Sheet metal welding process

Sheet metal parts processing and welding process includes pre-welding preparation, material selection, welding method, welding parameters selection, operation requirements, etc.

1) principle: the performance of welding parts manufacturing: promote strengths and avoid weaknesses, give play to the advantages of materials and processing methods, and ensure quality. Performance of welding parts: effectively control the influencing factors of manufacturing process and ensure the quality.

2) weldability of materials: the adaptability of materials to welding processing, or the difficulty of obtaining a good welding joint under welding process conditions, or the ability to weld components meeting design requirements and service requirements under limited construction conditions.

(1) influencing factors: material, welding method, component type and use requirements, of which material is the main factor.

(2) welding property of materials: only a few gold materials are suitable for welding processing, such as iron, nickel, aluminum, copper, titanium and alloy. Low carbon steel, low alloy structural steel with good weldability. (Ce) carbon content less than 0.4%, good weldability, Ce more than 0.6% difficult to weld. The composition of the welded joint is shown in the figure. Good welding joint is the embodiment of good weldability. The weak link that affects the joint performance is the coarse crystal part in the fusion zone or the heat-affected zone. The internal factors are the chemical composition and tissue state of the material itself. External cause is welding method, specification is determined. Therefore, the material design should control the chemical composition of the material, the microstructure of the smelting and rolling process and strictly control the harmful elements, oxygen, hydrogen, nitrogen, sulfur, phosphorus and so on. Selection of carbon content of low alloy structural steel:

Selection of welding method and specification parameters

(1) principle: make use of the advantages of each method to promote strengths and avoid weaknesses. See method classification.

(ii) welding specification parameters -- welding conditions and parameters

1. Welding conditions: plate thickness, joint form, groove shape, size, constraint state, ambient temperature, humidity, etc.

2. Welding parameters: welding current, arc voltage, speed, sequence, etc.