Valve disc multi-position plasma stellite spray welding process method

Abstract

The invention discloses a stellite spray welding process method, in particular to a valve disc multi-position plasma stellite spray welding process method, and belongs to the technical field of welding process methods. The method comprises the following steps that firstly, the to-be-spray-welded inner round face, the to-be-spray-welded inner conical face and the to-be-spray-welded outer conical face of a valve disc are subjected to plasma stellite spray welding; secondly, the valve disc is subjected to postwelding stress relief heat treatment for the first time; thirdly, the to-be-spray-welded outer end face, the to-be-spray-welded outer large round face, the to-be-spray-welded outer small round face and the like of the valve disc are subjected to plasma stellite spray welding; and fourthly, the valve disc is subjected to postwelding stress relief heat treatment for the second time. The process flow is simple, the working efficiency can be improved, the production cost is reduced, through reasonable welding and heat treatment process orders and in combination with matched welding process parameters, direct stellite spray welding on all the to-be-spray-welded faces of the valve disc can be performed, welding cracks can be avoided, the toughness of the heat affected zone is good, the weld seam dilution rate is low, and the weld seam pass percent is high.

Description

technical field

[0001] The invention relates to a process method of spray welding Stellite alloy, in particular to a process method of plasma spray welding Stellite alloy in multiple parts of a valve disc, belonging to the technical field of welding process methods. Background technique

[0002] As the operating temperature of steam turbine valves is getting higher and higher, the corrosion resistance, oxidation resistance, and wear resistance of heat-resistant steel materials under service conditions have been difficult to meet the requirements of use. Among them, for supercritical and ultra-supercritical unit valves, when the valve is opened and closed, multiple parts of the frequently moving valve core need to achieve anti-oxidation, anti-wear, anti-corrosion, and anti-impact properties. In order to reduce costs, Stellite alloying on the valve surface is the most effective and economical way.

[0003] However, since the steam turbine valve disc is mainly made of heat-res...

Images