Office Chair Welding Processing
Office chair welding processing requires special attention to aspects such as welding techniques, quality objectives, operational requirements, and practical processing examples.
Welding Technique Selection: The commonly used materials for office chairs are Q235 cold-rolled steel plates (with a thickness of 1.5 - 3mm) and 20 seamless steel pipes (with a wall thickness of 1.2 - 2.5mm), both of which are low-carbon steels. The core technique employed is Metal Active Gas (MAG) welding, utilizing a shielding gas mixture of 80% argon (Ar) and 20% carbon dioxide (COโ). This technique offers moderate penetration (2 - 4mm), high deposition efficiency (approximately 5 - 8kg per hour), and uniform weld formation. Its overall cost is more than 30% lower than that of Tungsten Inert Gas (TIG) welding. TIG welding serves as a supplementary technique for repair welding, suitable for local repairs of exposed decorative parts. It provides excellent argon shielding and pure welds but has low deposition efficiency (approximately 2kg per hour), making it suitable for precision welding of ultra-thin parts (0.8 - 2mm).
Welding Quality Objectives: The objectives must meet dual standards of strong connections and high aesthetics. For key load-bearing welds (such as the connections between the chair frame's five legs and the upright tube, and between the table legs and crossbeam), the tensile strength must be at least 380MPa (90% of the tensile strength of the Q235 steel base material). For non-load-bearing decorative welds (such as armrest decorative strips), the tensile strength must be at least 280MPa. Exposed welds must achieve a 'mirror-grade' standard, meaning no undercutting, no porosity, with a weld reinforcement height controlled between 0.8 - 1.2mm and a width deviation of no more than 0.5mm.
Welding Operational Requirements: By defining parameter ranges (such as current, voltage, and gas flow rate) and designing auxiliary tooling (such as positioning fixtures and anti-deformation tooling), intermediate-level welders (with over 2 years of experience) can master the technique after just 3 days of training, reducing reliance on 'master welders'. For example, standardizing operational procedures through work instructions and combining tooling for rapid positioning and fixation ensures welding consistency.
Practical Processing Examples: Common processing methods include square tube cutting and splicing. For instance, two 66cm lengths of 3x3 square tubes are cut, and notches are made at the 32cm mark before bending and welding to form the chair frame structure. Two 24cm lengths of 2x2 square tubes are aligned and welded together. Additionally, the frame for the cushion at the bottom of an office chair often uses No. 14 steel pipes, which are bent into shape using hydraulic power machines. After connecting the ends, steel bars are welded to support the seat adjustment mechanism.
