Effect of nitrogen content on microstructure, mechanical properties, and corrosion behaviour of coarse-grained heat-affected zone of nitrogen-containing austenitic stainless steel

Author(s):  
Jianguo Li ◽  
Huan Li ◽  
Zhangyin Xu ◽  
Jichun Yang ◽  
Lijun Yang
2021 ◽  
Vol 71 (03) ◽  
pp. 383-389
Author(s):  
Rahul Singh ◽  
Surya Deo Yadav ◽  
Biraj Kumar Sahoo ◽  
Sandip Ghosh Chowdhury ◽  
Abhishek Kumar

The present work investigates the effect of rolling (90% thickness reduction) on phase transformation, mechanical properties, and corrosion behaviour of 304L-austenitic stainless steel through cryorolling and room temperature rolling. The processed steel sheets were characterised through X-ray diffraction (XRD), electron backscattered diffraction (EBSD), and vibrating sample magnetometer (VSM). The analysis of XRD patterns, EBSD scan, and vibrating sample magnetometer results confirmed the transformation of the austenitic phase to the martensitic phase during rolling. Cryorolling resulted in improved tensile strength and microhardness of 1808 MPa and 538 VHN, respectively, as compared to 1566 MPa and 504 VHN for room temperature rolling. The enhancement in properties of cryorolled steel is attributed to its higher dislocation density compared to room temperature rolled steel. The corrosion behaviour was assessed via linear polarisation corrosion tests. Corrosion resistance was found to decrease with increasing rolling reduction in both room temperature rolled and cryorolled specimens.


Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.


Alloy Digest ◽  
2021 ◽  
Vol 70 (3) ◽  

Abstract ATI 201 HP is a 200-series, Cr-Mn-Ni austenitic stainless steel. It is comparable to the Cr-Ni stainless steel types 301, 304, and 304L in many respects, and can even provide some advantages over the 18-8 grades in certain applications. Because it possess a very desirable combination of economy plus good mechanical properties and corrosion resistance, it has been used in a wide variety of consumer and transportation applications. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-1332. Producer or source: ATI.


2021 ◽  
Author(s):  
Indrajit Dey ◽  
Pallabi Manna ◽  
Muralidhar Yadav ◽  
Nisith Kumar Tewary ◽  
Jayanta Kumar Saha ◽  
...  

In the present research, the effects of various alloying elements and microstructural constituents on the mechanical properties and corrosion behaviour have been studied for four different rebars. The microstructures of stainless steel and plain rebar primarily reveal equiaxed ferrite grains and ferrite-pearlite microstructures, respectively, with no evidence of transition zone, whereas tempered martensite at the outer rim, followed by a narrow bainitic transition zone with an internal core of ferrite-pearlite, has been observed for the thermomechanically treated (TMT) rebars. The hardness profiles obtained from this study display maximum hardness at the periphery, which decreases gradually towards the centre, thereby providing the classical U-shaped hardness profile for TMT rebars. The tensile test results confirm that stainless steel rebar exhibits the highest combination of strength (≈755 MPa) and ductility (≈27%). It has been witnessed that in Tafel plots, the corrosion rate increases for all the experimental rebars in 1% HCl solution, which is well expected because the acid solutions generally possess a higher corrosive environment than seawater (3.5% NaCl) due to their acidic nature and lower pH values. However, all the experimental results obtained from Tafel and Nyquist plots correlate well for both 1% HCl and 3.5% NaCl solutions.


2014 ◽  
Vol 45 (13) ◽  
pp. 6317-6328 ◽  
Author(s):  
P. Behjati ◽  
A. Kermanpur ◽  
A. Najafizadeh ◽  
H. Samaei Baghbadorani ◽  
L. P. Karjalainen ◽  
...  

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