1, chromium stainless steel with a certain degree of corrosion (oxidizing acids, organic acids, cavitation), heat and abrasion resistance. Typically used in power plants, chemical, oil, and other equipment and materials. Chromium stainless steel welded poor, should pay attention to the welding process, heat treatment conditions and the appropriate choice of Mig Welding Electrode.
2, chrome 13 stainless steel after welding sclerosing larger prone to cracks. The welding must be carried out about 300 ° C above the preheating and post weld 700 ° C slow cooling treatment using the same type of chromium stainless steel electrode (G202, G207). Weldment can not post-weld heat treatment should be used chrome-nickel stainless steel electrode (A107, A207).
3, Chromium 17 Stainless Steel, to improve the corrosion resistance and weldability and appropriately increase appropriate stability of the elements Ti, Nb, Mo, etc., a good weldability than 13 chromium stainless steel. Should be carried out using the same type of chromium stainless steel electrode (G302, G307), preheat and post-weld above 200 â„ƒ and 800 â„ƒ tempering. Weldment can not be heat treated, should be used chrome-nickel stainless steel electrode (A107, A207).
4, chrome-nickel stainless steel electrode has good corrosion resistance and oxidation resistance, widely used in chemical, fertilizer, petroleum, medical machinery manufacturing.
Chrome-nickel stainless steel welded carbide precipitation by repeated heating to reduce corrosion resistance and mechanical properties.
6, chrome-nickel stainless steel titanium calcium type low hydrogen type drug skin. Titanium calcium type can be used for AC-DC and AC welding penetration shallow, and at the same time easy to redness, so as much as possible with DC power. Diameter of 4.0 and below can be used for all-position welding pieces of 5.0 and above for flat welding and fillet welding.
7, the electrode should be kept dry, titanium calcium type shall be approved by the dried at 150 â„ƒ for 1 hour, low-hydrogen type shall be approved by of 200-250 â„ƒ dry for one hour (not repeated drying or drug skin prone to cracking peeling) to prevent electrode medicated skin sticky oil and other dirt, to avoid causing the weld to increase the quality of the carbon content and impact of the weldment.
8, in order to prevent the generated eye intergranular corrosion due to the heating, the Welding Wires current should not be too large, about 20% less than the carbon steel electrode, an arc is not too long, the interlayer fast cooling, preferably with narrow weld.
Cellulose type electrode arc blowing force, not only backing weld guaranteed one-side welding molding down welding by means of blowing force, and in all-position stand: on the one hand, holding a "melting pool of metal to make no less than drips; the other hand can be "blown open" above the slag of molten pool metal molten pool clear, so welders easy to operate, and to ensure the quality of welding; addition, larger electric blowing force can fully protect the weld pool metal. Therefore, the size of the Arc force reflect the important aspects of the cellulose type electrode process performance advantages and disadvantages. Cellulose-type electrode, the arc blowing force from the power of the air stream formed by the decomposition of the gas in the arc welding, the main factors are: (1) amount of organic matter in the drug skin; (2) moisture content in the electrode ; (3) carbonate fraction. In addition, with the carbon content in the Mig Electrode, the sleeve size the drug skin strong oxidizing component and the welding specification.
Organics in the electrode in the arc under high temperature decomposition gas of CO2, CO, H2, hydrocarbons and H2O, etc. , which are the main source of the arc gas Arc force is increased, when the content thereof is increased, but the trial found The different types of organisms under the same conditions, their Arc force is different, wherein the ratio of microcrystalline cellulose bamboo powder, CMC and other large. Comprehensive consideration of extrusion coating and process performance, the organic material added to the microcrystalline cellulose-based, bamboo powder, CMC, supplemented, were added in an amount of a total of 20% to 40%. The decomposition of hydrogen and oxygen the drug skin in water in the arc at high temperatures, not only can increase the arc blowing force, but also can increase the oxidation resistance of the arc atmosphere. The drug skin moisture content in the main determined by the baking process, when the water content of the drug skin is small (less than 2%), then the electrode process performance deteriorates; if the drug skin moisture, then the welding arc unstable and spatter increased, without conducive to the transportation and preservation of the electrode. Furthermore, in the testing process also found that if the drug skin moisture (such as about 10%, the baking process is 60 ° C × 2h), the changes in the process performance of the posterior segment of the electrode is large, will cause the posterior segment electrodes blowing force, molten pool is not clear, prone to porosity and other issues. This is because the posterior segment electrode in the water content is large in the evaporation of moisture in the welding more reason, and therefore should be adequate for controlling the moisture under the premise of ensuring Arc force.  pointed out that the high cellulose type electrode moisture content of between 5% to 7% is more appropriate, for the need to develop a suitable baking process. Carbonate in the electrodes in the arc under high temperature decomposition of the gases such as CO2, CO, and help to improve the electric blowing force, the test was found, in the case of the other components unchanged, to reduce the content of carbonate (reduced by 16% 7%) Arc force will decrease. Addition, under the same conditions, the impact of different types of carbonate on the Arc force also varies, and this may be related to the decomposition temperature of different. The oxidation of the carbon electrodes in the arc phase into CO gas, thereby increasing the arc blowing force, However, as the carbon content increases, the arc stability and spatter is gradually deteriorated. Also affect the size of theCopper Electrodesburning end of the sleeve formed in the welding process, the arc blowing force, the sleeve length can be constrained arc airflow divergence, thereby increasing arc stiffness, so that the arc blowing force can also be increased. Found in Austria Foxcel cellulose type electrode arc characteristics comparison, the real decision arc stiffness factor is the effect of the contraction of the arc itself, the welding rod sleeve is of secondary importance in this regard remains to be further . Number of strong oxidizing electrode coating component also affects the arc blowing force, strong oxidizing ingredients in sufficient quantity, the oxidation reaction in the arc phase drug skin can be sufficiently performed, which can generate more gas, thus increasing the arc blowing force.
Was found in the development process, if the lack of strong oxidizing component, even a further increase in the organic content of the drug skin, Arc force is also no significant improvement. Welding specification is the important factors affecting the blowing force of the arc, the current is large, the blowing force, otherwise smaller. Cellulose type electrode current large easy to over-burning cellulose type electrode welding process, both to keep the larger arc blowing force can prevent overfiring cellulose type electrode welding machine can be used. In the above the many factors affecting the Arc force, although the increase in the organic matter and moisture content and the current size can be significantly improved Arc force, but sometimes makes the process performance of the electrode segments before and after changed greatly, and the carbon, carbonates, and strong oxidizing component content increases will not be increased while increasing the arc blowing force of electrodes over-burning, and this is often to add the latter to improve the arc blowing force reasons. The actual pipe welding tests showed cellulose type electrode developed the Arc force to meet the pipeline all-position stand down welding requirements.