Effect of number of welding passes on the microstructure, mechanical and intergranular corrosion properties of 409M ferritic stainless steel

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sachin Ambade ◽  
Chetan Tembhurkar ◽  
Awanikumar Patil ◽  
Diwesh Babruwan Meshram

Purpose This paper aims to study the effect of number of welding passes on microstructure, mechanical and corrosion properties of 409 M ferritic stainless steel. Shielded metal arc welding (SMAW) process is used to weld two metal sheets of 409 M having 3 mm thickness as bead-on-plate with single, double and triple passes. Microstructures were observed at transverse section with the help of optical microscope and with increasing number of passes grain growth, and the width of heat-affected zone (HAZ) increases. The results of tensile tests revealed that as number of passes increases, there is reduction in tensile strength and ductility. Double loop electrochemical potentiokinetic reactivation (DL-EPR) test revealed that as number of passes increases, the degree of sensitization increases. This is due to the deposition of chromium carbides at the grain boundaries and the associated depletion of chromium. Design/methodology/approach Three welded plates of single, double and triple pass were welded by SMAW process. From three welded plates (single, double and triple passes), samples for microstructural examination were cut in transverse direction (perpendicular to welding direction) with the help of wire-cut electrical discharge machine (EDM). The welded plates were sliced using wire-cut EDM along transverse direction for preparing optical microscopy, tensile testing, microhardness and DL-EPR testing specimens. Findings From the microstructure, it was observed that the large grain growth, which is dendritic, and the structure become finer to increase in number of welding passes. As number of passes increases, the width of HAZ increases because of the higher temperature at the welded zone. The tensile strength decreases to increase the number of welding passes because of grain coarsening and chromium carbide precipitation in sensitized zone and wider HAZ. The maximum microhardness value was observed for single-pass weld as compared to double- and triple-pass welds because of the fast cooling rate. The degree of sensitization increases to increase the number of passes because of chromium carbide deposition at the grain boundaries. Originality/value The authors declare that the manuscript is original and not published elsewhere, and there is no conflict of interest to publish this manuscript.

2020 ◽  
Vol 26 (7) ◽  
pp. 1197-1208
Author(s):  
Subrata Deb Nath ◽  
Gautam Gupta ◽  
Martin Kearns ◽  
Ozkan Gulsoy ◽  
Sundar V. Atre

Purpose The purpose of this paper is to investigate effects of layer thickness on densification, surface morphology, microstructure and mechanical and corrosion properties of 420 stainless steel fabricated by laser-powder bed fusion (L-PBF). Design/methodology/approach Standard specimens were printed at layer thickness of 10, 20 and 30 µm to characterize Archimedes density, surface roughness, tensile strength, elongation, hardness, microstructural phases and corrosion performance in the as-printed and heat-treated condition. Findings Archimedes density slightly increased from 7.67 ± 0.02 to 7.70 ± 0.02g/cm3 and notably decreased to 7.35 ± 0.05 g/cm3 as the layer thickness was changed from 20 µm to 10 and 30 µm, respectively. The sensitivity to layer thickness variation was also evident in properties, the ultimate tensile strength of as-printed parts increased from 1050 ± 25 MPa to 1130 ± 35 MPa and decreased to 760 ± 35 MPa, elongation increased from 2.5 ± 0.2% to 2.8 ± 0.3% and decreased to 1.5 ± 0.2, and hardness increased from 55 ± 1 HRC to 57 ± 1 HRC and decreased to 51 ± 1 HRC, respectively. Following heat treatment, the ultimate tensile strength and elongation improved but the general trends of effects of layer thickness remained the same. Practical implications Properties obtained by L-PBF are superior to reported properties of 420 stainless steel fabricated by metal injection molding and comparable to wrought properties. Originality/value This study successfully the sensitivity of mechanical and corrosion properties of the as-printed and heat-treated parts to not only physical density but also microstructure (martensite content and tempering), as a result of changing the layer thickness. This manuscript also demonstrates porosity evolution as a combination of reduced energy flux and lower packing density for parts processed at an increasing layer thickness.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sourabh Shukla ◽  
Awanikumar P. Patil ◽  
Ashlesha Kawale ◽  
Anand Babu Kotta ◽  
Inayat Ullah

Purpose Effect of grain size on degree of sensitization (DOS) was been evaluated in Nickel free steel. Manganese and nitrogen contained alloy is a Ni-free austenitic stainless steels (ASS) having type 202 grade. The main purpose of this investigation is to find the effect of recrystallization on the DOS of stainless steel after the thermo-mechanical processing (cold work and thermal aging). Design/methodology/approach In the present investigation, the deformation of 202 grade analyzed using X-ray diffraction (XRD) and microstructural testing. Optical microstructure of Ni-free ASS has been done for cold worked samples with thermally aged at 900°C_6 h. Double loop electrochemical potentiodynamic reactivation test used for findings of degree of sensitization. Findings Ni-free ASS appears to be deformed more rapidly due to its higher stacking fault energy which gave results in rapid transformation from strain induced martensite to austenite in form of recrystallized grains, i.e. it concluded that as cold work percentage increases more rapidly recrystallization occurs. XRD results also indicate that more fraction of martensite formed as percentage of CW increases but as thermal aging reverted those all martensite to austenite. So investigation gives the conclusion which suggests that with high deformation at higher temperature and duration gives very less DOS. Originality/value Various literatures available for 300 series steel related to the effect of cold work on mechanical properties and sensitization mechanism. However, no one has investigated the effect of recrystallization through thermomechanical processing on the sensitization of nickel-free steel.


