THE MECHANISM OF HARDENING FOR MARAGING 300 STEEL

Document Type : Original Article

Authors

1 Senior Researcher, Dpt. Of Metallurgical Work, Prelucrari Metalurgice Ltd.,Bucharest, Romania.

2 Dr. Eng. Scientific Researcher, Dpt. Of Special Alloys - Sintered Products, Metallurgical Research Institute, Bucharest, Romania.

3 Professor Dr. Eng., Dpt. Of Materials Science, POLITEHNICA University, Bucharest, Romania.

4 Professor Dr.Lt. Col., Dpt of the Advanced Distributed Learning , „ Carol I” National Defence University, Bucharest, Romania.

Abstract

Maraging steels are characterised by ultra-high strength due to the precipitate formed during ageing. Development of new maraging steels has drawn much attention from civil and military industry, targeting for specific applications. Maraging steels work well in electro-mechanical components where ultra-high strength is required, along with good dimensional stability during heat treatment. Several desirable properties of maraging steels are: ultra-high strength at room temperature; good weldability ; section size is an important factor in the hardening process; simple heat treatment, which results in minimum distortion;superior fracture toughness compared to quenched and tempered steel of similar strength level ;low carbon content, which precludes decarburization problems. These factors indicate that maraging steels could be used in applications such as shafts, and substitute for long, thin, carburized or nitrided parts, and components subject to impact fatigue, such as print hammers or clutches. The study has been conducted on samples which have been placed in solutions with different cooling speeds (water, air) and then subjected to the thermal treatments for precipitation until the apparition of the austenite.

Keywords