Heat-resisting steel material used as vane or bolt of supercritical steam turbine and preparation method thereof

Abstract

The invention discloses a heat-resisting steel material used as a vane or a bolt of a supercritical steam turbine. The chemical composition of the material (in percentage by weight) is: 0.12 to 0.16 percent of C, 0.30 to 0.70 percent of Mn, 0.35 to 0.65 percent of Ni, 10.0 to 11.0 percent of Cr, 0.30 to 0.5 percent of Mo, 1.5 to 1.9 percent of W, 0.14 to 0.20 percent of V, 0.05 to 0.11 percent of Nb, 0.04 to 0.08 percent of N, and the balance of Fe and impurities. The chemical property of the material is that: tensile strength sigma b is more than or equal to 930MPa; yield strength sigma 0.2 is more than or equal to 765MPa; tensile stretch delta is more than or equal to 14 percent; percentage of area reduction psi is more than or equal to 32 percent; ballistic work AKv is more than or equal to 20J; and hardness HB is between 277 and 331.

Description

technical field [0001] The invention relates to a steam turbine material, in particular to a heat-resistant steel material used as a blade or a bolt of a supercritical steam turbine and a preparation method thereof. Background technique [0002] With the development of steam turbine manufacturing technology, the capacity of a single unit is getting larger and larger, and the steam turbine is developing towards a supercritical unit, and its working temperature is increased to 550°C. The mechanical properties of the existing steam turbine blades and bolt materials can no longer meet the requirements of this working condition. . Contents of the invention [0003] The problem to be solved by the present invention is to provide a heat-resistant steel material used as supercritical steam turbine blades and bolts, the mechanical properties of which meet the above requirements. [0004] Technical scheme of the present invention is: [0005] A heat-resistant steel used as steam t...

AI Technical Summary

Problems solved by technology

[0002] With the development of steam turbine manufacturing technology, the capacity of a single unit is getting larger and larger, and the steam turbine is developing towards a supercritical unit, and its working temperature is increased to 550°C. The mechanical properties of the existing steam turbine blades and bolt materials can no longer meet the requirements of this working condition.