For elevated temperatures, other materials, Mechanical Engineering

For Elevated Temperatures, Other Materials

 High temperature creep is a significant phenomenon to be guarded in various machines like gas turbines, missiles, reentry vehicles and propulsion engines. Ferritic and another stainless steel are good against creep but merely to limited extent. Refractory metals and their alloys are beneath close investigation for this point. The goal is not still achieved and some developments are still proprietary. This will be worthwhile to note several developments that have previously taken place.

Iron base super alloys are austenitic stainless steel modification. They are yet proprietory and manufactured via only single company. Austenitic steel is additionally alloyed along with some additional metals to generate super alloys. These alloying elements comprise Cobalt, W, Mo, V, Nb, Ti, Al, Zr, B and Copper. These super alloys are strengthened via strain hardening or via precipitation hardening. Such alloys are often utilized in between 650oC and 760oC, the range whether strain hardening effects are retained since addition of alloying elements raising recrystallization temperature to 925oC. The precipitation hardening is achieved because of precipitation of carbides nitrides of hard particles or boride that are stable above 750oC and thus super alloys are conveniently utilized in the range of 650oC-750oC.

Co and Nickel based super alloys have most of iron replaced via Co or Ni. These alloys can be hardened also by precipitation hardening or strain hardening. During precipitation in large size particles as 0.5 µ diameter made up of Ni3, Al or Ni3 Ti or their mixture are precipitated that are stable up to extremely high temperature. The utilizable temperature limit of these alloys is as high as 925oC.

Dispersion hardened alloys acquire their high temperature strength form finely dispersed ultrafine ceramic particles in the matrix of Ni. T. D. Nickel along with fine thoria or ThO2 dispersed in the matrix is possibly the only instance of that type. The material is extremely hard at room temperature and can't be deformed plastically. Still, it is very costly.

Posted Date: 2/27/2013 1:57:19 AM | Location : United States







Related Discussions:- For elevated temperatures, other materials, Assignment Help, Ask Question on For elevated temperatures, other materials, Get Answer, Expert's Help, For elevated temperatures, other materials Discussions

Write discussion on For elevated temperatures, other materials
Your posts are moderated
Related Questions

Maximum Extraordinary Effect Determine the direction of propagation in quartz (ne = 1.553 and no = 1.544) at which the angle between the wave vector k and the Poynting vector S

Illustrate working and construction of Hydraulic Dynamometer ? Determine Power transmitted.

diff.between direct stress and bending stress

a) Derive a mathematical expression for stability of an automobile while accelarating in a curved path? b) A motorcycle and its rider together have a mass of 250Kg and their cen

Theore m of perpendicular axis It states that if I X X and I Y Y   be the M.I. of plane section about the two mutually perpendicular axes meeting at a point. Th

ACSR (Aluminium Conductor Steel Reinforced) are used as  (A)  over head transmission lines.  (B)  super conductors. (C)  fuse  (D)  underground cables.

Compute minimum value of the horizontal force: Block A of weight 520N rest on horizontal top of block B having weight of 700N as shown in the figure given below. Block A

Wet saturated steam -  thermodynamics: we t saturated steam Wet steam is a 2-phase mixture comprising of boiling water particles and dry steam in equilibrium state. Its for

ELECTRIC DISCHARGE PHENOMENON The flow of electricity through metallic solids, or through liquid metals is called Conduction. The electricity  flow through ionic solutions