DW420 DNV Offshore Improved Weldability Steel

DW420 DNV Offshore Improved Weldability Steel
STEELMAX Steel Story

DW420 은 해양 구조물강이며
Extra High Strength Steels 입니다.

강재의 항복 강도 수준에 따라
NS : Nominal Strength Steels : YS≤235

HS : High Strength Steels : 235≤YS≤390
EHS : Extra High Strength Steels : 420≤YS≤690로 분류됩니다.

DW420에서
영어 알파벳 “W” 는

Improved Weldability를 의미하는
용접성 향상 강종임을 의미하며

Improved Weldability 강재에 요구되는 최소 항복 강도는
강재의 두께가 증가함에 따라, 감소하는 강종입니다.

숫자 “420”은 Yield Strength,
항복 강도를 나타냅니다.

※ Yield Strength (항복강도 : 降伏强度)
Yield strength is another result determined by tensile test.
The stress at which material changes from elastic deformation to
plastic deformation, causing permanent deformation.
This is one of the most important data for construction engineers to
calculate machine parts and components.
The yield strength is named after their yield strength like :
S275 (yield strength 275MPa) or S355 (yield strength 355MPa)

※ Tensile Strength — DIN EN
Measures the engineering stress applied at the point when it fails.
The maximum amount tensile stress is called “Tensile strength”
It is determined by the tensile test.
Years ago a lot of construction steels were named according to
their tensile strength.
For example St37 (tensile strength is 370 N/㎟) or St52 (tensile
strength 520 N/㎟).
Nowadays they changed their designation and method has been
changed and yield strength is used.
For example S355JR (yield strength is 355 N/㎟) or S420 (yield
strength 420 N/㎟).

Steel Grade		DW420	EW420
Chemical composition (%)	Carbon (C)	0.12 max	0.12 max
	Silicon (Si)	0.10~0.50	0.10~0.50
	Manganese (Mn)	1.65 max	1.65 max
	Phosphorus (P)	0.020 max	0.020 max
	Sulfur (S)	0.008 max	0.008 max
	Chromium (Cr)	0.25 max	0.25 max
	Molybdenum (Mo)	0.25 max	0.25 max
	Nickel (Ni)	1.00 max	1.00 max
	Aluminum total	0.06 max	0.06 max
	Copper (Cu)	0.50 max	0.50 max
	Boron (B)	0.010 max	0.010 max
	Niobium (Nb)	0.04 max	0.04 max
	Vanadium (V)	0.08 max	0.08 max
	Titanium (Ti)	0.05 max	0.05 max
Yield Strength (N/㎟)	t≤50	420	420
	50＜t≤75	400	400
	75＜t≤100	380	380
Tensile Strength (N/㎟)		530~680	530~680
Charpy V-Notch (CVN)		-20/60joule	-40/60joule