scholarly journals Hydrogen Effects on the Fracture Toughness Properties of Forged Stainless Steels

2008 ◽  
Author(s):  
Michael J. Morgan
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Ambient Temperature ◽  
Stainless Steels ◽  
316L Stainless Steel ◽  
Hydrogen Gas ◽  
Hydrogen Degradation ◽  
Type 316L ◽  
Fracture Appearance ◽  
Type 316L Stainless Steel

The effect of hydrogen on the fracture toughness properties of Types 304L, 316L and 21-6-9 forged stainless steels was investigated. Fracture toughness samples were fabricated from forward-extruded forgings. Samples were uniformly saturated with hydrogen after exposure to hydrogen gas at 34 MPa or 69 MPa and 623 K prior to testing. The fracture toughness properties were characterized by measuring the J-R behavior at ambient temperature in air. The results show that the hydrogen-charged steels have fracture toughness values that were about 50–60% of the values measured for the unexposed steels. The reduction in fracture toughness was accompanied by a change in fracture appearance. Both uncharged and hydrogen-charged samples failed by microvoid nucleation and coalescence, but the fracture surfaces of the hydrogen-charged steels had smaller microvoids. Type 316L stainless steel had the highest fracture toughness properties and the greatest resistance to hydrogen degradation.

scholarly journals Hydrogen Effects on Fracture Toughness of Type 316L Stainless Steel From 175 K to 425 K

2009 ◽  
Author(s):  
Michael J. Morgan ◽  
Glenn K. Chapman
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Ambient Temperature ◽  
Crack Extension ◽  
316L Stainless Steel ◽  
J Integral ◽  
Martensite Formation ◽  
Type 316L ◽  
Strain Induced Martensite ◽  
Type 316L Stainless Steel

The effects of hydrogen on the fracture-toughness properties of Type 316L stainless steel from 175 K to 425 K were measured. Fracture-toughness samples were fabricated from Type 316L stainless steel forgings and hydrogen-charged with hydrogen at 34 MPa and 623 K for two weeks prior to testing. The effect of hydrogen on the J-Integral vs. crack extension behavior was measured at various temperatures by fracturing non-charged and hydrogen-charged samples in an environmental chamber. Hydrogen-charged steels had lower toughness values than non-charged ones, but still retained good toughness properties. The fracture-toughness values of hydrogen-charged samples tested near ambient temperature were about 70% of non-charged values. For hydrogen-charged samples tested at 225 K and 425 K, the fracture-toughness values were 50% of the non-charged values. In all cases, fracture occurred by microvoid nucleation and coalescence, although the hydrogen-charged samples had smaller and more closely spaced microvoids. The results suggest that hydrogen effects on toughness are greater at 225 K than they are at ambient temperature because of strain-induced martensite formation. At 425 K, the hydrogen effects on toughness are greater than they are at ambient temperature because of the higher mobility of hydrogen.

ENDURAMET 316LN

Alloy Digest ◽  
2015 ◽  
Vol 64 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
316L Stainless Steel ◽  
Heat Treating ◽  
Type 316L ◽  
Technology Corporation ◽  
Carpenter Technology Corporation ◽  
Type 316L Stainless Steel

Abstract EnduraMet 316LN stainless is a nitrogen strengthened version of Type 316L stainless steel. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1219. Producer or source: Carpenter Technology Corporation.

PROJECT 70/PROJECT 7000 STAINLESS TYPE 316L

Alloy Digest ◽  
1997 ◽  
Vol 46 (7) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Stainless Steels ◽  
316L Stainless Steel ◽  
Heat Treating ◽  
Aisi Type ◽  
Type 316L ◽  
Type 316L Stainless Steel

Abstract Project 70 and Project 7000 Type 316L stainless steels are versions of conventional AISI Type 316L stainless steel having improved machinability, and having higher tensile and creep strengths than conventional 18-8 stainless steels. This datasheet provides information on composition and physical properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-515. Producer or source: Carpenter. Originally published November 1990, revised July 1997.

Effect of Hydrogen Isotopes on the Fracture Toughness Properties of Types 316L and 304L Stainless Steel Forgings

2019 ◽  
Author(s):  
Michael J. Morgan
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Yield Strength ◽  
316L Stainless Steel ◽  
Large Strain ◽  
Hydrogen Isotopes ◽  
High Yield ◽  
304L Stainless Steel ◽  
Type 316L ◽  
Type 316L Stainless Steel

Abstract Forged stainless steels are commonly used for the containment of hydrogen isotopes and fracture toughness properties are needed for structural integrity assessments. In this study, the effects of hydrogen and tritium precharging on the fracture-toughness properties of Types 316L and 304L stainless steel forgings were measured. The purpose of the study was to evaluate hydrogen and tritium effects on fracture toughness properties of: (1) Type 316 stainless steel stem-shaped and cup shaped forgings; and (2) Type 304L cylindrical block forgings with two different yield strengths. Arc-shaped fracture toughness specimens were cut from the forgings and precharged by exposing the specimens to hydrogen or tritium gas at 623K and 34.5 MPa. Tritium precharged specimens were aged at 193 K for 45 months prior to testing to build-in helium-3 from tritium decay. In the as-received condition, the J-Integral fracture toughness of the stem, cup, and block forgings were very high and exceeded 1200 kJ/m2 on average. The fracture toughness of specimens cut from the low yield strength Type 304L stainless steel block forging had the highest fracture toughness values and Type 316L stainless steel cup forging had the lowest. The reduced fracture toughness values were attributed to the large strain required to produce the cup forging and its high yield strength. Hydrogen precharging reduced the fracture toughness of the stem, cup, and block forgings to values between 34%–51% of a baseline value which was taken to be the fracture toughness value of the low yield strength block forging. Tritium precharging reduced the fracture-toughness values more than hydrogen precharging because of the effects of helium from radioactive decay of tritium. The fracture-toughness properties of tritium-precharged forgings ranged from 12% to 23% of the baseline values. In general, Type 316L stainless steel was more resistant to toughness reductions by hydrogen or tritium (and decay helium) than Type 304L stainless steel. Yield strength had only minor effects on fracture toughness for the precharged steels.

BIODUR 316LS

Alloy Digest ◽  
1995 ◽  
Vol 44 (6) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
316L Stainless Steel ◽  
Heat Treating ◽  
Vacuum Arc ◽  
Improve Corrosion Resistance ◽  
Type 316L ◽  
Type 316L Stainless Steel

Abstract BioDur 316LS stainless steel is a modified version of Type 316L stainless steel to improve corrosion resistance for surgical implant applications. The alloy is vacuum arc remelted. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-596. Producer or source: Carpenter.

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