控制杆铸造工艺优化及组织性能分析

Optimization of Casting Process and Analysis of Microstructure and Properties of Control Rod

根据控制杆的结构,对控制杆铸钢件的铸造工艺方案进行设计,再运用View Cast模拟软件对控制杆的铸造工艺进行数值模拟。模拟结果表明,在热节部位容易出现缩孔、缩松。设计冷铁数量及尺寸,在热节部位放置冷铁,同时重新设计冒口尺寸及数量,并且改为保温冒口。工艺优化后模拟结果显示,铸件大块的缩孔、缩松得到有效地消除,不仅能满足铸造需求,同时还提高了工艺出品率。对铸件进行900~920℃正火+580~600℃回火处理,测得其抗拉强度为815 MPa,硬度(HBW)为285,满足生产需要。

Considering of its structure,casting process of control rod was designed and simulated with the help of the View Cast software.The results reveal that shrinkage cavity and porosity can be easily generated in hot spots.In order to eliminate the defects,appropriate chilling blocks were designed and set at the hot spots.Simultaneously,insulating riser was used,and size and number of the riser were also designed.The optimized result shows that large defects can be eliminated effectively,which not only meet requirement of the casting,but also increase the production rate.And then,the castings were normalized at 900- 920 ℃firstly,and then tempered at 580-600 ℃.So hardness and tensile strength were measured.The results show that the tensile strength and hardness of the samples reach 815 MPa and285 HBW,respectively,meeting the pnduction requirement.