Suitability For Welding Of Sheet Pile

Welding involves fusing together two identical or very similar steels to form one homogenous component, and this is done by melting them together at their interface through liquefaction or plastic deformation. This can be carried out with or without the addition of another material. Arc welding isa very common method (manual metal-arc welding, shielded metal-arc welding). In this method an electric arc is generated between an electrode, which supplies the welding material, and the component. The suitability for welding depends not only on the material, but also on its shape, the dimensions and the fabrication conditions. Killed steels should generally be preferred.

According to EAU 2004 section 8.1.6.4 (R 67), and taking into account general welding speci- fications, arc welding can be used for all the grades of steel used for sheet piles. The building authority approvals must be adhered to for high-strength steel grades S 390 GP and S 430 GP. In addition, the carbon equivalent CEV should not exceed the value for steel grade S 355 to DIN EN 10025 table 4 if welding is to be employed. Furthermore, EAU 2004 section 8.1.6.4 (R 67) recommends using fully killed steels of the J2 G3 or K2 G3 groups to DIN EN 10025 in special cases, e.g. where plastic deformation due to heavy driving is expected, at low temperatures, in three-dimensional stress conditions and when the loads are principally dynamic, because of the better resistance to embrittlement and ageing required. Welding electrodes conforming to DIN EN 499, DIN EN 756 and DIN EN 440 or the specification of the supplier should be selected.

According to EAU 2004 section 8.1.18.2 (R 99), basic electrodes or filler materials with a high basicity should generally be used. The following table shows general information about the selection of suitable electrodes according to DIN EN 499.

Table:Welding electrodes for manual metal-arc welding to DIN EN 499 for steel grades S 240 GP to S 355 GP