在济南锻件中，有较大部分是轴类锻件，其成形模具是摔模，由上下两部分构成，锻造中锻件绕着轴线旋转，没有飞边，例如卡摔模和调直摔模。摔模成形特点是通过模具侧面压力来制约金属横向流动，使金属顺着轴线延长，和自由锻成形比起来，拔长率提高~1120%～40%。同时，内拔长时应力情况也能防止内部出现纵向裂纹。在生产中发现，台阶轴锻件使用一般摔模锻造时，往往在台阶部位发生折叠缺陷。

　　In the forging, there is a lot of shaft forgings, the forming die is broken die, from the upper and lower parts of two parts, forging forgings around the axis rotation, no flying edge, such as card drop die and straightening die. Die forming is characterized by the lateral pressure of the mold to control the lateral flow of metal, so that the metal along the axis extension, and the free forging forming ratio, the length of increase ~1120% ~ 40%. At the same time, the stress during the long drawing can also prevent longitudinal cracks in the interior. In production, it is found that when the step shaft forging is used in general die forging, the folding defects often occur at the step.

　　1、折叠缺陷问题下面是半轴锻件工艺，以此说明利用成形台阶轴过程中出现缺陷，和模具改进后的解决。半轴成形步骤是：①压肩直径是130mm;②拔长两端到直径130mm，自由锻成形;③一端压肩直径118mm;④拔长一端到直径115mm，自由锻成形;⑤压肩直径108mm;⑥拔长另一端到直径105mm，自由锻成形;⑦修整和调直成形，调直摔模。利用摔模时，在步骤①、③、⑤、⑦，都容易发生折叠缺陷，尤以调直摔模这一步最为严重。

　　1、In the forging, there is a lot of shaft forgings, the forming die is broken die, from the upper and lower parts of two parts, forging forgings around the axis rotation, no flying edge, such as card drop die and straightening die. Die forming is characterized by the lateral pressure of the mold to control the lateral flow of metal, so that the metal along the axis extension, and the free forging forming ratio, the length of increase ~1120% ~ 40%. At the same time, the stress during the long drawing can also prevent longitudinal cracks in the interior. In production, it is found that when the step shaft forging is used in general die forging, the folding defects often occur at the step.

　　2、问题的解决对工装进行修改，从根源上解决轴类锻件的折叠问题。在摔模的台阶处，在小直径型圆弧切向设置两条切线和大直径型圆角相切。这样部分消除存在于模块接触部位台阶，减慢形状上改变。当模块合拢时在圆角处产生一个容纳剩下金属的空腔，不是原来的台阶缝隙。锻打时剩下金属分流到这个部位时，不产生飞边，而产生一个棱形块，在锻件旋转锻造时，这部分剩下金属因为是棱形由于其厚度后所以不是先弯曲再折叠，而是经过锻粗和锻平然后融进锻件内部，成为一个整体，不会发生折叠缺陷。 3弯曲锻件的折叠缺陷弯曲锻件是常用的结构锻件，主要有连杆、曲轴和管接头等，这类锻件的多数缺陷是弯角转接部位的折叠，锻件流线要顺着零件方向分布时，这类折叠被锻件形状所制约，特别是弯曲角低于110。时，折叠难以避免。

　　2 、 solve the problem, modify the tooling, solve the problem of the folding of the shaft forgings from the root. At the step of the broken die, the two tangent lines and the big diameter round fillet are tangent in the tangential direction of the small diameter arc. This part eliminates the presence of steps at the module contact position and slows the change in shape. When the module is closed, a cavity containing the remaining metal is generated at the fillet, not the original step gap. When the rest of the metal forging shunt into this area, no flash, and a prismatic block, in rotary forging forging, the remaining part is due to the thickness of metal for prismatic after so not first bend and fold, but after upsetting and forging and forging into flat, become a overall, no folding defect. 3 fold curved forgings forging forging bending structure is used, the main connecting rod, crankshaft and pipe joints, most defects of this kind of forgings are the corner transfer parts of the folded forging streamline should follow the directions of the parts distribution, this type of folding is influenced by the shape of the forgings, especially the bending angle is less than 110. Folding is difficult to avoid.

