AL 29-4C Stainless Steel Material Data Sheet (Ferritic, Annealed)

AL 29-4C Stainless Steel Designation

AL 29-4C Alloy (UNS S44735), wrought
Condition	Annealed
UNS number	S44735

AL 29-4C Stainless Steel Composition detail

C (carbon)	0	–	0.03	%
Cr (chromium)	28	–	30	%
Fe (iron)	61.7	–	68.2	%
Mn (manganese)	0	–	1	%
Mo (molybdenum)	3.6	–	4.2	%
N (nitrogen)	0	–	0.045	%
Nb (niobium)	0.1	–	0.5	%
Ni (nickel)	0	–	1	%
P (phosphorus)	0	–	0.04	%
S (sulfur)	0	–	0.03	%
Si (silicon)	0	–	1	%
Ti (titanium)	0.1	–	0.5	%

AL 29-4C Stainless Steel Physical properties

Density

7.67

–

7.7

g/cm3

AL 29-4C Stainless Steel Mechanical properties

Young’s modulus	207			GPa
Specific stiffness	26.9	–	27	MN.m/kg
Yield strength (elastic limit)	415	–	520	MPa
Tensile strength	550	–	655	MPa
Specific strength	54	–	67.7	kN.m/kg
Elongation	18	–	22	% strain
Compressive strength	415	–	520	MPa
Flexural modulus	207			GPa
Flexural strength (modulus of rupture)	415	–	520	MPa
Shear modulus	75	–	85	GPa
Poisson’s ratio	0.27	–	0.3
Shape factor	50
Hardness – Vickers	192	–	243	HV
Hardness – Rockwell B	90	–	98	HRB
Hardness – Rockwell C	9	–	21	HRC
Hardness – Brinell	185	–	228	HB
Elastic stored energy (springs)	421	–	646	kJ/m3
Fatigue strength at 10^7 cycles	355	–	395	MPa
Fatigue strength model (stress range) Parameters: Stress Ratio = -1, Number of Cycles = 1e7cycles	314	–	446	MPa

AL 29-4C Stainless Steel Impact & fracture properties

Fracture toughness	80	–	120	MPa.m0.5
Toughness (G)	32	–	67.2	kJ/m2

AL 29-4C Stainless Steel Thermal properties

Melting point	1370	–	1480	°C
Maximum service temperature	300	–	330	°C
Minimum service temperature	-73	–	-43	°C
Thermal conductivity	15.1	–	17.2	W/m.°C
Specific heat capacity	440	–	457	J/kg.°C
Thermal expansion coefficient	9.1	–	9.5	µstrain/°C
Thermal shock resistance	215	–	271	°C
Thermal distortion resistance	1.62	–	1.86	MW/m
Latent heat of fusion	346	–	419	kJ/kg

AL 29-4C Stainless Steel Electrical properties

Electrical resistivity	70.5	–	73.5	µohm.cm
Electrical conductivity	2.35	–	2.45	%IACS
Galvanic potential	-0.24	–	-0.16	V

AL 29-4C Stainless Steel Magnetic properties

Magnetic type

Magnetic

AL 29-4C Stainless Steel Optical, aesthetic and acoustic properties

Transparency	Opaque
Acoustic velocity	5180	–	5200	m/s

AL 29-4C Stainless Steel Processing properties

Metal casting	Unsuitable
Metal cold forming	Limited use
Metal hot forming	Acceptable
Metal press forming	Limited use
Metal deep drawing	Limited use
Machining speed	21.6 m/min
Weldability Notes: Preheating and post weld heat treatment are not required	Good
Weldability – MIG	Good
Weldability – plasma	Good
Weldability – SAW	Not recommended
Weldability – TIG	Good
Brazeability	Fair
Carbon equivalency	1.17 – 1.39

AL 29-4C Stainless Steel Durability

Water (fresh)	Excellent
Water (salt)	Excellent
Weak acids	Excellent
Strong acids	Acceptable
Weak alkalis	Excellent
Strong alkalis	Limited use
Organic solvents	Excellent
Oxidation at 500C	Excellent
UV radiation (sunlight)	Excellent
Galling resistance (adhesive wear) Notes: Aluminum bronze is the most suitable mating material to minimize galling.	Limited use
Flammability	Non-flammable

AL 29-4C Stainless Steel Corrosion resistance

Pitting resistance equivalent number (PREN)	39.9 – 44.6
Pitting and crevice corrosion	Very high (>40)
Stress corrosion cracking Note: Rated in chloride; Other susceptible environments: Hydrogen sulfide	Not susceptible
Intergranular (weld line) corrosion	Excellent
Inorganic acids	Moderate
Organic acids	Good
Alkalis	Moderate
Humidity / water	Excellent
Sea water	Good
Sour oil and gas	Moderate

AL 29-4C Stainless Steel Standards with similar compositions

Mexico: 29-4 to NMX-B-171

UK: X2CrMoTi29-4 to BS EN 10088-1, X2CrMoTi29-4 to BS EN 10088-2

USA: 29-4 to ASTM A268/A268M, 29-4 to ASTM A511, 29-4 to ASTM A803/A803M, 29-4C to ASTM A803/A803M, S44700 to ASTM A240/A240M, S44700 to ASTM A276, S44700 to ASTM A479/A479M, S44700 to ASTM A493-95, S44700 to ASTM A580/A580M-98, S44700 to ASTM A959, S44700 to SAE J405, S44735 to ASTM A240/A240M, S44735 to ASTM A268/A268M, S44735 to ASTM A959, S44735 to SAE J405, UNS S44700, UNS S44735

Tradenames: AL 29-4C