煤机用耐磨复合材料耦合变形轧制界面微结构与性能控制研究

According to the existing technical bottleneck of wear-resistant composite for coal mine machinery processing, the composite method of coordinating micro tension bending with deformation rolling is put forward. By using the organic combination of theoretical analysis, numerical simulation and experiments, influence rules of thermal simulation deformation parameters on generation and growth about interfacial reaction diffusion layer and newly born phase, dispersion of brittle intermetallic compounds on the interface and fragmentation thermodynamic condition are discussed. Then the numerical analysis model for distribution of elements of dissimilar metal composite interface is established and the dynamic diffusion behavior of dissimilar metal composite interface elements is studied. The effects of composite process parameters of coordinating deformation rolling(temperature, rolling reduction, bending deformation, micro tension, deformation rate, etc) on spatial distribution state of interface diffusion transition zone, interfacial shear strength, internal stress of interface and microhardness is studied. Microstructure, fine structure and phase composition of dissimilar metal binding interface are analyzed. Then the relationship between mechanical properties (strength, toughness, etc.) and microstructure of the composite interface is established. Integrated control theory, technology and method of whole process optimization and reconstruction about thermal deformation parameter of rolling composite process are established, the control of metal interface bonding and diffusion preferred orientation is realized. The research has great theoretical significance and practical value to the manufacture of wear resistant composite plate for coal mine machinery and the enhancement of safety and reliability about coal mine machinery.

针对煤机用耐磨复合材料制备存在的技术瓶颈，提出了微张力弯曲耦合变形轧制复合新方法。采用理论解析、数值模拟和实验有机结合的方法，研究热模拟变形参数对界面反应扩散层与新生相生成和生长的影响规律，以及界面上脆性金属间化合物的弥散、碎化热力学条件，建立异种金属复合界面元素分布的数值分析模型，研究异种金属复合界面元素的动态扩散行为；研究耦合变形轧制复合工艺参数（温度、压下量、弯曲变形量、微张力、变形速率等）对界面扩散过渡区空间分布状态、界面剪切强度、界面内应力、显微硬度的影响规律，分析异种金属结合界面的组织、精细结构和相组成，建立复合界面区域的力学性能（强度、韧性等）与微观相结构之间的关系；建立其轧制复合过程热变形参数全过程优化与重构的控制理论、技术与方法，实现金属界面结合与扩散的择优取向控制。本研究对煤机用耐磨复合板制备及提升其安全可靠性具有重大的理论意义和工程实用价值。

本项目提出了针对煤机装备关键零件用耐磨金属材料开展微张力弯曲耦合变形轧制复合方法，以耐磨钢金属复合板为研究对象，采用理论分析、数值模拟、实验研究有机结合的方法，对耐磨钢/Q345R微张力弯曲耦合轧制变形复合界面扩散行为及界面强韧化机理进行系统深入的研究。获得研究成果如下：（1）得到揭示异种金属在微张力弯曲耦合变形轧制复合过程界面新相生成、微观结构和元素扩散对组织性能的影响结果。（2）通过一系列复合板高效组坯技术的研究和改进，提升耐磨钢复合板坯的制备效率和复合板坯成品率。（3）得到不同工艺参数对复合界面的强度和韧性的影响规律，其中包括两层和三层的NM360/Q345R，NM400/Q345R，NM500/Q345R，BTW1/Q345R耐磨钢热轧复合工艺，并重点对耐磨复合板的轧制温度，轧制压下率对耐磨钢复合板的影响进行了分析，掌握耐磨钢轧制复合试验工艺。（4）用两段式控制轧制，先在1100℃左右控制轧制压下率在50%以上，实现良好的耐磨钢复合界面，再在850~900℃左右控轧轧制，实行耐磨钢复合板的晶粒的细小和均匀化，为热处理奠定良好的组织基础。（5）通过热模拟试验机Gleeble－3800进行BTW1和Q345R复合压缩实验,建立了耐磨钢复合材料高温变形抗力等数学模型已经稳态流变应力本构关系模型，得到了不同工艺参数对复合界面的微观组织、形貌和金属界面扩散新生相生成、生长的影响规律。（6）添加微张力弯曲耦合变形轧制设备，研究耐磨钢复合板复合工艺，为后续更好的完善复合理论做基础。