2Cr11MoVNbN forge piece for steam turbine and manufacturing method of forge piece

Abstract

The invention discloses a 2Cr11MoVNbN forge piece for a steam turbine and a manufacturing method of the forge piece. The method comprises the steps that firstly, discharging is carried out; secondly, the charging temperature is raised and controlled to be smaller than 600 DEG C, preheating is carried out for 2 hours, the temperature is raised to 830 DEG C to 850 DEG C at the rising speed smaller than or equal to 150 DEG C/h, the temperature is kept for 3 hours, the temperature is raised to 1160 DEG C to 1200 DEG C at the rising speed smaller than or equal to 150 DEG C/h, the temperature is kept for 5 hours, and cooling is carried out; thirdly, forging is carried out; fourthly, annealing after forging is carried out; fifthly, preheat treatment is carried out, and incomplete annealing is achieved; sixthly, quenched-tempered heat treatment is carried out, wherein the temperature is raised to 1050 DEG C to 1070 DEG C at the rising speed smaller than or equal to 180 DEG C/h, the temperature is kept for quenching for 8.5 h, medium water cooling is carried out, the temperature rises to 620 DEG C to 640 DEG C at the rising speed smaller than or equal to 150 DEG C/h, the temperature is kept for one-time tempering for 16 h, air cooling is carried out, the temperature rises to 620 DEG C to 640 DEG C at the rising speed smaller than or equal to 150 DEG C/h, the temperature is kept for secondary tempering for 16 h, and air cooling is carried out; seventhly, stress relief annealing is carried out. In the forging and heat treatment process, a blank is not prone to cracking, high-temperature durability is good, and the mechanical property of products meets the requirement.

Description

technical field [0001] The application belongs to the technical field of ring forging forging, and in particular relates to a 2Cr11MoVNbN forging for a steam turbine and a manufacturing method thereof. Background technique [0002] 2Cr11MoVNbN forgings are mainly used in steam turbines, which have high requirements and high alloy elements, and are easy to crack during forging and heat treatment, and it is difficult to meet the requirements for long-term high temperature. Contents of the invention [0003] The purpose of the present invention is to provide a 2Cr11MoVNbN forging for steam turbine and its manufacturing method, so as to overcome the deficiencies in the prior art. [0004] To achieve the above object, the present invention provides the following technical solutions: [0005] The embodiment of the present application discloses a 2Cr11MoVNbN forging for steam turbines, its chemical composition includes: C: 0.15-0.2; Si: 0.2-0.6; Mn: 0.6-0.9; P≤0.025; S≤0.025; 1...

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Problems solved by technology

[0002] 2Cr11MoVNbN forgings are mainly used in steam turbines, which have high requirements, high alloy elements, and are e

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