METHOD FOR MANUFACTURING EXHAUST VALVE OF INTERNAL COMBUSTION ENGINE BY ELECTRONIC BEAM WELDING

摘要

PURPOSE: An exhaust valve manufacturing device of an internal combustion engine by using electronic beam welding is provided to improve the durability of an exhaust valve and to produce the exhaust valve precisely at high speed with electronic beam welding instead of frictional welding. CONSTITUTION: An exhaust valve(1) consists of a head part(2) and a stem part(3). The head part is manufactured with forging equipment and made of Nimonic 80A such as a Ni-based superalloy composed of 0.04-0.10wt% of C, 18-21wt% of Cr, 1.0-1.8wt% of Al, and 1.8-2.7wt% of Ti. The head part is manufactured to be similar to a final size by open die forging and closed die forging, and the stem part is manufactured near a final size by free forging. The forged head part of the exhaust valve is contacted to the stem part, and the contact portion is welded by irradiating an electronic beam(5) radially. The large exhaust valve having 120mm in diameter and excellent strength is manufactured with electronic beam welding.