Study And Application On System Of Forging Deformation For Large Forge Pieces

The large forgings，because of the compositio n segregatio n，poros ity and pipeexisted in the stee l ingot， the une ven d istrib ution o f de formation will occurredeasily in the high te mperature forging， whic h will lead to the detection d iffic ult tomeet the require ment or s hort of orga nization a nd mec hanica l performa ncerequire me nt after heat treatment．How to draw the appropriate forging technolo gyaccording to the d ifferent technica l require me nt o f the stee l，e liminate structuredefects and impro ve its organizatio n after forging is a diffic ult proble m faced bythe quality of big forge pieces．The commo nly materia ls of large forge pieces can be divided into threetypes，carbon steel and lowa lloy structura l stee l，p lastic d ie steel with gooduniformity， hot forging die stee l a nd hot e xtrus ion d ie stee l withthree-dime ns io nal isotropy． It sho uld be adopting different forging methodaccording to the d iffere nt require me nt of the orga nization and mecha nicalproperties．Be base on the concept of the conventio na l forging ratio a nd itscalculatio n method， in order to make up for its insuffic ie nt on depicting thedirections in the process of forging deformatio n，the deformation rate was putforward in this paper；at the same time，with the delto id(the ratio of thick wide andhigh is1:1.25:2.5) before upsetting，add to the comb inatio nal techno logy ofcriss-crossing forging， a good result have been achie ved by this method inzero-disfigurement and higher isotropy，details as follows：For no lateral or tange ntia l mec hanica l performance require ment s ofcarbon steel and lowa lloy stee l (such as S355J2G3，42CrMoS4，etc．)，when theaccumulated deformation rate is greater than or equa l to50%(the forging ratio isgreater than4) by us ing the above-mentio ned forging method，its testing le ve l canreach SEP1921D/d or GB/T6402-2008Ⅲ，its lo ngitud ina l mecha nica l propertiescan reach the requirements of EN10250after proper heat treatment．With the require me nt of pre hard on Structure and hard ness(suc h as1.2311， 1.2738，etc．)，in order to ensure the uniform hardness of the table and heart，theforging s yste m sho uld be satis fied that the latera l deformatio n rate reached60%(equivale nt to the forging ratio of4.5or above)， meanwhile， it must be usedwith great deformation；By its cumulative deformation rate can determine itsforging size， ensure its consistency requirements．For the hot forging d ie steel a nd hot extrus ion d ie stee l withthree-dime ns io nal isotropy(s uch as H13，1.2344，etc．)，the large gra nular carbidesis fully broken and wedd ing o n every k inds o f de fects， in order to achie veSEP1921E/e or GB/T6402-2008Ⅳ，the accumulative deformation rate on threedirection sho uld be controlled in100%or above，a nd the ingot should be duringa enough time and high te mperature ho mo genizatio n treatme nt， mea nwhile， itsaccumulative deformatio n rate should be close；According to this criteria，thedeformation system for higher isotropy steel can be setted．In this paper，base on the differe nt require ment of the steel，through thecomprehens ive application o f the introductio n of the defor matio n rate andcriss-crossing forging，s ummarized a set of de formation syste m whic h can meetthe detection standard at home and abroad．To reduce rejection，reduce productioncost，shorted production cycle has a certain guiding significance．...