Segregation in the welds of the following three:
⑴ microsegregation bath crystallization time, the central metal of the first crystallization of the crystallization of the most pure, the part after crystallization with other alloying elements and impurities slightly higher, part of the final crystallization, ie, crystallization of the outer end and the leading edge of the other alloying elements contained in impurities in the highest. A columnar grain interior and grain chemical composition of the uneven distribution of the phenomenon known as microsegregation. ⑵ regional segregation bath once crystallization, due to the columnar crystals continue to grow and goes on, will impurities "rush" to Types Of Welding Electrode, more than other parts of the impurity content of the bath centers, a phenomenon referred to as regional segregation. The weld cross-section shape of the distribution of regional segregation. Narrow and deep welds, the junction of columnar crystals in the center of the weld, the weld center gathered more impurities. This weld hot cracking in its central parts easily. Wide and shallow weld impurities gathered in the weld the upper part of Welding Material has a high resistance to thermal crack. ⑶ layered segregation bath in a crystallization process, to continue to release latent heat of crystallization, when the latent heat of crystallization reaches a certain value, the crystallization of molten pool on a temporary pause. After the heat with the bath, crystallization again began to form a periodic crystalline, accompanied by periodic changes in the concentration of impurities in the crystalline forefront of liquid metal, resulting in periodic segregation known as layered segregation. Layered segregation concentration of some harmful elements, defects often appear in the layered segregation. Pores caused by the layered segregation.