METHOD FOR CLADDING TUBES

摘要

The manufacture of clad tubes using powder metallurgy and hot isostatic pressing is described. A tube (10) of corrosion resistant material is placed inside another tube (12) and the annular space (20) filled with metal powder (26). The tubes (10,12) are covered, evacuated, sealed, and consolidated by hot isostatic pressing creating a billet. The billet is then reduced in thickness into a clad tube (18'). Alternatively, a low-alloy steel tube (10) is surrounded by a thin tube (12) of mild steel and the annular gap (20) formed between them is filled with powder alloy (26) with high corrosion resistance. The tubes (10,12) are covered, evacuated, sealed and consolidated by hot isostatic process into a billet for subsequent reduction to result in a clad tube (18'). The mild steel tube (12) is sacrificial and is removed by pickling to leave a low alloy tube (10) with a thin surface layer of corrosion-resistant alloy.