FERRALIUM® 255-SD50

 

ALLOY TYPE FERRALIUM®
ALLOY NAME FERRALIUM® 255-SD50

Stock Sizes
 
Basic Properties - Mechanical Properties

Bar - Ruling Sections up to and including 101.6mm (4")
0.2% Proof Stress (N/mm2) [ksi] minimum 600 [87]
Ultimate Tensile Strength (N/mm2) [ksi] minimum 790 [114.6]
Elongation (%) minimum 25
Hardness (HBN) 270max
Charpy V-notch Impact at ambient Temp (J) [ft.lb] 80min [59min]
Charpy V-notch Impact at -46°C (J) [ft.lb] 45av, 35min [33av, 25.8min]

 

Ruling Sections over 101.6mm (4") and Plate (all section sizes)
0.2% Proof Stress (N/mm2) [ksi] minimum 570 [82.6]
Ultimate Tensile Strength (N/mm2) [ksi] minimum 790 [114.6]
Elongation (%) minimum 25
Hardness (HBN) 270max
Charpy V-notch Impact at ambient Temp (J) [ft.lb] 80min [59min]
Charpy V-notch Impact at -46°C (J) [ft.lb] 45av, 35min [33av, 25.8min]


Additional Testing Back to Top
ASTM G48A Corrosion test at 50°C No pitting and weight loss <0.8g/m2
Ultrasonic Testing According to ASTM A388
Ferrite Content 35%-55%
Microstructure Microstructure certified free from grain boundary carbides, sigma, chi and laves phases.



Alloy Features Back to Top
   
FERRALIUM 255-SD50 sets a new bench mark for superduplex as the first to state 570N/mm2 as the minimum 0.2% Proof Stress
   
Excellent corrosion resistance in a wide variety of corrosive chemicals including sulphuric, phosphoric and nitric acids
   
Outstanding resistance to pitting and crevice corrosion in seawater and other chloride containing environments, with Critical Pitting Temperature exceeding 50°C
   
Excellent ductility and impact strength at both ambient and sub-zero temperatures
   
High resistance to abrasion, erosion and cavitation erosion
   
Excellent resistance to stress corrosion cracking in chloride containing environments
   
Listed in NACE MR 01 75 for sour service
   
Tested to the highest degree using tests designed to guarantee that the trade-marked product possesses high integrity, a correct phase balance and the absence of sigma and other deleterious phases.
   
Particularly applicable for large forgings, as the formation of sigma phase is much less likely than it is for other superduplexes.
   
ASME Approval for Pressure Vessel application



Chemical Specification Back to Top
Elements C Cr Cu Fe Mo Mn N Ni P S Si
Minimum   24.50 1.50 REMAINDER 3.10 0.80 0.20 5.50     0.20
Maximum 0.030 26.50 2.00   3.80 1.20 0.25 6.50 0.025 0.005 0.70



Physical Properties Back to Top
Density (Kg.m-1) 78.1
Magnetic Permeability 33
Young’s Modulus (N/mm2) 199 x 103
Specific Heat, 20°C (J.Kg-1.°K-1) 475
Fracture Toughness, KQ (MPa.m½) 98
Specific Electrical Resistance, 20°C (µΩ.m) 0.80
Thermal conductivity, 20°C (W.m-1.°K-1) 14.2
Mean coefficient of thermal expansion, 20-100°C (°K-1) 11.1 x 10-6



Specifications Back to Top
   
FERRALIUM to MSA-MPS-51VS-SD50-BAR
   
FERRALIUM to MSA-MPS-51VS-SD50-PLATE
   
NORSOK MDS D57 Bar
   
NORSOK MDS D55 Plate
   
EN 10088-1 1.4507
   
ASTM A182 Grade F61 UNS S32550 Forged Flanges
   
ASTM A240 UNS S32550 Sheet and Plate
   
ASTM A240 UNS S32520 Sheet and Plate
   
ASTM A479 UNS S32550 Bar
   
ASTM A276 UNS S32550 Condition A
   
ASME Approval as Table UHA 23 and Code Case 1883
   
NACE MR 01-75

 

Applications Back to Top
 
Chemical Process Industry:
Sulphuric Acid Production, Nitric Acid Processes, Polypropylene Production, PVC ProductionTitanium Dioxide Production, Caustic Evaporators, Equipment Handling Organic and Fatty Acids
 
 
Marine Industry and Shipbuilding:
Propellers and Shafts, Rudders, Shaft Seals, Pumps, Bolts and Fasteners, Valves, Instrumentation, Oil and Chemical Tankers
 
 
Oil and Gas Industry:
Pumps, Valves, Pipe, Vessels, Wellhead Equipment, Subsea Equipment
 
 
Pollution Control:
Fans and pumps, Wet Scrubbers, Incinerators
 
 
Copper Smelting:
ID Fans, Tuyere bars, Wet Scrubbers, Leaching Area Precipitators
 
 
Pulp and Paper Industry:
Black liquor heater tubes, Digester Blow Valves, Rotary Feed Valves, I.D.Fans, Brownstock Washers, Precipitators, Bleaching Components
 
 
Food Industry:
Sugar Cane Centrifuges, Corn and Vegetable processing plant
 
 
Agrochemicals:
Fertilizer Production (Wet phosphoric acid)
 
 
Civil Engineering:
Statue of Liberty supporting structure, Swimming Pools, Sewage Treatment
 

 

Machining Advice Back to Top

Operation Cutting Speed m/min (ft/min) Feed Rate
mm/rev (in/rev)		 Depth of cut mm(in)
Milling 40 (130) 0.05-0.13 mm/tooth
0.02-0.005 in/tooth		 0.5-6.0 (0.02-0.25)
Drilling – 6.4mm (1/4”) dia 250rpm 0.075 (0.003)  
Drilling – 12.7mm (1/2”) dia 250rpm 0.125 (0.005)  
Drilling – 25.4mm (1”) dia 150rpm 0.28 (0.011)  
Turning - Roughing 30-45 (100-150) 0.20 – 0.38 (0.008-0.015) 3 (0.125)
Turning - Finishing 50-60 (165-200) 0.13 – 0.20 (0.005-0.008) 0.5 (0.02)
Tooling Milling/Turning: Carbide (SANDVIK GC 235, SECO T25M)
Drilling: HSS, point angle 118°, chisel angle 120°



Alloy Comparisons S17400
(17- 4PH)		 S32205 718 S31254 FERRALIUM
255-SD50
0.2% Proof Strength (N/mm2) 1100 510 500 325 630
Corrosion Rate (mm.y-1) Seawater ~1 <0.01 <0.01 <0.01 <0.01
Corrosion Rate (mm.y-1)
10% sulphuric acid at 80°C		 10 0.4 <0.15 1.5 <0.15
Corrosion Rate (mm.y-1)
Boiling 50% nitric acid 		<0.15 <0.15 <0.15 0.4 <0.15
Wear Properties related to Hardness (HRC), typical RC38 RC25 RC20 RC20 RC28



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