| Clad pipe is composed of carbon steel (outer layer) and stainless steel (inner layer) using mechanical or metallurgical method. It combines the advantage of high strength of carbon steel and corrosion resistance of stainless steel. Hence, it can be employed to transport the acidic solution under high temperature and high pressure. This thesis mainly covers the following aspects:1. A new welding procedure has been developed according to the properties of the mechanical clad pipe.2. The welding procedure of the clad pipe weldment was assessed by the standard DNV OS F101. The results revealed that there was no crack observed in the macro pictures; the microstructure in different zones was uniform; the highest values of hardness were observed in the weld joint near the fusion line. The hardness in HAZ was higher than that in base metal. For SZP-86(2) specimens, there was no crack observed after longitudinal root bend or side bend tests. While for the SZP-88 specimens, four samples contained cracks after side bend tests. For transverse tensile tests, fracture was observed in base metal for all samples. For all weld tensile tests, the ductility of all stainless filler metal was better. For SZP-88 specimens, the ultimate tensile strength was about 30% higher than that of SZP-86(2) specimens and the ductility value was lower. The lowest impact toughness was observed in the weld joints.3. The corrosion rate of SZP-88 specimens increased with the increasing temperature. While for the case of SZP-86(2) specimens, the corrosion rate decreased with the increasing temperature. After removing the corrosion product layer, the surface of the weldment was uniform and bright. No local or pitting corrosion character was observed. Hence, the corrosion type was uniform corrosion.
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