1. Welding: refers to a processing method that achieves atomic bonding of weldments by heating or pressure, or both, with or without filler materials.
2. Weld seam: refers to the joint part formed after the weldment is welded.
3. Butt joint: a joint in which the end faces of two weldments are relatively parallel.
4. Groove: According to design or process requirements, a groove of a certain geometric shape is processed on the part to be welded of the weldment.
5. Reinforcement height: In the butt weld, the height of the part of the weld metal that exceeds the line above the surface of the weld toe.
6. Crystallization: Crystallization refers to the process of crystal nucleus formation and growth.
7. Primary crystallization: After the heat source leaves, the metal in the weld pool changes from liquid to solid, which is called primary crystallization of the weld pool.
8. Secondary crystallization: A series of phase transition processes that high-temperature metals undergo when they are cooled to room temperature are secondary crystallization.
9. Passivation treatment: In order to improve the corrosion resistance of stainless steel, an oxide film is artificially formed on the surface.
10. Diffusion deoxidation: When the temperature drops, the iron oxide originally dissolved in the molten pool continues to diffuse to the slag, thereby reducing the oxygen content in the weld. This deoxidation method is called diffusion deoxidation.
11. Plastic deformation: When the external force is removed, the deformation that cannot return to the original shape is plastic deformation.
12. Elastic deformation: When the external force is removed, the deformation that can restore the original shape is elastic deformation.
13. Welded structure: a metal structure made by welding.
14. Mechanical performance test: a destructive test method to understand whether the mechanical properties of the weld metal and welded joints meet the design requirements.
15. Non-destructive inspection: refers to the method of inspecting the internal defects of materials and finished products without damage or destruction.
16. Arc welding: refers to a welding method that uses an arc as a heat source.
17. Submerged arc welding: refers to the method in which the arc burns under the flux layer for welding.
18. Gas shielded arc welding: refers to the welding method that uses external gas as the arc medium and protects the arc and welding area.
19. Carbon dioxide gas shielded welding: a welding method that uses carbon dioxide as a shielding gas, referred to as carbon dioxide welding or second shielded welding.
20. Argon arc welding: gas shielded welding using argon as the shielding gas.
21. Metal argon arc welding: argon arc welding using melting electrodes.
22. Plasma cutting: A method of cutting using a plasma arc.
23. Carbon arc gouging: the method of using the arc generated between the graphite rod or carbon rod and the workpiece to melt the metal and blow it off with compressed air to realize the method of processing grooves on the metal surface.
24. Brittle fracture: It is a kind of fracture that occurs suddenly without macroscopic plastic deformation of the metal under the stress far below the yield point.
25. Normalizing: heating the steel above the critical temperature Ac3 line, keeping it at 30-50°C for a general time, and then cooling it in the air. This process is called normalizing.
26. Annealing: refers to the heat treatment process of heating the steel to an appropriate temperature, holding it for a general time and then cooling it slowly to obtain a structure close to the equilibrium state
27. Quenching: A heat treatment process in which steel is heated to a temperature above Ac3 or Ac1, and then rapidly cooled in water or oil after heat preservation to obtain a high-hardness structure.
28. Complete annealing: refers to the process of heating the workpiece above Ac3 to 30°C-50°C for a certain period of time, then slowly cooling to below 50°C with the furnace temperature, and then cooling in the air.
29. Welding fixtures: Fixtures used to ensure the size of the weldment, improve efficiency, and prevent welding deformation.
30. Slag inclusion: Welding slag remaining in the weld after welding.
31. Welding slag: solid slag covering the surface of the weld after welding.
32. Incomplete penetration: The phenomenon that the root of the joint is not completely penetrated during welding.
33. Tungsten inclusion: Tungsten particles that enter the weld from the tungsten electrode during tungsten inert gas shielded welding.
34. Porosity: During welding, the bubbles in the molten pool fail to escape when they solidify and remain to form holes. Stomata can be divided into dense stomata, worm-like stomata and needle-like stomata.
35. Undercut: due to improper selection of welding parameters or incorrect operation methods, grooves or depressions produced along the base metal of the weld toe.
36. Welding tumor: During the welding process, the molten metal flows to the unmelted base metal outside the weld to form a metal tumor.
37. Non-destructive testing: A method of detecting defects without damaging the performance and integrity of the inspected material or finished product.
38. Destruction test: a test method for cutting samples from weldments or test pieces, or doing destructive tests from the whole product (or simulated part) to check its various mechanical properties.
39. Welding manipulator: A device that sends and holds the welding head or welding torch to the position to be welded, or moves the welding machine along a prescribed trajectory at a selected welding speed.
40. Slag removal: the ease with which the slag shell falls off from the surface of the weld.
41. Electrode manufacturability: refers to the performance of the electrode during operation, including arc stability, weld shape, slag removal and spatter size, etc.
42. Root cleaning: The operation of cleaning the welding root from the back of the weld to prepare for the back welding is called root cleaning.
43. Welding position: the spatial position of the weldment seam during fusion welding, which can be represented by the inclination angle of the weld seam and the weld seam rotation angle, including flat welding, vertical welding, horizontal welding and overhead welding.
44. Positive connection: The welding piece is connected to the positive pole of the power supply, and the electrode is connected to the negative pole of the power supply.
45. Reverse connection: the wiring method that the weldment is connected to the negative pole of the power supply, and the electrode is connected to the positive pole of the power supply.
46. DC positive connection: When using DC power supply, the welding piece is connected to the positive pole of the power supply, and the welding rod is connected to the negative pole of the power supply.
