Use ESC craft to raise durability of razor blade of hard alloy whorl

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  • source:AVELLINO CNC Machining
Craft of ESC(Edge And Surface Conditioning) is to cutting tool point undertakes aggrandizement (passivation) , the technique of the integrated processing such as exterior polish. Pass ESC craft processing, can enhance strength of cutting tool point, improve exterior stress position, reduce exterior surface roughness to be worth, raise cutting tool durability 1 ～ 4 times. Our country is annual the wastage that oil getting collects steel tube exceeds 800 thousand tons, the treatment of oil steel tube needs to use many whorl bit (ten / year) , accordingly, the mass that employs ESC craft to improve whorl bit and durability have remarkable economic benefits. Article experiment place uses the appearance characteristic of 1 whorl razor blade razor blade of whorl of hard alloy much tine is one kind is used at the 3 tine of the whorl outside bushing of fine vehicle oil to comb bit, bit material is YT715 hard alloy character, if the graph is shown 1 times,appearance of blade point geometry and tooth form feature are nodded. Graph 1 3 tine comb the point geometry appearance of bit and dot of tooth form feature are in bit chooses A ～ Q on the cutting point of each tine in all 11 features dot, among them enunciation of blade of H dot delegate supports, dot of A, Q represents blade enunciation root, dot of D, L represents blade enunciation side. In observe times higher below microscope, the point of bit (namely before knife face and hind of knife face connect a section) be not simple and linear, however a complex curved surface. Point is sharp rate represents with point radius Re. Bit classics forms sharp natural point after grinding treatment, if pursue,2 are shown. The point radius that right now tooth form nods each is inhomogenous (Re=0.

002 ～ 0.

018mm) . To increase the dependability of cutting tool cutting and stability, use ESC craft to undertake accurate honing to point, can increase point strength (increase Re) , reduce point surface surface roughness to be worth (Ra ＜ 0.

3µm) , reduce exterior remains stress, the point radius that makes bit tooth form is nodded each agrees equably. Graph appearance of 2 blade point and craft of 2 ESC of point radius sketch map and point of ESC(of oscillatory honing law and exterior aggrandizement processing) craft presses a principle to be able to be divided wait for a variety of technique for mechanical, chemical, electrochemistry, abrasive, hot-working, electromagnetism, for example wool brushs law of bombard of particle of law of arenaceous aggrandizement of law of machine honing law, oscillatory abrasive honing, gush, high speed to wait. The article uses law of oscillatory abrasive honing to undertake to whorl razor blade point surface aggrandizement is handled, its characteristic is installation cost little, cost is low, can be reduced effectively or eliminate the leftover stress of bit surface, raise bit durability thereby. Traditional oscillatory honing machine is average by oscillatory orgnaization (electromotor, cam, bedspring) comprise with workbench, abrasive uses carborundum or alumina grain to wait, bit and abrasive outfit are in the box on workbench, through the attrition of bit and abrasive, concussion action makes point passivation. But when to whorl razor blade this kind of complex point undertakes passivation, make sure point radius agrees equably very hard, tine top and error of radius of tine root point are 0.

02 ～ 0.

09mm, affected the treatment quality of whorl razor blade and active life. The article uses method of new-style and mechanical oscillatory honing, replace traditional cam and electromotor orgnaization with new-style vibrating motor, abrasive uses corundum and carbonization boron to mix powder, use new-style clamping apparatus to improve the opposite motion between bit and abrasive, make the tine top of whorl razor blade and radius of tine root point evener, its error control is in 0.

01mm less than, improved thread machining percent of pass and bit thereby active life. The improvement of the function of cutting of whorl razor blade that experiment of 3 screw cutting and analysis handle for craft of ESC of classics of test and verify and durability circumstance, undertook screw cutting experiments. Workpiece material is bushing of J55 steel oil, bushing external diameter is 273.

1mm, the wall is large for 8.

89mm, 778MPa of ～ of B=735 of tensile strength σ , succumb 477MPa of ～ of intensity σ S=433, ～ of =26% of percentage elongation δ 33% , sectional shrinkage ψ =56% ～ 61% . The machine tool of silk of car of steel tube of HT16 CNC numerical control that treatment machine tool makes for French CRI-DAN company, cutting speed V=100m/min, feed F=3.

175mm/r, p=0 of cutting deepness δ .

4 ～ 0.

6mm. Type emulsion is irrigated to cool outside. Oil bushing length is 8 ～ 12m, every oil bushing two end part turning a paragraph (directly) length is 88.

The whorl of 9mm. The bushing of oil of turning of whorl razor blade that uses 10 groups of different point to pour round radius respectively, bit durability (with the head of turning whorl number shows) following rows that express place. The point of number of set of relation razor blade that expresses whorl blade point to pour round radius and bit durability pours round radius Re(µm) every groups of razor blade are counted (piece) bit durability machines percent of pass (qualification of number of total head of the treatment end tine of side of tine of %) tine top tastes a several reject head number is machined on average.

7579.

60H130303095244665851.

7888.

93H250505096125753763.

8993.

95H370707085394994062.

3892.

58H490806042342023250.

5086.

33H540302052522213144.

2087.

70H670503073703234746.

1487.

30H790704062862355139.

1782.

17H870656053303012960.

2091.

21H950454053252972859.

4091.

39 aggregate 663771335741450.

8689.

In 02 watches, point pours the public errand of round radius to be ± 8µm. H0 group (after grinding of Re=10µm) razor blade is machined, did not undertake blade ministry aggrandizement is handled, the natural point that tooth form nods each pours 18µm of ～ of round radius Re=2, the percent defective of whorl of turning of razor blade of this kind of sharp point is as high as 20% , especially stability of turning initial stage is poorer, bit dies easily blade and damaged, cause generation ripple (oscillatory knife mark) , the blemish such as nick and burr, the average and effective durability of every razor blade (the head that turning gives qualification to taste is counted) be less than 30; Two groups of razor blade have H1 and H5 minor point pours round radius, durability of its razor blade and treatment percent of pass prep above point not the razor blade of aggrandizement; 5 groups of razor blade have H2, H3, H6, H8 and H9 medium point pours round radius, durability of its razor blade and point of other of prep above of treatment percent of pass pour the bit of round radius, and cutting process is stable, among them the razor blade with the inhomogenous passivation of bit durability prep above with point even passivation; Two groups of razor blade have H4 and H7 bigger point pours round radius, durability of its razor blade and treatment percent of pass pour the bit of round radius under medium point. Test result makes clear, point pours neither of round radius Re to had been jumped over greatly more, also not be Yue Xiaoyue good, put in an optimal value however. 4 conclusion experiment through the turning of razor blade of hard alloy whorl, if make conclusions,can reach: 1) passes ESC craft processing, the durability of razor blade of hard alloy whorl can increase 1.

2 times. 2) ESC craft can raise the cutting stability of whorl razor blade and treatment percent of pass. Point of 3) whorl blade pours round radius to be put in Reo=50µm of an optimal value, when Re=Reo, bit durability is best. In addition, the Re that bit blade ministry nods each is evener, cutting performance is better. CNC Milling