CN103243233A

CN103243233A - Production process of lead-free cutting-easy magnesium brass rod

Info

Publication number: CN103243233A
Application number: CN2013101446640A
Authority: CN
Inventors: 梁亮
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-04-24
Filing date: 2013-04-24
Publication date: 2013-08-14

Abstract

The invention provides a production process of a lead-free cutting-easy magnesium brass rod. The production process is characterized by being prepared from the following materials in parts by weight: 60 parts of Cu, 30 parts of Zn, 8 parts of Mg, 0.1 part of Bi, 0.1 part of Si, 0.1 part of Al, 0.1 part of P and 0.2 part of Re. The specific production process comprises the following steps: adding the prepared materials to a medium-frequency induction furnace for smelting; sufficiently stirring so that each component is uniformly distributed; discharging the components out of the furnace and pouring the components to an iron mould to obtain alloy ingot; thermally extruding the ingot at 500 DEG C after turning, and drawing an extrusion rod by a single-chain horizontal drawer to obtain the magnesium brass rod. The production process of the lead-free free-cutting magnesium brass rod is simple, and the processed brass rod is easy to cut and corrosion-resistant.

Description

The Cutting Lead-free Brass Containing Magnesium rod production process

Technical field

The present invention relates to a kind of round brass rod production technique.

Background technology

Copper is the metal that the mankind are familiar with the earliest and use, and copper and alloy thereof have good conduction and heat conductivility, has the advantages such as solidity to corrosion, formability simultaneously, mostly contain at present metallic lead in the copper rod production process, this pot metal rod hardness is high, is not easy cutting, is unfavorable for deep processing.

Summary of the invention

Purpose of the present invention is exactly to provide a kind of crisp and not hard Cutting Lead-free Brass Containing Magnesium rod production process that has for above-mentioned situation .purpose of the present invention can realize by following scheme: a kind of Cutting Lead-free Brass Containing Magnesium rod production process, the raw material configuration that to it is characterized in that by following consumption be weight part forms: Cu 60, and Zn 30, and Mg 8, Bi 0.1, Si 0.1, and Al 0.1, and P 0.1, Re 0.2, concrete production technique is as follows: the raw material prepared is put into to medium-frequency induction furnace and carry out melting, fully stir so that each distributed components, coming out of the stove is poured into swage and obtains alloy cast ingot.Ingot casting is carried out to hot extrusion at 500 ℃ after turning processing, then extruded rod is carried out to drawing with the horizontal cold drawing bench of strand and make magnesium round brass rod of the present invention.It is simple that the present invention has technique, and the round brass rod processed easily cuts, corrosion-resistant.

Below by various detections and test, correlated performance of the present invention is described:

1,mechanical property of the present invention

The mechanical property of magnesium brass is as listed as table 1.The index of weighing material plasticity is unit elongation and relative reduction in area, and from table 1, the unit elongation of magnesium brass and relative reduction in area are respectively 16.30% and 32.4%, show that its plasticity is good.Although on the one hand magnesium not only solid solution in α mutually but also solid solution in β mutually in, its solubleness is not high, the solution strengthening effect of magnesium is little, less on the plasticity impact of brass; Be that on the other hand crisp and not hard magnesium-containing compound all has distribution at intracrystalline and crystal boundary, and its size little (size is 2 μ m left and right), pattern is roughly spherical, and the characteristic of magnesium-containing compound, pattern and distribution all can obviously not reduce the plasticity of magnesium brass.The tensile strength of half-hard state leaded brass C3604 is about 470～550MPa, and yield strength is about 350MPa, and unit elongation is greater than 7%.From table 1, the tensile strength 550MPa of half-hard state magnesium brass, unit elongation is 16.30%, relative reduction in area is 32.4%, and yield strength is approximately 280MPa, less than the yield strength of half-hard state C3604.The reason that the yield strength of half-hard state magnesium brass is lower is as follows: although adding of MAGNESIUM METAL has solution strengthening, the effect of precipitation strength, can improve the intensity of magnesium brass, but the alloying element added in experiment magnesium brass is more, the easy enrichment of impurity element at grain boundary segregation (as impurity such as bismuth, silicon at grain boundary segregation), frangible compounds also easily appears in intracrystalline, and these factors all can be fallen low-alloyed intensity.From the reinforcement theory of metal, the second-phase compound particles distributes and can produce strengthening effect at intracrystalline, and alloy strength is improved, and the factors such as the intensity of its strengthening effect and particle itself, pattern, distribution situation are relevant, but depends primarily on the intensity of particle.Can find out from the SEM microtexture of drawing state magnesium brass, exist spherical second phase particles between crystal grain inside and crystal boundary, and second phase particles small and scattered (intracrystalline and crystal boundary all have distribution).Second phase particles should be better to the strengthening effect of magnesium brass, but the yield strength of half-hard state magnesium brass is not high, and its major cause may be that second phase particles is crisp and not hard, and makes it not have the cause of strengthening effect.

