Special alloy material is profound the treatment of aperture

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  • source:CLAREY CNC Machining
One, turbine of introductive flue gas is a kind of energy in device of oil refining catalytic cracking recovers equipment, its are main component rotor is be assembled by turntable and main shaft and become. After turntable and main shaft are assembled, need to use bolt of 8 groups of pull rod to tighten its solid. The basis designs a requirement, 322 Mm of 8 hole depth, bus verticality 0.

05 Mm, aperture surface surface roughness 0.

4µm, accordingly this aperture needs beard bore with a reamer is made. The material of main shaft and turntable is 40CrNi2MoA of high strenth alloy steel and GH864 of high temperature alloy steel respectively, the mechanical performance list of two kinds of material sees a table 1. The brand of mechanical performance data that expresses two kinds of 1 material is mechanical SbMPa of function tensile strength succumbs intensity S0.

≥ of 10 of ≥ of 825 of ≥ of 1200 of ≥ of 45 GH864 of ≥ of 12 of ≥ of 885 of ≥ of 980 of ≥ of Y% 40CrNi2MoA of shrinkage of section of D% of 2MPa outspread rate 12 from the watch 1 can see, the mechanical function of two kinds of material is very special, accordingly its machine function and average capable person to differ character, choosing the respect such as parameter of angle of cutting tool material, geometry, craft to cause difficulty thereby. 2, the mechanical performance that the selection list of cutting tool material shows content 2 times to be material of a few kinds of commonly used cutting tool is comparative, by afore-mentioned knowing GH864 and 40CrNi2MoA tensile strength and percentage elongation are extremely tall, accordingly its " viscosity " bigger, treatment difficulty is great. High-speed steel relatively YT, YG kind hard alloy has enough strength and tenacity, contain vanadium because of its again the volume is not high, grind processability can good, so cutting tool material should be chosen from inside high-speed steel. Break off to avoid to because vibration makes blade of cutting tool collapse is mixed,be in when cutting, consider other factor integratedly, choose the W2Mo9Cr4VCo8 with high bending strength to regard cutting tool as material. The mechanical sex ability that expresses material of 2 cutting tool learns material of function cutting tool pledge high-speed steel YG kind hard alloy YT kind hard alloy hardness ~ of 93 90 of ~ of 84 ~ 85 91 ~ of 2000 1300 of ~ of 4000 1500 of ~ of MPa 2000 of 92 bending strength 1800 concussion tenacity (4 0 of ~ of 30 2 of J/cm²) 18 ~ .

3 ~ 0.

7 3, the designs cutting tool geometry parameter of main geometry angle is opposite cutting tool of the metal when cutting be out of shape, temperature of cutting force, cutting and cutting tool wear away to have distinct effect, affect quality of surface of durability of cutting efficiency, cutting tool, treatment and finished cost thereby. Because this is reasonable parameter of geometry of choice cutting tool is very important. Before the horn before option option of horn is bigger, can reduce cut bits to be out of shape, make cutting force and cutting power are reduced thereby, the quantity of heat of the generation when cutting is reduced, can restrain the generation of knife tumour at the same time, make the durability of cutting tool rises. But, too big before horn can make the intensity of edge is reduced, produce collapse blade easily. Because performance of high-speed steel cutting is good, the plasticity of GH864 and 40CrNi2MoA is good, so cutting tool should be chosen bigger before horn. Consider all sorts of factors integratedly, advocate ° of G=7 of the horn before cutting blade and corrective cutting blade - 9 ° . The main effect of the horn after the option that horn takes with pliable but strong after is the attrition between face of the knife after the cutting tool in reducing cutting process and treatment surface, it has very big effect to cutting tool durability and treatment surface quality. When cutting ply very hour, wear away to basically happen after on knife face, to reduce hind the sharp rate that wear away and raises cutting sword of knife face, appropriate is taken bigger hind horn, article place is narrated belong to small bit cutting, ° of A=9 of the horn after reason - 11 ° . High-speed steel reamer basically uses the sharp sex of edge to make machine the surface to obtain faster face to machine quality, do not cut in order to squeeze give priority to, ligament should be chosen more narrowly had better, so F=0 of cutting blade ligament.

05 ~ 0.

1 Mm, f=0 of calibration blade ligament.

1 ~ 0.

15 Mm. The chooses cutting tool structure of a few and geometrical angle diagram are blade dip in preventing bore with a reamer to cut a course because discharge bits up,affect exterior quality the exterior cut of aperture, cutting tool should use bigger blade dip angle, namely L=15 ° - 20 ° , bigger blade is obliquitous not only make platoon bits is down, the horn before still can making cutting tool actual at the same time increases, raise reamer durability. Right plan institute shows the structure that is cutting tool and geometrical angle diagram. 4, the choice cutting fluid of cutting fluid wears away to reducing cutting tool, improvement machines exterior quality, raise manufacturing efficiency to have main effect, its action is mixed to lubricate cooling. When bore with a reamer cuts high temperature alloy, appropriate is chosen extremely press fluid of additive vulcanization cutting, this cutting fluid and metallization close, form vulcanization iron, vulcanization iron melting point is as high as 1193 ℃ , vulcanization iron film is destroyed not easily below high temperature, good lubricant performance can maintain in 1000 ℃ , restrain the generation of knife tumour, raise the surface to machine quality. 5, craft course reachs craft deaf number to go up surely really jig, get bottom outlet on turntable and main shaft respectively. Assemble main shaft and turntable, make sure each aperture coaxial is spent be less than 0.

2 Mm. The bed clangs on workpiece, essence of life searchs hind close solid, hit hole of pull rod bolt, leave surplus 0.

5 Mm. Install clip reamer, thick bore with a reamer this aperture, bore with a reamer cuts quantity T=0.

20mm, reamer edge is in linear velocity V=1.

8 ~ 2.

2m/min, axial feed measures S=0.

15 ~ 0.

20mm/r; essence bore with a reamer this aperture, bore with a reamer cuts quantity T=0.

10mm, other parameter as above. 6, the reamer that the last word chooses W2Mo9Cr4VCo8 material to pledge processes special alloy data profound aperture is my factory ceaseless in old manufacturing practice summary reachs, its characteristic is treatment efficiency is tall, cutting tool life is long, the treatment precision of aperture is tall, exterior quality is good. Come two years, rotor of turbine of flue gas of treatment of my factory accumulative total more than 50, obtained favorable result. CNC Milling