CN103184395A - LY12 aluminium alloy quenching technique method - Google Patents

Abstract

The invention belongs to the field of aerial metal treatment, and particularly relates to an LY12 aluminium alloy quenching technique method. The method comprises the steps of surface cleaning, solution treatment, quenching, taking out from a furnace after the completion of parts insulation, cleaning, adjusting, natural aging and the like. According to the technique method, the quenching temperature for the LY12 aluminium alloy is properly lowered; possibilities of overburning and grain growth of microstructures of the parts are effectively prevented; the heating temperature for the LY12 aluminium alloy and that for frequently used 2024 alloy of subcontracting parts are united, so that the productivity is greatly improved and the production cycle is guaranteed; the solid solution heating and insulating time is properly improved; both the solid solution saturation degree and the separated out age hardening phases of the alloy are increased after quenching; the problem that unstable hardness testing value of a thin sheet metal part under natural low temperature in autumn and winter is solved; the repeated treatment frequency is reduced; the manufacturing cost of the parts is lowered; and the qualification rate is improved.

Description

A kind of LY12 aluminium alloy quenching process

Technical field

The invention belongs to the aerial metal process field, particularly relate to a kind of LY12 aluminium alloy quenching process.

Background technology

Existing LY12 aluminum alloy plate materials, extrusion (thickness is less than 4.0mm) part are heat-treated to the quenching heat treatment method of CZ state from the M state: be incubated the regular hour under 498 ℃ of temperature after (concrete soaking time sees the following form 1), behind quenching-in water, at room temperature natural aging is 96 hours.Existing processing method quenching temperature is higher, be easy to generate burning during part thermal treatment, surface color obfuscation, foaming and generation quenching crack etc., and with subcontract 494 ℃ of disunities of 2024 aluminium alloy Heating temperatures commonly used, it is slow with nitrate groove salt bath cooling rate now to quench, and is reduced to 494 ℃ from 498 ℃, and the centre is wanted 4～5 hours, have a strong impact on the part production cycle, reduced productivity; Existing processing method soaking time is short partially, when autumn and winter, natural temperature was low, the easy solid solution of thin sheet metal part is insufficient, precipitation strength is mutually on the low side after the timeliness, often cause the part hardness disqualified upon inspection, repeat thermal treatment again, increased the part production cost, influenced part and normally be delivered for use the cycle.

Table 1 has the soaking time table now

Part thickness mm	Soaking time min
		＜1.0	7
1.0～2.0	10
		2.1～3.0	10
3.1～5.0	15

Summary of the invention

Goal of the invention: a kind of LY12 aluminium alloy quenching process that material and technological standards require that can satisfy fully is provided.

Technical scheme:

A kind of LY12 aluminium alloy quenching process may further comprise the steps:

Step 1, surface cleaning: with grease, the greasy dirt on organic solvent cleaning components surface, keep piece surface cleaning and dry;

Step 2, solution treatment: after part framed up, part was gone into stove after nitrate groove is heated to 494 ℃, according to the difference of part thickness, determined different soaking times, and concrete soaking time is as shown in the table;

The soaking time tabulation

Part thickness mm	Soaking time min
		≤1.0	7～25
1.1～2.0	10～35
		2.1～3.0	10～40
3.1～5.0	15～45

Step 3, quenching: come out of the stove after the part insulation finishes, at 10 ℃～30 ℃ quenching-in waters;

Step 4, cleaning: behind the parts quenching, after in 40 ℃～60 ℃ warm water tanks, cleaning, dry;

Step 5, school shape: school shape: in back 1 hour of quenching, the workpiece that is out of shape is carried out school shape handle;

Step 6, natural aging: under 10 ℃～40 ℃ temperature of envrionment temperature, natural aging 96 hours.

Beneficial effect: the processing method that LY12 aluminium alloy of the present invention quenches has suitably reduced LY12 aluminium alloy quenching temperature, effectively prevented the possibility of part mirco structure generation burning, grain growth, and Heating temperature 2024 alloys commonly used with subcontracting part of LY12 aluminium alloy are unified, like this in actual production, heating just need not frequently be regulated temperature with nitrate groove, improve productivity greatly, guaranteed the production cycle; Suitably improved the solid solution heat tracing time, having increased quench back alloy solid solution degree of saturation and timeliness sclerosis separates out, solved thin sheet metal part when autumn and winter, natural temperature was low, hardness detected value instability problem, reduced the re-treatment number of times, effectively reduce the part production cost, improved qualification rate.This processing method through early stage a large amount of technological tests groping finally to determine, and carried out many batches trial production checkings subsequently, the mirco structure after the part thermal treatment, indexs such as mechanical property can satisfy material and technological standards requirement fully.

