阅读说明：本技术 一种浮桥用高强高韧7046铝合金热挤压型材的制造方法 (Manufacturing method of high-strength high-toughness 7046 aluminum alloy hot-extruded section for floating bridge ) 是由 王强 王艺琳 张燕飞 杨瑞青 石宏宇 王嘉君 谭艺哲 范春然 于 2020-12-14 设计创作，主要内容包括：一种浮桥用高强高韧7046铝合金热挤压型材的制造方法,本发明涉及浮桥用高强高韧7046铝合金热挤压型材的制造方法。本发明是要解决解决7046合金挤压型材韧性低的问题。方法：一、确定7046铝合金中各元素质量百分比；二、均匀化退火；三、热挤压；四、在线淬火；五、热挤压型材精整；六、热挤压型材时效热处理。本方法制造的的7046热挤压型材,合金成分满足美国标准要求,焊接及耐蚀性能良好,抗拉强度R-m＝500～580MPa、屈服强度R-(P0.2)＝450～500MPa、延伸率A＝12～18％,满足浮桥用高强高韧性7046铝合金热挤压型材使用需求,用户机加焊接后浮桥合格率达到100％。(The invention discloses a manufacturing method of a high-strength high-toughness 7046 aluminum alloy hot-extruded section for a floating bridge, and relates to a manufacturing method of a high-strength high-toughness 7046 aluminum alloy hot-extruded section for a floating bridge. The invention aims to solve the problem of low toughness of 7046 alloy extruded sections. The method comprises the following steps: firstly, determining the mass percentage of each element in 7046 aluminum alloy; secondly, homogenizing and annealing; thirdly, hot extrusion; fourthly, quenching on line; fifthly, finishing the hot extrusion section; sixthly, carrying out aging heat treatment on the hot extruded section. The 7046 hot extruded section produced by the method has alloy components meeting American standard requirements, good welding and corrosion resistance and tensile strength R m 500-580 MPa, yield strength R P0.2 450 to 500MPa, elongation A12-18%, the use requirements of the high-strength high-toughness 7046 aluminum alloy hot-extruded section for the floating bridge are met, and the qualification rate of the floating bridge after the floating bridge is machined and welded by a user reaches 100%.)

1. A manufacturing method of a high-strength high-toughness 7046 aluminum alloy hot extrusion section for a floating bridge is characterized by comprising the following steps:

firstly, preparing materials according to the mixture ratio, namely 6.7-7.3% of Zn, 1.2-1.5% of Mg, 0.18-0.25% of Cu, 0.23-0.3% of Mn, 0.1-0.18% of Zr, less than or equal to 0.05% of Cr, less than or equal to 0.06% of Ti, less than or equal to 0.3% of Fe, less than or equal to 0.2% of Si, the balance of Al and inevitable impurities, less than or equal to 0.05% of other single impurities and less than or equal to 0.1% of the total impurities, and then adding the raw materials into a smelting furnace for smelting to obtain an aluminum alloy round ingot;

secondly, placing the aluminum alloy round ingot in an annealing furnace for heating and carrying out homogenization annealing to obtain an annealed round ingot;

heating the annealed round cast ingot, and then carrying out hot extrusion molding on the heated round cast ingot through a die to obtain an aluminum alloy hot extrusion section;

fourthly, carrying out on-line quenching on the aluminum alloy hot extrusion section through a cooling device to obtain a quenched section;

fifthly, straightening the quenched section by tension to obtain the section after straightening by tension;

sixthly, carrying out aging heat treatment on the section bar after the tension straightening, and thus finishing the manufacture of the high-strength high-toughness 7046 aluminum alloy hot extrusion section bar for the floating bridge.

2. The method for manufacturing the high-strength high-toughness 7046 aluminum alloy hot-extruded profile for the floating bridge according to claim 1, wherein in the first step, the materials are mixed according to the mass percentage of 7.03% of Zn, 1.5% of Mg, 0.25% of Cu, 0.29% of Mn, 0.12% of Zr, 0.0009% of Cr, 0.027% of Ti, 0.29% of Fe, 0.12% of Si, the balance of Al and inevitable impurities, the total content of other single impurities is less than or equal to 0.05%, and the total content of impurities is less than or equal to 0.1%.

3. The manufacturing method of the high-strength high-toughness 7046 aluminum alloy hot-extruded profile for the floating bridge according to claim 1, wherein the smelting process parameters in the first step are as follows: the smelting temperature is 720-750 ℃, and the casting speed is 20-95 mm/min.

