CN1180593A - Extrusion and impact forging mould and preparation method - Google Patents

Abstract

An improved die for thermoextruding and thermoforging features that a layer of alloy including Cr (16-35%), W (2-20%) or Mo (1-10%), C (1-2.5%) and Co (rest) is metallurgically attached to the working surface of base body of die. Its advantages are high adhesion of compounded layer, high-temp red hardness, abration resistance and good resistance to oxidation, small friction coeffient, good seizure resistance, long service life increased by 5-10 times and low hardness under ordinary-temp so that it is easy to processing and modifying the die.

Description

A kind of extruding and impact forging mould and preparation

The present invention is to the improvement of metal fever extruding and heat (pressure) impact forging usefulness mould, relates in particular to a kind of hot extrusion and hot impact forging mould that is inlaid with wearing layer.

Be generally the wearability and red hardness and the resistance to high temperature oxidation that improve hot impact forging mould and hot extruding die, prolong the service life of mould, enhance productivity.A kind of method is to apply wear-resistant coating on the mold work surface by the method for physics or chemistry, as carburizing, nitriding, boronising or in refractory oxides coatings such as mold work position spray aluminum oxide, zirconias.Approach silicon nitride protective layer as Chinese patent 85105267 disclosed a kind of magnetically controlled sputter methods of using at heat pressing and molding mold surface sputtering deposition one deck, to improve mould high temperature oxidation resistance and wearability; Chinese patent 86106364 is disclosed to be nitride, the carbide with plasma-deposited 4b family metal, the method for carbonitride diaphragm; Chinese patent 90101498 is disclosed to be the high nitrogen titanium nitride of vapour deposition intermediate layer on the hot extruding die working face, applies titanium nitride coating again on the intermediate layer.These are by applying the method for wear-resistant coating on the mold work surface, though can improve the service life of mould, the coating mold red hardness is poor, normal temperature hardness height, and difficulty repairs a die; And the interior die cavity that these methods generally are not suitable for the extrusion die of die cavity working face in having applies coating, and especially to apply coating just more difficult for the less metering hole of die cavity; And the above-mentioned coating need special equipment that applies, cost is also high; The adhesion of coating and parent metal is strong inadequately in addition, particularly ceramic coating easily crisp, easily collapse, coating is generally thinner in addition, coefficient of friction is big, therefore at the maximum supporting region of mould, the coatings one such as the conical surface, calibrating strap transition region that are mould are that easily to come off two be that wearing and tearing are very fast, so still fall short of the service life of coating mold, using need repair a die after a period of time again applies coating.

The another kind of method that improves the die-face wearability is to inlay high-abrasive material at die-face, as described in Chinese patent 93225817, is to inlay one deck wolfram steel sheet at the mold work surface physics; Or make mould with the antifriction alloy powder, method as raising hot extruding die wearability as described in the Chinese patent 86107658, be the tungsten that adopts 40-70%, 12-38% chromium, the alundum (Al of 7-25%, the lanthanum sesquioxide of 0-10%, and the nickel of 1.5-20%, cobalt, iron one or more, make metal ceramic powder, directly make unitary mould with the powder metallurgical technique forming and sintering then.Yet the former is bigger because of wolfram steel sheet fragility, and difficulty of processing is big, and combines because of adopting physics to inlay with die matrix, and bond strength is not enough, and the wolfram steel sheet breaks away from die matrix easily; Latter's mould is many with material, the cost height, and the manufacturing process complexity needs special mould manufacturing, is difficult to the reparation of machined and mould.And both impact flexibility is all strong inadequately, is not suitable for being used for dashing (pressure) forging die.

The objective of the invention is to overcome the deficiency of above-mentioned prior art, provide a kind of improved wearability and red hardness better, coefficient of friction is little, anti-oxidant good with seizure resistance, normal temperature hardness is low, is easy to repair a die, to make simple cost low, and multiple layer is firm with matrix bond, long service life, the more reliable inserted extrusion die and dash (pressure) forging mould of working.

Another object of the present invention is to provide a kind of preparation method of above-mentioned mould.

The present invention's first purpose realizes, the main improvement is to use the compound one deck of metallurgical binding method certain thickness by (percentage by weight at the working face of mould, as follows) chromium (Cr) of 16-35%, the molybdenum (Mo) of the tungsten of 2-20% (W) or 1-10%, the carbon of 0.1-2.5% (C), surplus is cobalt (Co) component alloy layer, thereby has significantly improved the service life of mould.For further improving the adaptability of mould, adapt to the processing of various materials, visual alloy-layer is added with method and mould kind, the nickel (Ni) that also can add one or more 1-15% in the multiple laminated gold, the niobium of 2-8% (Nb), the silicon of 1-3% (Si), the boron of 0.5-4% (B).As make alloyed powder and be added with, suitable some boron, the silicon of suitably adding fuses technology or spray fusing, surfacing to increase the alloyed powder melt fluidity, to adapt to; As make alloy electrode, can not add yet.Each alloy composition ratio needs to be adjusted according to mold work requirement and the alloy-layer method of being added with, and as pressing the multiple layer of (dashing) mould, carbon, W content can suitably hang down in the alloy, and nickel content can be suitably higher, to reduce the fragility increase toughness of multiple layer; The multiple layer of extrusion die, in the alloy carbon, tungsten, cobalt, chromium content suitably height a bit, with increase hardness and seizure resistance.

