Generally speaking, it is 201 material, the difference is:
1. The thickness of the positive stainless steel plate will be within the specified size, for example, the thickness of the stainless steel plate is uniform, generally 1 word tail, such as 0.51, then only 0.5; The calender is generally only 0.5, or at 0.49, thinner at 0.45;
2. The stainless steel surface of the positive material is very soft milky white, and the rolling will have rollers and steel marks and other bad marks;
3 Stainless steel calendering will have uneven thickness phenomenon, the whole plate in the middle of the thick on both sides of the thin characteristics, stainless steel plate is generally not such a phenomenon
The above points are the main differences between positive and calender, and the most commonly used statement is that the thickness and surface condition of the card can be basically distinguished.
1. The backside adopts the blocking plate for blocking ventilation protection (i.e., solid core welding wire +TIG)
When the stainless steel pipe is prefabricated, the welding joint can usually be rotating welding, and the ventilation is very easy. At this time, the sealing plate is usually used to protect the welding joint on both sides of the stainless steel pipe (see Figure 1), and the outside is blocked with adhesive cloth.
When welding, the process of advance ventilation and delayed gas stop should be adopted. The outer adhesive cloth is torn off while welding. Because the blocking plate is composed of rubber and sheet iron, it is not easy to damage, so this welding method can ensure that the inside of the weld is full of argon and ensure its purity, so as to effectively ensure that the inside metal of the weld is not oxidized and ensure the quality of the weld bottom welding.
2. Only soluble paper is used or soluble paper is combined with the plug plate for plugging and ventilation protection (i.e., solid core wire +TIG+ water-soluble paper)
When stainless steel pipe fixed opening is installed and welded, the inner ventilation is more difficult, and some side is easier to plug, in this case, water-soluble paper + plugging plate can be used to plug. That is, the side that is easy to ventilate and easy to remove is blocked with a blocking plate, the side that is not easy to ventilate and difficult to remove the blocking plate is blocked with water-soluble paper, and the outside is blocked with adhesive cloth pasting the weld (see Figure 2).
When welding stainless steel fixed mouth, in many cases, both sides of the weld can not be ventilated, then how to ensure that the inside of the weld filled with argon protection has become a problem, in the actual construction of the site, we use water-soluble paper on both sides of the weld to seal, from the center of the weld ventilation, the outside of the adhesive cloth paste sealing method (see Figure 3), Successfully solved the above problems.
When the water-soluble paper is used to seal the ventilation, due to the ventilation from the center of the weld, the ventilation tube should be quickly pulled out at the last sealing link, and the remaining argon gas inside should be used for protection, and the bottom should be quickly completed and the mouth should be sealed.
Using this method, it should be noted that the water-soluble paper should be double-layered, and it must be pasted well, otherwise it is easy to cause damage to the water-soluble paper, fall off and make the inner weld lose the protection of argon, resulting in oxidation, resulting in the welding joint cutting and re-welding, which can not ensure the welding quality, but also seriously affect the construction period, so before welding should be strictly checked and pasted the water-soluble paper.
In many construction sites, we have adopted this welding method for the bottom, its quality can be effectively guaranteed, but also have a certain degree of difficulty in construction, so we should choose a careful, skilled welder for this job.
3. The back is not protected by argon, using flux-cored wire +TIG process
This method has been applied in China for several years, and has produced E308T1-1, E308LT1-1, E309T1-1, E309LT1-1, 347T1-1, E316T1-1, E316LT1-1 and other flux-cored welding wires, and has been applied in field welding, and achieved good economic benefits.
Because the back is not filled with argon, its advantages are obvious, mainly manifested as high efficiency, simple, low cost, suitable for construction site installation. However, due to its structural characteristics, the operation of flux-cored wire has higher requirements for welders, the wire feed speed is fast, the wire feed accuracy is high, there is a certain difficulty to master, welders should be specially trained, skilled behind can participate in welding, in Nanjing Yangba and foreign sites, we apply this method, successfully solved the problem of the collision port, repair port can not pass argon.
