bonded sheets under rolling with spontaneous welding

In rolling process that sometimes is done with two or three layer, in significant condition welding between layers is spontaneous and no need to extra action. this condition almost is confident able and is applicable in industry. scientific sources have no issue about this condition. in this research fem be applied to analysis this circumstantial. two layer and three layers rolling be simulated and results is that thickness of layers has no effect on spontaneous welding and material with arrangement of them has effect on spontaneous welding. this phenomenon is probable in two layer rolling in comparison with multilayer rolling.