MANUFACTURE OF FLANGE FOR PIPE

PURPOSE:To manufacture a pipe flange for high temperature and high pressure, which does not generate creep deformation, a crack, etc. during use, by executing the perforating machine work to a base material which has been forge- molded, and after that, executing heat treatment and finishing machine work. CONSTITUTION:To a base material 2 which has forge-molded a steel ingot such as alloy steel, etc., machine work is executed so that the center part forms a hollow shape 4 having the inside diameter which is more smaller than the inside diameter of a product, and subsequently, heat treatment and finishing machine work are executed, by which a pipe flange of a final shape 3 is obtained. As for the product obtained by said method, the base material shape is made an object shape, its thickness is made as thin as possible, its heat treatment is executed at the necessary heating or cooling speed, and it has a uniform metallic structure, therefore, a necessary creep characteristic whose variations are small, and material strength are held, and it is possible to prevent generation of a crack, etc. due to creep deformation or a local drop of material strength during use.