Nihado cast iron base material multilayer buildup carbon dioxide gas shielded arc welding method of

摘要

PROBLEM TO BE SOLVED: To provide a multilayered build-up carbon dioxide shielded arc welding method for Ni-hard cast iron base metals which is capable of forming high- hardness metal build-up layers without the occurrence of peeling or chipping and without degradation in welding workability. ;SOLUTION: The Ni-hard cast iron base metals contain C, So, Mn, Ni, Cr, Mo and V and a flux cored wire is used as a welding material. The component elements to be added from either one or both of a metallic outer cover and flux are C, Si, Mn, Ni, Cr, Mo, Al, V, B, Mg and slag forming agents. The value of the weld heat input quantity H calculated by H=60×I×E/v is over 2,500 and below 3,500 at the root pass and second pass and is limited to over 5,000 and below 7,500 at the third and subsequent passes. The preheating temperatures and inter-pass temperatures of the root pass and the second pass are regulated to ≤200°C and the inter-pass temperatures of the third and subsequent passes are regulated to ≤300°C. The distance between the tip in welding and the Ni-hard cast iron base metals is regulated to 15 to 20 mm.;COPYRIGHT: (C)2001,JPO