Microstructural Analysis of a Maraging Steel Welded with Laser

• Grant number: 13/20314-0
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): December 01, 2013
• Effective date (End): November 30, 2014
• Field of knowledge: Engineering - Aerospace Engineering
• Principal Investigator: Antonio Jorge Abdalla
• Grantee: Renan Nascimento Ferreira
• Home Institution: Faculdade de Engenharia (FEG). Universidade Estadual Paulista (UNESP). Campus de Guaratinguetá. Guaratinguetá , SP, Brazil

Abstract

The ultra high-strength steels, such as maraging steels, are part of a class of materials that are as important for industrial development and construction as for national defense. The maraging steel (martensite aging) of martensitic steels are low-carbon, high-alloy, in which high mechanical strength is achieved by aging in the martensitic state and not, as in conventional steels. Maraging steels are of fundamental interest in nuclear and aerospace industries due to high mechanical strength combined with excellent toughness, highly desirable features especially for weight reduction and increased safety.Regarding the process of laser welding this material there are few studies, although there is interest from the aircraft and aerospace industry with regard to the material, making it important and urgent studies on the feasibility of welding these materials .The laser welding, also known as Laser Beam Welding (LBW) applied to aircraft could replace the traditional use of rivets , thus reducing the weight in tons of an aircraft.The laser welding could also be used to join the plates that make up the envelope of motorcycle Brazilian satellite launch vehicle, currently made with 300M steel plates welded with plasma, but the intention is to replace this by maraging steel 300, material of this study.The main objectives of this work will be performed:a) The microstructural characterization by optical microscopy and microhardness analysis of a maraging300 steel laser welded;b ) Tests with various reagents to assess those that best reveal the welded region, the heat affected zone and the base material.This work will be of fundamental importance in the characterization of the welded region and the correlation of these features with the mechanical properties.