Method for plasma surfacing of cobalt-based alloy in inner hole of cylinder

Abstract

The invention provides a method for plasma surfacing of cobalt-based alloy in an inner hole of a cylinder. The method comprises the following steps that the pretreated cylinder is preheated to 350-450 DEG C; under the condition that the preheating temperature is kept, a layer of cobalt-based alloy is subjected to plasma surfacing on the inner hole of the cylinder to form a first surfacing layer; after slow cooling to the room temperature, the surfacing surface of the first surfacing layer is machined till the unilateral thickness is 1.6 mm-2mm; then the cylinder is preheated to 380 DEG C to 450 DEG C; under the condition that the preheating temperature is kept, a layer of cobalt-based alloy is subjected to plasma surfacing on the first surfacing layer to form a second surfacing layer; after the barrel is slowly cooled to the room temperature, the barrel is subjected to postweld treatment at the temperature of 410-430 DEG C; and the surfacing surface of the second surfacing layer is machined till the single-side thickness is 1.4 mm-1. 5 mm. According to the method for plasma surfacing of the cobalt-based alloy on the inner hole of the cylinder, the problem that cracks are prone to being generated in the surfacing process of the cobalt-based alloy on the inner hole of the cylinder made of austenite stainless steel can be solved.

Description

technical field [0001] The invention relates to the technical field of metal welding, in particular to a method for plasma surfacing welding of cobalt-based alloys in the inner hole of a cylinder. Background technique [0002] The guide bearing matrix of some pumps is usually made of austenitic stainless steel (such as S30408, S31608, etc.). A layer of cobalt-based alloy STE 6 (grade 6) is surfacing on the surface, making the guide bearing a bimetallic part with comprehensive performance, which not only prolongs the service life of the guide bearing, but also avoids the consumption of precious metals, thereby reducing the cost of the equipment. [0003] Since the hardness of the cobalt-based alloy STE 6 is as high as HRC39-47, the plasticity and toughness are very poor, while the rigidity of the guide bearing base is large, and the workload of the full-surface surfacing welding is large, the heat input is large, and a large welding stress is generated during the surfacing we...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a method for plasma surfacing cobalt-based alloy in the inner hole of a cylinder made of austenitic stainless steel, so as to solve the process of surfacing cobalt-based alloy in the inner hole of a cylinder made of austenitic stainless steel. Cracks are easy to occur in the middle, and the dilution of the base metal to the deposited metal of the surfacing layer is reduced, so that the contents of Fe, Ni and other alloys in the cladding layer after welding can meet the standard requirements of RCC-M S8000

Images