4. The manufacturing method of the high-strength high-toughness 7046 aluminum alloy hot-extruded section for the floating bridge according to claim 1, characterized in that the temperature of the homogenizing annealing in the second step is 460-470 ℃, the temperature is kept for 24 hours at 460-470 ℃, the section is discharged from a furnace for air cooling, and the skin is turned after the section is cut short.

5. The manufacturing method of the high-strength high-toughness 7046 aluminum alloy hot-extruded profile for the floating bridge according to claim 4, characterized in that the size of the short ingot is 300 mm-1500 mm.

6. The manufacturing method of the high-strength high-toughness 7046 aluminum alloy hot-extruded profile for the floating bridge according to claim 1, characterized in that in the third step, the annealed round ingot is heated and then is subjected to hot extrusion through a die to form the profile, and the method comprises the following steps: and (3) heating the annealed round ingot in a power frequency induction furnace, wherein the constant temperature of instruments in each area of the heating furnace is 490-530 ℃, the temperature of an extrusion cylinder is 450-480 ℃, and after the temperature of the ingot reaches 480-520 ℃, hot extrusion molding is carried out through a tool and a die according to the extrusion speed of not more than 1.5 mm/s.

7. The manufacturing method of the high-strength high-toughness 7046 aluminum alloy hot-extruded profile for the floating bridge according to claim 1 is characterized in that in the fourth step, the aluminum alloy hot-extruded profile is quenched on line by a cooling device, and the method specifically comprises the following steps: the aluminum alloy hot extrusion section with the surface temperature of more than or equal to 460 ℃ passes through a strong wind refrigerating device or a water mist refrigerating device, the surface temperature of the section after refrigeration is less than or equal to 80 ℃, and the refrigerating speed is more than or equal to 65 ℃/min.

8. The method for manufacturing the high-strength high-toughness 7046 aluminum alloy hot-extruded section for the floating bridge according to claim 1, wherein the elongation of the tension straightening in the fifth step is 1.0-1.5%.

9. The manufacturing method of the high-strength high-toughness 7046 aluminum alloy hot-extruded section for the pontoon bridge as claimed in claim 1, wherein the temperature of the aging heat treatment in step six is 115-125 ℃, and the holding time is 16-48 h.

Technical Field

The invention relates to a method for manufacturing a high-strength and high-toughness 7046 aluminum alloy hot extrusion section for a floating bridge.

Background

The 7046 alloy is a typical representative alloy of Al-Zn-Mg series, is the lightest of 7000 series aluminum alloys, has two properties of high strength and light weight, and can ensure no resonance phenomenon under the condition of high strength use. Because of less copper content, high corrosion resistance and excellent welding performance, the material is suitable for military floating bridge materials.

The elements of the 7046 alloy which play a strengthening role are Zn and Mg, Cu also has a certain strengthening effect, and in addition, elements for refining grains of Mn, Zr and Ti and impurity elements such as Fe, Si and the like are added, so the alloy has a complex phase structure, forms a large amount of insoluble compounds, is seriously segregated, and is difficult to achieve high toughness.

Disclosure of Invention

The invention aims to solve the problem of low toughness of 7046 alloy extruded sections, and provides a manufacturing method of a high-strength high-toughness 7046 aluminum alloy hot extruded section for a floating bridge.

The invention relates to a manufacturing method of a high-strength high-toughness 7046 aluminum alloy hot extrusion section for a floating bridge, which comprises the following steps:

firstly, preparing materials according to the mixture ratio, namely 6.7-7.3% of Zn, 1.2-1.5% of Mg, 0.18-0.25% of Cu, 0.23-0.3% of Mn, 0.1-0.18% of Zr, less than or equal to 0.05% of Cr, less than or equal to 0.06% of Ti, less than or equal to 0.3% of Fe, less than or equal to 0.2% of Si, the balance of Al and inevitable impurities, less than or equal to 0.05% of other single impurities and less than or equal to 0.1% of the total impurities, and then adding the raw materials into a smelting furnace for smelting to obtain an aluminum alloy round ingot;

secondly, placing the aluminum alloy round ingot in an annealing furnace for heating and carrying out homogenization annealing to obtain an annealed round ingot;

heating the annealed round cast ingot, and then carrying out hot extrusion molding on the heated round cast ingot through a die to obtain an aluminum alloy hot extrusion section;

fourthly, carrying out on-line quenching on the aluminum alloy hot extrusion section through a cooling device to obtain a quenched section;

fifthly, straightening the quenched section by tension to obtain the section after straightening by tension;

sixthly, carrying out aging heat treatment on the section bar after the tension straightening, and thus finishing the manufacture of the high-strength high-toughness 7046 aluminum alloy hot extrusion section bar for the floating bridge.

