Carbon Steel Elbow Technology Processing

Typically, 35 and the preheating temperature is 45 steel carbon content of 150 ~ 250  high again because of the thickness and rigidity or great tendency to crack is large, the preheating temperature can be increased to 250 ~ 400 . If the weldment is too large, the overall preheat difficult, it can be localized preheating, heating range for both sides of the weld locally preheat each 150 ~ 200mm. Preferred alkaline electrode when welding conditions permit. 
Can not stress relief heat treatment should be carried out immediately after the post-weld heat treatment if. Speaking only from the design stress, pressure resistance carbon steel elbow best. However, due to various factors, the actual floor heating pipe wall thickness is usually in the wall thickness of the various types of pipes under the floor heating can meet the requirements of national standard carbon steel elbow pipe pressure advantages not manifest; thermal conductivity: for floor heating pipes need to have good thermal resistance, low temperature impact properties of low-temperature thermal shock resistance is better. Carbon steel welding process requires careful use in a suitable environment, continue to meet important performance, welding important environment to ensure quality. Beveling the weldment try to open a U-shaped groove type welding. If you are casting defects, shovel dug the groove shape should be smooth, and its aim is to reduce the base metal melt into the weld metal proportion in order to reduce the carbon content of the weld to prevent cracks. Since the welding parameters to a first layer of the molten parent metal in the weld metal ratio of up to about 30%, so the first layer of the welding seam, should be as low current, the welding speed is slow, to reduce the depth of penetration of the base material . After the best butt-weld heat treatment weld stress relief heat treatment pieces immediately, especially more so for the next (dynamic loading or impact load) weldment weldment working great thickness, high rigidity structure and harsh conditions. Eliminate the stress of tempering temperature is 600 ~ 650 .
Elbow push hot forming process is the use of special elbow pushing machine, mandrel and heating device, so that the mold sets in the blank under the impetus of the movement system pushed forward, is heated in motion, expanding and bending process. Heat push elbow tube diameter deformation characteristics are determined in accordance with the law of constant volume before and after plastic deformation of metallic materials, used in tube diameter smaller than the diameter of the elbow, by controlling the deformation process mandrel blank, so the arc is compressed at metal flow to other parts of the compensation due to the thinning of the enlarged diameter, thereby obtaining a uniform wall thickness of the elbow.