Heat process capable of lowering ductile-brittle transition temperature and intergranular fracture ratio of turbine blades

Abstract

The invention provides a heat treatment process capable of lowering ductile-brittle transition temperature and intergranular fracture ratio of turbine blades. When the heat treatment process is used, the problem that the process effect is susceptible to influences of chemical components of the raw material of the blades when the conventional sub-temperature annealing process is used to treat the turbine blades and the problem of high ductile-brittle transition temperature and intergranular fracture ratio of the turbine blades due to overlong high-temperature retention during heat treatment ofthe blades in the sub-temperature annealing process are solved. In the invention, the blades are uniformly placed in a common quenching material basket according to a technical scheme and then the quenching material basket is placed in a heat treatment quenching furnace. The heat treatment process is characterized in that: the blades are quenched twice in a quenching furnace; the temperature of primary quenching is 980 to 1070 DEG C; the temperature is kept constant for 1 to 3 hours; the cooling speed is 20 to 50 DEG C per minute; the temperature of secondary quenching is 900 to 1,000 DEG C; the temperature is kept constant for 15 to 120 minutes; the cooling speed is 30 to 50 DEG C minutes; and the temperature of the primary quenching is 20 to 100 DEG C higher than the temperature of the secondary quenching.

Description

technical field [0001] The invention relates to the field of heat treatment technology for turbine blades, in particular to a heat treatment technology for reducing the ductile-brittle transition temperature and intergranular fracture ratio of turbine blades. Background technique [0002] Ductile-brittle transition temperature (FATT 50 ) and the intergranular fracture ratio are important indicators for evaluating turbine blades. Usually in an environment with low climatic temperature, if the ductile-brittle transition temperature (FATT 50 ) is too high, the turbine blade is prone to brittle fracture when starting and stopping, and if the intergranular fracture ratio is too high during high temperature operation, the grain boundary strength of the turbine blade will decrease, resulting in blade failure. At present, the production of turbine blades mostly adopts the conventional sub-temperature annealing process, that is, furnace cooling annealing at 880℃~920℃, and then oil c...

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Problems solved by technology

[0003] In view of the above problems, the present invention provides a heat treatment process for reducing the ductile-brittle transition temperature and the intergranular fracture ratio of turbine blades, which can effectively avoid the process effect being easily affected by the chemical properties of the blade raw materials when the existing sub-temperature annealing process is used to treat the turbine blades. It can solve the problem of the influence of components, and can solve the problem of high ductile-brittle transition temperature and intergranular fracture ratio of the blade caused by the high temperature residence time of the blade in the heat treatment process in the existing sub-temperature annealing process

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