Metal Things I Dont Know

Question 1

Hardening

Answer 1

Heating medium and high carbon steels to alter the crystalline structure

Question 2

How to temper a metal

Answer 2

Heat below the critical point then air cool

Question 3

Critical point

Answer 3

The temperature the atoms of carbon and steel mix freely before bonding together to become a solid

Question 4

Impressed current

Answer 4

The component be protected is connected to an electric power supply. The impressed direct current flows from an inert electrode through any liquid to the component to be protected. For example the buried pipeline receives direct current from an electrode buried in the ground the pipe becomes the anode and the electrode is the cathode. The cathode corrodes overtime and such corrosion is monitored so that the pipeline remains intact.

Question 5

Sacrificial anodes

Answer 5

This is a more basic method because it uses a sacrificial metal to protect the metal product of value. A more electrochemically active metal is wrapped around or joint to the less active metal to provide resistance to corrosion on large structures. The sacrificial metal is monitored the signs of corrosion and replaced when the base metal is no longer protected.

Question 6

Aluminium ore

Answer 6

Bauxite

Question 7

Aluminium ore

Answer 7

Bauxite

Question 8

Copper ore

Answer 8

Chalcopyrite

Question 9

Tin ore

Answer 9

Cassiterite

Question 10

Zinc ore

Answer 10

Zinc blended

Question 11

Temporary fasteners for metals

Answer 11

Self tapping screws

Machine screws

Nut and bolt