METHOD FOR THE WELDING PRODUCTION OF A LARGE-DIMENSIONED PART FROM DUCTILE IRON BY USING LASER-DEPOSITION-WELDED BUFFER MATERIALS AND ELECTRIC WELDING

摘要

The process comprises constructing a module (1) consisting of module components (2, 3), which are laid adjacent to each other, are placed on each other under the formation of partial joints (8), are dimensioned and designed, so that the module components are castable without critical defects in their material made of spheroidal graphite iron and are made of spheroidal graphite iron, and providing the module components in a pair-wise manner and providing a first of the module components and a second of the module components for adjacent disposition in succession. The process comprises constructing a module (1) consisting of module components (2, 3), which are laid adjacent to each other, are placed on each other under the formation of partial joints (8), are dimensioned and designed, so that the module components are castable without critical defects in their material made of spheroidal graphite iron and are made of spheroidal graphite iron, providing the module components in a pair-wise manner and providing a first of the module components and a second of the module components for adjacent disposition in succession, with which one of the partial joints is formed by a marginal edge of a marginal section (4) of the first component and by a marginal edge of a marginal section (5) of the second component, applying a buffer material at the marginal edge of the first module component and at the marginal edge of the second module component by deposition welding, placing the second module component with its marginal section at the marginal section of the first module component, so that the marginal edges lie adjacent to each other with its buffer materials, welding the marginal sections, so that the partial joint formed by the marginal sections is welded, and fastening the first and second module components with one another to partially form the module. The buffer material is selected, so that a structure change in the spheroidal graphite iron of the module components is suppressed during welding the marginal sections. The buffer material contains nickel and is applied in a multi-layered manner. A laser-powder-deposition welding process is used for the deposition welding process. The laser-powder-deposition welding process is used for the deposition welding of the buffer material on the first module component and a low-energy protective gas welding process is used for the deposition welding of the buffer material on the second module component, so that a heat influence zone does not develop at the marginal section. During welding the marginal section, an electron beam welding process is used with high welding depth, narrow welding bath and smaller heat influence zone. The strength of the powder material and the parameter of the electron beam welding process and the laser-powder-deposition welding process are selected, so that the heat influence zone of the welding process is arranged in the buffer material by the electron beam welding process.