【作者】 李建；

【导师】 王青峰；

【作者基本信息】 燕山大学 ， 材料学， 2019， 硕士

【摘要】 我国能源行业的大型容器因严苛腐蚀而导致寿命降低,每年急需约10万吨复合容器板以解决腐蚀问题,但传统的爆炸复合破坏环境且性能不稳,开发轧制复合技术迫在眉睫。本文通过模拟轧制钛钢复合板,并对复合界面性能和微观结构进行研究,为完善复合板理论体系做出了贡献,补充了工业化关键制造技术,为我国高性能容器用钢做出了贡献。本文采用gleeble-3500热模拟实验机,在<20 Pa的真空条件下对钛钢复合板进行轧制复合,通过改变基材的含碳量(0.06%~0.20%)、轧制温度(800℃~875℃)、轧制压下量(40%~80%)以及对轧后试样进行不同温度退火(550℃~900℃)制得不同状态的钛钢复合板;通过OM、SEM、EDS、EPMA、EBSD、XRD等分析测试方法,研究不同的条件下对复合界面组织,元素互扩散行为及垂直界面拉伸强度的影响。通过分析得出结果表明:不同基材含碳量的复合板界面两侧均出现Fe和Ti元素的互扩散行为以及C元素在界面处的富集,且随着基材含碳量的升高界面富集的C元素越多;四种含碳下,钛钢复合板复合界面的主要相都为FeTi相TiC相,其拉伸试样断裂位置皆为结合界面处。当基材含碳量较低时,复合界面较厚,垂直界面拉伸强度较低,当基材含碳量较高时,复合界面变薄,垂直界面拉伸强度升高。不同轧制工艺的研究表明,当轧制温度为850℃时,垂直界面拉伸强度最高,为337 MPa;当轧制温度低于850℃时,复合界面存在未结合区域,界面性能差;当轧制温度高于850℃时,复合界面结合良好。此外,随着轧制压下量的增加,复合界面的拉伸强度逐渐增加,当轧制压下量为80%时,界面拉伸强度最大。对不同退火条件的复合板分析表明,当退火温度低于850℃时,随着热处理温度的升高Ti元素的扩散距离增加,Fe元素的扩散距离基本不变,C元素在界面处的聚集现象增强,界面拉伸强度逐渐升高;当热处理温度高于850℃时,随着温度的升高,Fe和Ti元素的扩散更为剧烈,C元素的聚集现象减弱,拉伸强度降低。更多还原

【Abstract】 The large-scale containers in China’s energy industry have a reduced life due to severe corrosion.About 100,000 tons of composite container plates are urgently needed each year to solve the corrosion problem.However,the traditional explosion compound damages the environment and the performance is unstable.It is extremely urgent to develop rolling composite technology.In this paper,the titanium steel composite plate is simulated and rolled,and the composite interface properties and microstructure are studied.It contributes to the improvement of the composite plate theory system,supplements the key industrial manufacturing technology,and contributes to the high-performance container steel in China.In this paper,using gleeble-3500 thermal simulation test machine,the titanium steel composite plate is rolled and composited under the vacuum condition of <20 Pa,by changing the carbon content of the substrate(0.06%~0.20%),rolling temperature(800 °C~875 °C),rolling reduction(40%~80%)and different temperature annealing(550 °C~900 °C)for different samples of titanium steel composite panels;through OM,SEM,EDS,EPMA,EBSD,XRD and other analytical test methods were used to study the effects of different interface conditions on composite interfacial microstructure,elemental interdiffusion behavior and tensile strength of vertical interface.The results of the analysis show that:The interdiffusion behavior of Fe and Ti elements and the enrichment of C elements at the interface on both sides of the composite plate with different carbon content of different substrates,and the C element enriched at the interface with the increase of carbon content of the substrate In the four kinds of carbon,the main phases of the composite interface of the titanium steel composite plate are FeTi phase and TiC phase,and the fracture sites of the tensile specimens are all at the bonding interface.When the carbon content of the substrate is low,the composite interface is thicker and the tensile strength at the vertical interface is lower.When the carbon content of the substrate is higher,the composite interface becomes thinner and the tensile strength at the vertical interface increases.The research on different rolling processes shows that when the rolling temperature is 850 °C,the tensile strength of the vertical interface is the highest,which is 337 MPa.When the rolling temperature is lower than 850 °C,the composite interface has unbonded areas and the interface properties are poor.When the temperature is higher than 850 °C,the composite interface is well bonded.In addition,as the rolling reduction increases,the tensile strength of the composite interface gradually increases.When the rolling reduction is 80%,the interfacial tensile strength is the largest.The analysis of composite plates with different annealing conditions shows that when the heat treatment temperature is lower than 850 °C,the diffusion distance of Ti increases with the increase of heat treatment temperature,the diffusion distance of Fe element is basically unchanged,and the aggregation of C element at the interface The tensile strength of the interface increases gradually.When the heat treatment temperature is higher than 850 °C,the diffusion of Fe and Ti is more intense with the increase of temperature,the aggregation of C element is weakened,and the tensile strength is decreased.更多还原