Mechanical Engineering - Workshop Technology - Discussion

Sherardising uses a rotating drum to vaporize the zinc which then clings to the steel, whilst galvanizing involves the steel being dipped in a bath containing the zinc.

Sherardizing is a process of galvanization of ferrous metal surfaces, also called vapour galvanising and dry galvanizing. The process is named after the British metallurgist Sherard Osborn Cowper-Coles (son of naval inventor Cowper Phipps Coles) who invented and patented the method ca. 1900. This process involves heating the steel parts up to ca. 500°C in a closed rotating drum that also contains metallic zinc dust and possibly an inert filler, such as sand. At temperatures above 300°C, zinc evaporates and diffuses into the steel substrate forming diffusion bonded Zn-Fe-phases.

Sherardising is ideal for small parts and parts that require a coating of inner surfaces, such as batches of small items. Part size is only limited by the drum size. It is reported that pipes up to 6 m in length for the oil industry are sherried. If the metal surface is free of scale or oxides, no pretreatment is needed. The process is hydrogen free, therefore a hydrogen embrittlement is excluded.

What is sherardizing?

What about the parkerising process?

Sherardizing is a process of galvanization of ferrous metal surfaces, also called vapour galvanising and dry galvanising. The process is named after the British metallurgist Sherard Osborn Cowper-Coles (son of naval inventor Cowper Phipps Coles) who invented and patented the method ca. 1900. This process involves heating the steel parts up to ca.500°C in a closed rotating drum that also contains metallic zinc dust and possibly an inert filler, such as sand. At temperatures above 300°C, zinc evaporates and diffuses into the steel substrate forming diffusion bonded Zn-Fe-phases.

Sherardizing is ideal for small parts and parts that require a coating of inner surfaces, such as batches of small items. Part size is only limited by the drum size. It is reported that pipes up to 6 m in length for the oil industry are sherardized. [citation needed] If the metal surface is free of scale or oxides, no pretreatment is needed. The process is hydrogen free, therefore a hydrogen embrittlement is excluded.

Who this process of sheradizing take place?

What is the correct answer?

Sherardizing is a diffusion process in which articles are heated in the presence of zinc dust.

The process is normally carried out in a slowly rotating closed container at temperatures ranging from 320-500 degree C.

Why not Galvanizing?

If it's sherardizing and galvanising then what should be the answer?