J506 and J507 can be used, but high-speed steel (white steel) electrodes cannot be used.:
Do not use high-speed steel (white steel) electrodes. Cast steel can be divided into low carbon steel, medium carbon steel, etc. according to the composition. Different compositions require different welding rods. If it is low carbon steel, you can use ordinary welding rods, such as E4303 (J422); if it is medium carbon For steel composition, high-strength structural steel electrodes should be used, such as E5015 (J507), E5515 (J557), etc. The weldment must be preheated during welding to prevent cracks.
White steel welding rod: Scientific name: Chromium-nickel stainless steel welding rod implements GB/T983-1995 standard Instructions for use: Chromium-nickel stainless steel welding rod has good corrosion resistance and oxidation resistance, and is widely used in chemical industry, petroleum, and fertilizers , food machinery, medical equipment and other equipment manufacturing. When chromium-nickel stainless steel is welded, carbides will precipitate after repeated heating, which will reduce corrosion resistance and mechanical properties. Therefore, the welding rod should be selected according to the working conditions of the equipment (working temperature and medium type, etc.). Generally, the welding rod should be selected with the same or similar composition as the base material, and the welding rod should be selected mainly according to the medium and working temperature. 1. When the working temperature is above 300°C and there are strong corrosive media, it is necessary to choose stainless steel electrodes containing Ti or Nb stabilizing elements or ultra-low carbon stainless steel electrodes; for media containing dilute sulfuric acid or hydrochloric acid, stainless steel electrodes containing Mo and Cu are often used. . 2. It works at normal temperature and is weakly corrosive. Stainless steel electrodes that do not contain Ti or Nb can be used. 3. The carbon content of the deposited metal has a great influence on the corrosion resistance of stainless steel. Generally, stainless steel electrodes with a carbon content no higher than that of the base metal or ultra-low carbon stainless steel electrodes are selected. Stainless steel welding precautions: Chromium stainless steel has poor weldability, martensitic chromium stainless steel has a tendency to be brittle and hard when welded, and ferritic chromium stainless steel tends to have grains that grow under high welding temperatures, all of which make the weld highly brittle. Although chromium-nickel stainless steel has better weldability, high welding current is prone to problems such as intergranular corrosion of the welded joint, hot cracking of the weld seam, and increased welding stress and deformation. 1. Stainless steel welding rods usually come in two types: calcium titanium type and low hydrogen type. The welding current should use DC power source as much as possible, which is helpful to overcome the redness and shallow penetration of the welding rod. Welding electrodes with titanium-calcium coating are not suitable for all-position welding and are only suitable for flat welding and flat fillet welding; electrodes with low-hydrogen coating can be used for all-position welding. 2. Stainless steel welding rods should be kept dry during use. In order to prevent cracks, pits, pores and other defects, the titanium-calcium coating should be dried at 150-250℃ for 1 hour before welding, and the low-hydrogen coating should be dried at 200-300℃ for 1 hour before welding. Do not dry it repeatedly, otherwise the drug skin will easily fall off. 3. Clean the welding joint and prevent the welding rod from being stained with oil and other dirt to avoid increasing the carbon content of the weld and affecting the welding quality. 4. In order to prevent intergranular corrosion caused by heating, the welding current should not be too large. It should generally be about 20 times lower than that of carbon steel electrodes. The arc should not be too long. The interlayers will cool quickly. Narrow channel welding is appropriate. 5. When striking the arc, be careful not to strike the arc in non-welding parts. It is best to use an arc striking plate made of the same material as the weldment. 6. Short arc welding should be used as much as possible. The arc length is generally 2-3mm. If the arc is too long, it will easily cause thermal cracks. 7. Welding: Short arc fast welding should be used, and lateral swing is generally not allowed. The purpose is to reduce heat and the width of the heat-affected zone, improve the resistance of the weld to intergranular corrosion, and reduce the tendency of hot cracks. 8. When welding dissimilar steels, welding rods should be carefully selected to prevent thermal cracks caused by improper selection of welding rods or σ phase precipitation caused by high-temperature heat treatment and embrittlement of the metal. Refer to the welding rod selection standards for stainless steel and dissimilar steels and adopt appropriate welding techniques.