Methods for welding carbon steel elbow pipes to avoid cracks

Carbon steel elbow is easy to produce cold cracks, hot cracks and other deficiencies during welding, so it is necessary to adopt some special processes to carry out conventional welding.

So how to prevent cracks when welding?

Next, Matt Red pipe fittings will explain to us. All kinds of arc welding methods can be used to weld carbon steel bend pipe. It is mostly used to process machine parts, and will not be a large welding structure, so arc welding method is used more in production.

In order to prevent cold cracks and hot cracks in welded joints, low hydrogen electrode welding is usually selected when arc welding, which not only makes the hydrogen content low, but also has a certain degree of desulfurization and phosphorus.

When the content of carbon in steel is low and the joint tightness is not very large, you can choose ilmenite type or titanium-calcium type electrode welding, but must adopt strict technological methods to cooperate with each other

Method for welding carbon steel elbow pipes to prevent cracks

 Pre-welding heating is the most useful process method to prevent cracks when welding carbon steel bend pipe, so that there will be no cracking in the process of use, cracking, it will be a considerable loss for which party

Heating can not only reduce the cooling rate of the joint but also prevent the production of austenite, reduce the welding stress and accelerate the dispersion of hydrogen escape.

The key to the selection of heating temperature and interlayer temperature is the carbon equivalent of steel, base metal thickness, structural stiffness, electrode type, etc.

The heating temperature can be checked by weldability test or by calculation formula T0=550(C-0.12)+0.4δ, where T0 indicates the heating temperature (℃).

This temperature indicates the mass fraction of carbon in the base metal (%), and δ indicates the thickness of the plate (mm). It is appropriate for the welds to be U-shaped or V-shaped, which reduces the amount of the base metal fused into the weld.

Select several elements of the factory

Manufacturers of their credit are the accumulation of years, in the sales of bending pipe at the same time pay more attention to the opinions of customers, because it directly affects their visibility, good credit manufacturers pay attention to their brand image, corporate image, customer recognition of their situation

Keep an eye on the scale of its production and the volume of transactions per person. Due to good credit, the trading volume of the manufacturer is relatively good, so to better serve customers, and expand the trading volume, usually, the scale of the factory is relatively large, to ensure that the timely supply to customers, without affecting the construction period. The above are some views of the evaluation manufacturers.