The welding process for 304 stainless steel double deck workbench requires high precision, a conclusion stemming from the combined effects of the inherent properties of 304 stainless steel and the complexity of the welding process. 304 stainless steel is an austenitic stainless steel, its core components including chromium, nickel, and a small amount of carbon. This composition endows it with excellent corrosion resistance, heat resistance, and low-temperature strength, but also presents welding challenges. For example, at high temperatures, 304 stainless steel is prone to intergranular corrosion—chromium carbide precipitation at grain boundaries leads to localized chromium depletion, thus reducing corrosion resistance. Furthermore, stress concentration in the weld heat-affected zone can trigger stress corrosion cracking, especially in chloride-containing environments where the risk is higher. Therefore, the welding process must mitigate these defects by controlling heat input and optimizing operational procedures.
The choice of welding method directly affects the welding quality of 304 stainless steel double deck workbench. Commonly used methods include tungsten inert gas welding (TIG welding), metal inert gas welding (MIG/MAG welding), and manual arc welding (MMA welding). Among these, TIG welding, due to its stable arc, controllable heat input, and aesthetically pleasing weld formation, has become the preferred choice for welding thin plates (e.g., below 4mm). MIG welding, with its high efficiency and applicability to medium-thick plates, is more advantageous in welding double-deck workbench frames. For materials of different thicknesses, welding methods need to be flexibly adjusted: plates below 4mm can be directly welded on one side; 4-6mm requires double-sided welding; and plates above 6mm require V- or U-shaped beveling to ensure penetration. This differentiated treatment requires welders to have extensive experience and the ability to accurately select the process based on the material thickness and structural characteristics.
The selection of welding materials must be highly compatible with the composition of the base material to maintain the corrosion resistance and mechanical properties of the weld. For welding 304 stainless steel, 308 or 308L welding rods/wires are recommended. These materials have a low carbon content (≤0.03%), which reduces the precipitation of chromium carbide during welding, thereby reducing the risk of intergranular corrosion. If the base material is ultra-low carbon 304L stainless steel, then 308L welding consumables must be used. Precise control of its silicon content (0.30-0.65%) and manganese content (1.00-2.50%) can further optimize the crack resistance and toughness of the weld. Furthermore, the welding consumables must be stored and used in strict moisture-proof conditions to prevent hydrogen-induced cracking.
Parameter control during the welding process is a crucial aspect of ensuring quality. Heat input should be kept as low as possible to minimize the width of the heat-affected zone and reduce residual stress. For example, when using TIG welding, the matching of current, voltage, and welding speed must be accurate to the millimeter level. Gas protection must be strictly controlled throughout the process, and the argon flow rate (usually 8-15 L/min) needs to be dynamically adjusted according to the welding speed to prevent air intrusion and oxidation. In multi-pass welding, the interpass temperature must be controlled below 150℃ to avoid overheating and grain coarsening. Even slight deviations in these parameters can affect the density and corrosion resistance of the weld, therefore requiring operators to possess a high degree of concentration and technical proficiency. Post-welding treatment is equally crucial. The weld surface must be thoroughly cleaned to remove slag and spatter, and surface smoothness should be restored through processes such as grinding, pickling, and passivation to prevent residual corrosive media. For critical structures, non-destructive testing (such as ultrasonic testing and radiographic testing) and mechanical property testing (such as tensile and bending tests) are also required to ensure the weld is free of cracks, porosity, and other defects, and that its strength and toughness meet standards. Furthermore, stress-relieving annealing (holding at 550-650℃) can further release residual welding stress and improve the long-term stability of the structure.
The welding process for 304 stainless steel double deck workbench requires high precision, not only in the meticulous control of material properties, method selection, and parameter control, but also throughout the entire process from pre-weld preparation to post-weld inspection. This high standard stems from stringent requirements for product corrosion resistance, structural strength, and service life, especially in scenarios with extremely high hygiene and safety requirements such as food processing, laboratories, and medical settings, where any welding defect can lead to serious consequences. Therefore, only through systematic process management, a professional operating team, and rigorous quality testing can we ensure that the double-layer workbench meets high-standard application requirements.
