High strength anti-corrosion easy processing and low magnetic cast steel for manufacturing ship weldable structure

Abstract

The low magnetism cast steel for making weldable ship structure with high corrosion resistance and easy machining has the chemical components including C 0.05-0.15 wt%, Cr 10.0-22.0 wt%, Mn 3.1-12.0 wt%, Ni 2.0-12.0 wt%, N 0.10-0.28 wt%, and Fe for the rest. It may be produced with waste steel, ferrochromium, metal Mn, electrolytic Ni and recovered 0Cr18Ni9 alloy as material, and through smelting in weak oxidizing atmosphere inside a medium frequency induction furnace. In the smelting process in a medium frequency induction furnace, waste steel and electrolytic Ni is first added and molten down, ferrochromium and metal Mn is then added, metal Al is finally added to deoxidize, ferrosilicon and nitrided ferrochromium and added 5 min before tapping, and the steel is tapped at 1580-1650 deg.c and cast at 1520-1580 deg.c. The low magnetism cast steel may be used in making ship steering and propelling system with less maintenance and high safety.

Description

Technical field: [0001] The invention relates to the technical field of low-magnetism cast steel materials, in particular to a high-strength, corrosion-resistant and easy-to-process low-magnetism cast steel used for manufacturing weldable structures of ships. Background technique: [0002] The low-magnetism steel castings of the ship's weldable structural parts are mainly used in the propulsion system and steering system of the ship. The low-magnetism steel castings of the weldable structure are connected to the hull by welding. Because the main use environment is seawater, the requirements are low. Magnetic cast steel material has excellent seawater corrosion resistance, high strength and impact load resistance, and should also have excellent casting process performance, welding performance, and machining process performance. [0003] At present, the main problems of low-magnetism steel castings for ship weldable structures: (1) 917 (ZG45Mn17Al3) low-magnetism cast steel ma...

AI Technical Summary

Problems solved by technology

[0003] At present, the main problems of low-magnetic steel castings for ship weldable structures: (1) 917 (ZG45Mn17Al3) low-magnetic steel castings are severely machine-hardened and difficult to process; (2) 917 (ZG45Mn17Al3) low-magnetic steel castings are welded When the welding deformation is large, it is easy to produce high manganese steam pollution, the weld part is easy to produce pores and micro cracks, and the performance of the welded joint is difficult to guarantee; (3) MACR low magnetic cast steel has low magnetic properties and is unstable

The first three kinds of low-magnetic steels have high manganese content, difficult machining, large welding deformation, and difficult to guarantee the performance of welded joints. The latter low-magnetic steel materials have high cost and poor economy