scholarly journals Welding-Induced Local Maximum Residual Stress in Heat Affected Zone of Low-Carbon Austenitic Stainless Steel with Machined Surface Layer and Its Influential Factors

2015 ◽  
Vol 64 (7) ◽  
pp. 548-553 ◽  
Author(s):  
Shigetaka OKANO ◽  
Ryohei IHARA ◽  
Daisuke KANAMARU ◽  
Masahito MOCHIZUKI
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Surface Layer ◽  
Austenitic Stainless Steel ◽  
Heat Affected Zone ◽  
Local Maximum ◽  
Influential Factors ◽  
Low Carbon ◽  
Machined Surface ◽  
Maximum Residual Stress

Landmark Events in the Welding of Stainless Steels

2013 ◽  
Vol 794 ◽  
pp. 257-273
Author(s):  
Damian J. Kotecki
Keyword(s):  
Stainless Steel ◽  
Power Plant ◽  
Austenitic Stainless Steel ◽  
Weld Pool ◽  
Stainless Steels ◽  
Heat Affected Zone ◽  
Austenitic Stainless Steels ◽  
Duplex Stainless Steels ◽  
Low Carbon ◽  
Iron Chromium

This lecture presents the authors personal views on the landmark events that have strongly affected the welding of stainless steels over their lifetime. Although 1913 is commonly recognized as the birth of stainless steels with the commercialization of the martensitic alloy of Harry Brearly and the austenitic alloy of Eduard Maurer and Benno Straus, the story can be considered to begin as long ago as 1797 with the discovery of chromium by Klaproth and Vauquelin, and the observation by Vauquelin in 1798 that chromium resists acids surprisingly well. From the 1870s onwards, corrosion resisting properties of iron-chromium alloys were known. One might mark the first iron-chromium-nickel constitution diagram of Maurer and Strauss in 1920 as a major landmark in the science of welding of stainless steels. Their diagram evolved until the outbreak of World War II in Europe in 1939, and nominally austenitic stainless steel weld metals, containing ferrite that provided crack resistance, were extensively employed for armor welding during the war, based on their diagram. Improved diagrams for use in weld filler metal design and dissimilar welding were developed by Schaeffler (1947-1949), DeLong (1956-1973) and the Welding Research Council (1988 and 1992). Until about 1970, there was a major cost difference between low carbon austenitic stainless steels and those austenitic stainless steels of 0.04% carbon and more because the low carbon grades had to be produced using expensive low carbon ferro-chromium. Welding caused heat affected zone sensitization of the higher carbon alloys, which meant that they had to be solution annealed and quenched to obtain good corrosion resistance. In 1955, Krivsky invented the argon-oxygen decarburization process for refining stainless steels, which allowed low carbon alloys to be produced using high carbon ferro-chromium. AOD became widely used by 1970 in the industrialized countries and the cost penalty for low carbon stainless steel grades virtually vanished, as did the need to anneal and quench stainless steel weldments. Widespread use of AOD refining of stainless steels brought with it an unexpected welding problem. Automatic welding procedures for orbital gas tungsten arc welding of stainless steel tubing for power plant construction had been in place for many years and provided 100% penetration welds consistently. However, during the 1970s, inconsistent penetration began to appear in such welds, and numerous researchers sought the cause. The 1982 publication of Heiple and Roper pinpointed the cause as a reversal of the surface tension gradient as a function of temperature on the weld pool surface when weld pool sulfur became very low. The AOD refining process was largely responsible for the very low sulfur base metals that resulted in incomplete penetration. The first duplex ferritic-austenitic stainless steel was developed in 1933 by Avesta in Sweden. Duplex stainless steels were long considered unweldable unless solution annealed, due to excessive ferrite in the weld heat-affected zone. However, in 1971, Joslyn Steel began introducing nitrogen into the AOD refining of stainless steels, and the duplex stainless steel producers noticed. Ogawa and Koseki in 1989 demonstrated the dramatic effect of nitrogen additions on enhanced weldability of duplex stainless steels, and these are widely welded today without the need to anneal. Although earlier commercial embodiments of small diameter gas-shielded flux cored stainless steel welding electrodes were produced, the 1982 patent of Godai and colleagues became the basis for widespread market acceptance of these electrodes from many producers. The key to the patent was addition of a small amount of bismuth oxide which resulted in very attractive slag detachment. Electrodes based on this patent quickly came to dominate the flux cored stainless steel market. Then a primary steam line, welded with these electrodes, ruptured unexpectedly in a Japanese power plant. Investigations published in 1997 by Nishimoto et al and Toyoda et al, among others, pinpointed the cause as about 200 ppm of bismuth retained in the weld metal which led to reheat cracking along grain boundaries where the Bi segregated. Bismuth-free electrode designs were quickly developed for high temperature service, while the bismuth-containing designs remain popular today for service not involving high temperatures.

