â‘´ warm-up warm-up will help reduce the carbon steel heat-affected zone of maximum hardness, prevent cold cracking, which is the main Carbon Steel Welding Electrode process measures, but also to improve the joint warm-up plastic, reducing the residual stress after Welding Electrodes . Typically, 35 and 45 steel preheat temperature of 150 ~ 250 ℃ or higher in carbon content due to the thickness and stiffness of large, cracks tend to large, pre-heating temperature can be increased to 250 ~ 400 ℃.

If the weldment is too large, the overall warm-up difficulty, can be partial preheating, the heating range of local warm-up on each side of the weld 150 ~ 200mm.

⑵ electrode preferred alkaline conditions permit electrode.

⑶ groove weldment try to open the form of a U-groove-type welding. If casting defects, shovel dug the groove shape should be smooth, and its aim is to reduce the base metal melt into the weld metal in proportion to reduce the carbon content of the weld, to prevent cracks.

â‘· welding parameters due to the first layer of base metal molten weld metal in the highest proportion of 30%, so the first layer of seam welding, should maximize the use of small current, slow welding speed, to reduce the base metal melting deep.

⑸ weld heat treatment after welding, welded parts immediately the best stress relief heat treatment, especially for the large thickness of the weldments, structural parts and high rigidity under severe conditions (dynamic load or impact load) weldment work and even more so. Eliminate stress tempering temperature 600 ~ 650 ℃.

If post-weld stress relief heat treatment can not be carried out immediately after the heat treatment.