Embodiment

Below in conjunction with example the present invention is done and to describe in further detail.

A kind of LY12 aluminium alloy quenching process may further comprise the steps:

Step 1, surface cleaning: with grease, the greasy dirt on organic solvent cleaning components surface, keep piece surface cleaning and dry, the bad atmosphere that produces when preventing thermal treatment high temperature diffuses into workpiece surface, influences workpiece surface quality and high temperature oxidation takes place;

Step 2, solution treatment: after part framed up, part was gone into stove to temperature after nitrate groove is heated to 494 ℃, according to the part different thickness, determined different soaking times; In this stage, strengthening in the alloy mixes fully being dissolved in the sosoloid, for subsequently quenching provides tissue to guarantee.Concrete soaking time is as shown in the table;

Table: soaking time tabulation

Part thickness mm	Soaking time min
		≤1.0	7～25
1.1～2.0	10～35
		2.1～3.0	10～40
3.1～5.0	15～45

Step 3, quenching: part insulation is come out of the stove after finishing, and in the quenching transfer time less than 15 seconds, cooling rapidly forms supersaturated solid solution in 10 ℃～30 ℃ water; The fastest speed of cooling can obtain the best fit of maximum intensity and strength and toughness, also may reach corrosion resistance nature preferably simultaneously.

Step 4, cleaning: behind the parts quenching, after in 40 ℃～60 ℃ warm water tanks, cleaning, dry; When heating in nitrate groove, the residues of chloride in the tank liquor causes easily that at workpiece surface workpiece surface corrodes, and reduces the alloy corrosion resistance energy.

Step 5, school shape: in back 1 hour of quenching, the workpiece that is out of shape is carried out school shape handle; Prolongation in time, workpiece take place weathering, and performance improves, and it is bad to carry out school shape effect again, can cause also that seriously crackle produces, and causes part to scrap.

Step 6, natural aging: under 10 ℃～40 ℃ temperature of envrionment temperature, natural aging 96 hours; In the timeliness stage, strengthening phase is separated out gradually, and alloy strength and hardness improve constantly, and the LY12 alloy is after 96 hours, and timeliness finishes substantially, after Performance Detection is qualified, i.e. and referable.

Row: LY12M sheet metal part of certain engineering aircraft, net thickness is 1mm, needs the natural aging treatment of quenching after moulding.Actual heating installation is nitrate groove, the solution treatment design temperature is 494 ℃ in the production, soaking time is about 20 minutes, quench 8 seconds of transfer time, after school shape subsequently and 96 hours timeliness, carried out mechanical property, metallographic structure and hardness test, detected result meets the requirement of relevant mark fully; It is 393MPa that mark requires tensile strength, and the actual detected value is 425MPa; The mirco structure test passes; Standard hardness requirement＞51HRB, measured value are 59HRB.

Claims (1)

1. LY12 aluminium alloy quenching process may further comprise the steps:

Step 1, surface cleaning: with grease, the greasy dirt on organic solvent cleaning components surface, keep piece surface cleaning and dry;

Step 2, solution treatment: after part framed up, part was gone into stove after nitrate groove is heated to 494 ℃, according to the difference of part thickness, determined different soaking times, and concrete soaking time is as shown in the table;

The soaking time tabulation

Part thickness mm Soaking time min ≤1.0 7～25 1.1～2.0 10～35 2.1～3.0 10～40 3.1～5.0 15～45

Step 3, quenching: come out of the stove after the part insulation finishes, at 10 ℃～30 ℃ quenching-in waters;

Step 4, cleaning: behind the parts quenching, after in 40 ℃～60 ℃ warm water tanks, cleaning, dry;

Step 5, school shape: school shape: in back 1 hour of quenching, the workpiece that is out of shape is carried out school shape handle;

Step 6, natural aging: under 10 ℃～40 ℃ temperature of envrionment temperature, natural aging 96 hours.