Welding

203 type E materials have high carbon content levels for different thicknesses. It is usually supplied in the normalized condition though further improvements in toughness can be obtained by tempering after normalizing or tempering after quenching. This steel is welded with electrodes of AWS class E 8018-C2 or E 8016- C2 using preheat temperature in the range of 100 -125 0 C. Maintain low heat input to avoid problems during welding . Weld ment has to be stress relieved at about 625 0 C. E 8018-C2 with 3.5 % Ni is found to be suitable for service temperatures down to - 100 0 C and provides minimum impact value of 27 J ( 20 ft-lb) at -73 0 C. For SAW process use a special 3.0 % Ni – 0.25 % Mo wire with a multi pass welding technique with relatively low heat input rate. For MIG process welding with same type of wire , but additional AL is found to be beneficial. For Liquid Ethylene service a SS (E 309) or even Inconnel electrode is also considered. Sridhar