Abstract��The cracking of ERW high-frequency resistance straight welded pipe happened in the production process. The characteristics of the typical cracking were summarized through the analysis of the macromorphology and microstructure. It was considered that the main cause of the cracking was the surface crack of the hot rolled steel strip and the abnormal controlled rolling and cooling process. By optimizing the covering slag and the flow field of the mold�� the uniform slow cooling can improve the surface crack of the steel strip caused by the surface longitudinal crack of the slab. Reasonable formulation for the water temperature�� opening degree of the upper header�� opening or closing of the side nozzle�� coiling temperature and other key process parameters of laminar cooling can effectively avoid the occurrence of the abnormal microstructure and influence the processability of the steel strip.
2018, Vol. 36 
