螺柱焊接

焊接系统主机采用ARM+FPGA系统架构，具有世界最先进的50kHz全桥软开关、交直流输出、100K纯数字硬件电流环、纯数字控制线性伺服驱动技术、综合信息技术等特点。

Introduction In automotive Body-in-White (BIW), automotive components, and new energy vehicle structural manufacturing, stud welding is widely used for applications such as cable harness fixing, heat shield installation, interior component mounting, and structural part assembly. However, in actual production, issues such as poor weld integrity, porosity, slag inclusion, and incomplete fusion remain key factors affecting stud welding quality stability. In severe cases, these defects can reduce stud strength and even cause stud detachment, affecting downstream assembly processes and product reliability. Based on stud welding principles and practical industrial applications, this article systematically analyzes the formation mechanisms, major causes, and engineering solutions for porosity and slag inclusion defects. 1. Formation Mechanism of Porosity and Slag Inclusion 1.1 Porosity Formation Mechanism: During the stud welding process, the high-temperature arc rapidly melts the welding area and forms a weld pool. If gases (such as H₂, CO, and N₂) inside the weld pool cannot escape before the molten metal solidifies, they will remain trapped inside the weld and form porosity. Porosity is mainly classified into: Surface porosity Internal porosity Among them, internal porosity is more difficult to detect and can reduce the effective strength of the welded joint. 1.2 Slag Inclusion Formation Mechanism: Slag inclusion refers to non-metallic impurities generated during the welding process that fail to escape in time and remain trapped inside the weld after solidification, forming defects. The main sources include: Oxides on the base material surface Oil contamination and foreign materials Coating residues Oxidation products generated during the welding process Slag inclusion reduces the effective bonding area of the weld and creates stress concentration areas, affecting weld joint reliability. 2. Six Root Causes of Porosity and Slag Inclusion 2.1 Workpiece Surface Contamination — The Most Common Cause Insufficient cleaning before welding is the primary cause of porosity and slag inclusion….

Although defects such as weld nugget deviation and cold welds/incomplete fusion cannot be completely eliminated, their occurrence can be reduced to an extremely low level through systematic process control, real-time quality monitoring, and regular equipment maintenance. The following solutions focus on two critical defect areas — weld nugget deviation and cold welding/incomplete fusion — combining proven process optimization methods with advanced intelligent welding technologies. 1. Precise Control of Weld Nugget Deviation Weld nugget deviation is mainly caused by arc blow (magnetic arc deflection) and uneven heat dissipation conditions. 1.1 Eliminating Arc Blow — Prevention at the Source Symmetrical grounding (core measure) The ground connections should be positioned symmetrically on both sides of the welding location. This prevents uneven electromagnetic fields from deflecting the arc and is the most effective method for eliminating arc blow. Remove or ground nearby metal masses If large metal components, reinforcement plates, or conductive structures are located close to one side of the weld area, they should be removed or properly grounded to avoid magnetic field interference. Rotate the welding torch For manual stud welding, if arc deflection occurs toward one direction, rotating the torch handle by 90° can change the magnetic field distribution and improve arc stability. Control lift height Excessive lift height or missing ceramic ferrules can increase arc instability. Recommended lift height: General range: 1.0–1.6 mm Always use ceramic ferrules whenever possible to stabilize the arc. Figure: Symmetrical Grounding Configuration for Arc Blow Prevention Proper grounding layout plays a critical role in stabilizing the welding arc. Symmetrical grounding reduces magnetic field imbalance and prevents arc deflection, helping maintain consistent weld nugget positioning. 1.2 Optimizing Heat Distribution for Different Materials and Thicknesses Apply high-energy welding parameters Using a high current and short welding time (strong welding schedule) increases current density and reduces the influence…