47. DC reverse connection: When a DC power supply is used, the welding piece is connected to the negative pole of the power supply, and the electrode (or electrode) is connected to the positive pole of the power supply.
48. Arc stiffness: refers to the degree to which the arc is straight along the electrode axis under the effects of heat shrinkage and magnetic shrinkage.
49. Arc static characteristics: Under the condition of certain electrode material, gas medium and arc length, when the arc burns stably, the relationship between welding current and arc voltage change is generally called volt-ampere characteristic.
50. Molten pool: The liquid metal part with a certain geometric shape formed on the weldment under the action of the welding heat source during fusion welding.
51. Welding parameters: During welding, various parameters selected to ensure welding quality (such as welding current, arc voltage, welding speed, line energy, etc.).
52. Welding current: the current flowing through the welding circuit during welding.
53. Welding speed: the length of weld seam completed per unit time.
54. Twisting deformation: refers to the deformation that the two ends of the component are twisted at an angle around the neutral axis in the opposite direction after welding.
55. Wave deformation: refers to the deformation of components that resemble waves.
56. Angular deformation: It is the deformation caused by the inconsistency of the transverse shrinkage along the thickness direction due to the asymmetry of the cross section of the weld.
57. Lateral deformation: It is the deformation phenomenon of the weld due to the lateral shrinkage of the heating area.
58. Longitudinal deformation: refers to the deformation of the weld due to the longitudinal shrinkage of the heating area.
59. Bending deformation: refers to the deformation that the component bends to one side after welding.
60. Restraint degree: refers to a quantitative index to measure the rigidity of welded joints.
61. Intergranular corrosion: refers to a corrosion phenomenon that occurs along the grain boundaries of metals.
62. Heat treatment: the process of heating the metal to a certain temperature, keeping it at this temperature for a certain period of time, and then cooling it to room temperature at a certain cooling rate.
63. Ferrite: A solid solution of a body-centered cubic lattice formed of iron and carbon.
64. Hot cracks: During the welding process, the welding seam and the metal in the heat-affected zone are cooled to the high-temperature zone near the solidus line to produce welding cracks.
65. Reheat crack: refers to the crack generated when the weld and heat-affected zone are reheated.
66. Welding crack: Under the joint action of welding stress and other brittle factors, the bonding force of metal atoms in the local area of the welded joint is destroyed to form a gap generated by a new interface, which has a sharp gap and a large aspect ratio Characteristics.
67. Crater cracks: thermal cracks generated in arc craters.
68. Layered tearing: During welding, a crack in the shape of a ladder is formed along the rolling layer of the steel plate in the welded member.
69. Solid solution: It is a solid complex formed by the uniform distribution of one substance in another substance.
70. Welding flame: generally refers to the flame used in gas welding, which also includes hydrogen atomic flame and plasma flame. In combustible gases such as acetylene hydrogen and liquefied petroleum gas, acetylene emits a large amount of effective heat when burned in pure oxygen, and the flame The temperature is high, so oxyacetylene flame is mainly used in gas welding at present.
71. Stress: refers to the force borne by an object per unit area.
72. Thermal stress: refers to the stress caused by uneven temperature distribution during welding.
73. Tissue stress: refers to the stress caused by tissue changes caused by temperature changes.
74. Unidirectional stress: It is the stress existing in one direction in the weldment.
75. Two-way stress: It is the stress that exists in different directions in a plane.
76. The allowable stress of the weld: refers to the maximum stress allowed to exist in the weld.
77. Working stress: Working stress refers to the stress borne by the working weld.
78. Stress concentration: refers to the uneven distribution of working stress in the welded joint, and the maximum stress value is higher than the average stress value.
79. Internal stress: refers to the stress preserved in the elastic body when there is no external force.
80. Overheated zone: In the heat-affected zone of welding, there is an area with overheated structure or significantly coarse grains.
81. Overheated structure: During the welding process, the base metal near the fusion line is often overheated locally, which causes the grain to grow and form a structure with brittle properties.
82. Metal: 107 elements have been discovered in nature so far. Among these elements, those with good electrical conductivity, thermal conductivity, and flammability and metallic luster are called metals.
83. Toughness: The ability of a metal to resist impact and interception is called toughness.
84.475°C embrittlement: Ferrite + austenite dual-phase welds containing more ferrite phase (more than 15~20%), after heating at 350~500°C, the plasticity and toughness will be significantly reduced, that is, the material is brittle change. Because of the fastest embrittlement at 475°C, it is often called 475°C embrittlement.
85. Fusibility: Metal is a solid at normal temperature, and when heated to a certain temperature, it changes from a solid to a liquid state. This property is called fusibility.
86. Short-circuit transition: the droplet at the end of the electrode (or wire) is in short-circuit contact with the molten pool, and due to the strong overheating and magnetic shrinkage, it bursts and directly transitions to the molten pool.
87. Spray transition: The molten drop is in the form of fine particles and quickly passes through the arc space to the molten pool in a spray-like manner.
88. Wettability: During brazing, the brazing filler metal relies on capillary action to flow in the gap between the brazing joints. The ability of this liquid brazing filler metal to infiltrate and adhere to wood is called wettability.
89. Segregation: It is the uneven distribution of chemical components in welding.
90. Corrosion resistance: refers to the ability of metal materials to resist corrosion by various media.
91. Oxidation resistance: refers to the ability of metal materials to resist oxidation.
92. Hydrogen embrittlement: The phenomenon that hydrogen causes a serious decrease in the plasticity of steel.
93. Post-heating: It refers to the technological measure of heating the weldment to 150-200°C for a period of time immediately after welding as a whole or locally.
Post time: Mar-14-2023