تخمين عمر غلتك هاي نورد حلقه جهت شكل دهي اسپول موتور به روش مانسون-هالفورد-هايباخ

Ring rolling work rolls life estimation by means of Manson-Halford-Haibach method

نورد حلقه جهت توليد حلقههاي بدون درز كاربرد دارد. اين حلقهها داراي خواص منحصرر به فرد از جمله جريان مناسب دانهبندي و مقاومت در ﺑﺮاﺑﺮ رﺷـﺪ ﺗﺮك ﻣﯽﺑﺎﺷﻨﺪ. اﺳﭙﻮل ﻣﻮﺗﻮر ﻫﻮاﭘﯿﻤﺎ ﻣﻌﻤﻮﻻً ﺑﻪ اﯾﻦ روش ﺗﻮﻟﯿﺪ ﻣﯽﺷﻮد. ﺧﺮاﺑﯽ ﻏﻠﺘﮏﻫﺎ در ﻫﻨﮕﺎم ﺳﺎﺧﺖ ﺣﻠﻘﻪ، ﻣﻤﮑﻦ اﺳﺖ ﻣﻨﺠﺮ ﺑﻪ ﺧﺮاب ﺷـﺪن رﯾﺰﺳـﺎﺧﺘﺎر و ﻫﻨﺪﺳﻪ اﺳﭙﻮل ﻣﻮﺗﻮر و ﺑﺮوز ﺣﻮادث ﺟﺒﺮان ﻧﺎﭘﺬﯾﺮ ﮔﺮدد، ﻟﺬا ارزﯾﺎﺑﯽ ﻏﻠﺘﮏﻫﺎي دﺳﺘﮕﺎه ﻧﻮرد ﺣﻠﻘﻪ ﺟﻬﺖ ﺑﻬﺒﻮد ﺳﺎﺧﺘﺎر ﻫﻨﺪﺳــﯽ و ﻣﮑﺎﻧﯿﮑﯽ ﺣﻠﻘﻪ ﻻزم اﺳــﺖ. در اﯾﻦ ﭘﮋوﻫﺶ ﺑﻪ ﺗﺨﻤﯿﻦ ﻋﻤﺮ و ﭘﯿﺶﺑﯿﻨﯽ ﻣﮑﺎن ﺧﺮاﺑﯽ ﻏﻠﺘﮏﻫﺎي ﻧﻮرد ﺣﻠﻘﻪ ﭘﺮداﺧﺘﻪ ﺷــﺪه اﺳــﺖ. ﺑﺎ ﺷـــﺒﯿﻪﺳـــﺎزي ﻓﺮاﯾﻨﺪ ﻧﻮرد ﺣﻠﻘﻪ ﺟﻬﺖ ﺗﻮﻟﯿﺪ ﯾﮏ ﻧﻤﻮﻧﻪ اﺳـــﭙﻮل ﻣﻮﺗﻮر، ﺗﺎرﯾﺨﭽﻪ ﺑﺎرﮔﺬاري ﻏﻠﺘﮏﻫﺎ در ﻃﯽ ﻓﺮاﯾﻨﺪ اﺳـــﺘﺨﺮاج ﮔﺮدﯾﺪ. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺗﺎرﯾﺨﭽﻪ ﺑﺎرﮔﺬاري ﻣﻘﺪار ﺗﻨﺶﻫﺎي ﺗﺮﻣﻮﻣﮑﺎﻧﯿﮑﯽ اﯾﺠﺎد ﺷــﺪه در ﻏﻠﺘﮏﻫﺎ در ﯾﮏ ﺳــﯿﮑﻞ ﺑﺎرﮔﺬاري ﺗﻌﯿﯿﻦ و در اداﻣﻪ ﺑﺎ ﮐﻤﮏ روش ﺗﻨﺶ- ﻋﻤﺮ و روشﻫﺎي ﻣﺨﺘﻠﻒ آﺳـــﯿﺐ ﺗﺠﻤﻌﯽ، ﺗﺨﻤﯿﻦ ﻋﻤﺮ اﻧﺠﺎم ﮔﺮدﯾﺪ. ﺑﺎ اﻋﻤﺎل ﻧﯿﺮوﻫﺎي ﺗﺮﻣﻮﻣﮑﺎﻧﯿﮑﯽ ﻏﻠﺘﮏ اﺻـــﻠﯽ ﺑﻪ ﻃﻮر ﻗﺎﺑﻞ ﻣﻼﺣﻈﻪاي ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﺗﻨﺶﻫﺎي ﻣﮑﺎﻧﯿﮑﯽ و ﻣﻨﺪرل ﻣﺘﺎﺛﺮ از ﺗﻨﺶﻫﺎي ﺣﺮارﺗﯽ اﺳﺖ. ﺟﻬﺖ اﻓﺰاﯾﺶ ﻋﻤﺮ ﻣﻨﺪرل و ﮐﺎﻫﺶ اﺛﺮات ﻣﺨﺮب ﺗﻨﺶﻫﺎي ﺗﺮﻣﻮﻣﮑﺎﻧﯿﮑﯽ ﻣﯽﺑﺎﯾﺴﺖ دﻣـ ﺎي ﻏﻠﺘـﮏ ﻫـ ﺎ در ﺣﯿﻦ ﮐـﺎرﮐﺮد ﺗـﺎ ﺣـﺪ اﻣﮑﺎن در ﻣﺤﺪوده دﻣﺎي اوﻟﯿﻪ آﻧﻬﺎ ﺑﺎﻗﯽ ﺑﻤﺎﻧﺪ. ﺧﻨﮏﮐﺎري ﻣﺘﻨﺎﺳـــﺐ ﺑﺎ دﻣﺎي اوﻟﯿﻪ ﻣﻨﺪرل ﺗﺎﺛﯿﺮ ﻗﺎﺑﻞ ﻣﻼﺣﻈﻪاي ﺑﺮ اﻓﺰاﯾﺶ ﻋﻤﺮ آن ﺧﻮاﻫﺪ داﺷـﺖ. در ﺿـﻤﻦ اﺛﺮ ﺗﻨﺶ ﺧﻤﺸـﯽ ﺣﺎﺻـﻞ از ﺷـﮑﻞ دﻫﯽ اﺳﭙﻮل ﻣﻮرد ﻧﻈﺮ ﺑﺮ روي ﻋﻤﺮ ﻣﻨﺪرل ﻗﺎﺑﻞ ﺗﻮﺟﻪ ﻧﯿﺴــﺖ. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻧﺘﺎﯾﺞ ﺣﺎﺻــﻞ از ﭘﮋوﻫﺶ ﻣﺸــﺨﺺ ﮔﺮدﯾﺪ ﮐﻪ ﭘﺎﺳــﺦ ﺗﺮﻣﻮﻣﮑﺎﻧﯿﮑﯽ ﻏﻠﺘﮏﻫﺎ ﻧﻮرد ﺣﻠﻘﻪ ﮔﺮم ﺑﻪ ﻫﻨﮕﺎم ﺷــﮑﻞدﻫﯽ ﮐﺎﻣﻼً ﻣﺘﻔﺎوت .اﺳﺖ. اﺣﺘﻤﺎل ﺧﺮاﺑﯽ و اﯾﺠﺎد ﺗﺮك ﺑﻪ واﺳﻄﻪ ﻧﯿﺮوﻫﺎي ﺗﺮﻣﻮﻣﮑﺎﻧﯿﮑﯽ در ﻏﻠﺘﮏ اﺻﻠﯽ و ﻣﻨﺪرل ﺑﻪ ﺗﺮﺗﯿﺐ در زﯾﺮ و روي ﺳﻄﺢ آﻧﻬﺎ اﺳت

Ring rolling process is used in the production of seamless rings.The most important advantages of these rings are favorable grain flow and crack growth resistance. Aircraft engine spools are usually produced by means of this process. Failure of the work rolls during forming of spools leads to unacceptable geometrical structural and irreparable damages. Evaluation of the work rolls life of the ring rolling machine has a direct effect on the properties of the output ring. Initially, different types of life estimation and cumulative damage assessment methods were studied. By making use of Abaqus simulation, the loading history was extracted and applied to the work rolls. According to the loading history, stress-life method and cumulative damage relations were performed. The results of the research shows that the main roll is significantly affected by mechanical stresses. On the other hand, the mandrel is affected by thermal stresses by applying the thermo-mechanical forces. In general, in order to extend the work roll’s life, of the work rolls and reduce the effects of the thermo-mechanical stresses, the uniformity of temperature during work rolls operation should be maintained. So that proper cooling will have a significant effect on the service life. In addition, the effect of bending stress on the mandrel life is not significant.