Application of hollow billets for the production of railway wheels and hollow car axles by screw piercing method

The results of the inspection of mechanical properties were provided for very-thick-walled shells (D/S approximate to 3.06 and D/S approximate to 3.1) made from T-grade steel wheel manufactured by screw piercing using experimental and industrial two-high mill MISiS 130D with the feed angle beta = 12 degrees/mu = 1.26 and beta = 14 degrees/mu = 1.36. A comparison of the obtained results of mechanical properties showed that the piercing process with a larger feed angle (i.e., beta = 14 degrees/mu = 1.36) is more preferable than the piercing process with beta = 12 degrees/mu = 1.26 to improve the properties of initial hollow billets. The analysis of the dimensions of very-thick-walled shells made from steel wheel with the ratio of D/S approximate to 3.1 manufactured by piercing using the screw rolling mill MISiS 130D showed high precision, with outer diameter deviation triangle D = (-0.1 mm; +0.3 mm), inner diameter deviation triangle d = (0 mm; +0.4 mm), and wall thickness deviation triangle S = (-0.3 mm; +0.2 mm). When manufacturing hollow billets made from axle steel to manufacture hollow car axles using the industrial pipe rolling mill 70-270 (Vyksa Steel Works), we registered the positive effect of the screw piercing process (beta = 12 degrees/mu = 1.3) on strength, plastic properties, and impact strength, that is, relative elongation (delta; initial/as-pierced condition) was 38.9%/41.9 MPa and impact strength KCU+20 was 63.3/72 J/cm2.