Behavior of Type 304 and Type 316 Austenitic Stainless Steels in 55% Lithium Bromide Heavy Brine Environments

CORROSION ◽  
1994 ◽  
Vol 50 (2) ◽  
pp. 131-137 ◽  
Author(s):  
D. Itzhak ◽  
O. Elias
Keyword(s):  
Stainless Steels ◽  
Lithium Bromide ◽  
Austenitic Stainless Steels ◽  
Type 304

Strain-induced martensite effects on transgranular carbide precipitation in type 304 stainless steels

1991 ◽  
Vol 49 ◽  
pp. 604-605
Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D. Matlock
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Stress Corrosion Cracking ◽  
Stainless Steels ◽  
Deformation Twin ◽  
Austenitic Stainless Steels ◽  
Carbide Precipitation ◽  
Strain Induced Martensite ◽  
Type 304

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.

CARPENTER STAINLESS 304+B

Alloy Digest ◽  
1961 ◽  
Vol 10 (9) ◽  
Keyword(s):  
Fracture Toughness ◽  
Cross Section ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Heat Treating ◽  
Neutron Absorption ◽  
Absorption Cross ◽  
Type 304 ◽  
Conventional Type ◽  
Neutron Absorption Cross Section

Abstract Carpenter Stainless 304+B is similar to conventional Type 304 with the addition of boron to give it a much higher thermal neutron absorption cross-section than other austenitic stainless steels. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-121. Producer or source: Carpenter.

The Effect of Boron on the Corrosion Resistance of Austenitic Stainless Steels

CORROSION ◽  
1977 ◽  
Vol 33 (11) ◽  
pp. 408-417 ◽  
Author(s):  
F. P. A. ROBINSON ◽  
W. G. SCURR
Keyword(s):  
Corrosion Resistance ◽  
Stainless Steels ◽  
Intergranular Corrosion ◽  
Detrimental Effect ◽  
Austenitic Stainless Steels ◽  
The Other ◽  
Beneficial Effects ◽  
Identical Series ◽  
Type 304 ◽  
Intergranular Corrosion Resistance

Abstract Two Type 304 stainless steels, one boron free and the other containing 4 ppm boron were investigated. Both steels were subjected to an identical series of corrosion tests and the results compared with one another. It was found (1) Boron had no detrimental effect on the potentiostatic characteristics, intergranular corrosion “resistance and pitting resistance of the steels in the “as-received” condition; (2) boron in solid solution had no detrimental effect on the potentiostatic characteristics and intergranular corrosion resistance of the steel, while boron in solution had a beneficial effect on the pitting resistance of the steel, and (3) boron retarded Cr23C6 precipitation and thus boron had marked beneficial effects on the intergranular corrosion resistance of the steels in a sensitized condition. In addition the potentiostatic characteristics and pitting resistance of such steels were improved slightly by the presence of boron.

Effect of Strain-Induced Martensitic Transformation on Coaxing Effect of Austenitic Stainless Steels

2008 ◽  
Vol 385-387 ◽  
pp. 505-508
Author(s):  
Jae Woong Jung ◽  
Masaki Nakajima ◽  
Yoshihiko Uematsu ◽  
Keiro Tokaji ◽  
Masayuki Akita
Keyword(s):  
Martensitic Transformation ◽  
Stainless Steels ◽  
Work Hardening ◽  
Strain Aging ◽  
Austenitic Stainless Steels ◽  
Fatigue Tests ◽  
The Other ◽  
Conventional Tests ◽  
Materials Used ◽  
Type 304

The effects of martensitic transformation on the coaxing behavior were studied in austenitic stainless steels. The materials used were austenitic stainless steels, type 304 and 316. Conventional fatigue tests and stress-incremental fatigue tests were performed using specimens subjected to several tensile prestrains from 5% to 60%. Under conventional tests, the fatigue strengths of both steels increased with increasing prestrain. Under stress-incremental tests, 304 steel showed a marked coaxing effect, where the failure stress significantly increased irrespective of prestrain level. On the other hand, the coaxing effect in 316 steel decreased with increasing prestrain up to 15%, where the failure stresses were nearly the same. Above this prestrain level, the coaxing effect increased with increasing prestrain. In 304 steel, the coaxing effect is primarily dominated by work hardening at low prestrains, while the effect of strain-induced martensitic transformation increases with increasing prestrain. The coaxing effect in 316 steel is dominated by both work hardening and strain aging at low prestrains, but strain-induced martensitic transformation could play a significant role at high prestrains.

