【摘要】：隨著我國建筑,礦山等領(lǐng)域的快速發(fā)展,國內(nèi)目前對鋸片鋼的需求量很大,尤其在精密切割設(shè)備上使用的鋸片鋼,長期需要進口,而最早研發(fā)的鋼種50Mn2V已經(jīng)難以滿足國內(nèi)市場進一步發(fā)展的需要,研發(fā)一種新型的、性能更優(yōu)異的鋸片鋼成為眾多企業(yè)迫切的需要。高碳合金鋼75Cr1鋼以其高硬度、高彈性及優(yōu)異的淬透性及耐磨性成為高端鋸片鋼最新的代表。本文使用Gleeble-1500D熱模擬試驗機對試驗材料進行單道次熱變形試驗,并通過SEM、金相顯微鏡等設(shè)備,研究影響變形抗力等因素,研究結(jié)果表明:變形溫度越低、應(yīng)變速率越大,試驗鋼75Cr1的應(yīng)力應(yīng)變曲線則越容易呈現(xiàn)動態(tài)再結(jié)晶類型曲線;反之,則呈現(xiàn)加工硬化類型應(yīng)力應(yīng)變曲線。通過保溫加熱實驗研究75Cr1鋼的奧氏體晶粒長大行為,經(jīng)對比得到的實驗結(jié)果發(fā)現(xiàn):晶粒的長大速率隨溫度升高先增加后趨于平緩,并結(jié)合Sellars提出的C-Mn鋼晶粒長大模型,計算晶粒長大激活能Q=1.57×106J/mol,進一步推導(dǎo)出75Cr1鋼的晶粒長大模型根據(jù)Tegart提出的雙曲正弦函數(shù),并應(yīng)用線性回歸方法,推算試驗鋼75Cr1的熱變形激活能Qd=264.4KJ/mol,以此計算出75Cr1鋼的熱變形方程:E=9.43*10~(-3)[sinh(010105σ)]~(3.24)exp(264.4/RT)基于存儲能演化規(guī)律,并通過擬合原有熱變形實驗數(shù)據(jù),準(zhǔn)確定位應(yīng)力應(yīng)變曲線上的臨界回復(fù)/動態(tài)再結(jié)晶點。并以演化規(guī)律為基礎(chǔ),構(gòu)思一種新的方法計算75Cr1鋼的動態(tài)再結(jié)晶分?jǐn)?shù)XD。此構(gòu)思可以較好的解決對于求取無明顯峰值應(yīng)力應(yīng)變曲線上再結(jié)晶體積分?jǐn)?shù)存在的困難,但在實際應(yīng)用中的準(zhǔn)確度仍需討論。綜上建立的有關(guān)75Cr1鋼的奧氏體晶粒長大模型、熱變形模型、動態(tài)再結(jié)晶及流變應(yīng)力等模型,可以進一步成為研發(fā)75Cr1鋼組織性能預(yù)報軟件中的基礎(chǔ)物理冶金模型。
[Abstract]:With the rapid development of construction, mining and other fields in our country, the domestic demand for saw blade steel is very large, especially the saw blade steel used in precision cutting equipment, which needs to be imported for a long time. The earliest developed steel 50Mn2V has been difficult to meet the needs of the further development of the domestic market, the development of a new type of saw blade steel with better performance has become the urgent need of many enterprises. High carbon alloy steel 75Cr1 steel with high hardness, high elasticity and excellent hardenability and wear resistance has become the newest representative of high end saw blade steel. In this paper, the single pass thermal deformation test of the test material was carried out with Gleeble-1500D thermal simulator, and the influence factors such as deformation resistance were studied by means of SEM, metallographic microscope and other equipment. The results showed that the lower the deformation temperature, the greater the strain rate. The stress-strain curve of test steel 75Cr1 is easier to show dynamic recrystallization type curve, and conversely, the stress-strain curve of work hardening type. The austenitic grain growth behavior of 75Cr1 steel was studied by heat preservation experiment. The results showed that the grain growth rate increased first with the increase of temperature and then tended to be smooth, and combined with the model of grain growth of C-Mn steel proposed by Sellars, the austenite grain growth behavior of 75Cr1 steel was studied. The activation energy of grain growth Q1. 57 脳 10 6 J / mol was calculated, and the grain growth model of 75Cr1 steel was derived according to the hyperbolic sinusoidal function proposed by Tegart, and the linear regression method was applied. The thermal deformation activation energy (Qd=264.4KJ/mol,) of test steel 75Cr1 is calculated by calculating the thermal deformation equation of 75Cr1 steel: E9.4310-3 [sinh (010105 蟽)] 3.24) exp (264.4/RT based on the evolution of storage energy, and by fitting the original experimental data of thermal deformation, the critical recovery / dynamic recrystallization point on the stress-strain curve is accurately located. Based on the evolution law, a new method for calculating dynamic recrystallization fraction XD. of 75Cr1 steel was proposed. This idea can solve the difficulty of calculating the integral number of recrystallized volume on the stress-strain curve without obvious peak value, but the accuracy in practical application still needs to be discussed. The austenitic grain growth model, hot deformation model, dynamic recrystallization model and rheological stress model of 75Cr1 steel can be further developed as the basic physical metallurgical model in the research and development of 75Cr1 steel microstructure and properties prediction software.
【學(xué)位授予單位】：遼寧科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TG142.33
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本文編號：2210649