In the welding process of stainless steel shelves, weld strength is a core indicator for ensuring the structural safety and service life of the shelves. Achieving this requires a comprehensive approach encompassing material selection, process control, equipment debugging, operational procedures, quality inspection, and environmental management to form a systematic guarantee.
Material selection is fundamental to weld strength. Austenitic stainless steel is commonly used in stainless steel shelves, and its welding requires strict control of carbon content to avoid intergranular corrosion that reduces weld strength. Simultaneously, the welding material composition must match the base metal. For example, using welding rods or wires containing stabilizing elements (such as Ti and Nb) can preferentially form carbides and reduce chromium depletion at grain boundaries. Furthermore, the base metal surface must be thoroughly cleaned before welding to remove oil, scale, and other impurities to prevent porosity or cracks during welding.
Process control is crucial for weld strength. Welding should employ low heat input, rapid short-arc welding to reduce weld overheating, prevent the formation of coarse columnar grain structures, and thus reduce residual welding stress. For example, in flat welding, the current should be controlled within a suitable range and the voltage kept stable to ensure a uniform molten pool. Vertical and horizontal welding require parameter adjustments to prevent molten pool sagging or incomplete fusion. In multi-layer welding, the thickness of each weld bead must be strictly controlled, the interpass temperature maintained within a reasonable range, and slag must be thoroughly cleaned before each subsequent layer to prevent inclusions from affecting weld strength.
Equipment debugging directly impacts weld quality. Welding equipment parameters need to be adjusted according to material thickness and welding method. For example, DC welding machines require an argon gas pressure reducing flow meter to ensure laminar gas flow and prevent oxidation. The welding power source should have arc-stabilizing capabilities to avoid weld defects caused by arc instability. Furthermore, welding cables need regular inspection to prevent poor contact leading to current fluctuations that affect weld formation.
Proper operating procedures are the practical guarantee of weld strength. Welders must be professionally trained and certified, familiar with the electrode manipulation techniques for different welding positions, such as straight-line manipulation and small-amplitude oscillations, to ensure a uniform molten pool. The crater must be filled during arc initiation and termination to prevent crack formation. For critical welds, arc-starting plates should be installed, and the weld should be ground smooth after gas cutting to avoid defects at the starting point. Simultaneously, the welding sequence should follow the principle of "primary welds first, secondary welds secondarily, and symmetrical welding" to minimize the impact of structural deformation on the weld.
Quality inspection is the verification stage for weld strength. Visual inspection must ensure that the weld surface is free of defects such as cracks, slag inclusions, and porosity, and that the depth and length of undercut meet standards. Non-destructive testing uses techniques such as ultrasonic testing and radiographic testing to verify the internal quality of the weld, ensuring there are no hidden dangers such as incomplete fusion or incomplete penetration. Mechanical property testing requires sampling for tensile testing; the tensile strength should not be lower than a specific percentage of the standard value of the base material to ensure the weld's load-bearing capacity.
Environmental management is an external guarantee for weld strength. The welding area should be equipped with a rain shelter to control humidity and temperature, preventing environmental factors from causing fluctuations in weld quality. For example, excessive humidity may cause hydrogen-induced cracking, while excessively low temperatures require preheating. Furthermore, the welding area should be equipped with fireproof barriers and fire extinguishers to prevent the risk of ignition by welding slag and ensure operational safety. From material selection to environmental management, the welding process for stainless steel shelves requires systematic control to ensure weld strength. Strict adherence to process specifications, enhanced quality inspection, and optimized equipment performance can significantly improve the structural safety of the shelves, extend their service life, and provide reliable support for warehousing, logistics, and other scenarios.
