â‘´ Preheat conducive to reduce the maximum hardness of the heat affected zone of medium carbon steel, to prevent the generation of cold cracking, which is the main process for Stainless Steel Welding Electrodes, preheating can also improve the fitting plastic, to reduce the residual stresses after welding. Generally, the preheating temperature was 150 ~ 250 ℃ then high carbon content, or due to the thickness and stiffness, a tendency to crack when the preheating temperature was raised to 250 to 400 ° C for 35 and 45 steel.

The weldment too the overall preheat difficult, local preheating, heating range of local preheating of weld on each side 150 ~~ 200mm.

⑵ preferred basic electrode welding rod when conditions permit.

⑶ groove forms will try to open the weldment into a U-shaped groove for Welding Wires  If casting defects, dig out the bevel shape should be smooth, and its purpose is to reduce the base material is melted into the ratio of the weld metal, in order to reduce the carbon content in the weld and to prevent cracks.

â‘· welding parameters Since the base material is melted to the melting of the first layer of weld metal in the proportion of up to about 30%, so the first layer weld, should be adopted when the small current, slow welding speed, to reduce the base material deep.

Best weldments Claim ⑸ post-weld heat treatment after welding stress relief heat treatment, especially for large thickness of the weldment, the high-rigidity structure member, and under stringent conditions (dynamic load or impact load) weldment more so. Stress relief tempering temperature of 600 ~ 650 ℃.

Can not be post-weld stress relief heat treatment should be carried out immediately after the heat treatment.