METHOD FOR MAKING BUILTUP PRODUCTS WITH LENGTHWISE LAMINARITY Russian patent published in 1998 - IPC

FIELD: plastic metal working, namely processes for manufacturing builtup-thickness blanks for making tubes with clad working surfaces. SUBSTANCE: method for making builtup products with lengthwise laminarity includes steps of arranging one hollow blank inside another with use of inner blank of less strength material than outer one; assembling blanks and mutually fixing them, heating builtup blank, arranging it onto needle and extruding through cone die due to placing said blank in container and applying axial compression effort to end of builtup blank. Novelty is assembling of said blank by two stage. At first stage blank of less strength material is arranged only along a part of length of blank of more strength material. Said blanks are initially fixed by plastic compression of blank of less strength material at forming bottom portion. At second stage blank of less strength material is moved in axial direction until completing blank assembling in conditions of maximum tangential contact stresses on interface of said blanks. Then blanks are finally fixed at loading blank of less strength material by axial compression effort and providing radial irreversible deformation of builtup blank with formation of slope on one of its ends. Then bottom portion of blank is removed. When builtup blank is placed onto needle its slope is turned to side opposite relative to pressure pad. Builtup blank is assembled without reducing thickness of wall of blank of less strength material, or builtup blank is assembled with reduction of thickness of wall of blank of less strength material. Blanks are finally fixed at loading blank of less strength material by axial compression effort and alternating stages of plastic deformation of material and unloading, sustaining blank in unloaded state. EFFECT: enhanced efficiency. 4 cl, 11 dwg