Cryogenic treatment of metal - Essay Example

Supervisor’s due: Cryogenic Treatment of Metal Introduction Heat treatment is an industrial metal process used to change and alter the physical and chemical composition of a given metal. Heat treatment is of use in the manufacture of various metal components and it involves utilization of chilling or heating of metals at extreme temperatures so as one can achieve a given effect as softening or hardening (Xiaojun Jianga 28).Cryogenic Tempering Tampering, on the other hand, has a definition as a process of heat treatment, which results in the improvement of the metal’s ductility and hardness.

In the steel, there is formation of the martensite phase due to trapping of large amounts of carbon in the austenitic lath, which cools quickly through water quenching. Untempered martensite should, therefore, have treatment below the minimum critical temperatures of the metal so as to enable diffusion of the excess carbon from the body-centre tetragonal structure hence it creates a more stable structure. Tempering leads to an even distribution of alloying elements in precipitation-hardening alloys like super alloys of aluminum (L.K. Zhang. 148). The elements cause internal reactions, which results in the formation of inter-metallic phases referred to as precipitates.

The precipitates formed during tempering strengthen the alloys. In addition, multistep tempering can result in the formation of several precipitates that effect to high strength alloy. Cryogenic treatment is carried out in metals in the process to enhance metallic wear characteristics. Cryogenic metal treatment is quite a new metal treatment process in engineering and is one of the most utilized metal treatment processes in the industry (Xiaojun Jianga 62).Background Information Utilization of cryogenic temperature (below -2400 F) is a new application in metal treatment especially in the ultra-cold realm.

The method was tried in early 1940s, but it was found to produce thermal stresses because of the rapid cooling of the metal in liquid nitrogen. Because of the formation of thermal stresses, cryogenic treatment was not in use for industrial purposes until late 1960s. Cryogenic metal treatment process was improved to the use of gaseous nitrogen, which results in reduced formation of thermal stresses (L.K. Zhang. 32).Cryogenic treatment process There are three major cryogenic treatment process established in mechanical engineering.

Initially, the metal is slowly cooled down from ambient atmospheric temperatures to cryogenic temperatures. Cooling of the metal parts slowly leads to a reduction in the formation of thermal stresses. Slow cooling process also ensures that the general problems associated with the initial cryogenic tempering process are eliminated (N. Raghu Ram 78). Secondly, the metal is kept at cryogenic temperatures for a given duration of time mainly twenty to twenty four hours. This soaking results in improvement of the metals resistance to wear.

The metal undergoes a final exposure to a triple tempering process. The tempering process is carried out at temperature ranges of +3000 F. The tempering process ensures reduction of the metal’s brittleness resulting from martensite formed because of cryogenic metal treatment process (N. Raghu Ram 122).Conclusion Cryogenic treatment involves cooling of metals to approximately -1850C utilizing liquid or gaseous nitrogen. Cryogenic treatment has accomplishment on metals in order to increase the levels of martensite especially in steel.

Works citedJiang, Xiaojun et al. Improvement Of Adhesion Strength And Scratch Resistance Of Fluorocarbon Thin Films By Cryogenic Treatment. Applied Surface Science 288 (2014): 44--50. Print.Ram, N Raghu et al. Parametric Analysis On The Effect Of Cryogenic Treatment On The Work Piece Material Of EDM Process. 3.1 (January-2014) (2014): n. pag. Print.Zhang, LK et al. Cryogenic Treatment Induced Hardening Of Cu< Sub> 45 Zr< Sub> 45 Ag< Sub> 7 Al< Sub> 3 Bulk Metallic Glass. Physica B: Condensed Matter 433 (2014): 84--88. Print.