ASTM A242 steel

The  ASTM A242 specification is the standard specification  for high-strength low- alloy structural steel for structural members where weight savings and atmospheric corrosion resistance are important.  Mechanical property requirements are specified by  product type (plates and bars, and structural Shapes) and by thickness.

ASTM A242 steel has atmospheric corrosion resistance
The steel plate under ASTM A242 standard also called the weathering steel plate, referred to the semi-killed or fully killed steel. It has good atmospheric corrosion resistance so the steel could be used in a lot of working environments.

ASTM A242 weathering steel is substantially better than that of carbon structural steel with or without copper added-in.

Mechanical properties A242:
Tensile:
70 ksi min (3/4 and under), 67 ksi min (3/4-1.5) 63 ksi min (over 1.5-4)
Yield:
50 ksi min (3/4 and under), 46 ksi min (3/4-1.5) 42 ksi min (over 1.5-4)
Elongation:
16% min in 8” 19% min in 2” (for plates wider than 24”)

Chemical Composition For Corten Steel ASTM A242 Type 1 Plate & Sheet

	Corten – A	ASTM 588 Grade A	ASTM 242 TYPE -1	IRSM 41 -97
Carbon, Max	0.12	0.19	0.15	0.10
Manganese	0.20-50	0.80-1.25	1.00	0.25-0.45
Phosphorus	0.07-0.15	0.04	0.15	0.07-0.11
Sulphur, max	0.030	0.05	0.05	0.030
Silicon	0.25-0.75	0.30-0.65	0.25-0.40	0.28-0.72
Nickel, max	0.65	0.40	–	0.20-0.49
Chromium	0.50-1.25	0.40-065	–	0.30-0.50
Molybdenum, max	–	–	–	–
Copper	0.25-0.55	0.25-0.40	0.20 min	0.30-0.39
Vanadium	–	0.02-0.10	–	0.050
Aluminimum	–	…	–	0.030

Mechanical properties of corten steel ASTM A242 Type 1 plates & Sheets

	Tensile Strength	Min. Yield Point	Elongation
CORTEN A	[470 – 630 MPa]	[355 MPa]	20 % min
ASTM 588 GR. A	[485 MPa]	[345 MPa]	21% min
ASTM 242 TYPE -1	[480 MPa]	[345 MPa]	16% min
IRSM 41- 97	[480 MPa]	[340 MPa]	21% min