Patent ID: 9574684
Date: 2017-02-21
CPC Classifications: B21C,B21H,B21J,B22D,B32B,C21D,F16L

Claim:
1. A method of producing a seamless, composite tubular product, the method comprising: centrifugally casting a metal or alloy into a tubular workpiece having an inner diameter; centrifugally casting a corrosion resistant alloy in the inner diameter of the tubular workpiece to form a composite tubular workpiece having an inner diameter and an outer diameter, the inner diameter of the composite tubular workpiece formed of the corrosion resistant alloy and the outer diameter formed of the metal or alloy; and subjecting the composite tubular workpiece to at least about a 25% wall reduction using a metal forming process, the metal forming process comprising providing at least two rollers having a displacement from one another in an axial direction with respect to the composite tubular workpiece, and compressing the outer diameter of the composite tubular workpiece with the rollers at a temperature below a recrystallization temperature of the composite tubular workpiece using a combination of axial and radial forces so that the inner diameter of the composite tubular workpiece has a compressive hoop stress of at least 500 MPa.