Another purpose of the present invention realizes, comprise die matrix is processed the pit bigger than the moulding die cavity, with welding or surfacing or fuse technology at the chromium of pit periphery built-up welding one deck by 16-35%, the tungsten of 2-20% or the molybdenum of 1-10%, the carbon of 0.1-2.5%, surplus is the alloy that cobalt is formed, and leaves required die cavity with line cutting or electric pulse mode on alloy-layer then.For reducing again the stress of laminated gold, improve the fastness that combines of multiple laminated gold and die matrix, the mold cavity pit preferably is split into taper or step.Applying of the multiple laminated gold of mould can be to make the alloyed powder of mixing by the metal flouring technology in each alloy composition of determining ratio, is added to the mold work surface with methods such as vacuum fusion sintering or plasma spray heap; Also each alloy composition melting mixing can be made welding rod (silk), method heap with various welding adds (weldering) to the mold work surface, with adding as methods such as inferior arc-welding, oxy-acetylene welding, plasma welding heap, multiple layer thickness generally with 2-10mm for well, cut with line then or the electric pulse mode is left required pass or die cavity.Two class methods all can obtain to inlay multiple layer and the good metallurgical binding of die matrix, thereby improve the fastness that combines of multiple laminated gold and die matrix.

Description below in conjunction with several non-limiting embodiment further specifies invention.

Fig. 1 is a kind of aluminum profile extrusion die cross-sectional configuration figure.

Fig. 2 is Figure 1A-A insight structural map.

Fig. 3 is a kind of forging die cross-sectional configuration figure.

Fig. 4 is Fig. 3 B-B insight structural map.

Embodiment 1: referring to Fig. 1,2, on aluminum profile extrusion die matrix 1, leave the tapered pit big than mold cavity by direction of extrusion F on die matrix.Chromium with 28%, 6% tungsten, 1% carbon, 65% cobalt founding become welding rod, with welding manner the die matrix pit are filled up, and form the multiple layer 2 of alloy.Process required die cavity 3 with the line cutting mode then.

Embodiment 2: as embodiment 1, chromium with 19%, 13% tungsten, 1.3% carbon, 13% nickel, 3% silicon, 2.5% boron, 48.2% cobalt are made 160-320 purpose alloyed powder, with the vacuum fusion sintering mode mould pit is filled up, process required die cavity with the line cutting mode.

Embodiment 3: referring to Fig. 3,4, on drop stamping mould 1 matrix, leave the pit that step arranged bigger than the punching press shape, use the built-up welding mode in pit, the chromium 27%, 0.2% carbon, 2.8% nickel, 5% molybdenum, welding rod built-up welding one deck that 65% cobalt is melt into form the multiple layer 2 of alloy.Electricity consumption pulse mode then processes required form 3, promptly gets required composite die.

Embodiment 4: as embodiment 3, chromium with 22%, 4.5% tungsten, 0.1% carbon, 1.6% silicon, 2.6% boron, 69.2% cobalt, make alloyed powder with metallurgical flouring technology, use plasma spray welding method then, built-up welding one deck around pit processes required die cavity in the electric pulse mode at last.

The present invention is owing to adopt the multiple layer of chromium, carbon, cobalt, tungsten or molybdenum alloy, that mould has is high temperature resistant, impact resistance good, mold cavity is worked under the condition of high temperature, still has stronger red hardness, coefficient of friction is little, anti-oxidant, bite-resistant, abrasion resistance are good, and long service life can improve life-span 5-10 doubly.And hardness is low under the normal temperature easily processes, repairs a die.Goods fineness is good, the yield rate height, and mould consumption reduces, and reduces die change and can improve output.Multiple laminated golden consumption is few, and cost is low, applicable to various hot extruding dies and hot impact forging (pressure) mould.

For convenience of description, invention saidly is added with, piles and add as synonym.

Claims (6)

1, a kind of extruding or impact forging mould that sbrasion resistant coating is arranged is characterized in that the certain thickness chromium by 16-35% of metallurgical compound one deck on the die matrix working face, the tungsten of 2-20% or the molybdenum of 1-10%, and the carbon of 0.1-2.5%, surplus is the alloy-layer that cobalt is formed.

2,, it is characterized in that also being added with in the said multiple laminated gold nickel of one or more 1-15%, the niobium of 2-8%, the silicon of 1-3%, the boron of 0.5-4% according to described extruding or the impact forging mould that sbrasion resistant coating is arranged of claim 1.

3,, it is characterized in that said multiple layer thickness is 2-10mm according to claim 1 or 2 described extruding or the impact forging moulds that sbrasion resistant coating is arranged.

4,, it is characterized in that said multiple layer is tapered at the thickness direction of mould according to described extruding or the impact forging mould that sbrasion resistant coating is arranged of claim 3.

5, a kind of method of making the described mould of claim 1, comprise die matrix is processed the pit bigger than the moulding die cavity, with welding or surfacing or fuse technology at the chromium of pit periphery built-up welding one deck by 16-35%, the tungsten of 2-20% or the molybdenum of 1-10%, the carbon of 0.1-2.5%, surplus is the alloy that cobalt is formed, and leaves required die cavity with line cutting or electric pulse mode on alloy-layer then.

6,, it is characterized in that inlaying on the said mould the tapered or step of pit of alloy-layer according to the described mould manufacturing method of claim 5.