How to design non-standard welded parts to ensure sufficient strength and durability?
Publish Time: 2025-01-21
To ensure sufficient strength and durability, the design of non-standard welded parts needs to be comprehensively considered and implemented from multiple aspects. The following are some key design elements and measures:
1. Material selection
Select materials according to the application environment: Q235 is often used for structural parts and panel steel, 45# steel is often used for transmission parts and general parts, and 20~40Cr or other high-performance materials are specified for parts that require heat treatment.
Ensure material quality: All materials must have corresponding certificates of conformity or inspection certificates that meet quality requirements to ensure the reliability and stability of the materials.
2. Welding process
Develop welding specifications and standards: All welding operations should follow the corresponding welding specifications and standards, and conduct welding process verification to ensure the quality and reliability of the weld.
Control welding parameters: Strictly control parameters such as welding current, welding speed, and number of welding layers to obtain high-quality welds.
Weld quality inspection: There should be no cracks, pores, slag inclusions, incomplete fusion, incomplete penetration, cold welding, shape defects, etc. on the weld surface. The butt welds of the flange plate and web plate in the tension zone of the main beam should be subjected to non-destructive testing, such as ultrasonic testing or X-ray testing, to ensure that there are no defects inside the weld.
3. Structural design
Reasonable structural form: By optimizing the design section size or shape, increase the section inertia moment, and improve the rigidity and strength of the structure.
Avoid stress concentration: Try to reduce the stress concentration points in the structure, such as sharp angles and sharp edges, and reduce the stress concentration effect by blunting, rounding and other treatment methods.
Distribute the load: On components with longer lengths, the concentrated force or large concentrated force moment acting on the component will be dispersed and moved to both ends, or an intermediate support will be added to reduce its concentrated effect on a certain component section.
4. Surface treatment and protection
Surface cleaning: Before welding, the welding part should be cleaned to remove impurities such as oil, rust, etc. to improve the quality of the weld.
Sandblasting and painting: The surface of the steel structure needs to be sandblasted. After reaching a certain rust removal level, the primer and topcoat are sprayed to improve the corrosion resistance and durability of the structure.
Anti-corrosion treatment: For specific application environments, additional anti-corrosion measures may be required, such as hot-dip galvanizing, coating with anti-corrosion coatings, etc.
5. Quality control and inspection
Pre-welding preparation inspection: Before welding, the welding materials, equipment and processes should be fully inspected to ensure that they meet the design requirements.
Welding process monitoring: During the welding process, various parameters should be strictly controlled, and the slag and spatter on the weld surface should be cleaned regularly to keep the weld clean.
Post-weld inspection: After welding, the weld should be visually inspected, non-destructively tested and mechanically tested to ensure the quality and reliability of the weld.
The design of non-standard welded parts should ensure sufficient strength and durability, and comprehensive consideration and implementation should be made from multiple aspects such as material selection, welding process, structural design, surface treatment and protection, and quality control and inspection. Through scientific and reasonable design and strict process control, it can be ensured that non-standard welded parts meet the needs of various complex application environments.
