What is difference between austenitic and martensitic?
What is the Difference Between Austenitic and Martensitic Stainless Steel? Austenitic stainless steel is a form of stainless steel alloy which has exceptional corrosion resistance and impressive mechanical properties, while martensitic stainless steels is an alloy which has more chromium and ordinarily no nickel in it.
What is austenite martensite?
Austenite is gamma-phase iron (γ-Fe), a solid solution of iron and alloying elements. As a result of the quenching, the face-centered cubic austenite transforms to a highly strained body-centered tetragonal form called martensite that is supersaturated with carbon.
What is meant by austenitic?
What Does Austenitic Mean? Austenitic refers to an alloy consisting mainly of austenite. The most widely used grade of stainless steel is austenitic. Austenitic alloys contain a high percentage of nickel and chromium, which makes them, and the steel made from them, very resistant to corrosion.
Is 304 stainless steel austenitic or martensitic?
As both 316 and 304 stainless steels are austenitic, when they cool, the iron remains in the form of austenite (gamma iron), a phase of iron which is nonmagnetic.
Why is martensite so strong?
Untempered martensite is a strong, hard, brittle material. The stronger and harder it is, the more brittle it is. The strength and hardness is a due to elastic strain within the martensite, which is a result of too many carbon atoms being in the spaces between the iron atoms in the martensite.
Is martensite FCC or BCC?
Martensite is a metastable interstitial solid solution of carbon in iron. It is formed when austenite is quenched rapidly to room temperature and may have a bcc structure at low carbon concentrations or a body centered tetragonal structure at high carbon concentrations.
Is ferrite harder than pearlite?
The harder, stronger fine pearlite cells show more resistance to deformation than the surrounding ferrite and, thus, it is the ferrite which takes up most of the deformation of the material.
How is martensitic steel made?
They are hardenable by heat treatment (specifically by quenching and stress relieving, or by quenching and tempering (referred to as QT). The alloy composition, and the high cooling rate of quenching enable the formation of martensite. Untempered martensite is low in toughness and therefore brittle.
What is martensitic stainless steel used for?
Martensitic steels are very useful in automotive applications for door beams, bumpers, very lightweight and high strength lower side members (rocker panels), and cross car bars and beams that are designed to prevent intrusion into the passenger compartment.
What is austenitic steel used for?
Austenitic stainless steels are used for domestic, industrial, transport, and architectural products based primarily on their corrosion resistance but also for their formability, their strength, and their properties at extreme temperatures.