2006 ◽  
Vol 41 (8) ◽  
pp. 2381-2386 ◽  
Author(s):  
Regina Célia de Sousa ◽  
José Carlos Cardoso Filho ◽  
Auro Atsushi Tanaka ◽  
Ayana Cristina S. de Oliveira ◽  
Wilman Eduardo Italiano Ferreira

2020 ◽  
Vol 17 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Taiwo Ebenezer Abioye ◽  
Igbekele Samson Omotehinse ◽  
Isiaka Oluwole Oladele ◽  
Temitope Olumide Olugbade ◽  
Tunde Isaac Ogedengbe

Purpose The purpose of this study is to determine the effects of post-annealing and post-tempering processes on the microstructure, mechanical properties and corrosion resistance of the AISI 304 stainless steel gas metal arc weldment. Design/methodology/approach Gas metal arc welding of AISI 304 stainless steel was carried out at an optimized processing condition. Thereafter, post-annealing and post-tempering processes were performed on the weldment. The microstructure, mechanical and electrochemical corrosion properties of the post-weld heat treated samples, as compared with the as-welded, were investigated. Findings The as-welded joint was characterized with sub-granular grain structure, martensite formation and Cr-rich carbides precipitates. This made it harder than the post-annealed and post-tempered joints. Because of slower cooling in the furnace, the post-annealed joint contained Cr-rich carbides precipitates. However, the microstructure of the post-tempered joint is more refined and significantly devoid of the carbide precipitates. Post-tempering process improved the elongation (∼23%), tensile (∼10%) and impact (∼31%) strengths of the gas metal arc AISI 304 stainless steel weldment, while post-annealing process improved the elongation (∼20%) and impact strength (∼72%). Owing to the refined grain structure and significant elimination of the Cr-rich carbide precipitates at the joint, the post-tempered joint exhibited better corrosion resistance in 3.5 Wt.% NaCl solution than the post-annealed and the as-welded joints. Originality/value The appropriate post-weld heat treatment that enhances microstructural homogeneity and quality of the AISI 304 gas metal arc welded joint was determined.


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1088
Author(s):  
Niklas Sommer ◽  
Igor Kryukov ◽  
Christian Wolf ◽  
Michael Wiegand ◽  
Martin Kahlmeyer ◽  
...  

In the present investigation, thin sheets of stabilized and unstabilized ferritic stainless steel were welded in butt joint configuration using irradiation of a 1070 nm fiber-laser. Using optical microscopy, the microstructural evolution upon alternating heat input was characterized. In addition to that, hardness and tensile tests were carried out on the specimens. Detailed focus was given to the intergranular corrosion properties, which were investigated on basis of the Strauss test with different times of exposure to the corrosive environment. Following these tests, the mechanical properties of the joints were characterized using tensile tests. A combination of the latter with an inspection by μ-CT analysis allows for the proposition of an intergranular corrosion rate with regard to the degradation of the joint strength.


2013 ◽  
Vol 717 ◽  
pp. 62-66
Author(s):  
Prachya Peasura ◽  
Nansa Arng Santirat

Duplex stainless steel are good combination of economy, weldability and toughness and are often selected where both strength and corrosion properties are crucial. The research was study the effect of post weld aging parameter on mechanical properties. The specimen was duplex stainless steel UNS31803 grade sheet of 10 mm thickness. This experimental study aims at 23factorial design optimizing various post weld aging parameters including solution temperature at 900 and 1,050 °C, post weld aging temperature at 650 and 850 °C and post weld aging time were set at 4 and 8 hour. The welded specimens were tested by hardness testing in heat affected zone and tensile strength testing. The result showed that both of solution temperature, post weld aging temperature and post weld aging time interaction on hardness and tensile strength at 95% confidential (P value < 0.05). Factors affecting the optimum were solution temperature 1050 °C, PWA temperature 850°C and PWA time 4 hr. at hardness optimum of 282.36 HV and tensile strength optimum of 109.37 kN. This research can bring information to the foundation in choosing the appropriate post weld aging parameters to duplex stainless steel welds.


