电磁场对动力定位系统回转轴铸件凝固组织和性能的影响

Effects of Electromagnetic Field on Solidification Microstructure and Properties of Rotary Shaft Casting of Dynamic Positioning System

为了改善海洋动力定位系统DPS回转轴铸坯的组织和力学性能,在铸造的过程中加入电磁场,实现铸料的电磁搅拌。通过金相显微镜观察和MTS 322材料试验机测试了电磁搅拌铸造和传统铸造的铸坯的组织和力学性能。试验结果表明:电磁搅拌能减少铸坯凝固组织的柱状晶、增加等轴晶数量,降低铸坯中心疏松、中心缩孔、中间裂纹等缺陷,电磁搅拌铸造的铸坯的晶粒更加细小和均匀。与非电磁搅拌铸坯相比,电磁搅拌铸坯的力学性能也得到了很大的提高,抗拉强度提高了19.1%,伸长率提高了近倍1.6,硬度提高了34.6%。

In order to improve the microstructure and mechanical properties of rotary shaft billet in marine dynamic positioning system, electromagnetic stirring of casting material was realized by adding the electromagnetic field in the casting process. The microstructures and mechanical properties of the billet with and without electromagnetic stirring were tested by optical microcopy and MTS 322 material tasting machine. The results show that electromagnetic stirring can reduce the columnar crystals in solidification microstructure, increase the number of equal axis crystal, and reduce the casting billet center porosity, shrinkage, center of intermediate cracks. The grains of electromagnetic stirring casting billet are finer and more uniform. Compared with the non-electromagnetic stirring casting billet, the mechanical properties of electromagnetic stirring casting billet are greatly improved, the tensile strength is increased by 19.1%, the elongation is increased by nearly 1.6 times, and Rockwell hardness is increased by 34.6%.