REPAIR WELDING OF SPHEROIDAL GRAPHITE CAST IRON
A method for weld repairing a surface of a base material, wherein the base material has spheroidal graphite cast iron, wherein firstly a partial surface is configured, in a further step a two-ply buffer layer is used by means of MIG welding with the welding additive NiFe, wherein in a further step a fill layer is applied to the buffer layer, wherein the MIG welding method is used in conjunction with NiFe-2 in accordance with EN ISO 107 as welding additive material.
1 . A method for weld repairing a surface of a base material, wherein the base material comprises cast iron, the method comprising:
configuring a partial surface only on the surface of the base material, producing a buffer layer on the partial surface, wherein a buffer welding process is used in conjunction with a buffer welding material, the buffer layer is applied prior to a fill layer and the buffer layer is applied on the partial surface preventing contact between the fill layer and the base material,
wherein welding parameters of the buffer welding process are selected such that a heat input into the base material is low and the base material does not crack in a heat effected zone, producing the fill layer on the buffer layer with a fill welding process,
wherein no preheating is performed,
wherein a MIG welding process is employed during the buffer welding process, and the buffer welding material used during the buffer welding process comprises at least 55% by weight of Ni and substantially 30% by weight of Fe,
wherein, during the fill welding process a fill welding material is used which comprises substantially 55% by weight of Ni and substantially 30% by weight of Fe.
2 . The method as claimed in claim 1 , wherein argon is used during the production of the buffer layer; wherein a mixture of argon and CO 2 is used during the production of the fill layer.
3 . The method as claimed in claim 1 , wherein a WIG welding process is used during the buffer welding process and a MAG welding process is used during the fill welding process, wherein the buffer welding material and the fill welding material both comprise substantially 55% by weight of Ni and substantially 30% by weight of Fe.
4 . The method as claimed in claim 1 , wherein the base material comprises spheroidal graphite cast iron.
5 . The method as claimed in claim 1 , wherein the partial surface is configured to form an indentation.
6 . The method as claimed in claim 1 , wherein a WIG welding process is employed as the buffer welding process.
7 . The method as claimed in claim 1 , wherein the buffer welding material is used as the fill welding material.
8 . The method as claimed in claim 1 , wherein the MIG welding process is employed as the fill welding process.
9 . The method as claimed in claim 8 , wherein the buffer welding material is used as the fill welding material.
10 . The method as claimed in claim 1 , wherein the buffer layer further comprises a first buffer layer and a second buffer layer, both of which are applied prior to production of the fill layer.
11 . The method as claimed in claim 1 , wherein production of the buffer welding process takes place at temperatures below 100° C.
12 . A repair of a component for a turbomachine, produced by a method as claimed in claim 1 .
13 . The method as claimed in claim 1 , wherein the buffer welding material or the fill welding material comprises a NiFe-2 type in accordance with EN ISO 1071.
14 . The method as claimed in claim 7 , wherein the buffer welding material comprises NiFe-2 type in accordance with EN ISO 1071.
15 . The method as claimed in claim 1 , wherein the buffer welding material comprises NiFe-1 type in accordance with EN ISO 1071.