The invention has the beneficial effects that:

the alloy components of the 7046 aluminum alloy section manufactured by the invention meet the American standard requirements, the welding and corrosion resistance are good, and the tensile strength R is_m500-580 MPa, yield strength R_P0.2The alloy meets the use requirements of high-strength and high-toughness 7046 aluminum alloy hot extrusion profiles for floating bridges, and the qualification rate of the floating bridge reaches 100% after the floating bridge is machined and welded by a user.

Detailed Description

The first embodiment is as follows: the manufacturing method of the high-strength high-toughness 7046 aluminum alloy hot-extruded section for the floating bridge in the embodiment is carried out according to the following steps:

firstly, preparing materials according to the mixture ratio, namely 6.7-7.3% of Zn, 1.2-1.5% of Mg, 0.18-0.25% of Cu, 0.23-0.3% of Mn, 0.1-0.18% of Zr, less than or equal to 0.05% of Cr, less than or equal to 0.06% of Ti, less than or equal to 0.3% of Fe, less than or equal to 0.2% of Si, the balance of Al and inevitable impurities, less than or equal to 0.05% of other single impurities and less than or equal to 0.1% of the total impurities, and then adding the raw materials into a smelting furnace for smelting to obtain an aluminum alloy round ingot;

secondly, placing the aluminum alloy round ingot in an annealing furnace for heating and carrying out homogenization annealing to obtain an annealed round ingot;

heating the annealed round cast ingot, and then carrying out hot extrusion molding on the heated round cast ingot through a die to obtain an aluminum alloy hot extrusion section;

fourthly, carrying out on-line quenching on the aluminum alloy hot extrusion section through a cooling device to obtain a quenched section;

fifthly, straightening the quenched section by tension to obtain the section after straightening by tension;

sixthly, carrying out aging heat treatment on the section bar after the tension straightening, and thus finishing the manufacture of the high-strength high-toughness 7046 aluminum alloy hot extrusion section bar for the floating bridge.

In this embodiment, the 7046 alloy is added with Mn and Zr: the addition of a small amount of Mn and Zr has obvious influence on the structure and the performance of the alloy. These elements can produce dispersed particles during the ingot homogenizing annealing to prevent dislocation and grain boundary migration, raise the re-crystallization temperature, prevent the growth of crystal grains, refine crystal grains, ensure the structure to maintain un-re-crystallized or partially re-crystallized state after heat treatment and raise strength and raise corrosion resistance. 7046 the alloy must have strictly controlled Fe and Si contents as impurities. Fe forms poorly soluble coarse compounds with Mn and Zr, and the second term of these insolubilities has a very adverse effect on the toughness of the alloy.

The 7046 aluminum alloy section manufactured by the embodiment has straightness meeting the GB/T6892 standard requirement.

The second embodiment is as follows: the first difference between the present embodiment and the specific embodiment is: in the first step, the raw materials are mixed according to the mass percentage of 7.03 percent of Zn, 1.5 percent of Mg, 0.25 percent of Cu, 0.29 percent of Mn, 0.12 percent of Zr, 0.0009 percent of Cr, 0.027 percent of Ti, 0.29 percent of Fe, 0.12 percent of Si, less than or equal to 0.05 percent of single impurity, less than or equal to 0.1 percent of total impurity and the balance of Al. The rest is the same as the first embodiment.

The third concrete implementation mode: the present embodiment differs from the first or second embodiment in that: the smelting process parameters in the first step are as follows: the smelting temperature is 720-750 ℃, and the casting speed is 20-95 mm/min. The others are the same as in the first or second embodiment.

The fourth concrete implementation mode: the difference between this embodiment mode and one of the first to third embodiment modes is: and in the second step, the temperature of the homogenizing annealing is 460-470 ℃, the heat is preserved for 24 hours under the condition that the temperature is 460-470 ℃, the ingot is taken out of the furnace and cooled in air, and the ingot is cut into a skin after the ingot is cut short. The rest is the same as one of the first to third embodiments.

The fifth concrete implementation mode: the difference between this embodiment and one of the first to fourth embodiments is: the size of the short cast ingot is 300-1500 mm. The rest is the same as one of the first to fourth embodiments.