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2, electrochemical corrosion experimental

The electrochemical corrosion experimental of magnesium brass and leaded brass the results are shown in Table 2.From the corrosion of metal theory, when erosion rate is less than 0.02mm Π a, solidity to corrosion is fabulous; When erosion rate is 0.02～0.1mm Π a, solidity to corrosion is better; In the time of between 0.1～0.5mm Π a, solidity to corrosion is good.Visible, newly the solidity to corrosion of alloy in sour neutralized salt of development is all better, and comparatively speaking salt tolerance is more excellent.The factor that affects metallic corrosion is a lot, and the factor of existing metal itself is as also as relevant as corrosive medium etc. with residing environment in one-tenth grades.The current potential calibration of copper, all more stable in many media, this is the chemical stability based on itself mainly, so the solidity to corrosion of experiment magnesium brass and C3604 is all better.After adding magnesium in magnesium brass; due to the chemical property of magnesium very active (corrosion potential is 22.34V); and the oxide film produced in corrosive medium is loose porous; magnesian molecular volume VM is less than 1 with the ratio of magnesium atoms volume VA, and this loose porous oxide film can not produce good provide protection to matrix.Second phase particles between intracrystalline and crystal boundary, increased the potential difference between each phase in addition, more easily forms the corrosion microbattery, although this can make its solidity to corrosion slightly reduce, can meet service requirements,

3, cutting experiment

The size of magnesium brass and lead brass alloy smear metal is all less.The smear metal of lead brass alloy is elongated, is the hour hand shape, and the smear metal of magnesium brass is sheet and C type bits, and its internal surface is smooth shape, the metal that outside surface has one deck hair to cover a roof with straw.The working angles of magnesium brass is more steady, and cutting force is more stable, fluctuates less, and the alloy surface of having processed is smooth, and surfaceness is less.From the cutting scheme research of metal, we can find out, for leaded brass, lead is thin crystalline state and is uniformly distributed, with being arranged on the blade osculatory, a large amount of lead button exist, the plumbous particle of these disperses plays cracked smear metal, reduces bonding and the seam of smear metal to blade, thereby make chip fracture, reduce the size of smear metal.Fusing point lower (plumbous fusing point is 327.5 ℃) due to plumbous particle, thereby contact local heating and instant melting (hot-short) at cutter head and bits, this contributes to change the shape of smear metal, and plays the effect of lubricating tool and make blade keep sharp, therefore its cutting ability is good.Also be distributed with the second phase particles of disperse in the tissue of magnesium brass, from the mechanical property of magnesium brass, can find, the magnesium-containing compound particle has crisp and not hard characteristic, be easy to fragmentation while contacting with blade under the effect of shear-stress, after the compound particles fragmentation, the metal generation stress concentration contacted with incision position, be easy to germinate crackle expansion, smear metal is ruptured and discontinuous growing up very soon, reduce the size of smear metal.In addition, the magnesium-containing compound particle has crisp and not hard characteristic also can reduce the cohesive action of smear metal to blade, therefore its cutting ability is also good.From the SEM microtexture of drawing state magnesium brass, can find out, magnesium copper zinc ternary compound has distribution at intracrystalline, makes smear metal intracrystalline germinating crackle under the effect of cutting force, can effectively reduce the size of smear metal, and this is the major cause that magnesium brass cutting ability improves.

Claims

1. a Cutting Lead-free Brass Containing Magnesium rod production process, the raw material configuration that to it is characterized in that by following consumption be weight part forms: Cu 60, Zn 30, Mg 8, Bi 0.1, Si 0.1, Al 0.1, P 0.1, and Re 0.2, and concrete production technique is as follows: the raw material prepared is put into to medium-frequency induction furnace and carry out melting, fully stir so that each distributed components, coming out of the stove is poured into swage and obtains alloy cast ingot, and ingot casting is carried out to hot extrusion at 500 ℃ after turning processing, then extruded rod is carried out to drawing with the horizontal cold drawing bench of strand and makes magnesium round brass rod of the present invention.