The diameter of lead-free solder rods and the coordination of welding positions are crucial. During welding, it is important to control the welding speed and current. Due to the narrow root size, when performing a root weld on a fully penetrating corner joint, if the welding speed is too fast, there is insufficient time for the root gases and slag to be expelled, leading to defects such as incomplete fusion, slag inclusions, and pores. During face welding, a fast welding speed also tends to produce pores. A slow welding speed results in excessive weld bead height and an uneven appearance. When welding thin plates or joints with small钝edges, a slow welding speed can easily cause burn-through. When selecting the welding speed, it should be coordinated with the welding current, joint position (root welding, face welding), joint thickness, and bevel size. Opt for an appropriate welding speed to ensure penetration, easy expulsion of gases and slag, prevent burn-through, and achieve good formation. Larger welding speeds should be chosen under these conditions to enhance production efficiency.
Welding rods can be categorized into two expression forms based on their use. According to the original compilation by the former Ministry of Mechanical Industry, welding rods can be divided into: structural steel welding rods, heat-resistant steel welding rods, stainless steel welding rods, surfacing welding rods, low-temperature steel welding rods, cast iron welding rods, nickel and nickel alloy welding rods, copper and copper alloy welding rods, aluminum and aluminum alloy welding rods, and special-purpose welding rods. For carbon steel welding rods, low-alloy welding rods, stainless steel welding rods, surfacing welding rods, cast iron welding rods, copper and copper alloy welding rods, and aluminum and aluminum alloy welding rods. There is no fundamental difference between the two; the former is represented by commercial brand names, while the latter is represented by models. If categorized based on the primary chemical composition of the welding rod sheath, welding rods can be divided into: titanium oxide welding rods, calcium oxide titanium welding rods, rutile welding rods, iron oxide welding rods, cellulose welding rods, low-hydrogen welding rods, graphite welding rods, and salt-base welding rods. Based on the characteristics of the slag, welding rods can be classified as acidic welding rods and alkaline welding rods. The main component of the acidic welding rod sheath is acidic oxides, such as silicon dioxide, titanium dioxide, and ferric oxide.
Lead-free solder wire is difficult to melt the solder tip or iron block with the workpiece during welding, resulting in defects such as incomplete fusion and under-fusion, which reduce the connection strength. Filling with rusty solder tips or iron blocks makes it hard to ensure consistency with the base material. Using solder tips or iron blocks contaminated with oil, impurities, etc., can lead to defects such as air holes, slag inclusions, and cracks in the weld. These conditions all degrade the quality of the joint welds, failing to meet the design and specification requirements for weld quality.
The measures taken do not exceed the permissible scope of use for the specified range. When the assembly gap between workpieces is significant, if the gap exceeds twice the thickness of the thin plate or is greater than 20mm, the method of surfacing should be employed to fill in the raised areas or reduce the assembly gap. It is strictly prohibited to use filling welding rods or iron blocks to weld in the joint gaps. Sufficient cutting allowance and welding shrinkage allowance after cutting should be left, especially when marking the parts for machining. Control the part dimensions properly and do not determine the外形尺寸 by increasing the gap.
Cautionary Notes for Cutting Lead-Free Solder Bars
One: Prevent material deformation due to pressure. Limit blocks are installed at the top of the guide shaft. Based on the height of the material being cut, they limit the downward travel of the pressure cover, thereby preventing deformation in certain materials. By adjusting the distance appropriately, it ensures that thin-walled materials, non-standard materials, and plastics can be securely pressed during cutting without deforming.
Two, align the materials. When cutting some round tubes or bars in parallel, if the top pressing device does not press down after the side pressing device is applied, it's easy to misalign the entire row of materials. Adjusting the timing of the top and side pressing devices becomes difficult. In this case, we can use the pressing limit blocks to solve this problem.
The third point is to control the stroke of the material feeding cover. When the inserted material is smaller or the height of the cut material is lower, it is not necessary to lift the feeding cover too high. By using limit blocks to lock it on the guide shaft of the feeding cover, it can limit the stroke of the cover. This saves the time for lifting and moving the feeding cover and reduces the gas consumption.
What are the advantages of laser welding?
Excellent power stability during welding.
Automatic control of abnormal conditions.
Pulse mode generates less heat.
Lead-free solder bars can be焊接 using a defocusing method to produce large laser spots.
Pulse or continuous modes offer high-quality welding.
Six: Weldable materials with defects
Seven: Welding speed in continuous mode is not slow.
Pulse Shaping Capability
Nine: Weldable high reflectivity material.
