在濟南鍛件中，有較大部分是軸類鍛件，其成形模具是摔模，由上下兩部分構成，鍛造中鍛件繞著軸線旋轉，沒有飛邊，例如卡摔模和調直摔模。摔模成形特點是通過模具側面壓力來制約金屬橫向流動，使金屬順著軸線延長，和自由鍛成形比起來，拔長率提高~1120%～40%。同時，內拔長時應力情況也能防止內部出現縱向裂紋。在生產中發現，臺階軸鍛件使用一般摔模鍛造時，往往在臺階部位發生折疊缺陷。

　　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、折疊缺陷問題下面是半軸鍛件工藝，以此說明利用成形臺階軸過程中出現缺陷，和模具改進后的解決。半軸成形步驟是：①壓肩直徑是130mm;②拔長兩端到直徑130mm，自由鍛成形;③一端壓肩直徑118mm;④拔長一端到直徑115mm，自由鍛成形;⑤壓肩直徑108mm;⑥拔長另一端到直徑105mm，自由鍛成形;⑦修整和調直成形，調直摔模。利用摔模時，在步驟①、③、⑤、⑦，都容易發生折疊缺陷，尤以調直摔模這一步最為嚴重。

　　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、問題的解決對工裝進行修改，從根源上解決軸類鍛件的折疊問題。在摔模的臺階處，在小直徑型圓弧切向設置兩條切線和大直徑型圓角相切。這樣部分消除存在于模塊接觸部位臺階，減慢形狀上改變。當模塊合攏時在圓角處產生一個容納剩下金屬的空腔，不是原來的臺階縫隙。鍛打時剩下金屬分流到這個部位時，不產生飛邊，而產生一個棱形塊，在鍛件旋轉鍛造時，這部分剩下金屬因為是棱形由于其厚度后所以不是先彎曲再折疊，而是經過鍛粗和鍛平然后融進鍛件內部，成為一個整體，不會發生折疊缺陷。 3彎曲鍛件的折疊缺陷彎曲鍛件是常用的結構鍛件，主要有連桿、曲軸和管接頭等，這類鍛件的多數缺陷是彎角轉接部位的折疊，鍛件流線要順著零件方向分布時，這類折疊被鍛件形狀所制約，特別是彎曲角低于110。時，折疊難以避免。

　　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、零件形狀與缺陷位置鍛件材料為不銹鋼，使用設備是摩擦壓力機，工藝是彎曲制坯和開式模鍛和冷校正。缺陷位置與深度有這種特征：位置是彎曲轉角和平臺相接處。缺陷打磨以后深度是1-2mm，經過剖開后檢查，確定缺陷性質是折疊。

　　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、缺陷產生原因該缺陷產生主要因為模鍛成型時，已彎曲棒料彎曲端用料少，變形區處圓臺用料多，所以在模鍛時，彎曲端材料向著最大用料圓臺處匯集，圓臺處金屬部分填到型腔，部分朝型腔外部流，與彎曲端流動來充型材料匯流，這時彎曲棒料若有褶皺等問題，會增加材料流動的差異性，因此發生折疊。

　　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、解決缺陷措施對缺陷發生原因，要采取這種措施來解決，彎曲工序是引起折疊關鍵一步，由實驗可知，在溫度與打擊力度合適時，該種材料彎曲后，彎曲角超過120。，彎曲半徑超過8mm時，坯料一般不出現褶皺。綜合分析該鍛件放置與用料，把彎曲角由110。改為115。，彎曲的內半徑由5mm改成10mm，從而降低彎曲褶皺發生可能性，消除褶皺發展成折疊隱患。還有，彎曲模具設計時，彎曲槽設計很重要。棒材彎曲以后，變形區會出現橢圓狀變形，應注意折彎后截面是否發生凹陷，如果有，要及時調整彎曲槽設計，加大傾斜角尺寸，從135。加到150。 4結語通過對鍛件折疊發生的原因分析，進而對鍛件毛料改進和模具尺寸更改，使鍛件尺寸良好，鍛件表面和低倍組織都沒有出現折疊，鍛件力學性能都符合標準要求，其質量穩定，像臺階軸，工裝改進設計已經在生產中用到全部摔模設計，基本解決了臺階軸折疊缺陷問題。彎曲鍛件折疊缺陷，重要的是鍛造工藝與模具設計必須合理、恰當。

　　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.