LOW ALLOY STEEL EXCELLENT IN RESISTANCE TO CORROSION BY HYDROCHLORIC ACID AND CORROSION BY SULFURIC ACID AND WELD JOINT COMPRISING THE SAME

摘要

The present invention provides a low alloy steel and a weld joint thereof excellent in hydrochloric acid corrosion resistance and sulfuric acid corrosion resistance, said low alloy steel containing, in mass, C: 0.001 to 0.2%, Si: 0.01 to 2.5%, Mn: 0.1 to 2%, Cu: 0.1 to 1%, Mo: 0.001 to 1%, Sb: 0.01 to 0.2%, P: 0.05% or less, and S: 0.05% or less, with the balance consisting of Fe and unavoidable impurities; and the acid corrosion resistance index AI of said low alloy steel being zero or positive. ??Here, said AI is given by the following expression, DFAI/10,000 = 0.0005 + 0.045 x Sb% - C% x Mo%, /DF where % means mass %. IMAGE