Analytical Study of the Relaxation of Welding Residual Stress by Excessive Loading for Austenitic Stainless Steel Piping Welds

2009 ◽  
Author(s):  
Jinya Katsuyama ◽  
Kunio Onizawa
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Nuclear Power ◽  
Power Plants ◽  
Three Dimensional ◽  
Welding Residual Stress ◽  
Low Carbon ◽  
Three Dimensional Model ◽  
Butt Weld

Welding residual stress is one of the most important factors of stress corrosion cracking (SCC) for austenitic stainless steel in pressure boundary piping in nuclear power plants. The effect of excessive loading, such as an earthquake, on the residual stress was evaluated by three-dimensional analyses based on finite element method (FEM). The FEM analyses were performed using three-dimensional model for a 250A piping butt weld of low carbon stainless steel of Type 316L. A welding simulation method used in this work is based on the moving heat source with the double ellipsoid model and was confirmed by comparing with the experimental measurements. After conducting welding residual stress simulation, several loading patterns of bending moment and uni-axial displacements have been applied to a model by varying amount of moment and displacement. The analyses indicated that higher loading to bending and axial stresses caused higher relaxation of welding residual stress near piping welds. The difference in the effect of loading direction was observed for both cases. It is concluded that the SCC growth rate might be decreased as loading level increased.

The Influence of Shot Peening Process on the Residual Stress and Microstructure in Deformed Surface Layer of S30432 Austenitic Stainless Steel

2013 ◽  
Vol 768-769 ◽  
pp. 550-556 ◽  
Author(s):  
Ke Zhan ◽  
Chuan Hai Jiang ◽  
Henry Pan
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Surface Layer ◽  
Austenitic Stainless Steel ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Micro Structure ◽  
Near Surface ◽  
Deformed Layer

Shot peening is an important surface treatment which can induce compressive residual stress and refine micro-structure in the deformed surface layer. In this paper, the conventional shot peening, dual shot peening and triple shot peening have been applied to S30432 austenitic stainless steel. The residual stress and micro-structure in the deformed layer were investigated by X-ray diffraction method. The results revealed that a compressive residual stress field was induced in the deformed layer for all shot peening conditions. As the shot peening step increased, the compressive residual stresses increased in near surface layer, and then deceased faster in deeper deformed layer. In terms of microstructure, the domain size increased, while the micro-strain decreased with the depth increasing in the deformed layer. Compare with the effect of three different shot peening method, triple shot peenng is more effective to optimize the compressive residual stress, microstructure and micro-hardness of S30432 austenitic stainless steel.

scholarly journals Effects of Surface Grinding on Hardness Distribution and Residual Stress in Low Carbon Austenitic Stainless Steel SUS316L

2004 ◽  
Vol 44 (10) ◽  
pp. 1780-1782 ◽  
Author(s):  
Atsushi Yamamoto ◽  
Takayuki Yamada ◽  
Shigeo Nakahigashi ◽  
Li Liu ◽  
Michitaka Terasawa ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Surface Grinding ◽  
Hardness Distribution ◽  
Low Carbon

Estimation of Some Mechanical Properties for Similar & Dissimilar Welded Joints

2014 ◽  
Vol 2 (1) ◽  
pp. 59-76
Author(s):  
Abdullah Daie'e Assi
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Austenitic Stainless Steel ◽  
Base Metal ◽  
Welded Joints ◽  
Plate Thickness ◽  
Low Carbon Steel ◽  
Dissimilar Metals ◽  
Low Carbon ◽  
Steel Type

This research deals with the choice of the suitable filler metal to weld the similar and dissimilar metals (Low carbon steel type A516 & Austenitic stainless steel type 316L) under constant conditions such as, plate thickness (6 mm), voltage (78 v), current (120 A), straight polarity. This research deals with three major parts. The first parts Four types of electrodes were used for welding of dissimilar metals (C.St A516 And St.St 316L) two from mild steel (E7018, E6013) and other two from austenitic stainless steel (E309L, E308L) various inspection were carried out include (Visual T., X-ray T., δ- Ferrite phase T., and Microstructures T.) and mechanical testing include (tensile T., bending T. and micro hardness T.) The second parts done by used the same parameters to welding similar metals from (C.St A516) Or (St.St 316L). The third parts deals with welding of dissimilar weldments (C.St And St.St) by two processes, gas tungsten are welding (GTAW) and shielded metal are welding (SMAW).        The results indicated that the spread of carbon from low carbon steel to the welding zone in the case of welding stainless steel elect pole (E309L) led to Configuration Carbides and then high hardness the link to high values ​​compared with the base metal. In most similar weldments showed hardness of the welding area is  higher than the hardness of the base metal. The electrode (E309L) is the most suitable to welding dissimilar metals from (C.St A516 With St.St 316L). The results also showed that the method of welding (GTAW) were better than the method of welding (SMAW) in dissimilar welded joints (St.St 316L with C.St A516) in terms of irregular shape and integrity of the welding defects, as well as characterized this weldments the high-lift and resistance ductility good when using the welding conditions are similar.

CLC 18.10LN

Alloy Digest ◽  
2006 ◽  
Vol 55 (1) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Stainless Steels ◽  
The Other ◽  
Low Carbon ◽  
Good Corrosion Resistance ◽  
Temperature Performance

Abstract CLC 18.10LN is an austenitic stainless steel with 18% Cr, 9.5% Ni, and 0.14% N to provide good corrosion resistance at strengths above the other low-carbon stainless steels. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, machining, and joining. Filing Code: SS-950. Producer or source: Industeel USA, LLC.

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