新FM锻造法

NEW FM FORGING METHOD

提出一个能控制毛坯变形区中心，既不出现轴向拉应力，也不出现横向拉应力，上用平砧、下用大平台的锻造方法，称之为新ＦＭ锻造法（ＦｒｅｅｆｒｏｍＭａｎｎｅｓｍａｎｎｅｆｆｅｃｔ）。给出了展宽率〔＝（ｂ－ｂ_０）／ｂ_０〕与压下率（η＝△ｈ／ｈ_０）之间量的关系，根据提供的数据表，可进行新ＦＭ法压缩毛坯过程中的截面变换计算，且能使砧宽比（ω／ｈ）、料宽比（ｂ／ｈ）与压下率达到最佳匹配。

A sort of forging method is proposed, which can control there exists neither axial tension stress nor crosswise tension stress in the centre of the deformation zone of blank, which requires that a flat platen is used over and a big platform below. The method is called new FM forging method.In the paper, the quantity relation between the spreading ratio [=(b-b_0)/b_0] and the relative reduction (n=Δh/h_0) is given. According to the given data table, the section varying calculation during the blank being compressed by the new FM method can be done and the best matching among tool width ratio (ω/h). blank width ratio (b/h) and relative reduction can be achieved.