STAINLESS STEEL DATASHEETS

Transcription

1 STAINLESS STEEL DATASHEETS Alloys: L L 316LN 316Ti 316LVM 6Mo L

2 Alloys 304 / 304L Alloys 304 / 304L (UNS S30400 / S30403) Alloys 304 (S30400) and 304L (S30403) stainless steels are variations of the 18 percent chromium 8 percent nickel austenitic alloy, the most familiar and most frequently used alloy in the stainless steel family. High strength, excellent corrosion resistance and minimized carbon content make Alloy 304 and 304L Stainless Steels useful for applications where welding is required. Uses include architectural mouldings and trim, welded components of chemical, textile, paper, pharmaceutical and chemical industry processing equipment. Other advantages are its resistance to oxidation, excellent formability, ease of fabrication and cleaning, excellent strength to weight ratio and good toughness at cryogenic temperatures For severely corrosive environments, the lower content of Type 304L is preferred because of its greater immunity to intergranular corrosion. COILED Seam welded and Cold Redrawn Seam welded, Cold Redrawn and Annealed AMS 5566 ASTM A213 NFA AMS 5569 ASTM A269 NFA AMS5647 ASTM A312 Mil-T 8504 AMS 6845 ASTM A632 Mil-T 8606 BS Pt 5 BS 3605 Pt 1 MOISTURE SEPERATOR REHEATERS HEAT EXCHANGERS Feedwater tubes Stator bars nuclear AND Power General engineering Temper L Tensile Rm 76 ksi (min) 70 ksi (min) Tensile Rm 517 MPa (min) 485 MPa (min) R.p. 0.2% Yield 31 ksi (min) 25 ksi(min) R.p. 0.2% Yield 207 MPa (min) 170 MPa (min) Elongation (2 or 4D gl) 40 % (min) 40 % (min) Specific Heat (0-100 C) 500 J.kg-1. K-1 Thermal Conductivity 16.2 W.m -1. K-1 Thermal Expansion 17.2 mm/m/ C Modulus Elasticity 19.3 GPa Electrical Resistivity 7.23 µohm/cm Density 8.00 g/cm L Min Max C Mn Ni Cr S N Si P

3 Alloy 310 Alloy 310 (UNS S31000) A heat resisting stainless steel with high resistance to oxidation scaling and has high strength at elevated temperatures. This is combined with better creep properties at temperature and 310 stainless is very tough and ductile. 310 stainless has good resistance to oxidation and may be used in continuous service up to 1140ºC provided reducing sulphur gases are not present. With its high chromium content 310 stainless offers good corrosion resistance to increase high temperature properties. ASTM A632 ASTM A213 ASTM A312 FURNACE PARTS HEAT EXCHANGERS HEAT TREATMENT BASKETS AND JIGS OIL AND GAS CHEMICAL PROCESSES Temper Annealed Tensile Rm 76 ksi (min) Tensile Rm 517 MPa (min) R.p. 0.2% Yield 31 ksi (min) R.p. 0.2% Yield 207 MPa (min) Elongation (2 or 4D gl) 40 % (min) Specific Heat (0-100 C) 500 J.kg-1. K-1 Thermal Conductivity 14.2 W.m -1. K-1 Thermal Expansion 15.9 mm/m/ C Modulus Elasticity 20 GPa Electrical Resistivity 72 µohm/cm Density 7.75 g/cm3 C Mn - 2 Ni Cr Si P S

