint of the weldment. 15. A joint is formed by two or more parts joined by welding or existing welded connections. When testing joint performance, the mutual influences among different areas such as the weld seam, fusion zone, heat-affected zone, and even the base material must be taken into account. 16. Bevel surface angle: the angle between the end face of the bevel to be processed and the bevel surface. 17. The root of the joint is the part where the two components of the joint are closest to each other. 18. The gap reserved between the roots of the joints prior to root gap welding. 19. The root radius is the fillet radius at the bottom of J-shaped and U-shaped grooves. 20. When beveling a weldment with blunt edges, it refers to the straight edge portion along the root of the groove at the joint of the weldment. 21. A joint is formed by two or more parts that are combined by welding or by pre-welded contacts. When testing joint performance, the mutual influences among different areas such as the weld seam, fusion zone, heat-affected zone, and even the base material must be taken into account. 22. Joint design includes the joint type, groove type and dimensions, as well as weld dimensions, determined based on the operating conditions. 23. A joint in which the surfaces of the two mating parts form an angle of 135° or more, and 180° or less. 24. A fillet joint is a joint in which the ends of the two parts form an angle of more than 30° and less than 135°. 25. A T-joint is a joint in which one end face of one piece forms a right angle or an angle close to a right angle with the surface of another piece. 26. A joint formed by the overlapping of two parts of a butt joint. 27. The three components of the cross joint are assembled to form a cross-shaped joint. 28. An end joint formed by placing two terminal fittings overlapping each other, or with an angle between their surfaces of no more than 30°. 29. A joint in which the ends of the parts to be welded are pre-crimped, and the crimp melts only partially after welding. 30. A sleeve joint is a joint formed by fitting a short tube with a slightly larger diameter over the ends of the two tubes to be connected. 31. Obliquely butted joint: a butted joint whose joint seam is arranged obliquely in the plane of the welded parts. 32. A lock-bottom joint is a joint formed by placing the end of one piece against the pre-defined bottom edge of another piece. 33. The base metal is a general term for the metal material that is welded. 34. The area in which the material undergoes changes in microstructure and mechanical properties due to heating (without melting) during welding or cutting in the heat-affected zone. 35. The fusion zone is the transition area where the weld seam meets the base material, namely the semi-melted region of the base material as observed microscopically at the fusion line. 36. The weld profile as shown by macroscopic corrosion on the cross-section of a fusion (fusion welding) weld joint. 37. A general term for the weld area and the areas adjacent to it. 38. The weld metal zone is the area of weld metal measured on the cross-section of the welded joint. During fusion welding, it refers to the area enclosed by the weld surface and the fusion line. In resistance welding, it refers to the molten pool formed after welding. 39. A short weld welded before the main weld to determine the position of the joint between the components for assembly and fixation. 40. Load-bearing welds are the welds on a welded joint that are used to bear loads. 41. Continuous weld: a weld that is formed by continuous welding. 42. intermittent welds are welded to form welds at certain intervals. 43. Longitudinal welds are welds that run along the length of the welded piece. 44. A transverse weld is a weld that is perpendicular to the length direction of the welded piece. 45. A closed weld that runs end to end along a cylindrical welded part. 46. In plug welding, two parts are overlapped, with a circular hole made in one of them; the weld formed by welding the two plates within that hole is not considered plug welding if only fillet welds are used inside the hole. 47. Groove weld seams involve overlapping plates, with a long hole made in one of the plates; the weld connecting the two plates is formed within this long hole. A weld that consists only of fillet welds is not considered a groove weld. 48. Weld width: The distance between the two weld toes on the surface of the weld. 49. Weld thickness is the distance in the weld cross-section from the front side of the weld to the back side of the weld. 50. The junction between the surface of the weld toe and the base metal. 51. In the cross-section of a leg fillet weld, the minimum distance from the weld toe on one right-angled surface to the surface of the other right-angled surface. 52. The leg size is the length of the legs of the largest right-angled isosceles triangle drawn in the cross-section of a fillet weld. 53. The excess height is the maximum height of the weld metal above the line connecting the surfaces of the base material. 54. The junction between the back side of the root weld and the base metal. 55. Weld axis: The line connecting the geometric center of the weld cross-section along the length direction of the weld. 56. Weld length: The length of the weld along its axial direction. 57. Weld symbols are marks on drawings that indicate technical details such as the welding method, weld type, and weld dimensions. 58. Manual welding – handheld welding torch,