Design and Development of 125 mm Pass of Φ180 mm PQF Mill

To expand the product size range,a new 125 mm pass of the Φ180 mm PQF mill is designed and developed based on the original pass.Taking the production of the Φ73 mm×4.0 mm pipe as an example,the design and development of 125 mm pass for the piercer,the PQF proper and sizing (reducing) mill are described,focusing on the design thinking,the development activities and the trial production.The actual production result demonstrates that the design of the 125 mm pass is reasonable,the pipe surface quality is good,and the WT accuracy is high.The successful development of the 125 mm pass has got the lower limit of the product size range of the Φ180 mm PQF mill enhanced from the original Φ114 mm×4.0 mm up to Φ73 mm×4.0 mm.