4 Alloys 316 / 316L Alloys 316 / 316L (UNS S31600 / UNS S31603) Grade 316 is the standard molybdenum-bearing grade, second in overall volume production to 304 amongst the austenitic stainless steels. The molybdenum gives 316 better overall corrosion resistant properties than Grade 304, particularly higher resistance to pitting and crevice corrosion in chloride environments. Grade 316L, the low carbon version of 316 and has very high immunity from sensitization (grain boundary carbide precipitation). It is extensively used in the oil and gas and chemical industries for its cost effective corrosion resistance and ease of fabrication. There is commonly no appreciable price difference between 316 and 316L stainless steel. The austenitic structure also gives these grades excellent toughness, even down to cryogenic temperatures. Compared to chromiumnickel austenitic stainless steels, 316L stainless steel offers higher creep, stress to rupture and tensile strength at elevated temperatures. These alloys may be considered for a wide variety of applications where one or more properties are important. Coiled Seam welded and Cold Redrawn Seam welded, Cold Redrawn and Annealed ASTM A213 ASME SA213 ASTM A269 NFA ASTM A312 BS ASTM A632 Process engineering Control lines High Performance Liquid Chromatography (HPLC) Heat Exchangers Condensers Semiconductors Medical implants (including Pins, screws and implants) OIL AND GAS High performance CHEMICAL PROCESSES commercial Temper Annealed Cold worked (approx. 20%) Material L L Tensile Rm ksi (min) ksi (min) Tensile Rm MPa (min) MPa (min) R.p. 0.2% Yield ksi (min) ksi(min) R.p. 0.2% Yield MPa (min) MPa (min) Elongation (2 or 4D gl) 35 % (min) 40 % (min) Specific Heat (0-100 C) 500 J.kg-1. K-1 Thermal Conductivity 16.3 W.m -1. K-1 Thermal Expansion 15.9 mm/m/ C Modulus Elasticity 193 GPa Electrical Resistivity 7.4 µohm/cm Density 7.99 g/cm L Min Max C Mn Ni Cr Mo S Si P

5 Alloy 316Ti Alloy 316Ti (UNS S31635) 316Ti (UNS S31635) is a titanium stabilised version of 316 molybdenum-bearing austenitic stainless steel. The 316 alloys are more resistant to general corrosion and pitting/crevice corrosion than the conventional chromium-nickel austenitic stainless steels such as 304. They also offer higher creep, stress-rupture and tensile strength at elevated temperature. High carbon Alloy 316 stainless steel can be susceptible to sensitisation, the formation of grain boundary chromium carbides at temperatures between approximately 900 and 1500 F (425 to 815 C) which can result in intergranular corrosion. Resistance to sensitisation is achieved in Alloy 316Ti with titanium additions to stabilise the structure against chromium carbide precipitation, which is the source of sensitisation. This stabilisation is achieved by an intermediate temperature heat treatment, during which the titanium reacts with carbon to form titanium carbides. This significantly reduces susceptibility to sensitisation in service by limiting the formation of chromium carbides. Thus, the alloy can be used for extended periods at elevated temperatures without compromising its corrosion resistance. 316Ti has equivalent corrosion resistance to sensitisation as the low carbon version 316L. COILED SEAM WELDED, COLD REDRAWN AND ANNEALED ASTM A213 BS EN part 5 CHEMICAL PROCESSES HIGH TEMPERATURE AUTOMOTIVE CONTROL LINES CHEMICAL PROCESSES OIL AND GAS AUTOMOTIVE Temper Annealed Tensile Rm 75 ksi (min) Tensile Rm 515 MPa (min) R.p. 0.2% Yield 30 ksi (min) R.p. 0.2% Yield 205 MPa (min) Elongation (2 or 4D gl) 35 % (min) Specific Heat (0-100 C) 500 J.kg-1. K-1 Thermal Conductivity 14.6 W.m -1. K-1 Thermal Expansion 16.5 mm/m/ C Modulus Elasticity 193 GPa Electrical Resistivity 7.4 µohm/cm Density 7.99 g/cm3 C Si Mn - 2 P S Cr Mo 2 3 N Fe Balance Ni 10 14s Ti 5x%(C+N)

