CN101381825B - Environment friendly free-cutting bronze alloy processing technique - Google Patents

Abstract

The invention relates to a technique for processing bronze alloy which is environment-friendly and easy to cut. The technique comprises the following steps of mixture, melting, refining, analysis, casting, straightening, saw cutting, inspection, package and warehousing. The compositions in weight percentage of the bronze alloy are 2.0 to 10.0 percent of tin, 3.0 to 12.0 percent of zinc, 2.0 to 8.0 percent of bismuth or 2.0 to 8.0 percent of the bismuth and 0.1 to 0.5 percent of nickel (plumbum, stibium, iron, phosphor, sulfur, silicon and aluminum), less than or equal to 0.5 percent of unavoidable impurities, and the balance being copper. The copper or the copper and the nickel are thrown into a smelting furnace hearth for smelting; the tin, the bismuth and the zinc are added into the smelting furnace hearth after melting; the liquid level is covered with calcined charcoal; after complete smelting, the temperature is raised and the refining is performed, wherein the temperature is between 1,100 and 1,250 DEG C and the time is between 10 and 30 minutes; after stirring and sampling, horizontal continuous casting is performed; and a crystallizer is a water-cooling crystallizer which is lined with a high-purity graphite sleeve, wherein the casting temperature is between 1,140 and 1,220 DEG C, the speed is between 15 and 30 meters per hour, and the cooling water pressure is between 0.01 and 0.05 MPa.

Description

A kind of environment friendly free-cutting bronze alloy complete processing

Technical field

The invention belongs to the non-ferrous metal technical field, refer more particularly to a kind of environment friendly free-cutting bronze alloy complete processing.

Background technology

Tin zinc lead bronze alloy is owing to have castability, wear resistance, corrosion-resistant and easy machinability well, be mainly used in fields such as mechanical bearing, automobile device, processing wear resistant corrosion resistant part is as bearing shell, axle sleeve, cylinder sleeve, piston clutch coupling, friction plate etc.

In recent years along with the growing continuously and fast of China's economy, particularly the fast development of machine industry makes the steady-state growth year by year of tin zinc lead bronze materials demand amount.But, the lead in the copper alloy play improve the material cutting ability in, but have because contaminate environment, the harmful former thereby problem that will progressively be replaced.Since World Health Organization in 1992 (WTO) stipulate " lead content in the tap water is preferably in below the 0.01mg/L " in guidelines for drinking water quality since, the demand of Lead free cutting copper alloys and research have spread to multiple industries such as machinofacture and have come from building, water supply utensil industry.In recent years, countries in the world constantly have free-cutting copper alloy or environmental protection copper alloy to come out.Wherein, the free-cutting copper alloy that adopts bismuth to substitute plumbous exploitation becomes an important research direction.But bismuth resource-constrained and costing an arm and a leg, and castability, free cutting property, mechanical property that bismuthiferous copper alloy exists can not be taken into account problem simultaneously.

Summary of the invention

For addressing the above problem, the invention provides a kind of environment friendly free-cutting bronze alloy complete processing, this complete processing is to add Bi to constitute the bell metal of Cu-Sn-Zn-Bi or add the bell metal that nickel element constitutes Cu-Sn-Zn-Bi-Ni again in the Cu-Sn-Zn element; Because Pb is as the unavoidable impurities element, so content is extremely low in alloy, constitutes impurity content jointly with other inevitable Sb, Fe, P, S, Si, Al; This processing process is short, and production cost is low.

In order to realize the foregoing invention purpose, the present invention has adopted following technical scheme:

Described environment friendly free-cutting bronze alloy complete processing comprises batching, melting, refining, analysis, casting, aligning, sawing, inspection, packing warehouse-in, and wherein batching, melting, refining, analysis, casting processing technology division are as follows:

I, batching

Get Sn2.0～10.0 by weight percentage, Zn3.0～12.0, Bi2.0～8.0 or Bi2.0～8.0+Ni0.1～0.5, inevitable impurity Pb+Sb+Fe+P+S+Si+Al sum≤0.5%, the Cu surplus is prepared burden;

II, melting

Earlier Cu or Cu+Ni input smelting furnace are carried out melting, treat to add Sn, Bi, Zn again after Cu or Cu+Ni dissolve, liquid level covers and adopts the calcining charcoal to make insulating covering agent;

III, refining

Treat that raw material all melts the back intensification and carries out refining, 1100～1250 ℃ of refining temperatures, refining time 10～30 minutes;

IV, analysis

The stirring sampling is done the Chemical Composition analysis and is seen whether meet batching proportion;

V, casting

Carry out horizontal continuous-casting after sampling analysis is qualified, crystallizer adopts water mold liner high purity graphite cover, and 1140～1220 ℃ of casting temps were stopped cooling water pressure 0.01～0.05MPa 1～5 second in drop-down 1～5 second 15～30 meters/hour of casting speeds.

