Patent ID: 6821362
Filing Date: 2004-11-23
Classification: C21D

Abstract:
A method for manufacturing an auger composed of an auger body integrally formed with a spiral blade and at its opposite ends with a pair of shaft portions, said method comprising the steps of:forming annular recesses on the shaft portions in a cutting process, building up an anti-abrasive and anti-corrosive alloy by plasma-arc welding in the annular recesses of the shaft portions and finishing each built-up portion of the alloy in a grinding process to form a journal portion on the respective shaft portions of the auger, wherein precipitation hardening stainless steel used as a base metal of the auger body is preheated for a predetermined time in a separate step prior to the plasma-arc welding of the alloy thereby subjecting the body to aging heat treatment caused by the combination of preheating and welding heat during the plasma-arc welding process.