The composite steel grating is a kind of steel product in which the flat steel is crossed according to a certain spacing and cross bars, and welded into a square lattice in the middle. board etc. The grille composite plate is generally made of carbon steel, and the surface is hot-dip galvanized, which can prevent oxidation. It can also be made of stainless steel. It has the properties of ventilation, lighting, heat dissipation, anti-skid, explosion-proof, etc. The advantages of light weight, saving steel, and easy installation are widely used in ladder structures.
There are strict technical requirements and precision requirements for the manufacture and welding of composite steel gratings: various residual stresses caused by assembly and welding should be minimized during the manufacturing process. Welds of all connecting nodes should be of good quality, with smooth surface grinding to reduce stress concentration and improve fatigue resistance.
At present, for the production of composite steel grating in this industry, the pattern plate and steel grating are dispersed and acid-treated and then hot-dip galvanized. After the treatment, electric welding or gas shielded welding is used for integrated welding. The disadvantages of this welding production method are:
1. Repeated operations result in low production efficiency.
2. After integrated welding, the hot-dip galvanized layer at the position of the weld is burned and oxidized due to the high temperature generated during welding, which seriously affects the appearance quality and normal service life of the product. At the same time, in the welding process, the selection of the solder joint sequence has a great influence on the product quality.
In order to solve the above-mentioned technical problems, the technical scheme adopted is: a welding method for a grid composite plate, which is characterized in that: the pattern plate and the steel grating without pre-plating treatment are integrated and welded by gas shielded welding, and the pattern plate is firstly welded. The plate and the steel grating are superimposed and spot welded at the central position to determine the positioning point. Then longitudinally from the middle to the two ends, the welding is carried out in a scattered manner, with three flat steels and a horizontal bar spacing in each horizontal direction, and finally the pattern is carried out. Circumferential welding of plate and steel grating; after welding, galvanize the composite grille. In the welding method, under the condition of ensuring the strength of the whole grid composite plate, the welding points and welding times are as few as possible, so as to ensure the practicality and beauty of the whole structure.
In the integrated welding process, except that the outermost main body flat steel and the wrapping flat steel can be welded with the checker plate, the rest can only ensure that there is a weld between the checker plate and the twist steel on the steel grating.
The length of the welding seam is 15-20 mm, and the height of the welding leg is 4-6 mm. The limit on the length of the weld and the height of the weld foot is suitable for all welding requirements of the composite steel grating, and the strength can meet the requirements of on-site use. If it exceeds this range, it is not necessary if it is too large, and it affects the aesthetics. product quality.
A table number is welded beside the central position. The station number is a sign with the function of identification, indicating the operator and the operation time for subsequent inquiries. The station number is welded after the welding of other solder joints is completed.
After the checker plate and the steel grating are superimposed, the boundary of the checker plate exceeds the boundary of the steel grating by less than or equal to 3 mm. If the upper and lower boundaries of the grid composite panel are not aligned and exceed 3mm, it will not be easy to weld in place for the welding of the peripheral ring, which will affect the welding quality. On the other hand, when the composite steel grid is installed, due to the gap, Not easy to fix.
The main welding equipment used in the welding process is a CO2 gas shielded welding machine. The CO2 gas shielded welding used is a semi-automatic operation. The deformation caused by heat during the welding process is small, and it can be continuously operated with high productivity. After welding, there is no need to clean the slag. The welding spot is smooth and beautiful, and the intermediate links are reduced, which greatly improves the welding construction efficiency. , which is conducive to ensuring the construction progress and welding quality.
The beneficial effect of adopting the above technical solution is that it is a one-time forming welding technology, which can effectively solve the time caused by repeated acid treatment and dip plating by changing the traditional integrated welding after galvanizing to first integrated welding and then galvanizing. waste, and effectively improve the consistency of appearance and color of steel grating products.
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