Owing to adopted technical scheme as mentioned above, the present invention has following superiority:

1, the present invention has castability preferably, be difficult for to adopt hot-work (hot rolling, extruding, forging are easy to crack), and so subsequent technique can adopt: horizontal casting-aligning-scale sawing-inspection-packing is put in storage etc.

2, the tin zinc bismuth bronze of processing and fabricating of the present invention or tin zinc bismuth nickel bronze alloy material, belong to environment-friendly copper alloy, technology is simple, quality is good, alloy mechanical property: tensile strength Rm 〉=240MPa, regulation disproportional extension strength Rp0.2 〉=120MPa, elongation A 〉=15%, hardness HB 〉=50, cutting ability: being equal to or slightly lower than the cutting ability of tin zinc lead bronze, is good tin zinc lead bronze alloy replacing product.

3, processing process of the present invention is short, and production cost is low.If the surface requirements strictness, can also increase between aligning and scale sawing operation strips off the skin stretches or the polishing operation.

Embodiment

Embodiment 1: make Φ 16.8 * 2000mm bell metal bar

Batching: prepare burden by weight percentage, wherein tin 4%, zinc 3%, bismuth 3%, unavoidable impurities Pb+Sb+Fe+P+S+Si+Al sum be 0.5%, copper surplus.

Melting: earlier Cu is dropped into smelting furnace and carry out melting, treat to add Sn, Bi, Zn again after Cu dissolves, liquid level is made insulating covering agent by the calcining charcoal.

Refining: treat that raw material all melts the back intensification and carries out refining, 1100 ℃ of refining temperatures, refining time 10 minutes.

Analyze: stir sampling and do the Chemical Composition analysis.

Casting; Carry out horizontal continuous-casting after sampling analysis is qualified, crystallizer adopts water mold liner high purity graphite cover, and 1140 ℃ of casting temps were stopped cooling water pressure 0.01MPa 1 second in drop-down 1 second 15 meters/hour of casting speeds.

Embodiment 2: make Φ 16.8 * 2000mm bell metal bar

Batching: prepare burden by weight percentage, wherein tin 6%, zinc 5%, bismuth 6%, unavoidable impurities Pb+Sb+Fe+P+S+Si+Al sum be 0.3%, copper surplus.

Melting: earlier Cu is dropped into smelting furnace and carry out melting, treat to add Sn, Bi, Zn again after Cu dissolves, liquid level is made insulating covering agent by the calcining charcoal.

Refining: treat that raw material all melts the back intensification and carries out refining, 1800 ℃ of refining temperatures, refining time 15 minutes.

Analyze: stir sampling and do the Chemical Composition analysis.

Casting; Carry out horizontal continuous-casting after sampling analysis is qualified, crystallizer adopts water mold liner high purity graphite cover, and 1180 ℃ of casting temps were stopped cooling water pressure 0.03MPa 3 seconds in drop-down 3 seconds 23 meters/hour of casting speeds.

Embodiment 3: make Φ 16.8 * 2000mm bell metal bar

Batching: prepare burden by weight percentage, wherein tin 10.0%, zinc 12.0%, bismuth 8%, unavoidable impurities Pb+Sb+Fe+P+S+Si+Al sum be 0.2%, copper surplus.

Melting: earlier Cu is dropped into smelting furnace and carry out melting, treat to add Sn, Bi, Zn again after Cu dissolves, liquid level is made insulating covering agent by the calcining charcoal.

Refining: treat that raw material all melts the back intensification and carries out refining, 1250 ℃ of refining temperatures, refining time 30 minutes.

Analyze: stir sampling and do the Chemical Composition analysis.

Casting; Carry out horizontal continuous-casting after sampling analysis is qualified, crystallizer adopts water mold liner high purity graphite cover, and 1220 ℃ of casting temps were stopped cooling water pressure 0.05MPa 5 seconds in drop-down 5 seconds 303 meters/hour of casting speeds.

Embodiment 4: make Φ 16.8 * 2000mm bell metal bar

Batching: prepare burden by weight percentage, wherein tin 4%, zinc 3%, bismuth 2.0%+ nickel 0.1%, unavoidable impurities Pb+Sb+Fe+P+S+Si+Al sum be 0.5%, copper surplus.

Melting: earlier Cu or Ni input smelting furnace are carried out melting, treat to add Sn, Bi, Zn again after Cu or Ni dissolve, liquid level is made insulating covering agent by the calcining charcoal.

