冷轧和退火对HTCR 5052合金板材成形性能的影响

发布时间：2018-07-09 15:33

本文选题：高通量连铸连轧 + 中间退火　；参考：《郑州大学》2017年硕士论文

【摘要】：5XXX系铝合金属于不可热处理强化型铝合金,具有比重小,比强度高,良好的耐蚀性、焊接性和易于加工成形等优点,是交通运输工业的重要材料。5052铝合金是5XXX系铝合金中应用范围最广的合金之一。高通量连铸连轧工艺(即HTCR工艺)是一种新型高效的铝合金板带坯料生产工艺,该工艺具有短流程、生产效率高、节能环保等优点。利用高通量连铸连轧工艺生产的5052铝合金板材,由于连铸过程铝液凝固速度较快,连轧过程板材温度降低过快导致板材内部组织不均匀、性能不稳定。本文以高通量连铸连轧工艺生产的6mm厚5052合金板坯作为试验材料,通过显微组织分析、能谱分析、宏观织构分析、力学性能和成形性能测试等方法研究了中间退火、冷轧加工率、成品退火温度及横轧工艺对2mm厚5052合金成品板材的微观组织、宏观织构、力学性能和成形性能的影响,为工业生产提供理论指导。主要研究结果如下:1.连铸连轧工艺生产的6mm厚5052合金板材内部组织为轧制组织。经过480℃×8h中间退火后板材组织变为为再结晶组织,且晶粒内部析出大量细小的铝铁相粒子。6mm厚5052合金板材中间退火后冷轧至2mm,其完成再结晶过程所需时间较短,计算发现经过中间退火的冷轧板材再结晶激活能为164.3KJ/mol,相比未中间退火冷轧板材降低了18%。2.经过480℃×8h中间退火的5052合金冷轧板材和未中间退火5052合金冷轧板材中均含有黄铜织构、S织构和铜型织构组分,其中中间退火板材轧制织构最大强度为11,较未中间退火板材最大织构强度低35%,另外中间退火冷轧板材中含有最大强度为5的立方织构组分;中间退火5052合金再结晶板材和未中间退火5052合金再结晶板材中均含有立方织构和R织构,中间退火板材再结晶织构最大强度为6.6,较未中间退火再结晶板材最大织构强度高15%。3.经过480℃×8h中间退火的5052合金成品板材n值为0.396,相比未中间退火的成品板材高12.6%;经过中间退火的成品板材r值为0.696,(35)r值为-0.084,相比未中间退火的成品板材r值低10.5%,(35)r值高54.8%;经过中间退火的成品板材杯凸值为9.73,相比未中间退火的成品板材高1.1%。经过中间退火的成品板材与未中间退火的成品板材相比,成形性能明显提高。4.冷轧变形率和成品退火温度对5052合金成品板材力学性能和成形性能均有显著影响。冷轧变形率为66.7%,成品退火温度为400℃保温3h时,成品板材的抗拉强度为190.8Mpa,屈服强度为86.8Mpa,延伸率为26%,力学性能达到最佳;成品板材的n值平均值为0.409,r值平均值为0.695,(35)r值为-0.08,杯凸值为9.9,成形性能也达到最佳。5.横轧轧制板材含有典型的沿?取向线分布的轧制织构组分,直接冷轧轧制板材含有典型的沿β取向线分布的轧制织构组分。横轧A工艺轧制板材最大织构强度为19,比直接冷轧板材高10.5%,横轧B工艺轧制板材最大织构强度为23,比直接冷轧板材高26.1%。横轧成品板材中含有立方织构和黄铜织构,直接冷轧成品板材中含有立方织构和R织构。横轧A工艺成品板材立方织构强度为2.9,比直接冷轧板材低47.3%,横轧B工艺轧制板材立方织构强度为2.6,比直接冷轧板材低52.7%。6.横轧A工艺成品板材n值平均值为0.378,横轧B工艺成品板材n值平均值为0.38,两种横轧成品板材的n值平均值比直接冷轧成品板材提高了8.9%;横轧A工艺成品板材r值平均值为0.77,横轧B工艺成品板材r值平均值为0.764,两种横轧成品板材的r值平均值与直接冷轧板材相比并未发生明显变化;横轧A工艺成品板材(35)r值为-0.156,比直接冷轧成品板材高16.1%,横轧B工艺成品板材(35)r值为-0.09,比直接冷轧成品板材高51.6%;横轧后的两种板材杯凸值分别为9.7和9.67,比直接冷轧板材提高了0.8%。横轧成品板材与直接冷轧成品板材相比,成形性能显著改善。
[Abstract]:5XXX aluminum alloy is a kind of non heat-treated reinforced aluminum alloy. It has the advantages of small specific gravity, high specific strength, good corrosion resistance, weldability and easy processing..5052 aluminum alloy is one of the most widely used alloys in 5XXX system aluminum alloy. High flux continuous casting continuous rolling process (HTCR process) is one of the most important alloys. This technology has the advantages of short process, high production efficiency and energy saving and environmental protection. The 5052 aluminum alloy sheet produced by high flux continuous casting and continuous rolling process has fast solidification rate of aluminum liquid, and the internal structure of plate is not uniform in continuous rolling process, and the properties of the plate are not uniform. In this paper, the 6mm thick 5052 alloy slab produced by high flux continuous casting and rolling process is used as a test material. Through microstructure analysis, energy spectrum analysis, macroscopic texture analysis, mechanical properties and formability testing, the intermediate annealing, cold rolling processing rate, finished annealing temperature and cross rolling process for 2mm thick 5052 alloy sheet are studied. The effects of microstructure, macroscopic texture, mechanical properties and forming properties provide theoretical guidance for industrial production. The main results are as follows: 1. the internal microstructure of 6mm thick 5052 alloy sheet produced by continuous casting and continuous rolling process is rolled. After 480 C 8h intermediate annealing, the plate microstructure becomes recrystallized and the grain is precipitated in a large amount of fine grain. A small aluminum iron phase particle.6mm thick 5052 alloy sheet was annealed to 2mm in the middle, and the time needed to complete the recrystallization process was shorter. It was found that the activation energy of the recrystallization of the cold rolled sheet through intermediate annealing was 164.3KJ/mol. Compared with the unannealed cold rolled sheet, the 5052 alloy cold rolled sheet of 18%.2. after 480 C 8h intermediate annealing was reduced. The 5052 alloy cold rolled plate without intermediate annealing contains brass