Alloy C-4 is an austenitic nickel-molybdenum-chromium alloy with a low carbon, silicon, and iron content. This alloy has a significantly lower tendency to form precipitation in the temperature range between 650 and 1,040 °C(1,202 - 1,904 °F), improving its resistance to inter-crystalline corrosion. When machined perfectly, no knife line attack occurs in the heat-affected zones of awelding edge. Alloy C-4 is characterized by: Very good resistance in a broad field of corrosive media, in particular under strongly oxidizing conditions.The surface of the plate is smooth, with high plasticity, toughness and mechanical strength, resistant to acid, alkaline gas, solution and other media corrosion. It is an alloy steel that is not easy to rust, but it is not absolutely rust free. The plate refers to the steel plate that is resistant to the corrosion of weak media such as atmosphere, steam and water, and the acid-resistant steel plate refers to the plate that is resistant to the corrosion of chemical corrosive media such as acid, alkali and salt.