6 Alloy 316LVM Alloy 316LVM (UNS S31673) 316LVM (low carbon vacuum melt) stainless steel, regarded as a medical grade, this stainless steel is vacuum melted to achieve high levels of purity and cleanliness. It has excellent resistance to both general and intergranular corrosion, and pitting and crevice corrosion. The vacuum melt allows for superior surface finish. 316LVM stainless steel is our most commonly sold medical stainless steel. Breaking down the name, this is a low-carbon version of 316 that has been vacuum arc remelted to reduce impurities. Beyond removing impurities, this process, in combination with the unique nickel and chromium content of 316, tends to facilitate the formation of the surface chromium oxide layer that makes stainless steel corrosion resistant. There is some belief that T-316 LVM forms a more substantial surface layer, and that this plays a strong role in protecting the host body from reactions to the nickel content of the material. COILED Seam welded and Cold Redrawn SEAM WELDED, COLD REDRAWN AND ANNEALED ASTM F138 ASTM F2181 Orthopedic implants Trauma nails Neurological applications Surgical Instruments Chromatography columns Medical High performance Liquid chromatography (HPLC) Temper Annealed Cold worked Tensile Rm 75 ksi (min) 125 ksi (min) Tensile Rm 515 MPa (min) 860 MPa (min) R.p. 0.2% Yield 30 ksi (min) 100 ksi (min) R.p. 0.2% Yield 205 MPa (min) 690 MPa (min) Elongation (2 or 4D gl) 35 % (min) 15 % (min) Specific Heat (0-100 C) 485 J.kg-1. K-1 Thermal Conductivity 16.3 W.m -1. K-1 Thermal Expansion 16.5 mm/m/ C Modulus Elasticity 200 GPa Electrical Resistivity 7.4 µohm/cm Density 7.99 g/cm3 C Mn - 2 Ni Cr Mo 2 3 S Si P

7 Alloy 6Mo Alloy 6Mo (UNS S31254) 6Mo (UNS S31254) is a super austenitic stainless steel with a high level of molybdenum and nitrogen, providing high resistance to pitting and crevice corrosion as well as high strength compared with conventional austenitic stainless steels such as 316L. The alloy can provide excellent resistance to stress corrosion cracking allowing tube cold forming and may be used without the necessity to re-anneal at testing up to 120 C. Higher cost, higher alloy Alloy 625 (UNS N06625) with PREN value 50. Base Alloy 6Mo (UNS S31254) with PREN 43. COILED Seam welded and Cold Redrawn SEAM WELDED, COLD REDRAWN AND ANNEALED ASTM A213 ASTM A312 ASTM A269 BS EN pt.5 SEAWATER HANDLING SYSTEMS DESALINATION PLANT EQUIPMENT PAPER AND PULP FLUE GAS DESULPHURISATION UNITS IN POWER PLANTS CHEMICAL PROCESSING CONTROL AND INSTRUMENTATION Lower cost, lower alloy (316L) (UNS S31603) with PREN 25. CHEMICAL PROCESSES OIL AND GAS Typical Title UNS Werkstof C Si Mn P S Cr Ni Mo Cu N 316L S L S L N Mo S < N C276 N Co 2.5 W3.75 Specific Heat (0-100 C) 500 J.kg-1. K-1 Thermal Conductivity 14 W.m -1. K-1 Thermal Expansion 16.5 mm/m/ C Modulus Elasticity 196 GPa Electrical Resistivity 8.5 µohm/cm Density 8.00 g/cm3 Temper Annealed Tensile Rm 98 ksi (min) Tensile Rm 675 MPa (min) R.p. 0.2% Yield 45 ksi (min) R.p. 0.2% Yield 310 MPa (min) Elongation (2 or 4D gl) 35 % (min) Properties The steel grade was developed for use in halide containing environments such as seawater, hydrochloric acid and sulphuric acid. The increased levels of molybdenum combined with chromium and nitrogen provide levels of pitting and crevice corrosion resistance more typically associated with higher alloy nickel base alloys such as alloy 625 (UNS N06625). Structure Austenitic when annealed in the range C. In the hot working range between C (Under certain process conditions traces of the chi and sigma intermetallic phases could form.) These could exist as grain boundary precipitates. Suitable procedures for heat treatment and welding will be required to ensure that there is no impact of precipitation on corrosion resistance. The typical microstructure of the 6Mo sheet is shown in Diagram 1 & 2.

