Specific Elimination Method of Galvanized Pipe

1. The banded structure caused by component segregation, i.e. when the galvanized pipe contains harmful impurities such as phosphorus and is calendered, the impurities elongate along the calendering direction.

　　2. The banded structure caused by improper hot working temperature, i.e. when the stop forging temperature is in the two-phase zone, ferrite precipitates from austenite along the direction of galvanized pipe. The undissolved austenite is cut into bands, and the banded austenite is transformed into banded pearlite.

　　3. Galvanized pipe is difficult to eliminate the banded structure caused by segregation by heat treatment. Normally normalizing can alleviate the segregation to a certain extent.

　　The reason for the formation of banded structure is the segregation of alloy elements ASTM A106 Cold Rolled Seamless Steel Galvanized Pipe, especially the segregation of sulfur and phosphorus and various non-metallic inclusions, such as MnS and silicate inclusions, which are easy to form banded structure. Dendrite segregation during solidification of steel can not be eliminated during subsequent pressure processing, and often retains the banded structure. In addition, improper hot-binding and forging processes, especially without repeated forging and reversal forging in different directions, will also preserve the ribbon structure of raw materials.