Effect of Coal Liquefaction Solvents on Fatigue Crack Initiation in 2 1/4 Cr-1 Mo Steel and 316L Stainless Steel

1985 ◽  
Vol 107 (4) ◽  
pp. 325-328
Author(s):  
T. S. Gross ◽  
V. K. Mathews ◽  
P. N. Kanga
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Crack Initiation ◽  
Room Temperature ◽  
316L Stainless Steel ◽  
Fatigue Crack Initiation ◽  
Coal Liquefaction ◽  
Coal Liquids ◽  
Sulfide Corrosion ◽  
Order Of Magnitude

Blunt notch fatigue crack initiation tests were carried out on 2.25 Cr – 1 Mo steel and 316L stainless steel in room temperature air and in the process solvent from the Wilsonville, Alabama coal liquefaction pilot plant at 100°C. The crack initiation lifetime in the coal liquids at 100°C was an order of magnitude greater than the crack initiation lifetime in air for the 2.25 Cr–1 Mo steel. The crack initiation lifetime in the coal liquids for the 316L stainless steel was increased a factor of five over the crack initiation lifetime in air. The improvement in crack initiation lifetime was attributed to the coal liquids shielding the materials from atmospheric embrittlement. The coal liquids did not show any tendency to form sulfide corrosion products at 100°C.

Environmental Effects on Fatigue Crack Initiation in 2.25 Cr-1 Mo Steel and 316L Stainless Steel

1988 ◽  
Vol 110 (3) ◽  
pp. 240-246
Author(s):  
V. K. Mathews ◽  
T. S. Gross
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Crack Initiation ◽  
Room Temperature ◽  
316L Stainless Steel ◽  
Silicone Oil ◽  
Fatigue Crack Initiation ◽  
Type A ◽  
Order Of Magnitude ◽  
Number Of Cycles

Blunt notch fatigue crack initiation tests for Type A387 2.25 Cr-1 Mo steel and 316L stainless steel were performed in air at room temperature, in silicone oil at room temperature, in V-131B coal process solvent at 100°C, and in chlorine-modified V-131B coal process solvent at 100°C. For both steels the most damaging environment was room temperature air. The number of cycles to initiate a crack were almost identical in the coal process solvent and the silicone oil for the Type A-387 steel. These two environments resulted in the longest crack initiation lifetime for the Type A-387 steel. The crack initiation lifetime for the Type A-387 steel in the chlorine modified V-131 B coal process solvent was roughly a factor of five less than the lifetime in the silicone oil and the unmodified coal process solvent. The crack initiation lifetime for the Type A-387 steel in room temperature air was a factor of 30 less than the lifetime in the silicone oil or the unmodified coal process solvent. The improvement of the crack initiation lifetime for the Type A-387 steel in the unmodified coal process solvent and the silicone oil is attributed to protection of the material from embrittlement from room temperature air. The decrease in crack initiation lifetime in the chlorine modified coal process solvent indicates that chlorine can be an active embrittling agent in the coal process solvent. The crack initiation lifetime for 316L stainless steel was longest in the silicone oil. The lifetime decreased somewhat in the unmodified coal process solvent with a further decrease for the chlorine modified coal solvent. The crack initiation lifetime in air was an order of magnitude lower than the lifetime in the silicone oil. The silicone oil and the coal process solvent apparently protected the 316L stainless from the embrittlement in air. However, the coal process solvent is not entirely inert as in the case of Type A-387 steel. The chlorine is an active embrittling agent for the 316L stainless steel in the coal process solvent.

Fatigue Crack Initiation and Growth Behaviour of 316L Stainless Steel Manufactured Through Selective Laser Melting

2017 ◽  
Author(s):  
C. M. Davies ◽  
H. Thomlinson ◽  
P. A. Hooper
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Initiation ◽  
Crack Growth ◽  
316L Stainless Steel ◽  
Fatigue Crack Initiation ◽  
Compact Tension ◽  
Growth Behaviour ◽  
Laser Melting

Selective Laser Melting (SLM) is a relatively new manufacturing technique that offers many benefits. However the utilisation of SLM manufactured components depends on the assurance of their integrity during operation. Tensile and high cycle fatigue tests have been performed on uniaxial samples manufactured using SLM of 316L stainless steel to examine the elastic-plastic deformation and fatigue crack initiation behaviour of the material. In addition, the fatigue crack growth behaviour has been determined from tests on compact tension samples manufactured using SLM. The influence of build orientation has been examined on the compact tension samples. The results are compared to values obtained from conventional manufacturing methods. The tensile samples have a higher strength but significantly lower ductility than wrought material. The fatigue strength of the SLM material was substantially less than wrought material, though a similar fatigue limit maybe seen, this may be attributed to porosity in the material. The fatigue crack growth rate of the SLM material was 5–10 times faster, for a given stress intensity factor, than wrought materials and strongly depended on crack orientation in relation to the build direction.

Assessment and Test of the Creep-Fatigue Crack Behaviour for a High Temperature Component

2008 ◽  
Author(s):  
Hyeong-Yeon Lee ◽  
Jae-Han Lee ◽  
Kamran Nikbin
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Crack Initiation ◽  
316L Stainless Steel ◽  
Fatigue Crack Initiation ◽  
Present Specimen ◽  
High Temperature Component ◽  
Creep Fatigue ◽  
Temperature Component ◽  
Creep Fatigue Crack

Creep-fatigue crack behaviour has been investigated for a welded component with 316L stainless steel and Mod. 9Cr-1Mo steel through an assessment and test. The evaluation of creep-fatigue crack initiation and propagation was carried out for 316L stainless steel according to the French RCC-MR A16 guide, and evaluation on creep-fatigue crack initiation for Mod.9Cr-1Mo steel in a specimen was carried out with an extended A16 method. A test for a structural specimen with a diameter of 500mm, height of 440mm and thickness of 6.3mm was performed to compare its results with that by assessment according to the A16 guide. The specimen was subjected to creep-fatigue loads with two hours of a dwell time at 600°C and variable primary loads. The creep-fatigue crack behaviours for the two materials were assessed, observed and compared. The results showed that the A16 guide for the austenitic stainless steel was overly conservative for the assessment of creep-fatigue crack initiation while it was reasonably conservative for creep-fatigue crack growth for the present specimen.

Assessment and Test of the Creep-Fatigue Crack Behavior for a High Temperature Component

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Hyeong-Yeon Lee ◽  
Jae-Han Lee ◽  
Kamran Nikbin
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Crack Initiation ◽  
316L Stainless Steel ◽  
Fatigue Crack Initiation ◽  
Steel Specimen ◽  
Present Specimen ◽  
Crack Behavior ◽  
Creep Fatigue ◽  
Creep Fatigue Crack

Creep-fatigue crack behavior has been investigated for a welded component with 316L stainless steel and Mod. 9Cr–1Mo steel through assessment and test. The evaluation of creep-fatigue crack initiation and propagation was carried out for 316L stainless steel according to the French RCC-MR A16 guide, and the evaluation of creep-fatigue crack initiation for a Mod.9Cr–1Mo steel specimen was carried out with an extended A16 method. A test for a structural specimen with a diameter of 500 mm, height of 440 mm, and thickness of 6.3 mm was performed to compare its results with that by an assessment according to the A16 guide. The specimen was subjected to creep-fatigue loads with 2 h of dwell time at 600°C and various primary loads. The creep-fatigue crack behaviors for the two materials were assessed, observed, and compared. The results showed that the A16 guide for the austenitic stainless steel was fairly conservative for the assessment of creep-fatigue crack initiation while it was reasonably conservative for creep-fatigue crack growth for the present specimen.

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