Cross head surface induction hardening method of marine diesel engine

Abstract

The invention relates to a cross head surface induction hardening method of a marine diesel engine, wherein, a notch on the cross head hardening surface of the marine diesel engine is filled by a technique block, and all the holes are sealed by moist clay; a cross head is mounted on a hardening machine; and a circular self-water spraying induction coil is mounted to be used for carrying out continuous hardening. Through filling the notch by the technique block and sealing the holes by the moist clay when hardening, the invention can reduce the sharp corner effect when hardening workpieces, thehardening speed at the sharp corner can be controlled by the numerical control technique, and the internal stress is reduced, thereby hardening cracks of the workpieces are avoided. After being treated by the induction hardening method, the hardening hardness of the cross head of the marine diesel engine is uniform and has no hardening soft belt; the hardness and the hardened layer of all the required hardening surfaces conform to the specification of drawings and technical files, and thereby, the difficult problem of hardening is solved, the quality is more stable, the hardening time of theparts is shortened, and the production efficiency is improved.

Description

technical field [0001] The invention relates to a heat treatment process for surface induction hardening of parts with holes or notches to prevent quenching cracks, in particular to a surface induction hardening method for a crosshead of a marine diesel engine. Background technique [0002] In some models of marine diesel engines, the surface of the crosshead is induction hardened, and the material of the crosshead is 45 steel. Because there is a large gap and some holes in the outer surface of the quenched crosshead, the temperature of the sharp corner is very high during induction heating, and it may be overheated, overburned, or even melted, and cracks are easy to occur after quenching. For example, S35ME-B diesel engine crosshead, the size of the notch on the outer circle is 136 mm (width) × 40.3 mm (height), there are 4 φ35.4 mm taper holes, 1 φ40 mm straight hole, and 2 φ21 mm straight holes , 1 φ26 mm oblique hole, such as figure 1 shown. [0003] The prior art doe...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the disadvantages of easy quenching cracks and soft bands left on the quenching surface in the existing quenching technology, solve the problems of uneven quenching hardness and low yield of crossheads, and provide a crosshead for marine diesel engines Surface induction hardening method

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