2005 ◽  
Vol 495-497 ◽  
pp. 363-368
Author(s):  
Soo Ho Park ◽  
Hyung Gu Kang ◽  
Yong Deuk Lee ◽  
Jae Chul Lee ◽  
Moo Young Huh

In order to investigate the effect of the reduction degree per rolling pass on the evolution of recrystallization textures and microstructures, the hot band of 17.5 Cr-1.1 Mo ferritic stainless steel sheets were cold rolled with lubrication according to two processing routes, by which different reduction degrees per pass were introduced. Rolling with a large number of passes led to the formation of fairly homogeneous rolling textures at all through-thickness positions. In contrast, cold rolling with large draughts resulted in pronounced texture gradients along the thickness direction. After recrystallization annealing, the texture maximum was obtained at {334}<483> in all samples regardless of the rolling routes and thickness layers. During subsequent annealing, recrystallization was observed to be faster in those grains with {111}<uvw> orientations, while it was retarded in grains having orientations close to {001}<110>.


2019 ◽  
Vol 29 ◽  
pp. 1-12
Author(s):  
Juan Manuel Salgado López ◽  
Marc Preud homme ◽  
Francisco Lopez Monroy ◽  
Jose Luis Ojeda Elizarráraz ◽  
Arturo Toscano Giles

In literature, it has been reported that a current intensity lower than 120 A leads to a microstructure without grain growth in the heat affected zone (HAZ) of ferritic stainless steel welds. Nevertheless, in technical literature there is little information about the reduction in mechanical properties of ferritic stainless steel welds without filler metal due to grain growth in the HAZ. In this work, thin plates of ferritic stainless 439 steel were welded using pulse current gas tungsten arc welding (P-GTAW) without filler metal. The microstructures in the HAZ were analyzed and the mechanical properties on the welded joint were found by tensile test. This was carried out by cutting samples for the tensile test from the weldments and then tested in a universal testing machine. The fracture surface were observed using scanning electron microscope.


Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 86 ◽  
Author(s):  
Ying Han ◽  
Jiaqi Sun ◽  
Yu Sun ◽  
Jiapeng Sun ◽  
Xu Ran

The influence of temperature and strain rate on the hot tensile properties of 0Cr18AlSi ferritic stainless steel, a potential structural material in the ultra-supercritical generation industry, was investigated at temperatures ranging from 873 to 1123 K and strain rates of 1.7 × 10−4–1.7 × 10−2 s−1. The microstructural evolution linked to the hot deformation mechanism was characterized by electron backscatter diffraction (EBSD). At the same strain rate, the yield strength and ultimate tensile strength decrease rapidly from 873 K to 1023 K and then gradually to 1123 K. Meanwhile, both yield strength and ultimate tensile strength increase with the increase in strain rate. At high temperatures and low strain rates, the prolonged necking deformation can be observed, which determines the ductility of the steel to some extent. The maximum elongation is obtained at 1023 K for the strain rates of 1.7 × 10−3 and 1.7 × 10−2 s−1, while this temperature is postponed to 1073 K once decreasing the strain rate to 1.7 × 10−4 s−1. Dynamic recovery (DRV) and continuous dynamic recrystallization (CDRX) are found to be the main softening mechanisms during the hot tensile deformation. With the increase of temperature and the decrease of strain rate (i.e., 1123 K and 1.7 × 10−4 s−1), the sub-grain coalescence becomes the main mode of CDRX that evolved from the sub-grain rotation. The gradual decrease in strength above 1023 K is related to the limited increase of dynamic recrystallization and the sufficient DRV. The area around the new small recrystallized grains on the coarse grain boundaries provides the nucleation site for cavity, which generally results in a reduction in ductility. Constitutive analysis shows that the stress exponent and the deformation activation energy are 5.9 and 355 kJ·mol−1 respectively, indicating that the dominant deformation mechanism is the dislocations motion controlled by climb. This work makes a deeply understanding of the hot deformation behavior and its mechanism of the Al-bearing ferritic stainless steel and thus provides a basal design consideration for its extensive application.


2013 ◽  
Vol 721 ◽  
pp. 77-81 ◽  
Author(s):  
Jian Bin Zhang ◽  
Dong Mei Yu ◽  
Shao Rui Niu ◽  
Gen Shun Ji

The tensile test of casting ferritic stainless steel was conducted on SHIMADZU AG-10 at different temperatures of 300, 500, 600, 700, 800, and 950°C, respectively. The engineering stress-strain curves with the thermal deformation at the different temperatures, the tensile strength and elongation curves were obtained. Metallographic test samples were prepared and the morphology of deforming zone was observed by optical microscopy. The experimental results showed that the tensile strength of the test samples decreased with increasing temperature. From 300 to 500°C, the work hardening occurred and the tensile strength increased with increasing engineering strain. The softening occurred and the tensile strength decreased with increasing engineering strain at temperatures from 600 to 950°C. The strength of 430 stainless steel decreased, and the plasticity increased with the increase in temperature. The fractures were basically intergranular fractures within the range of 300~950°C. A transition occurred to the form of fracture from the ductile to the brittle, which might be related to the nitrogen atom in the 430. Grain deformation along specimen tensile direction concentrated in the necking region, where appeared banded structure in martensite. The organization at the edge of the sample was fine, while the organization at the central region was coarser.


Sign in / Sign up

Export Citation Format

Share Document