A kind of preparation method of low alloy bucket teeth

In order further to improve the bucket tooth performance, Chinese invention patent CN101876025A discloses a kind of preparation method of low alloy bucket teeth.Earlier iron is put into and is smelted into molten iron in the induction furnace, then after going out molten iron and removing slag with following each component (weight %) carbon 3.3～3.7, silicon 0.4～0.7; Manganese 5～7, phosphorus＜0.07, chromium 0.6～0.9; Vanadium 0.15～0.3 joins in the molten iron and pours into bucket tooth, will become the bucket tooth of as cast condition to put into water more; Quench, fully eliminate as-cast structure.Chinese invention patent CN101862813A also discloses a kind of method of manufacture of excavator bucket teeth; Its technical characterstic is to adopt the lost foam hollow-shell casting technique to make excavator bucket teeth; Before Pour Steel, adopt the incendiary method with PS model burning-off, obtain die cavity as clay-bonded sand; Can not penetrate into molten steel surface after making molten steel inject die cavity, cause molten steel recarburization, slagging scorification and foundry goods is scrapped because of the carbon that the gasification of PS model produces.The method of manufacture of the excavator bucket teeth of this invention, it is simple to have production technique, and cost is low, characteristics such as efficient height.Chinese invention patent CN101737045A also discloses a kind of high abrasion composite nose bucket tooth, comprises the bucket tooth body, it is characterized in that: the head at the bucket tooth body is coated with the high abrasion clad steel plate, or at the head built-up welding high antifriction layer of bucket tooth body.

Its advantage is: bucket tooth head wear resisting property is high, the life-span of bucket tooth is significantly increased, but have the deficiency of complex manufacturing.Chinese invention patent CN101446097 also discloses a kind of metal pattern, core cast steel bucket tooth mold, method of manufacture and cast steel bucket tooth thereof, has solved the technical problem that the sand mold casting bucket tooth exists.The mould that adopts is outside metal tire core both sides and metal, to form ” people ” font bucket tooth die cavity between the loose tool, at bucket tooth die cavity ” people ” font infall sprue gate is set; It is rotatable that the outer loose tool of metal upper end has axis hole to be inserted on the fixed rotating shaft of backing plate upper end, and there is draft angle the opening and closing place, upper end, and the folding handle is equipped with in the lower end.Method of manufacture is at mold spraying interior high-temperature resistant coating before the cast; Cast molten steel cooling back becomes cast steel bucket tooth, opens separately two outer loose tools of metal of folding handle, and draft angle promotes the cast steel bucket tooth slippage and goes out metal tire core, accomplishes the demoulding.This invention mould structure is simple, reasonable;

Manufacturing processed can manual work or power operation; Cast steel bucket tooth does not have shrinkage cavity, loose, sand holes etc., and tensile strength and wear resistance are than sand mold casting bucket tooth improve 15%～25%.Chinese invention patent CN101444841 also discloses a kind of preparation method of wear-resistant cast steel bucket tooth; This invention 96.3～97.0%, 1.5～1.8%, 0.8～1.2%, 0.4～0.6%, 0.025～0.035%, 0.045～0.055% and 0.18～0.25% is mixed in one respectively by mass percentage through with tinplate tin scrap stock, high carbon ferro-chrome, mid-carbon fe-mn, ferrosilicon, ferro-boron, ferrozirconium and ferrotianium, and after being compacted into square on the pressing machine; Put into the induction furnace heat fused; And in cured formwork, pour into bucket tooth, after bucket tooth solidifies, directly into water cooling; Tempering at low temperatures obtains wear-resistant cast steel bucket tooth at last.Chinese invention patent CN101408030 also discloses a kind of pressing machine with split type mould, method of manufacture and forging cutting teeth thereof, utilizes split type mould to solve the ejection technique problem.The mould that adopts is divided into upper and lower split, and last split is formed by overlapping on the drift and being embedded in the drift that overlaps the lower end on the drift; Following split is on pad is pulled, to be fixedly connected overcoat, and the tube mould of split is housed in its external sleeve, at the tube mould internal upper part disengagement side’s cover is housed; Pull at pad knock-pin is housed in the center drilling. Method of manufacture is; Utilize drift hammering blank at the tube mould excellent suitability for press forming, drift moves up during the pressing machine return, and disengagement side’s cover stops forging cutting teeth to move; Drift and forging cutting teeth are thrown off; Knock-pin upwards ejects the tube mould of forging cutting teeth and split, and tube mould is divided into two along overcoat, the forging cutting teeth automatic demoulding.This invention has solved bucket tooth excellent suitability for press forming automatic demoulding; Forging cutting teeth improves more than 30% than casting bucket tooth mechanical property and wear resisting property, particularly under mal-conditions such as mine, uses, and it is superior that its performance more shows.But the forging cutting teeth complex process, die life is short, and manufacturing cost is high.Chinese invention patent CN101392314 also discloses the thermal treatment process of trolley sawtooth casting; This is bright to be that different mining according to the thick cross section crown thickness of bucket tooth and tooth cavity thickness is with different medium quenchings; Promptly earlier with the teeth head at 10%NaCL solution precooling 10-15S; Whole then at oil quenching, thus prevent and reduce product phenomenon to occur scrapping because of crackle occurring.Low alloy steel trolley sawtooth casting is warmed to 910 ℃ and be incubated 2 hours, and the furnace temperature precooling 30S that comes out of the stove after evenly cools off 10-15S with the head of teeth in the 10%NaCL aqueous solution, carry out whole oil cooling then, again to 250 ℃ of low-temperaturetempering stoves.This technology can obtain good hardness and toughness, but troublesome poeration, controllability is relatively poor.Chinese invention patent CN1621554 also discloses a kind of complex alloy cast-steel excavator bucket teeth and production technique thereof; The complex alloy cast-steel excavator bucket teeth that this invention provided is to constitute like this;

Described excavator bucket teeth is that the composition (weight %) of the complex alloy cast-steel that contains is: 0.22～0.30C, 1.1～1.4Cr, 1.25～1.65Mn, 1.21～1.58Si, 0.20～0.31Mo, 0.05～0.11Ti, surplus is Fe.Described thermal treatment process is: anneal after bucket tooth has watered, the control rate of heating is being 60～80 ℃/h below 200 ℃, is 100～120 ℃/h more than 200 ℃; 840～900 ℃ of insulations 3～5 hours, stove was as cold as 680～700 ℃ of insulations 4 hours, and stove is as cold as 500 ℃ and takes out air cooling; Bucket tooth quenches after machining, and workpiece is heated to 840～900 ℃ with 100～120 ℃/h, is incubated 3～5 hours; Treated coldly 1～2 minute by taking out in the stove, quench then, heat-eliminating medium is a sodium silicate solution; Its proportion is 1.15, and workpiece is chilled to 300 ℃ and takes out air cooling to room temperature, and quenching finishes; Carry out tempering then immediately, be heated to 240 ℃, be incubated 3～4 hours and take out air cooling with 40～60 ℃/h.But, adopt aforesaid method to make bucket tooth, thermal treatment process is complicated, and contains expensive molybdenum element in the bucket tooth material, causes the bucket tooth production cost to increase.