texture, S texture and copper type texture, of which the maximum strength of the rolling texture of the intermediate annealing plate is 11, and the maximum texture strength is 35% lower than that of the non intermediate annealing plate. In addition, the intermediate annealing cold rolled sheet contains the cube texture with the maximum strength of 5, and the intermediate annealing 5052 alloy is re bonded. The recrystallized sheet and unannealed 5052 alloy sheet contain cubic texture and R texture. The maximum strength of the recrystallized texture is 6.6, and the maximum texture strength of the annealed plate is higher than that of the unintermediate annealed sheet. The n value of 5052 alloy after annealing at 480 C 8h is 0.396, compared with the unannealed finished plate. The material is 12.6% high, the R value of the finished sheet after the intermediate annealing is 0.696, and the (35) r value is -0.084, which is 10.5% lower than that of the unannealed finished sheet metal 10.5%, (35) r value 54.8%, and the cup convex value of the finished plate is 9.73 after the intermediate annealing, and is 1.1% higher than that of the unannealed finished plate. The deformation ratio of.4. cold rolling and the annealing temperature of the finished product have significant influence on the mechanical properties and forming properties of the 5052 alloy sheet. The tensile strength of the finished sheet is 190.8Mpa, the yield strength is 86.8Mpa, the elongation is 26%, and the mechanical properties are 26%. The average value of n value of finished sheet is 0.409, the average value of R value is 0.695, (35) r value is -0.08, the cup convex value is 9.9, the forming performance also reaches the best.5. rolling rolling sheet, which contains typical rolling texture components along the orientation line distribution, and the direct cold rolled rolled sheet contains typical rolling texture along the beta orientation line. Cross rolling A The maximum texture strength of the rolled sheet is 19, which is 10.5% higher than that of the direct cold rolled sheet. The maximum texture strength of the rolled sheet rolled by the cross rolling B process is 23. The cubic texture and the brass texture are contained in the finished sheet of 26.1%. cross rolled products higher than the direct cold rolled sheet. The cubic texture and the R texture are contained in the direct cold rolled finished sheet. The cubic texture of the finished plate of the cross rolling A process is the cube texture of the finished sheet. The strength is 2.9, which is 47.3% lower than that of direct cold rolling sheet. The cubic texture strength of the rolled sheet rolling sheet of the cross rolling B process is 2.6, the average N value of the finished sheet of the 52.7%.6. cross rolling A process is 0.378 compared with the direct cold rolled sheet, and the mean value of the n value of the finished product plate of the cross rolling B process is 0.38. The average value of the n value of the two cross rolled finished sheet plates is 8.9% higher than that of the direct cold rolled sheet. The average value of R value of the finished sheet of cross rolling A process is 0.77, and the average r value of the finished product plate of the cross rolling B process is 0.764. The average r value of the two kinds of cross rolled finished products has not changed obviously compared with that of the direct cold rolled sheet. The finished sheet of the cross rolling A process is -0.156, 16.1% higher than the direct cold rolled sheet, and the finished sheet (35) r value of the cross rolling B process is (35) r value. The -0.09 is 51.6% higher than that of the direct cold rolled sheet, and the convex values of the two plate cups after cross rolling are 9.7 and 9.67 respectively. Compared with the direct cold rolled sheet, the forming properties of the 0.8%. cross rolled sheet and the direct cold rolled finished sheet are significantly improved.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG339;TG166.3

【相似文献】