ASTM A765 / A765M

This specification2 covers heat-treated carbon steel and alloy steel forgings with mandatory toughness requirements.These forgings are intended for pressure vessels, feedwater heaters, and similar uses.These forgings include tube sheets, covers, channel barrels, integral forged channels, rings, nozzles, flanges, and similar parts.All grades are considered weldable under proper conditions.The maximum thickness of forgings produced to this specification is limited only by the capacity of the selected grade to respond to any heat treatment specified and to meet the specified mechanical tests, including impact tests at the specified temperature.Material supplied to this specification shall conform to the requirements of Specification A 788/A 788M, which outlines additional ordering information, manufacturing requirements,testing and retesting methods and procedures, marking,certification, product analysis variations, and additional supplementary requirements.If the requirements of this specification are in conflict with the requirements of Specification A 788/A 788M, the requirements of this specification shall prevail.

Grade

Grade	Description
I	-
II	-
III	-
IV	-
V	-

Chemical Properties

Grade	Carbon, max	Manganese	Phosphorus,	Sulfur, max	Silicon, max	Chromium,^A max	Nickel, max^A	Molybdenum,^A max	Vanadium, max	Aluminum, max	Copper, max
I	0.30	0.60 to 1.35	0.020	0.020	0.15 to 0.35	0.40	0.50	0.10	0.05	0.05	0.35
II	0.30	0.60 to 1.35	0.020	0.020	0.15 to 0.35	0.40	0.50	0.10	0.05	0.05	0.35
III	0.20	0.90 max	0.020	0.020	0.15 to 0.35	0.20	3.3 to 3.8	0.06	0.05	0.05	0.35
IV	0.20	1.00–1.60	0.020	0.020	0.15–0.50	0.40	0.50 max	0.10	0.06	0.05	0.35
V	0.30	0.60–1.35	0.020	0.020	0.15–0.35	0.30	1.0–2.0	0.12	0.03	0.05	0.35

Note: A Intentional additions of Cr, Mo, and Ni up to the specified maximum are permitted to be made to Grades I, II, and IV by the manufacturer.

Mechanical Properties

Class		Tensile strength, ksi [MPa]	Yield strength^A min, ksi [MPa]	Elongation in 2 in. or 50 mm, min, %	Reduction of area, min, %
I		60 to 85 [415 to 585]	30 [205]	25	38
II		70 to 95 [485 to 655]	36 [250]	22	30
III		70 to 95 [485 to 655]	37.5 [260]	22	35
IV		80–105 [550–725]	50 [345]	22	30
V	Class 1	60–85 [415– 585]	30 [205]	25	38
V	Class 2	70–95 [485–655]	37.5 [260]	22	35