Stainless Steel - Grade 440 (UNS S44000)

Key Properties

The following section discusses the properties of grade 440 bar products covered under ASTM A276. These values may not be similar to that of other forms such as forgings and plates.

Composition

The chemical compositions of various elements of grade 440 stainless steels are tabulated below:

Table 1. Chemical composition ranges of grade 440 stainless steels

Grade		C	Mn	Si	P	S	Cr	Mo	Ni	N
440A	min. max.	0.6 0.75	- 1	- 1	- 0.04	- 0.03	16 18	- 0.75	-	-
440B	min. max.	0.75 0.95	- 1	- 1	- 0.04	- 0.03	16 18	- 0.75	-	-
440C	min. max.	0.95 1.20	- 1	- 1	- 0.04	- 0.03	16 18	- 0.75	-	-

Mechanical Properties

Table 2. Mechanical properties of grade 440C stainless steels

Tempering Temperature (°C)	Tensile Strength (MPa)	Yield Strength 0.2% Proof (MPa)	Elongation (% in 50mm)	Hardness Rockwell (HR C)	Impact Charpy V (J)
Annealed*	758	448	14	269HB max#	-
204	2030	1900	4	59	9
260	1960	1830	4	57	9
316	1860	1740	4	56	9
371	1790	1660	4	56	9

* Annealed properties are typical for Condition A of ASTM A276# Brinell hardness is ASTM A276 specified maximum for annealed 440A, B and C.

Physical Properties

The following table outlines the physical properties of grade 440 stainless steels:

Table 3. Typical physical properties of grade 440 stainless steels

Grade	Density (kg/m3)	Elastic Modulus (GPa)	Mean Coefficient of Thermal Expansion (μm/m/°C)			Thermal Conductivity (W/m.K)		Specific Heat 0-100°C (J/kg.K)	Electrical Resistivity (nΩ.m)
			0-100°C	0-200°C	0-600°C	at 100°C	at 500°C
440A/B/C	7650	200	10.1	10.3	11.7	24.2	-	460	600