Carbon Steel Weldability
Date:2018-01-19 View:636 Tag:Carbon Steel Weldability
Welding materials under specified conditions, the construction of components required by the design of welding methods, and to meet the intended use requirements. Through the welding material, welding, component type and the requirements of the four factors.
Low carbon steel welding
Due to low carbon steel, manganese carbon content, less silicon content, so there is usually no serious welding quench hardened tissue or tissue. Low-carbon steel welded joints have good plasticity and impact toughness. Generally, they do not need to be preheated to control the temperature and heat in the interlayer. The structure of the post-weld heat treatment is not perfect. The whole process does not need special welding process and welding.
Medium carbon steel welding
Carbon structural steel carbon mass fraction of 0.60% 0.25% ~. Nearly 0.25% carbon, manganese content of the mass fraction is not high, good solderability. As the carbon content increases, the weldability gradually deteriorates. If the carbon content is about 0.45%, but according to the heat-affected zone used for welding mild steel may produce brittle martensite, easy to crack, crack formation. Welding, the amount of base metal is integrated into the weld, the weld to increase the carbon content, and promote the welding of hot cracks, especially in the strict control of sulfur impurities, more likely. This crack is more sensitive to crater heat in the weld cracking and flake, the wavy lines perpendicular to the distribution of the weld.
High-carbon steel welding
When the carbon content of high-carbon steel is more than 0.60%, the tendency to be hardened is large, so the weldability is poor and the weld crack sensitivity can not be used in the manufacture of welded structures. Requires more common manufacturing of hard or worn parts, the welding work is the main welding repair. As the high-strength carbon steel mainly in the 675mpa above, so the common electrode model e7015, e6015, optional E5016, E5015 electrode structure when the members require too much. In addition, we can use chrome-nickel austenitic steel welding electrodes. Due to high carbon steel parts to obtain high hardness and wear resistance, the material itself is heat treatment, welding should be annealed before welding. Preheating should be carried out before welding, preheating temperature generally above 250 ~ 350 ℃, the welding process shall not be less than the preheating temperature between the temperature of the insulation layer. The heat of the slow cooling of the weldment after welding requires the stress relieving heat treatment at 650 ℃ immediately into the furnace.