High speed milling processes medium application in mould of hard steel of temper by dipping in water

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Undertake to hard steel of temper by dipping in water high speed milling is a kind of advanced processing technique, attribute one of effective hard mill skills. Long-term since, people uses milling all the time one grinding or milling, electric spark is machined (the treatment that the method of EDM) realizes pair of moulds. Although electric spark adds a tool to have the craft characteristic that has nothing to do with workpiece hardness, but inferior material purify rate makes its applied limits is restricted. As the development of contemporary processing technique and the occurrence that exceed material of strong cutting tool, with mill era is ground, the mould treatment that replaces EDM to have efficient economy with milling already became a possibility, and aborning obtained remarkable economic benefits. Use hard mill technology to machine a mould, not only make treatment cycle shortens greatly, and treatment quality got assuring reliably. Rotate to undertake hard milling can gain the face of the mark that do not have mill in main shaft high speed, its surface surface roughness can amount to Ra0.

6µm. The treatment characteristic hard milling of 1 hard milling and electric spark machine photograph comparing to have the following characteristic: Efficient a large number of time that hard mill treatment saved EDM electrode to design production place to take up and have higher material purify rate, treatment quality rises significantly, shorten greatly or eliminated tool benchwork deserve to grind long rub time, make the mould machines efficiency to rise greatly. When high quality hard milling machines a mould, install steel of strong tool of temper by dipping in water treatment figuration directly, avoided a spare parts effectively to install the error holding clip that cause for many times, raised the geometrical position precision of the spare parts. Use high speed milling to be able to gain the treatment face of the mark that do not have mill, make quality of spare parts surface rises greatly. Cooling and lubricant demand is low normally hard milling can use Gan Xi or use a few cooling lubricating fluid, need not fluid of EDM special job filters circularly system, at the same time the processing process of cooling lubricating fluid also goes to the lavatory more than EDM. Invest treatment of little hard mill to be able to be already on appropriative CNC machine tool or machining center undertake, also can undertaking with high speed main shaft on the general accuracy machine tool that change one's costume or dress. Latter has the process capability of general accuracy machine tool not only, and still can undertake hard milling, reduced installation cost, increased a machine tool flexible. Current, a few manufacturers of foreign already developed main shaft of high speed of a few appropriative in succession, like 0 what IBAG Zurich company develops.

The auger of 125 ～ 60kW spends clamp main shaft, its rotate speed can amount to 12 × 80 × of 103 ～ 103r/min, deserve to cooling fluid supplies a system. Graph the high temperature hardness of all sorts of 1 tool material 1.

KT9 2.

LN10 3.

CR1 4.

NIT 5.

Hard alloy 6.

Cermet pursues the choice of material of the tool below condition of 2 different cutting cutting tool of 2 hard mill and the option that cutting dosage chooses hard milling cutter to provide data are current, the cutting tool data that is used at hard milling basically has get together nitrogen of brilliant cubic metre changes boron (CBN) , pottery and porcelain, new-style hard alloy and coating hard alloy. The crystal structure of CBN of material of CBN cutting tool is face heart cubic metre, have extremely very tall hardness, strong wearability and good thermal conductivity, and with there is very big laziness between element of iron a group of things with common features, also won't produce remarkable chemistry in 1300 ℃ . In the meantime, also have good stability to soda acid. Consider to make clear, with CBN compound a ～ of HRC35 of hardness of cutting tool cutting of 67 quench steel succeeds particularly. Accordingly, CBN cutting tool has special place in hard mill treatment. Material of pottery and porcelain of pottery and porcelain has good wearability and thermochemistry stability, its hardness, tenacity under CBN, can use at machining the spare parts of hardness HRC<50. New-style hard alloy and coating hard alloy these two kinds of cost of material are inferior, suit cutting hardness to be in HRC40 ～ the 50 workpiece between. If the graph is shown 1 times,the high temperature hardness of all sorts of tool material is compared. It is in feed 0.

15mm/r, cutting deepness 0.

