1) Applied scientist 2) Engineer 3) Metallurgical engineer 4) Technologist 1) Bessemer 
• (n.) One who works in metals, or prepares them for use; one who is skilled in metallurgy.
Met'al·lur`gist noun [ Confer French métallurgiste .] One who works in metals, or prepares them for use; one who is skilled in metallurgy. 
[n] - an engineer trained in the extraction and refining and alloying and fabrication of metals
Someone who specializes in metallurgy, the branch of science and technology concerned with the properties of metals and their production and purification.
metallurgical engineer noun an engineer trained in the extraction and refining and alloying and fabrication of metals