CN103388116A

CN103388116A - Method for effectively rolling Mg-Al-Zn magnesium alloys

Info

Publication number: CN103388116A
Application number: CN2013103468409A
Authority: CN
Inventors: 张丁非; 郭非; 蒋璐瑶; 柴森森; 胡光山; 董井忍; 余大亮; 潘复生
Original assignee: Chongqing University
Current assignee: Chongqing University
Priority date: 2013-08-09
Filing date: 2013-08-09
Publication date: 2013-11-13
Anticipated expiration: 2033-08-09
Also published as: CN103388116B

Abstract

The invention discloses a method for effectively rolling Mg-Al-Zn magnesium alloys. The method comprises the following steps: panel surface treatment; panel heating and insulating; roll heating and insulating; and rolling and cooling. The panel is an Mg-Al-Zn magnesium alloy panel. In the panel heating and insulating step, the insulating temperature is 450-550 DEG C, and the insulating time is 30-40 minutes. In the rolling step, the panel is rolled and formed in one step, wherein the rolling reduction of rolling is 50-60%. In the roll heating and insulating step, the insulating temperature is 300-400 DEC, and the insulating time is 10-20 minutes. According to the efficient magnesium alloy high temperature rolling process disclosed by the invention, the panel is processed and formed by single pass, so that the production cost is lowered and the processing period is short. The method is suitable for continuous large-scale rolling production of magnesium alloy panels. The panel rolled by the method disclosed by the invention is excellent in performance, free from remarkable edge cracks and high in yield.

Description

A kind of method of efficient rolling Mg-Al-Zn series magnesium alloy

Technical field

The present invention relates to a kind of magnesium alloy working method, particularly a kind of method of efficient rolling Mg-Al-Zn series magnesium alloy.

Background technology

Magnesium alloy is as the lightest commercial structural metallic materials, and conventional magnesium alloy is than the light 30-50% of aluminium alloy, and is lighter more than 70% than iron and steel, can greatly alleviate structural part weight.Simultaneously, magnesium alloy has specific tenacity, specific rigidity is high, damping capacity is good, mechanical workout is convenient, be easy to recycle, have the characteristics such as environmental protection, be described as " 21 century green engineering structural metallic materials ", be widely used in fields such as automobile, track traffic, aerospace, household electrical appliances and 3C, have important commercial application value.

According to the difference of the mode of production, magnesium alloy is divided into cast magnesium alloys and the large class of wrought magnesium alloys two.The cast magnesium alloys coarse grains, component segregation is serious, and poor-performing is difficult to meet application demand.In this case, the wrought magnesium alloys product that adopts the plastic working techniques such as extruding, rolling, forging to produce, more and more come into one's own owing to having better mechanical property, diversified structure.Wherein, rolling has obtained significant progress as the important means of magnesium alloy plastic working, has produced multiple rolling method.

At first the technique of existing commercial rolling magnesium alloy carry out long term annealing processing, then preheating magnesium alloy plate between 150-330 ℃ to magnesium alloy plate; Carry out finally the light reduction multi-pass rolling.Existing method rolling temperature is low, need to adopt repeatedly rolling,, in order to guarantee carrying out smoothly of rolling, need to reheat insulation to sheet material between each rolling pass, greatly reduces production efficiency, increases production cost.

Summary of the invention

In view of this, the invention provides a kind of method of Mg-Al-Zn series magnesium alloy, the method working (machining) efficiency is high, and technique is simple, the products obtained therefrom excellent performance.

The method of efficient rolling Mg-Al-Zn series magnesium alloy of the present invention, comprise plate surface processing, sheet material heat tracing, roll heat tracing, rolling and cooling step, described sheet material is Mg-Al-Zn series magnesium alloy sheet material, in described sheet material heat tracing step, holding temperature is 450-550 ℃, soaking time is 30-40min, adopt a roll forming in described rolling step, the rolling draught is 50%-60%.

Further, in described roll heat tracing step, holding temperature is 300-400 ℃, and soaking time is 10-20min.

Beneficial effect of the present invention is: before rolling of the present invention, sheet material is heated to 450-550 ℃ and insulation, the quick recrystallize of the at this moment inner generation of magnesium alloy, eliminated unrelieved stress and microdefect, increased the moulding deformation performance of sheet material; In addition, in magnesium alloy, basal slip, Prismatic slip and conical surface slippage are opened simultaneously when this temperature rolling, can carry out heavy reduction one-pass roller moulding, simplified complicated volume complete processing in the past, reduced production cost, shorten the production cycle, be fit to the continuous large-scale Rolling Production of magnesium alloy plate.In addition, before rolling of the present invention, roll is heated to 300-400 ℃, reduces sheet material with roll and external environment generation heat exchange, especially sheet material edge and environment directly produce heat exchange, have avoided the rolled parts limit to split phenomenon, the excellent property of products obtained therefrom, split without obvious limit, lumber recovery is high.

Description of drawings

In order to make the purpose, technical solutions and advantages of the present invention clearer, the invention will be further described below in conjunction with accompanying drawing.

Fig. 1 is original plate sample appearance pattern;

Fig. 2 is that rolling obtains sheet material sample appearance pattern;

Fig. 3 is the microstructure morphology of embodiment 1 rolling surface;

Fig. 4 is the microstructure morphology of embodiment 2 rolling surfaces;

Fig. 5 is the microstructure morphology of embodiment 3 rolling surfaces;

Fig. 6 is the microstructure morphology of embodiment 4 rolling surfaces.

Embodiment

Below the present invention will be further described with embodiment, and the per-cent in following examples is mass percent.

