For welding stainless steel rods, assembly and welding are very important steps. Only by mastering the correct splicing welding method can the safety of welded stainless steel rods be ensured. Therefore, in order to weld the safety quality of stainless steel rods, it is necessary to splicing and welding the welding stainless steel rods. Do some understanding.
First, the assembly of welded stainless steel rods
In order to reduce the accumulation error of the welded stainless steel rod in the assembly process, the assembly of the lower string of the whole stainless steel rod should start from the center, assemble the vertical and horizontal axes first, and correct the size at any time. It can be unfolded from the center to the periphery without any error. The line (small unit) error is allowed to be ±3mm, the lower chord node is offset by 2mm, and the overall vertical and horizontal deviation value shall not be greater than ±2mm.
2. After the assembly of the whole lower string is finished, check the geometrical dimensions. If necessary, apply the theodolite calibration and use the level to copy the height difference of each point to make adjustments.
3. In order to facilitate the construction and improve the progress of the project, the web and the upper chord can be seated according to the drawings before the assembly of the lower string, and the loading is in place.
4. The assembly of the web and the upper chord should be assembled after the assembly of the lower chord is completed. The method is assembled on the basis of no over-measurement. The method is assembled from the center, and the vertical and horizontal axes are inspected at any time for geometrical dimensions, corrected and assembled to the periphery.
5. The spot welding of stainless steel rods is suitable for three points, and the diameter of the tube is four points. When spot welding, the arc should not be randomly placed outside the joint between the rod and the joint.
Second, welding
After the stainless steel rods are inspected and tightened, they are welded with stainless steel rods, and the fireproof asbestos board is laid on the operating platform under the welding point. The welding of the rod to the ball is one of the key processes in the construction of the entire stainless steel rod. The strength and quality of the weld is critical to the safety of the entire stainless steel rod.
1. Develop a reasonable welding process, including reasonable selection of groove shape, welding rod diameter, welding current, weldment form, weldment cleaning, determination of welding sequence and operation focus. After the welding process is established, the welder is organized to learn and memorize the process operation requirements.
2. Stainless steel rod welding. Adopting the new technology of “single-sided welding double-sided welded stainless steel rod pipe butt weld”, the method is as follows: bottom welding (including fixed spot welding) adopts φ2.5 welding rod, and the welding current is adapted according to the welding position. After arcing The blunt edge of the bevel is dissolved to form a dissolved pore, and at the same time, the corresponding part of the ball is dissolved, and then the arc is pressed down, so that the molten iron is condensed on the inner wall of the weld in turn, forming a reinforcing weld on the back, in order to improve the efficiency, The layer weld can be repaired to the specified height by φ3.2~φ4.0 welding rod.
Each weld is welded in two layers, but the most important one is the first weld, which is to ensure that the root is welded and the back is well formed. Divide each weld into 4 sections, firstly weld 1/4 arc, and then weld the remaining 2 1/4 arcs. The second welding sequence is the same as the first one, and the whole stainless steel rod welding work is completed again and again. .
3. It is strictly forbidden to form each weld seam once. After welding, the welder must clean the weld seam and the surrounding splash slag coating. If there is a hole, the weld must be removed to weld the second pass. The weld appearance The forming should be beautiful and uniform, and the height of the weld should meet the design requirements.
The above is the main point of the welding of welded stainless steel rods, which is the key to maintaining the safety of welded stainless steel rods, so be sure to pay attention.