corrosion resistance ( 내식성 )

Corrosion Resistance(내식성 )

2010012243 Hwang Chang Seok2011011460 Kim Sang Hyun2011011473 Park Young Ju

What is corrosion resistance?

CORROSION?

FORM OF CORROSION

Corrosion

Uniform of gen-eral Corrosion

Galvanic Cor-rosionErosion Cor-

rosion

Crevice Cor-rosionStress Corro-

sion

Intergranular Corrosion

Pitting Corro-sionEnvironment

Corrosion

How to prevent corrosion (1/2)

To block water and oxygen : Paint, Oil, Enamel : Passive metal film (ex. Fe₃O₄, Al₂O₃)

Plating : Other metals coated on a metal surface (ex. Fe+Sn, Fe+Zn)

Fe + Sn Fe + Zn

Reactivity Fe > Sn Fe < Zn

Surface scratch Corrosion Fe Protect Fe(Corrosion Zn)

Process

How to prevent corrosion (2/2) Cathodic protection -Use reactivity of metal : By connecting the greater reactivity metals, a

structure made of metal to prevent corrosion

Alloy -Some metal alloy have corrosion resistance. (ex. Cu,Al,Mg Alloy)

FOR EXAMPLE Bronze [Cu+Sn+Ni] (Adornment)

Stainless steel [St+Cr+Ni] (Building Supplies, Automotive)

Duralumin [Al+Cu+Mg] (Airplane)

Titanium alloys (Airplane)

Nickel and Chromium alloys

ETC Platinum and Gold - Stability

Plastic - Strong chemical bonding - intentionally weakened (ex : Bbtan)

Ceramic - Metal + non-metal compounds - Strong corrosion resistance At normal temperature

Thank you.