Φ7.3m特大型09MnNiD低温钢法兰锻件成形工艺

Forming process of super large flange forgings withΦ7.3 m for 09MnNiD low temperature steel

针对首次锻造生产的Φ7.3 m特大型09MnNiD低温钢法兰锻件,通过分析对比3种成形方案,包括分段弯曲后拼焊成形、辗环成形和自由锻扩孔成形,确定了采用自由锻扩孔成形的方案。为了消除锻造成形过程中扩孔展宽量和热态锻件冷缩率对法兰锻件成品尺寸的影响,通过对特大型环圈锻造成形过程中扩孔展宽量和热态锻件冷缩率的分析,确定了锻造工艺设计时扩孔展宽量的参数设置依据,统计分析出热态锻件冷缩率的参考数据。针对09MnNiD低温钢法兰锻件壁厚超过400 mm从而导致的热处理淬透效果差、性能不合格而风险较大的问题,系统开展了热处理工艺试验。根据热处理工艺试验的结果,确定了09MnNiD低温钢的最佳热处理工艺方案。通过实际生产,验证了09MnNiD低温钢特大型法兰锻造成形工艺设计中扩孔展宽量、热态锻件冷缩率和热处理工艺参数的合理性。

For the super large flange forgings withΦ7.3 m for 09 MnNiD low temperature steel produced by forging for the first time,through analysis and comparison of three kinds of forming schemes,including tailor welding after segment bending,ring rolling and free forging and reaming,and the scheme of free forging and reaming was determined.In order to eliminate the influences of widening amount of reaming and cold shrinkage rate of hot forgings during the forging process on the sizes of finished flange forgings,through the analysis on the widening amount of reaming and the cold shrinkage rate of hot forgings during the forging process of super large ring,the parameter setting basis for the widening amount of reaming in the forging process design was determined,and the reference data for the cold shrinkage rate of hot forgings were statistically analyzed.In view of the problem that the wall thickness of flange forgings for 09 MnNiD low temperature steel exceeded 400 mm,which resulted in poor heat treatment hardening effect and high risk of unqualified performance,the heat treatment process test was systematically carried out,and according to the results of heat treatment process test,the best heat treatment process scheme of 09 MnNiD low temperature steel was determined.The actual production shows that the rationality of the widening amount of reaming,the cold shrinkage rate of hot forgings and the heat treatment process parameters in the forging process design for super large ring of 09 MnNiD low temperature steel is verified.