Analysis Region

Microstructure

Elbow

Pearlite + Ferrite(a)

HAR

Proeutectoid pearlite + fine pearlite

Welding joint

Proeutectoid pearlite + dendrites

HAR

Proeutectoid pearlite + fine pearlite

Tube

Pearlite + Ferrite(b)

Tube in corroded region

Pearlite + Ferrite

Elbow in corroded region

Pearlite + Ferrite