Hard alloy solders the heat treatment technology of milling cutter is improved

Of the problem put forward what my factory abstains to solder milling cutter is used all the time so undertake cutter hub quenching first, go up in cutter hub again after that high frequency solder the making method of head of hard alloy knife. This kind of method that make asks to cutter hub intensity not tall milling cutter is feasible, but tall to cutting speed, cutting muscularity, especially the cutting tool with lesser area of cutter hub cut cannot obtain satisfactory result. The B1279 machine tool that my factory manufactures, the special cutting tool that when the user orders goods, asks my factory provides form a complete set if: R7.

25, R7.

5 chamfer milling cutter (1) seeing a picture; 2 1 date, milling cutter pouring wine cup (2) seeing a picture. Speed of the cutting when working as a result of these a few kinds of milling cutter is as high as 5600 ～ 6000r/min, cutting muscularity, after pressing traditional method to make such milling cutter investment use break off very quickly or be out of shape, cannot satisfy user requirement. The factory outside be like my factory again makes shape flat auger (3) seeing a picture, press blueprint sample: Cutter hub is W18Cr4V, knife head is YG6. Press blueprint type capable person to pledge, use first cutter hub of temper by dipping in water after that again investment uses this kind of cutting tool that the method of solder knife head makes to break off, cannot use at all. Be like again, my factory product uses enlarge of 44mm of 38mm of φ 75mm milling cutter, φ , φ to get (see a picture 4, when graph 5) uses former method to make, have: The cutting tool of 30 ％ can machine every on average only 200 ～ 400 spare partses, its damage the form basically is the cutter hub part near solder mouth breaks off or twist is out of shape; In addition screwy be out of shape still make cutting tool precision is lost, cause be machined of the spare parts discard as useless. 2.

The reason investigation that produces a problem uses cutter hub to quench first to make clear go up in cutter hub again after that high frequency solder the account that blemish relates before the making method of head of hard alloy knife arises, we did the test below: Above all tailor-made experiment milling cutter, the affirmatory principle of size of shape of experiment milling cutter basically is for easily metallographic assay sampling. Experiment milling cutter is shown 6 times like the graph, material of its cutter hub is 40Cr, knife head material is YG8 character. Undertake quenching first to experiment cutter hub, craft heats for 830 ℃ 30min oil is cooling, 90min of 200 ℃ temper, curve of craft of its heat treatment sees a picture 7. Experiment cutter hub is martensite via quenching the metallographic after is organized + a few ferrite (8) seeing a picture, to its test hardness sees watch 1) for 52 ～ 54HRC(. In quench on cutter hub high frequency solder after head of hard alloy knife, the cutter hub that is in to be apart from solder mouth 1mm has metallographic laboratory test, metallographic organization is pearlite of bodily form of all alone family name + shiver shape ferrite (9) seeing a picture, the hardness that approachs knife head office sees watch 1) for 20 ～ 24HRC(. The hardness that be organized by metallographic and measures is knowable, cutter hub is in via quenching the martensite of the high strenth after, tall hardness is organized high frequency solder process change trains turns into the pearlite of bodily form of all alone family name with intensity and inferior hardness and shiver shape ferrite. In this change, the hardness of cutter hub and intensity are reduced greatly. As a result of,producing such change is high frequency on cutter hub solder when knife head, solder temperature is higher, be in commonly 950 ℃ of 900 ～ ; The cutter hub after so high temperature makes quench is standing by solder mouth to be in by normalizing, drop what cause here hardness, strength thereby greatly. And closer from solder mouth area also is conducted as a result of the heat when soldering, make the temperature of this area elevatory, cause the temper of medium, high temperature of this area, also make the intensity of this area, hardness drops. When cutting tool is used, cutting tool attaint appears the most easily also in weld, showing hardness of weld cutter hub, intensity to drop is the main reason that cutting tool damages. 3.

The improvement of heat treatment craft experiments by above and analyse, first the heat treatment effect that the method of head of knife of the solder after cutter hub of temper by dipping in water makes cutter hub stands by solder mouth to be in is lost basically. Want to increase cutter hub strength, improve cutting tool life, the whole that milling cutter undertakes again after answering to solder knife head to go up in cutter hub quenchs, in order to maintain the heat treatment effect of cutter hub. But my factory never has been used before this kind of method, people concern heats in what quench and can make in cooling process addle of function of head of hard alloy knife, heating even mouth of the solder in the process produces change to cause knife head to fall off etc. For this, the performance below the heat treatment craft that we are in all sorts of differring with respect to head of hard alloy knife varies (include hardness and craze case) did a test, test result sees a table 2. Had a test to degree of solder mouth heat-resisting, test result sees a table 3. By above two experiments can reach: (Head of 1) hard alloy knife heats below in 900 ℃ and cool, knife head hardness does not produce apparent change. (Head of 2) hard alloy knife is in quench in refrigeration, when if quench,medium is brine, head of hard alloy knife cools as a result of quickness and craze; When be like medium to be oil, heat below in 900 ℃ , cooling, head of hard alloy knife won't produce craze. This makes clear using solder when cutting tool whole quenchs, cutter hub should choose oily refrigeration can the alloy steel with hard temper by dipping in water, and cannot use oily cold temper by dipping in water the carbon steel with not hard, hard temper by dipping in water of the ability that use water, if cutter hub uses the cutting tool of 45 steel or high-carbon steel, when the whole after solder quenchs, cutter hub material should instead alloy steel. (3) heats to prevent solder of place of mouth of solder of the milling cutter in the process is fused, generation solder flows or knife head and knife posture buy change, quench temperature cannot exceed 900 ℃ , had better be under 850 ℃ . Of major alloy steel quench temperature is near 850 ℃ , and of medium, tall alloy steel quench temperature is in commonly 900 ℃ above, when accordingly appliance whole quenchs, xiaoying of cutter hub material chooses medium, tall alloy steel, shape like what preamble mentions flat auger, cutter hub material is W18Cr4V, quench temperature surmounted 900 ℃ , cannot undertake whole quenchs. Abide by above 3, we are opposite above all experiment milling cutter (6) seeing a picture undertakes whole quenchs, cutter hub material, quench craft all with first the experiment milling cutter of the solder after temper by dipping in water is identical, hind of temper by dipping in water is apart from place of solder mouth 1mm to have metallographic laboratory test to cutter hub, metallographic organization is martensite + a few ferrite, hardness 52 ～ 54HRC, with not the metallographic that the cutter hub when solder knife head quenchs, hardness is consistent. All sorts of milling cutter that to the graph 1 ～ graph shows 5 times, broach undertook above whole quenchs the experiment brought into formal production to all obtain better result. Those who need an attention is, when milling cutter whole quenchs, go up at cutter hub as a result of knife head solder, and head of hard alloy knife is extremely good and fragile, a bit knock against can drop horn to cause discard as useless, be in consequently quench, temper and the following gush are arenaceous in must keep one's eyes peeled, can have knock against anything but. 4.

The effect uses milling cutter whole to quench, the cutter hub hardness that solder mouth is in is more original first head of knife of the solder after cutter hub of temper by dipping in water had substantially rise. If pursue 1, the groovy milling cutter that the graph shows 2 times, knife pouring wine cup, after using whole to quench, solved the problem that these milling cutter work to break off. Be like what the graph shows 3 times to shape flat auger, cutter hub material by W18Cr4v instead 40Cr, the use effect after whole quenchs is very good. Be like a graph again 4, after the whole of cutting tool classics that the graph shows 5 times quenchs, every knife can machine a spare parts 2000 above, cutting tool life gets rising greatly. CNC Milling CNC Machining