What is the acceptance standard of electroslag pressure welding?

The height of the welding package evenly protruding from the surrounding steel bar surface should be greater than or equal to 4mm, and the axis deviation of the joint should not be greater than 0. 1 times of the steel bar diameter, and should not be greater than 2 mm. The joints that fail to pass the visual inspection should be rejected for re-welding, or steel bar welding measures should be taken. The tensile test results of electroslag pressure welding joint show that the tensile strength of the three specimens should not be less than the specified tensile strength of the steel bar of this grade.

Electroslag pressure welding is a pressure welding method. Two steel bars are placed vertically or obliquely (the inclination is in the range of 4: 1), and the welding current passes through the gap between the two steel bars, forming arc process and electroslag process under the flux layer, generating arc heat and resistance heat, melting the steel bars and pressurizing them.

Matters needing attention in electroslag pressure welding

The welded ends of steel bars should be straight, and the upper and lower steel bars must be concentric, otherwise they should be adjusted. During the welding process, it is not allowed to move the steel bar to ensure that the steel bar falls freely and normally, otherwise, a "false welded" joint with good appearance will be produced.

When jacking steel bar, it must be straightened and cannot be moved for about 0.5 minutes to ensure the solidification of molten iron at the joint. The cooling time is about 2 ~ 3min, and then the medicine box can be removed. When the flux box can be turned around, remove the flux box as late as possible to ensure the slow cooling of the joint.

Before formal welding, specimens should be made according to the same batch of steel bars and the same welding parameters, and the welding parameters can only be determined for construction after inspection. After the type and specification of steel bar are changed or repaired by welding machine, pre-welding test is needed.