The sixth specific implementation mode: the difference between this embodiment and one of the first to fifth embodiments is: in the third step, the annealed round cast ingot is heated and then is subjected to hot extrusion molding through a die, and the hot extrusion molding is specifically carried out according to the following steps: and (3) heating the annealed round ingot in a power frequency induction furnace, wherein the constant temperature of instruments in each area of the heating furnace is 490-530 ℃, the temperature of an extrusion cylinder is 450-480 ℃, and after the temperature of the ingot reaches 480-520 ℃, hot extrusion molding is carried out through a tool and a die according to the extrusion speed of not more than 1.5 mm/s. The rest is the same as one of the first to fifth embodiments.

The seventh embodiment: the difference between this embodiment and one of the first to sixth embodiments is: in the fourth step, the aluminum alloy hot extrusion section is quenched on line through a cooling device, and the quenching method specifically comprises the following steps: the aluminum alloy hot extrusion section with the surface temperature of more than or equal to 460 ℃ passes through a strong wind refrigerating device or a water mist refrigerating device, the surface temperature of the section after refrigeration is less than or equal to 80 ℃, and the refrigerating speed is more than or equal to 65 ℃/min. The rest is the same as one of the first to sixth embodiments.

The specific implementation mode is eight: the present embodiment differs from one of the first to seventh embodiments in that: and fifthly, the tension straightening stretch rate is 1.0-1.5%. The rest is the same as one of the first to seventh embodiments.

The specific implementation method nine: the present embodiment differs from the first to eighth embodiments in that: and sixthly, the temperature of the aging heat treatment is 115-125 ℃, and the heat preservation time is 16-48 h. The rest is the same as the first to eighth embodiments.

The following examples were used to demonstrate the beneficial effects of the present invention:

the first embodiment is as follows: the manufacturing method of the high-strength high-toughness 7046 aluminum alloy hot-extruded section for the floating bridge comprises the following steps of:

firstly, preparing materials according to the weight percentage of 7.03% of Zn, 1.5% of Mg, 0.25% of Cu, 0.29% of Mn, 0.12% of Zr, 0.0009% of Cr, 0.027% of Ti, 0.29% of Fe, 0.12% of Si, the balance of Al and inevitable impurities, less than or equal to 0.05% of other single impurities and less than or equal to 0.1% of the total amount of the impurities, and then adding the raw materials into a smelting furnace for smelting to obtain an aluminum alloy round ingot;

placing the aluminum alloy round ingot in an annealing furnace, keeping the temperature of the homogenization annealing at 460-470 ℃, keeping the temperature for 24 hours at 460-470 ℃, discharging the aluminum alloy round ingot out of the furnace, air cooling, cutting the aluminum alloy round ingot into 1500mm short ingots, and then turning the aluminum alloy round ingot to obtain annealed round ingots;

heating the annealed round cast ingot, and then performing hot extrusion molding on the heated round cast ingot through a die to obtain a material, wherein the hot extrusion molding is performed according to the following steps: placing the annealed round cast ingot in a power frequency induction furnace for heating, wherein the constant temperature of instruments in each area of the heating furnace is 500 ℃, the temperature of an extrusion cylinder is 480 ℃, and after the temperature of the cast ingot reaches 490 ℃, carrying out hot extrusion molding through a tool and a die according to the extrusion speed of 1mm/s to obtain an aluminum alloy hot extrusion section with the surface temperature of 465 ℃;

fourthly, enabling the aluminum alloy hot extrusion section to pass through a strong wind refrigerating device or a water mist refrigerating device, wherein the surface temperature of the refrigerated section is 60 ℃, and the refrigerating speed is more than or equal to 65 ℃/min; obtaining a quenched section;

fifthly, straightening the quenched section by tension to obtain the section after straightening by tension; the tensile rate of tension straightening is 1.2 percent;

sixthly, carrying out aging heat treatment on the tension-straightened section bar to finish the manufacture of the high-strength high-toughness 7046 aluminum alloy hot extrusion section bar for the floating bridge; the temperature of the aging heat treatment is 120 ℃, and the heat preservation time is 24 h.

The alloy components of the 7046 aluminum alloy section manufactured by the embodiment meet the American standard requirements, the welding and corrosion resistance are good, and the tensile strength R is_m500-580 MPa, yield strength R_P0.2The alloy meets the use requirements of high-strength and high-toughness 7046 aluminum alloy hot extrusion profiles for floating bridges, and the qualification rate of the floating bridge reaches 100% after the floating bridge is machined and welded by a user.