Estimation system of weldability for materials joining based on knowledge data base of fusion processing technologies

研究的目的是开发基于熔合加工技术知识数据库的结构材料连接可焊性评估系统，为具有新功能特性的结构材料的可焊性知识数据库提供支撑数据。根据钢板种类、接头类型、焊接工艺、焊接材料、焊缝强度、防止焊缝冷裂的氢含量等框架，以及钢板种类、接头类型、焊接工艺、焊缝韧性的Charpy值和CTOD值，构建了焊缝韧性评估体系。该系统对焊缝裂纹试验、Charpy试验和CTOD试验进行了大量的数据分析。该系统可以控制合适的预热和后加热温度，并对焊缝的韧性进行预估。对SiC/Ti系纤维增强金属基复合材料、Ti- ni形状记忆合金的连接性能和结构钢的表面改性进行了试验研究。采用真空热压法制备了SiC/Ti复合材料，分析了纤维-基体反应对强度的影响。研究了钛镍形状记忆合金及其激光焊接接头的力学性能和断裂情况。采用lOkW激光进行对接焊接。激光焊接试样具有良好的形状记忆效应和超弹性。这些性质与母材的性质相同。采用等离子体转移电弧法、等离子体喷涂法和激光熔覆法等熔融加工技术，在某些结构钢基体上制备了碳化物分散复合材料和NiCrAlY复合材料。作为基体的结构钢通过上述方法覆盖了一层复合合金，使其表面具有新的功能性能。

The purpose of the study is to develop a estimation system of weldability for structural materials joining based on a knowledge data base of fusion processing technologies and to prepare the supporting data of the knowledge data base for weldability of structural materials having a new functional properties.The estimation system was constructed of the various frame such as kind of steel plates, type of joints, welding procedures, welding materials, strength of weld and contents of hydrogen for the prevention of weld cold cracking, and also, such as kind of steel plates, type of joints, welding procedures and Charpy and CTOD values for estimation of toughness of weld. The system were put into numerous data which the weld cracking test, Charpy and CTOD tests were curried out. The system can be controlled the suitable preheating and post-heating temperature, and estimated the toughness of weld.The works were curried out some experiments to investigated the joining properties for SiC/Ti system fiber reinforced metal matrix composite, Ti-Ni shape memory alloy and surface modification of structural steel. SiC/Ti FRM was produced by vacuum hot pressing and analyzed the effect of reaction of fiber-matrix on strength. Mechanical properties and fracture of Ti-Ni shape memory alloy and its laser weld joint have been investigated. Butt welding was performed using lOkW laser. The laser welded specimens showed a successful shape memory effect and super elasticity. These properties were identical with those of the base metal.The composite materials such as carbide dispersed composite materials and NiCrAlY composite material were produced on some structural steel substrate using various metal powders and carbide powders by fusion processing technologies such as plasma transfer arc method, plasma spraying and laser cladding process. As the structural steel using as substrate was overlaid the layer of composite alloy by above method, it's surface has new functional property.