8 Alloy 6Mo Pitting Corrosion Some comparative test results for the different steel grades are shown in diagram 3. Fine Tubes investigated the pitting corrosion resistance of 6Mo grade by measuring pitting potentials using ASTM G5 test method. The experiments conducted in an autoclave at 130 C in 3.5wt% NaCI has shown that 6Mo has the highest pitting potentials, compared to the super duplex stainless steels S32750 as shown is Diagram 3. Crevice Corrosion 6Mo grade steels show higher pitting and crevice corrosion resistance compared to the traditional duplex and austenitic grades as shown in Diagram 4. Tests conducted in 6% FeCl3 (ASTM G48 A & B) to determine the critical pitting temperature (CPT) and critical crevice corrosion temperature (CCT) has shown that 6Mo grade is superior to the other austenitic stainless steel grades. Diagram 1: Band contract map plus grain boundary maps of 6Mo Fabrication Cold working - the alloy is fully cold workable and the increased level of nitrogen will lead to high work hardening rates such that will produce increased mechanical strength and toughness. Machining - the high work hardening rate attributable to increased nitrogen levels and low sulphur levels make this alloy tougher to machine and hence lower cutting speeds are required compared with conventional austenetic stainless steels. Hardness Testing & Fittings Compatibility The nature of our seamless tube production process control ensures a level of hardness is achieved which faciltates compatibility with compression settings where, typically a maximum hardness of Rockwell B 90 is specified. Hardness testing on small diameter tubes is typically not performed using the Rockwell test methodology as the level of loading required tends to distort surfaces or the ball impression can fall away due to the curvature of surface. The alloy has excellent forming characteristics permitting cold bending to very tight radii. Annealing is not normally necessary after forming. Fine Tubes use the Vickers hardness testing as the most meaningful test methodology. Pitting potential (mv vs Ag/AgCI) Temperature( C) Diagram 2: IPF map showing microstructure of 6Mo stainless steel Mo UNS31254 UNS32760 UNS L Diagram 3: pitting potentials in 3.5wt% NaCI at 130 C in 8ppm dissolved oxygen CPT( 0 C) CCT( 0 C) UNS Cr 6Mo UNS31254 UNS Diagram 4: Graph showing critical pitting and crevice temperatures in 6% FeCI3, 24 hours (ASTM G48 A & B)

9 Alloy Alloy (UNS S21900) 21Cr-6Ni-9Mn is a high manganese nitrogen strengthened, austenitic stainless steel. It combines high strength in the annealed condition, excellent resistance to oxidation at high temperatures as well as good resistance to lead oxide and a high level of corrosion resistance at ambient temperatures. The alloy can be fabricated and formed much the same as type 304 and 316, and is readily wieldable. It remains nonmagnetic after severe cold work. Seam welded and Cold Redrawn SEAM WELDED, COLD REDRAWN AND ANNEALED AMS 5561 AIRCRAFT HYDRAULIC TUBES AIRCRAFT ENGINE COMPONENTS AEROSPACE Temper Annealed Cold-worked Tensile Rm 95 ksi (min) 142 ksi (min) Tensile Rm 655 MPa (min) 979 MPa (min) R.p. 0.2% Yield 48 ksi (min) 120 ksi(min) R.p. 0.2% Yield 330 MPa (min) 827 MPa (min) Elongation (2 or 4D gl) 35 % (min) 20 % (min) Specific Heat (0-100 C) 500 J.kg-1. K-1 Thermal Conductivity 14 W.m -1. K-1 Thermal Expansion 16.7 mm/m/ C Modulus Elasticity 19.6 GPa Electrical Resistivity 73 µohm/cm Density 7.83 g/cm3 C Mn 8 10 Ni Cr Fe Balance Mo N Si - 1 P S

10 Alloy Alloy (UNS S20910) S20910 stainless steel provides a combination of good corrosion resistance and strength not found in any other commercial material available in its price range. This austenitic stainless steel has corrosion resistance greater than that provided by types 316 and 316L, plus approximately twice the yield strength at room temperature in the annealed condition. In addition S20910 stainless steel has very good mechanical properties at both elevated and sub-zero temperatures a well as outstanding cryogenic properties. And, unlike many austenitic stainless steels, stainless steel can be heavily cold worked to enhance its yield strength and remain non-magnetic. ASTM F1314 MEDICAL IMPLANTS PRESSURE TUBE DOWNHOLE MEDICAL OIL AND GAS Temper Annealed Cold-worked* Tensile Rm 105 ksi (min) 125 ksi (min) Tensile Rm 725 MPa (min) 862 MPa (min) R.p. 0.2% Yield 60 ksi (min) 100 ksi(min) R.p. 0.2% Yield 415 MPa (min) 690 MPa (min) Elongation (2 or 4D gl) 35 % (min) 20 % (min) * or manufactured to customer specification Specific Heat (0-100 C) 475 J.kg-1. K-1 Thermal Conductivity 13.3 W.m -1. K-1 Thermal Expansion 16.2 mm/m/ C Modulus Elasticity 10.8 GPa Electrical Resistivity 82 µohm/cm Density 7.88 g/cm3 C Mn 4 6 Ni Cr Fe Balance Mo 2 3 N Si P S Nb V Cu

