Iron casting digging-replacement welding repair method

Abstract

The invention discloses an iron casting digging-replacement welding repair method. The method comprises the following steps that (1) a damaged part of an iron casting is cut off through plasma cutting, and a replacement insert is manufactured through a steel plate according to the shape of the cut part; (2) according to the thickness of the steel plate, a cut iron casting kerf and the edge of thereplacement insert are grooved and ground cleanly, and brand-new base metal is exposed; and (3) carbon dioxide arc welding machine is adopted, power source poles adopt the direct current electrode positive mode, molten pool protection gas is 100% carbon dioxide, a carbon dioxide flux-cored wire is adopted, carbon-dioxide arc welding is conducted at the room temperature, and the replacement insertis connected to the iron casting in an inserted mode. The method is simple in process, convenient to operate, easy in welding and good in fusing performance, through the repair method, the iron casting can be repeatedly used, resources are saved, the ship repair period is shortened, components scrapped due to corrosion and rotting are reduced, cost of shipowners is reduced, and the ship repair cost is reduced.

Description

Technical field [0001] The invention relates to the technical field of welding repair, in particular to a method for excavating and welding repairing iron castings. Background technique [0002] Cast iron is an iron-carbon alloy with a carbon content of more than 2%. Because cast iron has excellent wear resistance, shock absorption, and castability and machinability, cast iron parts are widely used in various equipment components of ships. The main engine is the heart of the ship, and certain parts of the ship’s equipment, such as various pump seats and end covers (main sea water pumps, fire pumps, ballast pumps, jet pumps, oil pumps, etc.), are all components that maintain the “heart” of the ship. It is cast iron. [0003] However, the welding of iron castings is a difficult problem in the industry due to its characteristics. A large number of graphite flakes are distributed inside the cast iron, just like the steel matrix is ​​split by a large number of small cracks, so the st...

AI Technical Summary

Problems solved by technology

[0005] (1) Severely corroded cast iron will disappear together with the base metal during welding (unable to weld);

[0006] (2) Welded joints are prone to white and hardened structures;

[0007] (3) Welded joints are prone to cracks;

[0008] (4) The cast iron parts that have deteriorated are difficult to weld and cannot be welded

[0009] Small cast iron damage can still be repaired by manual arc welding. When the above-mentioned cast iron equipment of the ship is severely corroded by seawater and has a large area of ​​mildew, any welding method cannot repair it.

If it is recast, it will not only take time, but also be restricted by problems such as matching the shape and internal configuration of the original equipment; under normal circumstances, cast iron components with large areas of severe corrosion have always been scrapped, and new parts can only be purchased separately. more expensive to repair