SSRT and Fatigue Crack Growth Properties of High-Strength Austenitic Stainless Steels in High-Pressure Hydrogen Gas

2014 ◽  
Author(s):  
Hisatake Itoga ◽  
Takashi Matsuo ◽  
Akihiro Orita ◽  
Hisao Matsunaga ◽  
Saburo Matsuoka ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Hydrogen Gas ◽  
Internal Hydrogen ◽  
Acceleration Rate ◽  
Type 304

Slow strain rate tests (SSRTs) were performed with two types of high-strength austenitic stainless steels, Types AH and BX, as well as with two types of conventional austenitic stainless steels, Types 304 and 316L. The tests used the following combinations of specimen types and test atmospheres: (i) non-charged specimens tested in air, (ii) hydrogen-charged specimens tested in air (tests for internal hydrogen), and (iii) non-charged specimens tested in hydrogen gas at pressures of 78 ∼ 115 MPa (tests for external hydrogen). Type 304 exhibited a marked reduction of ductility in the tests for both internal hydrogen and external hydrogen, whereas Types AH, BX and 316L exhibited little or no degradation. In addition, fatigue crack growth (FCG) tests for the four types of steels were also carried out in air and hydrogen gas at pressures of 100 ∼ 115 MPa. In Type 304, FCG in hydrogen gas was more than 10 times as fast as that in air, whereas the acceleration rate remained within 1.5 ∼ 3 times in Types AH, BX and 316L. It was presumed that, in Types AH and BX, a small amount of additive elements, e.g. nitrogen and niobium, increased the strength as well as the stability of the austenitic phase, which thereby led to the excellent resistance against hydrogen.

A TEM/STEM and APFIM study of nitrogen distribution in inert-gas-atomized type 304 stainless steels

1994 ◽  
Vol 52 ◽  
pp. 960-961
Author(s):  
M. Zhou ◽  
T. F. Kelly ◽  
J. E. Flinn
Keyword(s):  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Strengthening Mechanism ◽  
Austenitic Steels ◽  
Alloying Element ◽  
Atomic Size ◽  
High Toughness ◽  
Mechanical And Physical Properties ◽  
Interstitial Nitrogen ◽  
Type 304

The attraction of austenitic stainless steels lies in the combination of their mechanical and physical properties and corrosion resistance. However, a major disappointment is their relatively low strength. Over the years, continued efforts have been made to try to improve the strength of conventionally processed austenitic steels without sacrificing other properties. Using nitrogen as an alloying element can very effectively increase the strength of austenitic stainless steels while maintaining a high toughness. Improved resistance to intergranular corrosion and longer creep-to-rupture time1 werealso reported among nitrogen-containing austenitic steels. Though there is little doubt that interstitial nitrogen is responsible for the improved mechanical properties, the strengthening mechanism by nitrogen can not be explained successfully in a “conventional sense”, i.e. despite its smaller atomic size, nitrogen was found to increase the yield strength at 4K more than carbon does by a factor of about 2. One reason for the lack of understanding of nitrogen strengthening mechanism is because of thedifficulty of detecting low atomic number elements as well as possible short range order that may exist between interstitial and substitutional atoms.

Molybdenum solubility differences in MC phases formed in titanium and niobium modified austenitic stainless steels determined using AEM

1984 ◽  
Vol 42 ◽  
pp. 496-497
Author(s):  
P. J. Maziasz
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Elevated Temperature ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
304 Stainless Steel ◽  
Elevated Temperature Strength ◽  
Helium Embrittlement ◽  
Type 304 ◽  
Type 304 Stainless Steel

Molybdenum is added to improve elevated temperature strength and corrosion resistance for type 316 compared to type 304 stainless steel. Strong carbide forming elements, like titanium and niobium, are also added to these steels to improve creep strength and reduce stress corrosion cracking, as well as to improve resistance to irradiation induced swelling and helium embrittlement. This work shows that fairly pure TiC and NbC form in Ti- and Nb- stabilized versions of type 304 stainless steel (types 321 and 347, respectively); however, the Ti-rich MC dissolves Mo considerably whereas the NbC remains compositionally quite pure when these phases form in Ti- and Nb- modified type 316 stainless steels, respectively.

A Fatigue Crack Growth Model for Type 304 Austenitic Stainless Steels in an Elevated Temperature Air Environment

2021 ◽  
Author(s):  
Kathleen C. Barron
Keyword(s):  
Fatigue Crack ◽  
Elevated Temperature ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Reference Curve ◽  
Paris Law ◽  
R Ratio ◽  
Type 304

Abstract The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section XI utilizes reference fatigue crack growth rate (FCGR) curves for flaw evaluations. The current ASME reference curve for austenitic stainless steels in air environments is a Paris-Law relation with a single ΔK exponent that covers the entire ΔK range. Since generation of the model that became the ASME reference curve, extensive additional FCGR testing of Type 304, Type 304L, and Type 304/304L dual-certified stainless steel and the corresponding weld metal has been performed in an elevated temperature air environment. This testing revealed fatigue crack growth (FCG) behaviors that were not adequately captured by the ASME reference curve. In particular, the ASME reference curve failed to capture a flattening of the FCGR curve in the intermediate ΔK range before the FCGRs sharply dropped off as the threshold behavior is approached. Additionally, the FCGR data showed a slight frequency-dependence. Based on this new data, a new FCGR model was generated for Type 304 austenitic stainless steels in air environments between 250°C and 338°C. A tri-linear Paris-Law style correlation was chosen for the updated FCGR model to accommodate both the flattening of the FCGR curve at intermediate ΔK levels and the sharp downturn in the near-threshold ΔK regime. Each of the three branches of the FCGR curve exhibit a different R-ratio dependence, with the near-threshold regime being the most sensitive to changes in the R-ratio.

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