11 Alloy 904L Alloy 904L (UNS N08904) UNS NO8904, commonly known as 904L, is a low carbon high alloy austenitic stainless steel which is widely used in applications where the corrosion properties of AISI 316L and AISI 317L are not adequate. The addition of copper to this grade gives it corrosion resistant properties superior to the conventional chrome nickel stainless steels, in particular to sulphuric, phosphoric and acetic acids. However, there is limited use with hydrochloric acids. It also has a high resistance to pitting in chloride solutions, a high resistance to both crevice and stress corrosion cracking. Alloy 904L performs better than other austenitic stainless steels due to the higher alloying of nickel and molybdenum. The grade is non-magnetic in all conditions and has excellent formability and weldability. The austenitic structure also gives this grade excellent toughness, even down to cryogenic temperatures The high chromium content promotes and maintains a passive film which protects the material in many corrosive environments. 904L has a greater resistance to precipitation of ferrite and sigma phases on cooling and welding than other stainless steels containing molybdenum such as 316L and 317L. There is no risk of intercrystalline corrosion on cooling or welding due to the low carbon content. Its maximum service temperature is at 450 C. This grade is particularly useful in control and instrumentation tubing applications where 316 and 317L are not suitable. COILED ASTM A213 ASTM A312 ASTM A269 BS EN pt.5 SEAWATER COOLING EQUIPMENT CHEMICAL PROCESSING FOR SULPHURIC, PHOSPHORIC AND ACETIC ACIDS GAS WASHING CONDENSER TUBES HEAT EXCHANGERS CONTROL AND INSTRUMENTATION CHEMICAL PROCESSES OIL AND GAS PHARMACEUTICAL Temper Annealed Tensile Rm 71 ksi (min) Tensile Rm 490 MPa (min) R.p. 0.2% Yield 32 ksi (min) R.p. 0.2% Yield 220 MPa (min) Elongation (2 or 4D gl) 35 % (min) Specific Heat (0-100 C) 450 J.kg-1. K-1 Thermal Conductivity 11.5 W.m -1. K-1 Thermal Expansion 15.8 mm/m/ C Modulus Elasticity 190 GPa Electrical Resistivity 9.52 µohm/cm Density 7.95 g/cm3 C Mn - 2 Ni Cr S Mo 4 5 N Cu 1 2 P Si - 0.7

12 Alloy 316LN Alloy 316LN (UNS S31653) 316LN (UNS S31653) is a lowcarbon, nitrogen-enhanced version of Type 316 molybdenum-bearing austenitic stainless steel. The Type 316 alloys are more resistant to general corrosion and pitting/crevice corrosion than the conventional chromium-nickel austenitic stainless steels such as Type 304. They also offer higher creep, stress-rupture and tensile strength at elevated temperature. The nitrogen in Type 316LN adds additional resistance to sensitization in some circumstances and it also provides some solid solution hardening, raising its minimum specified yield strength compared to Type 316L stainless steel. Like Types 316 and 316L, the Type 316LN alloy also offers good resistance to general corrosion and pitting/crevice corrosion. COILED ASTM F138 ASTM F2181 ORTHOPAEDIC IMPLANTS TRAUMA NAILS NEUROLOGICAL APPLICATIONS SURGICAL INSTRUMENTS MEDICAL CHEMICAL PROCESSES HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC) Temper Annealed Cold worked Tensile Rm 75 ksi (min) 125 ksi (min) Tensile Rm 515 MPa (min) 860 MPa (min) R.p. 0.2% Yield 30 ksi (min) 100 ksi(min) R.p. 0.2% Yield 205 MPa (min) 690 MPa (min) Elongation (2 or 4D gl) 35 % (min) 15 % (min) Specific Heat (0-100 C) 485 J.kg-1. K-1 Thermal Conductivity 16.3 W.m -1. K-1 Thermal Expansion 16.5 mm/m/ C Modulus Elasticity 200 GPa Electrical Resistivity 7.4 µohm/cm Density 7.99 g/cm3 C Mn - 2 Ni Cr Mo 2 3 S Si P