Precautions for the use of the hottest stainless s

2022-08-22
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Precautions for the use of stainless steel welding rods

precautions for the use of stainless steel welding rods are:

1. Chromium stainless steel has certain corrosion resistance (oxidizing acid, organic acid, cavitation). In order to meet the requirements of various laws and regulations, and the accuracy can be reached, two-point extensometer must be added for heat resistance and wear resistance. It is usually used for power station, chemical industry, petroleum and other equipment and materials. Chromium stainless steel has poor weldability, so attention should be paid to the welding process, heat treatment conditions and the selection of appropriate electrodes

2. Chromium 13 stainless steel has high hardenability after welding and is prone to cracks. If the same type of chromium stainless steel electrodes (g202, G207) are used for welding, preheating above 300 ℃ and slow cooling treatment at about 700 ℃ after welding must be carried out. If the weldment cannot be subject to post weld heat treatment, chromium nickel stainless steel electrodes (A107, A207) shall be selected

3. Chromium 17 stainless steel, in order to improve the corrosion resistance and weldability, appropriately add an appropriate amount of stability elements Ti, Nb, Mo, etc., and the weldability is better than chromium 13 stainless steel. When the same type of chromium stainless steel welding rods (G302, G307) are used, preheating and welding above 200 ℃ should be carried out. These are issues that need to be focused on, and tempering treatment at about 800 ℃ should be carried out. If the weldment cannot be heat treated, chromium nickel stainless steel electrodes (A107, A207) shall be selected

4. Chromium nickel stainless steel electrode has good corrosion resistance and oxidation resistance. If high wear resistance is required, it is widely used in chemical industry, chemical fertilizer, petroleum and medical machinery manufacturing

5. When chromium nickel stainless steel is welded, carbides are precipitated by repeated heating, which reduces the corrosion resistance and mechanical properties

6. Chromium nickel stainless steel coating has titanium calcium type and low hydrogen type. Titanium calcium type can be used for AC and DC, but AC welding has shallow penetration and is easy to redden, so DC power supply should be used as much as possible. Diameter 4.0 and below can be used for all position weldments, and 5.0 and above can be used for flat welding and flat fillet welding

7. The welding rod should be kept dry when used. The titanium calcium type should be dried at 150 ℃ for 1 hour, and the low hydrogen type should be dried at ℃ for 1 hour (do not repeatedly dry, otherwise the coating is easy to crack and peel off), so as to prevent the coating of the welding rod from sticking oil and other dirt, so as to avoid increasing the carbon content of the weld and affecting the quality of the weldment

8. In order to prevent eye corrosion due to heating, the welding current should not be too large, which is about 20% less than that of carbon steel electrode. The arc should not be too long, and the interlayer should be cooled quickly. Narrow weld beads are preferred

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