本文選題：鑄態(tài)Q235B + 熱輾擴(kuò)成形�。� 參考：《太原科技大學(xué)》2015年碩士論文

【摘要】：隨著大型環(huán)件、法蘭在工業(yè)、航天、核電等高科技等領(lǐng)域的廣泛應(yīng)用,對環(huán)件的需求量日益增多,對環(huán)件性能、生產(chǎn)工藝的要求越來越嚴(yán)格。因此,節(jié)約能源、降低成本、提高質(zhì)量和生產(chǎn)率已成為環(huán)件生產(chǎn)和裝備制造業(yè)發(fā)展的必然趨勢。金屬環(huán)件短流程鑄輾復(fù)合精確成形工藝,在傳統(tǒng)環(huán)形零件生產(chǎn)工藝的基礎(chǔ)上進(jìn)行突破性地改進(jìn),具有流程短、節(jié)能、節(jié)材、高效、低成本、環(huán)保等顯著優(yōu)勢。本文以離心與砂型鑄坯Q235B鋼為研究對象,采用理論分析方法、數(shù)值模擬方法和對比分析方法,從宏觀上研究了金屬環(huán)件鑄輾復(fù)合成形過程中成形參數(shù)對環(huán)件組織和性能的影響規(guī)律,從微觀上研究了成形參數(shù)對熱變形再結(jié)晶體積分?jǐn)?shù)、再結(jié)晶晶粒尺寸及平均晶粒尺寸的影響規(guī)律。研究結(jié)果表明:(1)熱輾擴(kuò)成形中,芯輥的進(jìn)給速度越大,等效塑性應(yīng)變分布越來越均勻,溫度場變形更加均勻,輾擴(kuò)力也越大。芯輥進(jìn)給速度為變速時,等效應(yīng)變和溫度場的最大值減小和最小值加大,分布更加均勻,輾擴(kuò)初期輾擴(kuò)力增加較為緩慢。通過對離心鑄坯與砂型鑄坯宏觀變形對比分析,在相同輾擴(kuò)參數(shù)下,離心鑄坯比砂型的等效塑性應(yīng)變和溫度場分布更加均勻,但輾擴(kuò)力要高。(2)隨著芯輥進(jìn)給速度的變大,動態(tài)再結(jié)晶體積分?jǐn)?shù)變小,且更加均勻,動態(tài)再結(jié)晶晶粒尺寸稍有變小,但分布越來越均勻,平均晶粒尺寸分布也越均勻。芯輥進(jìn)給速度采用加速度變速時,其動態(tài)再結(jié)晶體積分?jǐn)?shù)、再結(jié)晶晶粒尺寸、平均晶粒尺寸分布比勻速更加均勻。(3)結(jié)果分析可得,在滿足環(huán)件輾擴(kuò)成形設(shè)備的使用條件下,采用Q235B離心鑄坯,芯輥進(jìn)給速度以(先以加速度2?/1.0 smma加速運動,達(dá)到速度V=1.6mm/s,再勻速進(jìn)給34s,最后再以加速度為2??/1.0 smma運動,減速到零)的變速,初始溫度為1150℃,可以使環(huán)件輾擴(kuò)變形更加均勻,晶粒更加細(xì)化,輾擴(kuò)質(zhì)量和生產(chǎn)效率都達(dá)到理想的目標(biāo)。
[Abstract]:With the wide application of large ring, flange and other high-tech fields, such as industry, aerospace, nuclear power, etc., the demand for ring parts is increasing day by day, and the requirements for the performance and production process of ring parts are becoming more and more strict. Therefore, saving energy, reducing cost, improving quality and productivity has become an inevitable trend in the development of ring production and equipment manufacturing industry. Based on the traditional annular parts production technology, the metal ring short process casting and rolling compound precise forming process is improved by a breakthrough, which has the advantages of short process, energy saving, material saving, high efficiency, low cost, environmental protection and so on. In this paper, centrifugal and sand billet Q235B steel is taken as the research object, theoretical analysis method, numerical simulation method and comparative analysis method are used. The influence of forming parameters on the microstructure and properties of the ring in the process of casting and rolling composite forming of metal ring is studied macroscopically, and the integral number of the forming parameters on the recrystallization volume of hot deformation is studied from the microscopic point of view. The effect of recrystallization grain size and average grain size. The results show that the larger the feed speed of the core roll, the more uniform the equivalent plastic strain distribution, the more uniform the temperature field deformation and the greater the rolling force in the hot rolling forming. When the feed speed of core-roller is variable, the maximum value and minimum value of equivalent strain and temperature field decrease, the distribution is more uniform, and the rolling force increases slowly at the beginning of rolling. Through the comparative analysis of macro deformation of centrifugal and sand casting billet, under the same rolling parameters, the distribution of equivalent plastic strain and temperature field of centrifugal billet is more uniform than that of sand mold, but the rolling force is higher than that of sand mold, but the rolling force increases with the feed speed of core roll. The dynamic recrystallization volume integral number becomes smaller and more uniform, and the dynamic recrystallization grain size is slightly smaller, but the distribution is more and more uniform, and the average grain size distribution is more uniform. The dynamic recrystallization volume integral number, recrystallized grain size and average grain size distribution are more uniform than uniform velocity when the feed speed of core-roller is changed by acceleration. The results can be obtained under the condition that the ring rolling forming equipment can be used. Using Q235B centrifugal casting billet, the feed speed of core roll is changed to 1150 鈩，

本文編號：1876402