Research on the grain refinement method of cylindrical parts by power spinning

Investigation on dimensional accuracy and mechanical properties of cylindrical parts by flow forming

“…Figure 2 shows the principle of stagger spinning and counter-roller spinning. Figure 3 shows the devices used in the stagger spinning and the counter-roller spinning, respectively [3]. For flow forming, the main processing parameters influencing the dimensional accuracy and mechanical properties are the feed rate of roller f , per pass thinning ratio of wall thickness i ( i = (t i−1 -t i )/t i−1 , where t i−1 is the wall thickness of the cylindrical parts after i-1 passes spinning, t i is the wall thickness of the cylindrical parts after i passes spinning), and axial offset a and radial offset b between rollers (Fig.…”

“…Flow forming, which belongs to power spinning, is one of the most effective methods to manufacture cylindrical parts. It mainly includes the stagger spinning and counter-roller spinning [3]. During stagger spinning, the thinning ratio of thickness in one pass is divided among three rollers, the productivity is improved considerably, thus the processing method has been widely used in MATEC Web of Conferences aviation, aerospace and automotive industries [4].…”

“…During stagger spinning, the thinning ratio of thickness in one pass is divided among three rollers, the productivity is improved considerably, thus the processing method has been widely used in MATEC Web of Conferences aviation, aerospace and automotive industries [4]. During counter-roller spinning, however, the mandrel is replaced by the inner rollers and the spinning force is reduced to 50% of that in stagger spinning, it is particularly suitable for manufacturing large dimensional cylindrical parts and has attracted significant research interests in recent investigations [3].…”

“…They also reported that the value of LSP (layer spacing of pearlite) had been decreased with the increasing of the thinning ratio of the wall thickness during power spinning, and the tensile strength of spun tubes had been founded to be proportional to the reciprocal of LSP and the elongation was inversely proportional to the reciprocal of LSP [4]. Xiao et al reported that the distribution of equivalent strains and the percentage of grain refinement of the spun parts obtained by counter-roller spinning were more homogeneous than that of the stagger spinning [3]. The distribution of the equivalent strains of the spun parts obtained by stagger spinning and counter-roller spinning was different, which affected the dimensional accuracy and mechanical properties of the spun parts [3,4].…”

“…Xiao et al reported that the distribution of equivalent strains and the percentage of grain refinement of the spun parts obtained by counter-roller spinning were more homogeneous than that of the stagger spinning [3]. The distribution of the equivalent strains of the spun parts obtained by stagger spinning and counter-roller spinning was different, which affected the dimensional accuracy and mechanical properties of the spun parts [3,4]. To obtain the cylindrical parts with required mechanical properties and microstructure, the effect of different spinning methods and the total thinning ratio of wall thickness on the dimensional accuracy and mechanical properties of the spun parts are studied.…”