When 5mm is the following, if the cutting tool material that recommends hard steel of milling temper by dipping in water according to cutting treatment condition pursues 2 are shown. In recent years, the tool made a manufacturer roll out newest product in succession. Be like Japanese black high speed of outstanding JBN milling cutter (when the tall hardness material of above of HRC60 of cutting of 100m/min) of ≥ of cutting speed V, durability of its cutting tool amounts to 60min above, fashion series product. Swedish Seco milling cutter also forms whole set, machine a requirement in order to satisfy all sorts of milling. Milling cutter diameter chooses an experiment to consider to make clear, hard steel of effective treatment temper by dipping in water needs to use small diameter milling cutter. No matter use ball head milling cutter or columnar milling cutter to machine three-dimensional curved surface, cutting tool diameter is smaller, its are fore-and-aft interference is smaller. Accordingly, when choosing cutting tool diameter, to having outside convex is fore-and-aft the workpiece of outline curved surface, should reach treatment efficiency to consider integratedly according to intensity of its work structure, milling cutter, stiffness; To inside sunken form is fore-and-aft the workpiece of outline face, the radius of the smallest curvature that even if inward sunken outline is in,is equal to. Material of the cutting processability that cutting dosage chooses workpiece material, cutting tool chooses to produce immediate effect to cutting dosage. Harder, intensity jumps over workpiece material tall, cutting speed should be jumped over low. The cutting speed limits of hard milling 90 ～ 200m/min is advisable. If the cutting rate value that recommends according to workpiece hardness and cutting tool material pursues 2 are shown. Cutting deepness is taken commonly 0.

1 ～ 0.

4mm, feed is taken 0.

1 ～ 0.

2mm/r is advisable, when use JBN300 processes the hard steel of temper by dipping in water with different qualitative capable person, below condition of cooling and lubricant successive cutting, its recommend cutting dosage to see a table 1. The cutting dosage that expresses 1 JBN300 to process hard steel of temper by dipping in water is machined cementite of steel of structure of Dmm of material and deepness of cutting of Fmm/r of feed of Vm/min of hardness cutting speed quenchs 65100 ～ of HRC55 ～ 1200.

05 ～ 0.

300.

1 ～ 0.

Cementite of 5 structures steel quenchs 55150 ～ of HRC45 ～ 2000.

05 ～ 0.

300.

1 ～ 0.

5 tools steel quenchs 65100 ～ of HRC55 ～ 1200.

05 ～ 0.

200.

1 ～ 0.

When 5 essence mill, to acquire taller precision and exterior quality, can choose higher cutting rate and lesser feed. 3 hard milling because use small diameter,to the requirement high rotate speed of the machine tool milling cutter is mixed cut high fast, the machine tool must have high speed main shaft. Tall tigidity machines quality goodly to obtain, the machine tool must be had enough tall stiffness, in order to avoid the adverse effect of flutter of the cutting tool when cutting to machining quality. In order to of good device of cutting tool clamp makes sure the best coaxial of cutting tool and main shaft is spent. Than horizontal machining center more of vertical machining center of economy popularize application, for complex model the hard mill treatment of the face offerred a machine tool to assure. Express Ⅰ of thick mill of Mm of radius of circular arc of point of Mm of diameter of milling cutter of Dmm of deepness of cutting of Fmm/r of feed of Vm/min of speed of cutting of working procedure of parameter of craft of milling of high speed of forging die of 2 connecting rod 1600.

1770.

360.

8 Ⅱ 1510.

1500.

340.

5 Ⅲ 1510.

1250.

340.

Ⅰ of 5 essence mill 1510.

100.

23- Ⅱ 1510.

050.

0753-4 hard milling machines medium applied hard milling to regard efficient treatment as the new method of the mould in the mould, in the mould in making, got applied extensively. For example, foreign some company makes connecting rod forging die, with electric spark treatment antrum needs 12 ～ 15h, electrode makes 2h. Convert after hard milling, use Torus to establish milling cutter to undertake machining to the steel of strong tool of temper by dipping in water of hardness HRC60, craft parameter is like a watch related its 2 are shown. Treatment of whole forging die needs 3h20min only, work efficiency raises 4 ～ 5 times, treatment surface surface roughness amounts to Ra0.

5 ～ 0.

6µm, quality accords with a requirement completely. CNC Milling