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

Abstract

The results of the inspection of mechanical properties were provided for very-thick-walled shells (D/S ≈ 3.06 and D/S ≈ 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 β = 12°/μ = 1.26 and β = 14°/μ = 1.36. A comparison of the obtained results of mechanical properties showed that the piercing process with a larger feed angle (i.e., β = 14°/μ = 1.36) is more preferable than the piercing process with β = 12°/μ = 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 ≈ 3.1 manufactured by piercing using the screw rolling mill MISiS 130D showed high precision, with outer diameter deviation ∆D = (−0.1 mm; +0.3 mm), inner diameter deviation ∆d = (0 mm; +0.4 mm), and wall thickness deviation ∆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 (β = 12°/μ = 1.3) on strength, plastic properties, and impact strength, that is, relative elongation (δ; initial/as-pierced condition) was 38.9%/41.9 MPa and impact strength KCU⁺²⁰ was 63.3/72 J/cm².