1) carbon (C) Carbon is the main alloying elements in steel, when the carbon content increases, the steel {strength, hardness markedly improved, and the plastic lower. In the welding process, the carbon oxygen play a role in the arc under high temperature and oxygen compounds, generating carbon monoxide and carbon dioxide gas, the air around the arc and weld pool exclusion zone to prevent the oxygen in the air, nitrogen gases adverse impact on the pool, reducing the weld metal oxygen and nitrogen. If the carbon content is too high, to restore the role of severe, will cause a larger splash and pores. Taking into account the carbon steel hardened to the crack and its increased sensitivity to the effects of low-carbon steel welding core of the general cluster 0.1%.
2) Manganese (Mn) of manganese in steel is a good alloying agent, as the manganese content increases, the strength and toughness will be increased. In the welding process, the manganese is also a good dose of oxygen, can reduce the oxygen content in the weld. Together to form manganese sulfide and manganese sulfide float in the slag, thus reducing the tendency to weld hot cracking. Therefore, carbon structural Stainless Steel Electrode core general's manganese content is 0.30% ~ 0.55%, some special-purpose wire welding, the manganese content of up to 1. 70% to 2.10%.
3) Silicon (Si) silicon is a good alloying agent in steel by adding an appropriate amount of silicon can increase the steel yield strength, flexibility and acid resistance; if the content is too high, reduce the plasticity and toughness. In the welding process, silicon also has good oxygen capacity and oxygen to form silicon dioxide, but it will increase the slag viscosity, easy to promote non-metallic inclusions generated.
4) Chromium (Cr) chromium steel to improve hardness, wear resistance and corrosion resistance. For low carbon steel, the chromium is a kind of accidental impurities. The main features of chrome is easy to rapid oxidation of metallurgy, the formation of refractory oxide chromium oxide (Cr203), which increases the likelihood of weld metal inclusions. Transition to the chromium oxide slag, the slag viscosity can improve, lower liquidity.
5) Nickel (Ni Ni toughness of steel have more significant effects, generally require a higher temperature impact value, the appropriate incorporation of some of the nickel.
6) Sulfur (S) Sulfur is a harmful impurity, with the sulfur content increases, the tendency to increase weld hot cracking, so the welding core sulfur content of no greater than 0.04%. Important in the welded structure, the sulfur content not more than 0.03%.
7), phosphorus (P)

keywords: Welding Electrode

stainless steel welding rod should be used with the following questions:

1, chromium stainless steel with a certain degree of corrosion (oxidizing acids, organic acids, cavitation), heat and wear resistance. Typically used for power plants, chemical, oil and other equipment and materials. Chromium Stainless Steel Electrode is poor, should pay attention to welding, heat treatment conditions and selection of appropriate welding rod.

2, chromium stainless steel after welding, hardening of 13 large, easy to crack. If using the same type of chromium stainless steel electrode (G202, G207) welding must be carried out more than 300 ℃ 700 ℃ preheating and post-weld around the slow cooling process. If the weldment can be post weld heat treatment, should be used chrome-nickel stainless steel electrode.

3, 17 chromium stainless steel to improve corrosion resistance and weldability increased amount of stability and appropriate elements Ti, Nb, Mo, etc., welding of stainless steel better than the chrome 13. Using the same type of chromium stainless steel electrode (G302, G307), should be preheated above 200 ℃ 800 ℃ and after welding so tempered. If the weldment can be heat treated, chrome-nickel stainless steel welding rod should be used

4, Cr-Ni stainless steel electrode has good corrosion resistance and oxidation resistance, widely used in chemical, fertilizer, petroleum, medical equipment manufacturing.

5, chrome-nickel stainless steel welding, carbide precipitation by repeated heating and reduce corrosion resistance and mechanical properties.

6, chrome-nickel stainless steel skin with titanium calcium type drugs and low-hydrogen type. Titanium calcium type can be used for AC and DC, but AC welding penetration shallow and easy to redness, so as far as possible dc power supply. Diameter of 4.0 and below can be used for all position welding pieces, 5.0 and above for flat butt and fillet weld.

7, the electrode should be used to keep dry, titanium calcium type shall be 150 ℃ drying 1 hour, low-hydrogen should be dried by 200-250 ℃ for 1 hour (can not be repeated drying, easy to crack and peel off the skin or drugs) to prevent the electrode drug skin oil and other sticky dirt, so as not to increase the carbon content of the weld and the resulting impact on the quality of weldments.

8, to prevent corrosion between the eyes resulting from heating, Aluminum Electrode current is not too large, less than about 20% of carbon steel electrode, the arc should not be too long, rapid cooling layer to narrow weld appropriate.