A kind of fine casting method that prevents the distortion of high-pressure turbine guide vane
Technical field
The present invention relates to blade essence casting technical field, be specially a kind of fine casting method that prevents the distortion of high-pressure turbine guide vane.
Background technology
The main employing investment pattern precision casting technique monoblock cast at present of novel aero-engine core component high-pressure turbine guide vane.This high-pressure turbine guide vane is large listrium structure, and diagonal-size reaches 170mm, and cantilever reaches 55mm, very easily distortion after essence casting.Therefore in order to guarantee the designing requirement of guide vane size conforms, need to take in process of production the measure of listrium anti-deformation.Prevent that listrium distortion from also becoming the key whether this guide vane can successfully be developed.
For meeting the requirement of this blade design figure paper size, traditional way is the distortion that the thin rod wax of artificial weld diameter 3mm after wax-pattern injection-compression molding prevents from melting casting process, after cast, blade listrium is proofreaied and correct, although the method can solve part guide vane listrium problem on deformation, but the uniformity of every batch is poor, and correction is easy to leave blemish and proofread and correct stress at blade surface, cause blade fatigue strength to reduce, the performance of so actual blade is just far below design performance, and this is also one of reason causing in blade " life-span short, poor reliability ".Traditional bearing calibration cannot be applied in the large listrium structure of novel aero-engine high-pressure turbine guide vane.
Summary of the invention
The technical problem solving
In order to suppress the distortion of high-pressure turbine guide vane listrium cast cooling procedure from source, the present invention proposes a kind of fine casting method that prevents the distortion of high-pressure turbine guide vane, design technology muscle between inframarginal on blade essence casting blank just when carrying out Blank Design, in blade essence casting process, suppress the distortion of listrium, obtain size accurately, free of surface defects, without the qualified blade of proofreading and correct stress.
Technical scheme
Technical scheme of the present invention is:
Described a kind of fine casting method that prevents the distortion of high-pressure turbine guide vane, is characterized in that: adopt following steps:
Step 1: according to high-pressure turbine guide vane design high-pressure turbine guide vane blank to be processed, wherein in blank, be designed with process bar, blade back one side of described process bar in high-pressure turbine guide vane, and be positioned at apart from blade leading edge apart from maximum blade listrium cantilever edge position; Process bar two ends are connected with blade inframarginal with blade supramarginal plate respectively; Process bar length is that the designed distance L of blade supramarginal plate and blade inframarginal deducts blade listrium deflection Δ X, Δ X=L (σ h-1) (ε z-ε e) wherein, σ h is that blade material is cast comprehensive shrinkage factor, the directional solidificating alloy elastic elongation amount that ε z is blade material, the equiax crystal alloy elastic elongation amount that ε e is blade material;
Step 2: according to the high-pressure turbine guide vane Blank Design result processing high-pressure turbine guide vane blank of step 1;
Step 3: high-pressure turbine guide vane blank essence is cast to shape, then by process bar respectively along upper inframarginal skin cut.
Described a kind of fine casting method that prevents the distortion of high-pressure turbine guide vane, is characterized in that: the cross section of described process bar is the isosceles trapezoidal structure of foursquare arc transition.
Beneficial effect
The fine casting method that prevents the distortion of high-pressure turbine guide vane that the present invention proposes, in blade blank design process, just pass through to increase process bar, the distortion of blade listrium is carried out to Contrary compensation, thereby from source, reduced the large listrium distortion of turbo blade, improved greatly product percent of pass.
Accompanying drawing explanation
Fig. 1: certain high-pressure turbine guide vane essence casting blank schematic diagram;
Fig. 2: process bar cross sectional representation;
Wherein: 1. turborotor; 2. blade back; 3. leading edge; 4. supramarginal plate; 5. inframarginal; 6. inside process bar 7. process bar; 8. outside process bar.
The specific embodiment
Below in conjunction with specific embodiment, the present invention is described:
The present embodiment is processed certain machine high-pressure turbine directional solidification guide vane, adopts following steps:
Step 1: according to high-pressure turbine guide vane design high-pressure turbine guide vane blank to be processed, wherein in blank, be designed with process bar 6, prevent the distortion of listrium, blade back 2 one sides of described process bar in high-pressure turbine guide vane 1, and be positioned at apart from the blade leading edge 3 maximum blade listrium cantilever edge positions of distance; Process bar two ends are connected with blade inframarginal with blade supramarginal plate respectively; Process bar length is that the designed distance L of blade supramarginal plate and blade inframarginal deducts blade listrium deflection Δ X, Δ X=L (σ h-1) (ε z-ε e) wherein, σ h is that blade material is cast comprehensive shrinkage factor, the directional solidificating alloy elastic elongation amount that ε z is blade material, the equiax crystal alloy elastic elongation amount that ε e is blade material; The present embodiment Leaf listrium deflection Δ X is 0.76 ε e.
With reference to accompanying drawing 2, the cross section of process bar is the isosceles trapezoidal structure of foursquare arc transition, its inner side (upper base 7) long 6mm, the long 9mm in outside (going to the bottom 8), high 3mm, process bar lateral surface 8 and supramarginal plate 4 and inframarginal 5 surface co-planar, four jiaos of process bar are with R1(mm) circular arc transfers.
Step 2: according to the high-pressure turbine guide vane Blank Design result processing high-pressure turbine guide vane blank of step 1;
Step 3: high-pressure turbine guide vane blank essence is cast to shape, then by process bar respectively along upper inframarginal skin cut.
In the present embodiment, adopt anti-deformation process muscle that the deflection of the large listrium of blade is reduced greatly.Pass through contrast test: two do not add anti-deformation process muscle wherein 12 measurement points of a blade are all overproof, the minimum 0.32mm of overproof amount, maximum 0.68mm, the minimum 0.37mm of overproof amount of 12 measurement points of an other blade, maximum 0.72mm; And use two blades of anti-deformation process muscle, wherein one 2 overproof all the other points are all qualified, 1 overproof 0.01mm, 1 overproof 0.03mm.Other one only 1 overproof, overproof 0.03mm.