　　3、零件形状与缺陷位置锻件材料为不锈钢，使用设备是摩擦压力机，工艺是弯曲制坯和开式模锻和冷校正。缺陷位置与深度有这种特征：位置是弯曲转角和平台相接处。缺陷打磨以后深度是1-2mm，经过剖开后检查，确定缺陷性质是折叠。

　　3, parts shape and location of defects, forgings materials for stainless steel, the use of equipment is friction press, the process is bending billet and open die forging and cold correction. The position and depth of the defect are characterized by the position of the bending angle and the connection of the platform. After the defect has been polished, the depth is 1-2mm. After checking it, the defects are determined to be folded.

　　4、缺陷产生原因该缺陷产生主要因为模锻成型时，已弯曲棒料弯曲端用料少，变形区处圆台用料多，所以在模锻时，弯曲端材料向着最大用料圆台处汇集，圆台处金属部分填到型腔，部分朝型腔外部流，与弯曲端流动来充型材料汇流，这时弯曲棒料若有褶皱等问题，会增加材料流动的差异性，因此发生折叠。

　　The causes of the defects of die forging, mainly because of 4 defects, have been bending bar bending deformation zone at the end of less material, cone materials, so in the end forging, bending material toward the maximum material cone gathered at the round table, the metal part to fill the cavity, the cavity part toward the external flow, flow and bending at the end of the filling material to confluence, then bending bar if there are folds and other issues, will increase the difference of material flow, so fold.

　　5、解决缺陷措施对缺陷发生原因，要采取这种措施来解决，弯曲工序是引起折叠关键一步，由实验可知，在温度与打击力度合适时，该种材料弯曲后，弯曲角超过120。，弯曲半径超过8mm时，坯料一般不出现褶皱。综合分析该锻件放置与用料，把弯曲角由110。改为115。，弯曲的内半径由5mm改成10mm，从而降低弯曲褶皱发生可能性，消除褶皱发展成折叠隐患。还有，弯曲模具设计时，弯曲槽设计很重要。棒材弯曲以后，变形区会出现椭圆状变形，应注意折弯后截面是否发生凹陷，如果有，要及时调整弯曲槽设计，加大倾斜角尺寸，从135。加到150。 4结语通过对锻件折叠发生的原因分析，进而对锻件毛料改进和模具尺寸更改，使锻件尺寸良好，锻件表面和低倍组织都没有出现折叠，锻件力学性能都符合标准要求，其质量稳定，像台阶轴，工装改进设计已经在生产中用到全部摔模设计，基本解决了台阶轴折叠缺陷问题。弯曲锻件折叠缺陷，重要的是锻造工艺与模具设计必须合理、恰当。

　　5, to solve the defects of measures causes of defects, to take such measures to solve the bending process is caused by folding a key step of the experiment showed that the temperature and the crackdown is right, this kind of material after bending, the bending angle of more than 120. When the bending radius exceeds 8mm, the blank usually does not fold. Comprehensive analysis of the placement of the forgings and materials, the bending angle from 110. Change to 115. The bending radius is changed from 5mm to 10mm, thus reducing the possibility of bending fold and eliminating fold development. Also, the bending groove design is important when bending die is designed. After the bar bending, deformation area will appear elliptical deformation, should pay attention to bending section after the depression, if there is, should promptly adjust the bending groove design, increase the tilt angle size, from 135. Add to 150. 4 conclusion through the cause of forging and folding analysis of forging die size change and improvement of wool, the forging size, forging surface and macrostructure are not folded, the mechanical properties of the steel can meet the standard requirements, the quality is stable, like the axle. The improvement of tooling design has been used in all fall die design in the production, basically solved the problem of folding defect of stepped shaft. It is important that the forging process and die design be reasonable and proper.