Between Shanghai weld corrosion detection

Room 316L stainless steel corrosion test reports Zhejiang capacity Okawa Detection Technology Services Ltd., to provide product testing and certification services and export certification services. Shu workers: 18121031197, phone: 021-58337982, QQ: 1749526762 intergranular corrosion refers to corrosion occurs mainly in the grain boundary region of metallic materials, development along the grain boundaries, namely the dissolution rate of the grain boundary area is much larger than the grain dissolution rate. ? Intergranular corrosion electrochemical conditions (1) the occurrence of different organizations grains and grain boundary area, so there is a significant difference in the electrochemical properties. -? Internal (2) differences in grain and grain boundaries should, under appropriate circumstances to be revealed. - The main measures to intergranular corrosion of external precautions to prevent: 1 to adjust the chemical composition of the weld, adding a stabilizing element to reduce the possibility of the formation of chromium carbides, such as titanium or niobium added?. ? 2 to reduce the carbon content of the weld, can reduce and avoid the formation of chromium carbides, thereby reducing the tendency to form intergranular corrosion, the carbon content of 0.04% or less, known as the "ultra-low carbon" stainless steel, it is chromium carbides can be avoided. ? 3 craft measures to control the residence time of the temperature danger zone, to prevent overheating, fast welding rapid cooling, the carbon precipitates too late. ? To prevent or mitigate intergranular corrosion measures a. Selection of resistance to intergranular corrosion of alloys;? B. Select the appropriate heat treatment process, such as aluminum over-aging treatment;? C. In determining the welding process, aluminum bonding and milling processes, avoiding prone to intergranular corrosion under temperature treatment. ?