DN300大规格90°铜镍合金弯头推制成形工艺研究

Molding Process of DN300 Large Size 90°Cu-Ni Alloy Elbow

随着船舶和海洋石油工程平台的大型化,大规格铜镍合金弯头管件的市场需求随之增加。相较于传统过球法成形的弯头,冷推制弯头工艺具有较高的生产效率和稳定的成形质量。尽管冷推弯头工艺具有较大优势,但成形过程中也存在外侧壁厚减薄破裂、内侧失稳起皱、端面畸变等缺陷。针对DN300大规格90°铜镍合金弯头成形过程中出现开裂、起皱等现象,造成表面质量差、成品率低的问题,本文采用有限元方法,建立DN300大规格铜镍合金弯头冷推模型并进行数值模拟,分析了模具间隙、弯头推杆运动速度和推杆与管坯、管坯与模具之间摩擦系数对大规格弯头推制成形过程的影响,在原有生产工艺的基础上优化弯头成形参数,重新设计制造DN300大规格弯头推制成形模具,并进行生产验证,制造出尺寸合格、外形无缺陷的弯头,该工艺研究提高了大规格铜镍合金弯头成形的成品率。

With the development of large-scale ships and offshore petroleum engineering platforms,the demand for large size Cu-Ni and batch stability of forming quality.Although cold push elbow process has great advantages,alloy elbow pipe fittings is increasing.Compared with traditional ball-forming elbow,cold push elbow has higher production efficiency there are some defects in the forming pushing model of DN300 large specification Cuing occur in the forming process of DN300 large Cu-Ni alloy elbow,resulting in poor surface quality and low yield.In this paper,a cold Ni alloy elbow was established by using finite element method and numerical results were carried out,the mold clearance,pushing speed and friction coefficient on the large size elbow was analyzed,and selected the appropriate combination of forming process parameters,design and manufactured DN300 large size elbow mold,the actual production was versified.The results showed good agreement with the simulation,finally the forming yield of the large size elbow was improved.