Influence factors of copper brittleness defects in ASTM Corten B weathering steel

Copper element is often added to the ASTM Corten B weathering steel to improve the corrosion resistance of Corten B steel. The copper steel in the heating process is heated. Because of the selective oxidation, the iron on the surface of the slab is prior to the copper oxidation, resulting in the enrichment of the copper element. When the iron is dissolved in the copper, the copper element will be precipitated on the interface of iron and phosphorus with the steel, and it is difficult to remove the phosphorus. Retained in the steel, to a certain extent, resulting in hot brittleness of ASTM Corten B weathering steel.

The typical copper brittle defects in ASTM Corten B weathering steel are like cracks or pitting shaped skin, and are distributed in sheets, and the length is distributed on the upper surface of the strip, and the oil stone is not polished. The analysis shows that the copper brittleness of ASTM Corten B weathering steel is related to the furnace temperature, the furnace temperature, the time of furnace, the thickness, the width reduction and the ratio of copper to nickel. Among these factors, the influence of furnace time is the most significant, followed by thickness and furnace temperature, and the copper nickel ratio is the least significant.