Other technology is with embodiment 1.

Embodiment 5: make Φ 16.8 * 2000mm bell metal bar

Batching: prepare burden by weight percentage, wherein tin 5%, zinc 4%, bismuth 6.0%+ nickel 0.3%, unavoidable impurities Pb+Sb+Fe+P+S+Si+Al sum be 0.3%, copper surplus.

Melting: earlier Cu or Ni input smelting furnace are carried out melting, treat to add Sn, Bi, Zn again after Cu or Ni dissolve, liquid level is made insulating covering agent by the calcining charcoal.

Other technology is with embodiment 2.

Embodiment 6: make Φ 16.8 * 2000mm bell metal bar

Batching: prepare burden by weight percentage, wherein tin 6%, zinc 5%, bismuth 8.0%+ nickel 0.5%, unavoidable impurities Pb+Sb+Fe+P+S+Si+Al sum be 0.2%, copper surplus.

Melting: earlier Cu or Ni input smelting furnace are carried out melting, treat to add Sn, Bi, Zn again after Cu or Ni dissolve, liquid level is made insulating covering agent by the calcining charcoal.

Other technology is with embodiment 3.

Subsequent technique adopts in the foregoing description:

Aligning: adopt seven roller straighteners that bar is carried out straightening;

Sawing: adopt circular saw machine that the finished product bar is according to the contract required to carry out sawing;

Check: the bar to sawing carries out Chemical Composition, mechanical property, cutting ability inspection;

Packing warehouse-in: the bar after the passed examination is packed warehouse-in.

Each alloy element action division is as follows among the present invention:

Copper: have high conduction, heat conductivility and good solidity to corrosion, weight ratio is the highest in tin zinc bismuth bronze.

Tin: stanniferous copper alloy has stronger corrosion stability and wear resistance, and its mechanical property is high fairly good and nonmagnetic with processing performance, does not produce spark during impact, but easily air-breathing and generation segregation, for proof strength and plasticity, its content should not be too high, should be controlled in 2.0～10.0% scopes.

Zinc: zinc is one of important interpolation element in the copper alloy, can improve the flowability of tin and copper containing alloy, dwindles the Tc interval, alleviate segregation and exhaust, but should not add too much, otherwise can make alloy property not reach desirable requirement, its content should be controlled in 3.0～12.0% scopes.

Bismuth: fusing point is lower, solid solubility in copper alloy matrix is minimum, has the effect of molten metal supply between the dendrite that promotes alloy final set part, effectively reduces the casting flaw of copper alloy, improve the machinability of alloy, harmless as the substitute element of lead.Because bismuth is present in crystal boundary with the simple substance state, too high levels can cause the on the low side and hetero-organization defective of plasticity, has a strong impact on alloy property; Content is crossed to hang down and is not then reached the alloy property condition that requires, so its content should be strict controlled between 2～8%.

Nickel: improve the corrosion stability and the toughness of alloy, its content is strict controlled between 0.1～0.5%.

Owing to do not add lead, extremely low as the lead in the foreign matter content, and strictnesses such as unavoidable impurities element such as Pb, Sb, Fe, P, S, Si, Al be controlled to be≤0.5%.

Claims (1)

1. an environment friendly free-cutting bronze alloy complete processing comprises batching, melting, refining, analysis, casting, aligning, sawing, inspection, packing warehouse-in, it is characterized in that: the batching in this complete processing, melting, refining, analysis, casting division are as follows:

I, batching

Get Sn2.0～10.0 by weight percentage, Zn3.0～12.0, Bi2.0～8.0 or Bi2.0～8.0+Ni0.1～0.5, inevitable impurity Pb+Sb+Fe+P+S+Si+Al sum≤0.5%, the Cu surplus is prepared burden;

II, melting

Earlier Cu or Cu+Ni input smelting furnace are carried out melting, treat to add Sn, Bi, Zn again after Cu or Cu+Ni dissolve, liquid level covers and adopts the calcining charcoal to make insulating covering agent;

III, refining

Treat that raw material all melts the back intensification and carries out refining, 1100～1250 ℃ of refining temperatures, refining time 10～30 minutes;

IV, analysis

The stirring sampling is done the Chemical Composition analysis and is seen whether meet batching proportion;

V, casting

Carry out horizontal continuous-casting after sampling analysis is qualified, crystallizer adopts water mold liner high purity graphite cover, and 1140～1220 ℃ of casting temps were stopped cooling water pressure 0.01～0.05MPa 1～5 second in drop-down 1～5 second 15～30 meters/hour of casting speeds.