تحلیل اثر خوردگی بر استحکام باقیمانده کششی ورق کشتی های سال خورده به کمک آزمایش کشش

ﺻﻨﻌﺖ درﯾﺎﯾﯽ اﯾﺮان ﺑﻪ ﺻﻮرت ﺧﺎص از آﻟﯿﺎژﻫﺎی درﯾﺎﯾﯽ ﻓﻮﻻد و آﻟﻮﻣﯿﻨﯿﻮم ﺟﻬﺖ ﺳﺎﺧﺖ ﺷﻨﺎورﻫﺎ و زﯾﺮدرﯾﺎﯾﯽﻫﺎ اﺳﺘﻔﺎده ﻣﯽﮐﻨﺪ. ﺿﻤﻦ اﯾﻨﮑﻪ ﺣﺠﻢ زﯾﺎدی ازﺳﺎزهﻫﺎی درﯾﺎﯾﯽ ﻣﻮﺟﻮد درﮐﺸﻮر ﻧﯿﺰ از اﯾﻦ آﻟﯿﺎژﻫﺎ ﻣﯽﺑﺎﺷﻨﺪ. ﯾﮑﯽ ازﻣﺸﮑﻼت اﺳﺘﻔﺎده ازﺳﺎزهﻫﺎی ﻓﻠﺰی دراﯾﻦ ﺻﻨﺎﯾﻊ ﻣﺒﺎﺣﺚ ﻣﺮﺗﺒﻂ ﺑﺎﺧﻮردﮔﯽ اﺳﺖ. ﭘﺪﯾﺪه ﺧﻮردﮔﯽ ﺳﺒﺐ زﯾﺎنﻫﺎی ﺑﺴﯿﺎر زﯾﺎدی ﺑﻪ ﺳﺎزﻫﺎی درﯾﺎﯾﯽ وﮐﺸﺘﯽﻫﺎ ﻣﯽﺷﻮد وﻧﯿﺎز اﺳﺖ ﮐﻪ ﺑﻪ ﺻﻮرت ﻣﺪاوم ﻣﻘﺪار و ﭼﮕﻮﻧﮕﯽ ﺧﻮردﮔﯽ اﯾﻦ ﺳﺎزهﻫﺎ ﮐﻨﺘﺮل ﺷﻮد. درﺑﯿﻦ روشﻫﺎی ﻣﺨﺘﻠﻒ ﺟﻠﻮﮔﯿﺮی ازﺧﻮردﮔﯽ، ﺣﻔﺎﻇﺖ ﮐﺎﺗﺪی ازﻣﻬﻢﺗﺮﯾﻦ روشﻫﺎی ﻣﻮرداﺳﺘﻔﺎده درﺻﻨﺎﯾﻊ درﯾﺎﯾﯽ اﺳﺖ. ﺑﺮرﺳﯽ روشﻫﺎی ﺟﻠﻮﮔﯿﺮی از ﺧﻮردﮔﯽ و ﭘﯿﺎدهﺳﺎزی آن در ﺷﻨﺎورﻫﺎی ﻧﻈﺎﻣﯽ ﻣﯽﺗﻮاﻧﺪ ﮐﻤﮏ ﺑﺴﯿﺎر زﯾﺎدی ﺑﻪ ﻋﻤﺮ ﺷﻨﺎور و ﮐﺎﻫﺶ ﻫﺰﯾﻨﻪﻫﺎی اﻋﻤﺎﻟﯽ ﺑﺮ ﻓﺮاﯾﻨﺪ ﻧﮕﻬﺪاری و ﺗﻌﻤﯿﺮ داﺷﺘﻪ ﺑﺎﺷﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﺑﻪﺻﻮرت ﺧﺎص ﭘﺪﯾﺪه ﺧﻮردﮔﯽ ﻣﻮرد در ﺷﻨﺎورﻫﺎی ﻧﻈﺎﻣﯽ ﻧﺪاﺟﺎ ﻣﻮرد ﺗﻮﺟﻪ ﻗﺮارﮔﺮﻓﺘﻪ و روشﻫﺎی ﺣﻔﺎﻇﺖ در ﺑﺮاﺑﺮ ﺧﻮردﮔﯽ در اﯾﻦ ﺷﻨﺎورﻫﺎ ﺑﺮرﺳﯽ و ﺗﺄﺛﯿﺮ ﭘﯿﺎدهﺳﺎزی آن در ﺷﻨﺎورﻫﺎی ﻣﻮﺟﻮد ﻣﻮردﻣﻄﺎﻟﻌﻪ ﻗﺮارﮔﺮﻓﺘﻪ اﺳﺖ. ﺑﺮای اﯾﻦ ﻣﻨﻈﻮر از ورقﻫﺎی اﺻﻠﯽ ﺑﺪﻧﻪ ﺷﻨﺎورﻫﺎی ﻧﻈﺎﻣﯽ ﺑﺎ ﺳﻦﻫﺎی ﻣﺨﺘﻠﻒ اﺳﺘﻔﺎده ﮔﺮدﯾﺪ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از آزﻣﻮن ﮐﺸﺸﯽ ﻧﺸﺎن ﻣﯽدﻫﻨﺪ ﮐﻪ ﺑﻌﻀﯽ از ﻧﻤﻮﻧﻪﻫﺎ ﺑﺎﺳﻦ ﮐﻤﺘﺮ ﻣﻘﺎوﻣﺖ ﮐﻤﺘﺮ در ﺑﺮاﺑﺮ آزﻣﻮن ﮐﺸﺶ ﻧﺴﺒﺖ ﺑﻪ ﻧﻤﻮﻧﻪﻫﺎﯾﯽ ﺑﺎﺳﻦ ﺑﺎﻻﺗﺮ دارد. ﺑﻨﺎﺑﺮاﯾﻦ ﻣﯽﺗﻮان ﺑﻪ اﯾﻦ ﻧﺘﯿﺠﻪ رﺳﯿﺪ ﮐﻪ ﺳﻦ ورقﻫﺎ ﺗﻨﻬﺎ ﻓﺎﮐﺘﻮر ﺑﺮ روی ﻣﯿﺰان ﺧﻮردﮔﯽ آنﻫﺎ و ﻫﻤﭽﻨﯿﻦ ﮐﺎﻫﺶ ﻣﻘﺎوﻣﺖ آنﻫﺎﻧﻤﯽﺑﺎﺷﺪ. ﺑﻪﺑﯿﺎن دﯾﮕﺮ، ﻣﺪﯾﺮﯾﺖ ﺗﻌﻤﯿﺮ و ﻧﮕﻬﺪاری ﻧﻤﻮﻧﻪﻫﺎ ﺑﻪاﻧﺪازه اﻫﻤﯿﺖ ﺳﻦ آنﻫﺎ ﺣﺎﺋﺰ اﻫﻤﯿﺖ ﻣﯽﺑﺎﺷﻨﺪ.

Analysis of Corrosion Effect on Tensile Strength of Sheets of Aged Vessels Using Tensile Testing

During a ship’s service life, the hull is exposed to different types of loads and subjected to different damage scenarios, including corrosion deterioration that reduces the structural capacity. The most important degradation effects of ship structures are corrosion and fatigue cracks. Both of these aging effects have clear consequences of increasing stress levels and degrading the strength of ship structures for almost all relevant failure modes.Aging of ship structures may be defined as the progressive deterioration of structures as a result of normal operational use and environmental influences. The structural deterioration comes in the following forms: Coating damage, Corrosion, Cracking, Deformations and Changes in material properties. Investigation of corrosion prevention methods and their implementation in military vessels can greatly help the life of the vessel and reduce the cost of maintenance and repair. In this research, in particular, the phenomenon of corrosion in relation to the Marine Steel of military vessels has been studied. By examining the results of the experiments it was found that the vessel age is not the only criterion for assessing the strength of the sheets remaining since the results of the tensile test show that some of the lower hip specimens have less resistance to the tensile test than the higher hip specimens. In addition, maintenance management is as important as the age of the vessels.