Essential Weld Quality Control for Reliable Steel Structures

In steel structure welding, Positioning weld is a basic but important step before formal welding. It is used to fix the joint position and prevent movement during the welding process. Although it is usually smaller than the final weld, Positioning weld directly affects the quality and safety of the whole welding joint.

According to GB50661 welding procedure requirements, Positioning weld must be completed by qualified Welders. The welding material should be similar to the material used for the final weld. The surface of the base metal near the Positioning weld should also meet the welding preparation requirements.

The thickness of Positioning weld should not be less than 3mm. When the thickness of the final weld is more than 6mm, the thickness of the Positioning weld should not be more than two-thirds of the final weld thickness. The length of each Positioning weld should not be less than 40mm, and the recommended distance between each Positioning weld is 300-600mm.

For steel liner welding joints, the Positioning weld should be made inside the joint groove. The preheating temperature during Positioning weld should be 20℃ to 50℃ higher than the temperature used for formal welding. This helps reduce welding cracks and improves welding reliability.

The welding process and quality requirements of Positioning weld should be the same as the final weld. If defects such as cracks, pores, or slag appear in the Positioning weld, they must be completely removed before continuing welding.

For structures under dynamic loads and requiring fatigue analysis, special welding procedure documents for Positioning weld should be prepared. This helps control welding quality and reduces repair work after welding.

Morrow Welding Provides Stable Welding Power for High-quality Welding

Good welding quality requires not only correct welding procedures but also stable welding equipment. Morrow Welding Development Co., Ltd. focuses on the research, production, and sales of welding power sources. Our products are widely used in steel structures, shipbuilding, oil industry, metallurgy, and other industrial fields.

For modern industrial welding, Morrow provides advanced welding solutions including digital pulse welding machines, MIG/MAG welding machines, MMA welding machines, TIG welding machines, and automatic welding equipment.

Our DSP series digital high-speed pulse inverter welding machines use DSP all-digital control technology with 30 saving channels. They support high-speed pulse welding, double pulse welding, root welding, vertical upward welding, and cold arc welding. The machines can weld carbon steel, stainless steel, high-strength steel, alloy steel, and other materials with stable arc performance.

For medium and thick plate welding, Morrow NBC-G series deep penetration MIG welding machines provide strong arc force and better penetration. The machines support deep penetration welding, high-speed pulse welding, and DC MAG welding. They are suitable for industries such as steel structures, shipbuilding, bridges, and wind power equipment.

Morrow welding machines also provide a 100% duty cycle design for industrial applications. For example, the DSP-350, DSP-500, and DSP-630 models provide stable welding current output and support solid wire, flux-cored wire, and stainless steel wire welding.

Improve Welding Reliability from Every Detail

The quality of a welding joint depends on every step of the welding process. Positioning weld control is one of the important parts that cannot be ignored. Proper welding procedures, qualified operators, suitable welding materials, and reliable welding equipment work together to achieve better welding performance.

Morrow Welding continues to improve welding technology and provide professional welding power solutions for customers around the world. With stable performance and advanced control technology, Morrow welding machines help customers improve welding efficiency and achieve consistent welding quality.