Embodiment 1:

The composition of the selected Mg-Al-Zn series magnesium alloy of the present embodiment sample is identical with table 1 embodiment 1, and before processing, as shown in Figure 1, its thickness is 10mm to alloy sample, and long is 100mm, and wide is 85mm.

The method of the present embodiment efficient rolling magnesium alloy comprises the following steps: 1) surface treatment: sample thief also carries out grinding process to sample surfaces, removes the zone of oxidation on surface, makes the sample finished surface totally smooth; 2) blank heating: sample is placed in process furnace, carries out heat tracing, Heating temperature is set as 550 ℃, be incubated 35min after reaching design temperature, make the sample thermally equivalent, and make microtexture change, remove internal stress, for next step hot rolling ready; 3) roll heating: resistive heating device is installed at the top and bottom rolls place, and the breaker roll homogeneous heating, finally make the top and bottom rolls surface arrive 375 ℃; 4) hot rolling: take out fast step 2 from heat treatment furnace), the sample of heating, put into preheated milling train and be rolled, and regulating roll location is that the rolling draught is 50%; 5) cooling: air cooling cooling step 4) gained sample.After rolling processing, as shown in Figure 2, as can be seen from Figure 2, limit, almost do not occur and split the macro morphology of sample in sheet material well-tended appearance after roll forming, there is no the macroscopic defects loss.

Embodiment 2:

Embodiment 2 and the difference of embodiment 1 are in embodiment 2 that in each element quality proportioning and table 1, the formula of embodiment 2 is identical, and during blank heating, Heating temperature is 525 ℃, and during the roll heating, Heating temperature is 350 ℃, and during rolling, draught is 52%.

Embodiment 3:

Embodiment 3 and the difference of embodiment 1 are in embodiment 3 that in each element quality proportioning and table 1, the formula of embodiment 3 is identical, and during blank heating, Heating temperature is 500 ℃, and during the roll heating, Heating temperature is 325 ℃, and during rolling, draught is 54%.

Embodiment 4:

Embodiment 4 and the difference of embodiment 1 are in embodiment 4 that in each element quality proportioning and table 1, the formula of embodiment 4 is identical, and during blank heating, Heating temperature is 475 ℃, and during the roll heating, Heating temperature is 300 ℃, and during rolling, draught is 58%.

Table 1 embodiment of the present invention sample composition

Embodiment	Al(%)	Zn(%)	Mn(%)	Si(%)	Mg(%)
						Embodiment 1	2.96	0.94	0.32	0.09	Surplus
Embodiment 2	2.96	0.94	0.32	0.09	Surplus
						Embodiment 3	2.96	0.94	0.32	0.09	Surplus
Embodiment 4	3.41	1.32	0.42	0.06	Surplus

Below in conjunction with experimental data, the performance of the magnesium alloy of embodiment 1-4 institute rolling is analyzed.

1, microtexture characterizes: get the rolled sample of embodiment 1-4, adopt successively 600#, 800#, 1000# and 1200# silicon carbide silicon carbide paper to polish surface; Then adopt picric acid-Glacial acetic acid etching reagent corrosion; After the sample corrosion, adopt laser confocal microscope (LEXT) to take metallograph, respectively as shown in Fig. 3-6.

Can be seen by Fig. 3-6, embodiment rolling products obtained therefrom microtexture is even, and average grain size is less, without microtexture defects such as composition segregations.In addition, owing to producing dynamic recrystallization in the operation of rolling, the crystal grain of the many 1-3 of being of a size of μ m has appearred on every side in crystal grain larger in figure, and these small-size grains can promote material mechanical performance significantly.

2, Mechanics Performance Testing:, according to the standard of GB GB228-2002, the described magnesium alloy rolling plates of the embodiment of the present invention is processed into the standard tensile sample carries out tension test.Along rolling direction intercepting tension specimen, measured mechanical property is in Table 2.

The mechanical property of table 2 embodiment rolled sample

Embodiment	Yield strength/Mpa	Tensile strength/Mpa	Unit elongation
				Embodiment 1	178	272	10.1%
Embodiment 2	181	273	9.7%
				Embodiment 3	190	271	7.1%
Embodiment 4	192	272	5.9%

As can be seen from Table 2, the magnesium alloy plate that uses the rolling of this technique to obtain, have good mechanical property, and its performance reaches the desired plate property of ASTMB90/B90M-07 standard.

The technique of efficient rolling magnesium alloy of the present invention, adopt single track high temperature time roll forming, simplifies in the past complicated complete processing, and production cost is low, and the process-cycle is short, is fit to the continuous large-scale Rolling Production of magnesium alloy plate.The product good mechanical performance of rolling gained, split without obvious limit, and lumber recovery is high.

Finally, it is pointed out that above embodiment just is used for explanation the present invention and unrestricted, in fact, method of the present invention is applicable equally to other serial magnesium alloy; When those skilled in the art only do simple the replacement to rolled products under instruction of the present invention, still belong to protection scope of the present invention.

Claims

1. the method for an efficient rolling Mg-Al-Zn series magnesium alloy, comprise plate surface processing, sheet material heat tracing, roll heat tracing, rolling and cooling step, it is characterized in that: described sheet material is Mg-Al-Zn series magnesium alloy sheet material, in described sheet material heat tracing step, holding temperature is 450-550 ℃, soaking time is 30-40min, adopt a roll forming in described rolling step, the rolling draught is 50%-60%.

2. the method for rolling magnesium alloy according to claim 1, it is characterized in that: the rolling deformation temperature is at 450-550 ℃, and in described roll heat tracing step, holding temperature is 300-400 ℃, and soaking time is 10-20min.