Regarding the wall thickness reduction issue of conical flanged heads?
Thread Content
I once read a paper that conducted a comparative analysis of the thickness of the conical transition section (the rounded part) of tapered flanged heads and the thickness of the conical shell connected to this transition section; the conclusion was that only the thickness of the conical shell needs to be considered, as there is no need to take into account the thickness of the conical transition section (the rounded part). In fact, due to the favorable stress conditions in the conical transition section (the rounded part), its calculated wall thickness is relatively thin, whereas the thickness of the conical shell, calculated as that of a cylinder, is thicker. Does this mean that there is no need to consider the thickness reduction due to the forming of the conical section (the rounded part), and that the nominal thickness of the conical shell at the junction of the sections should be used as the cutting thickness? I wonder how everyone goes about it in practice?
If hot pressing requires consideration for the thinning of the formed wall thickness
The wall thickness reduction must be taken into account; if the design specifies a minimum formability thickness, that value shall be used. For the cold and hot forming, stamping, spinning, segment pressing, etc., of the transition section, the amount of thinning varies; unless the minimum design forming thickness requirement is met, the material used must be thicker!
In fact, whether it is cold pressing or hot pressing, thinning does occur, as it is related to the rate of deformation. In a standard elliptical head, the small radius of curvature is 0.17D; under such conditions, thinning is inevitable. In flanged conical heads, the radius of curvature is often 0.1D, resulting in a greater degree of deformation; therefore, thinning is inevitable. As long as the thickness is the same, thinning after molding can still meet the usage requirements.
In fact, whether it is cold pressing or hot pressing, thinning does occur, as it is related to the rate of deformation. In a standard elliptical head, the small radius of curvature is 0.17D; under such conditions, thinning is inevitable. In flanged conical heads, the radius of curvature is often 0.1D, resulting in a greater degree of deformation; therefore, thinning is inevitable. As long as the thickness is the same, thinning after molding can still meet the usage requirements.
I agree with what was said on the 3rd floor: regardless of other forming methods such as cold or hot forming, the thickness of the material fed in must meet the minimum thickness requirement specified in the drawings after forming.
The wall thickness reduction must be taken into account; if the design specifies a minimum formability thickness, that value shall be used. For the cold and hot forming, stamping, spinning, segment pressing, etc., of the transition section, the amount of thinning varies; unless the minimum design forming thickness requirement is met, the material used must be thicker!
The wall thickness reduction must be taken into account; if the design specifies a minimum formability thickness, that value shall be used. For the cold and hot forming, stamping, spinning, segment pressing, etc., of the transition section, the amount of thinning varies; unless the minimum design forming thickness requirement is met, the material used must be thicker!