Electroslag casting manufacturing method of hydraulic turbine blade compact

Abstract

An electroslag casting production method for a waterwheel blade green compact is characterized by comprising the following steps: confirming the outline of the blade green compact according to the intelligent three-dimensional expanded size of a water turbine blade; producing a crystallizer and a consumable electrode of the blade green compact; preparing the qualified blade green compact of the electroslag casting water turbine by optimizing electroslag casting process parameters and the anti-cracking heat treatment process. The method has the advantages that the detects of the conventional blade green compact of the water turbine can be overcome; a near-net forming green compact producing process is provided for the water turbine blade formed through heated-die pressing process; the produced blade green compact material is high in degree of purity, uniform in chemical constituents, compact in structure, free of defects such as looseness, slag inclusion and hole shrinkage, favorable in mechanical property, and higher in fatigue resistance performance, anti-cracking performance and expansibility, and can reach the mechanical property of forge pieces made of the same material and meet the requirements of flaw detection indexes.

Description

technical field [0001] The invention relates to a manufacturing process of a three-dimensional curved surface compact, and in particular provides an electroslag casting manufacturing method of a water turbine blade compact. Background technique [0002] With the demand for high-quality turbine blades for large and medium-sized hydroelectric generating units, some domestic and foreign enterprises have begun to use hot molding to produce turbine blades. The produced turbine blades avoid the shortcomings of sand casting blades, and have high product quality and relatively short construction period. Short and does not damage the metal streamline and other advantages, so this method has been paid attention to in the domestic and foreign water turbine manufacturing industry. As the raw material for hot-molded blades of hydraulic turbines, the quality and dimensions of the molded compacts have a great influence on the performance of the blades, the amount of post-processing and the...

AI Technical Summary

Problems solved by technology

The molding process of the cast compact is simple, and the back of the compact can be directly cast into the space curved surface required by the blade expansion diagram, and the processing workload of the compact is small, but due to the limitation of the casting process itself, the inherent quality of the cast compact is low, and conventional casting defects are inevitable , the quality of the compact is poor, and the workload of welding repair and relief grinding of the cast compact is large, the production cycle is long, and the production efficiency is low; equal-thickness steel plate is the most commonly used compact structure type for molded blades at present, and the internal quality of the steel plate is relatively low. good, few defects

However, for blades with large changes in blade curvature and thickness (such as "X" blades), the material utilization rate of the steel blank is low because the steel blank is of equal thickness; the back of the blade compact is a space curved surface, And the difference in margin is very large, and the amount of post-processing is large, which greatly increases the production cost and restricts the development of hot molding technology for turbine blades