Study on the Effects of Multiple Laser Shock Peening Treatments on the Electrochemical Corrosion Performance of Welded 316L Stainless Steel Joints
Round 1
Reviewer 1 Report
Line 11: with different laser impact treatments. The word Impact appeared many times and it has the meaning of mechanical loading. It is better to change it to laser shot peening in the whole paper.
Line 31: “solid-state welding”, your paper related to Tungsten Arc Welding, it is fusion welding. Discuss and concentrate on the effect of fusion welding not solid-state welding.
Line 87-88: the dimensions you mentions seems to be the base metal not the filler metal. So, rephrase the sentences to be after the base metal, then mention the filler materials. Also, use metal instead of materials.
Line 89: “(i.e., mass fractions)” and in Table 1, it is mentioned wt.%, which one is correct?
Line 90: The parameters of Tungsten Arc Welding process must me mentioned such as current, voltage, speed, argon flow rate……
Line 90-92: “. The welding equipment adopted in the study 90 included a WS-300 argon tungsten arc welding machine, which was filled with inert gas 91 for protection, and the welded parts and filler metal were melted by arc heating to form 92 welded joints.” Is not clear and must be reviewed
Line 99: use word “grinded “instead of “polished”
Figures 2 and 3: where is the EBSD diagram and grain boundary orientation angles for two and three laser shoot peening?
There is the difference between Fig. 4 and Fig. 5. It seems Fig. 4 discuss the surface area and Fig. 5 discuss the interior of the plate. You have to clarify to avoid misunderstanding
Line 224-225 and Fig. 7: Martensite structure never appeared in 316 stainless steel alloys under any conditions, please check your XRD data
Line 363: it is mentioned “strengthened”. What I understood from this paper that this is not the target of the paper.
I tried to review the English. My review is in the attached file. Also, there are many other errors in this document in several places, please check English grammar. Proof reading by native speaker recommended.
Comments for author File: 
Comments.pdf
Author Response
Response 1：Changed "Impact" to "laser shock peening" in the whole paper.
Response 2：Modifications have been made in the paper.
Response 3：Changed content order and changed "material" to "metal"
Response 4：“mass fractions” is correct, have been revised in the paper.
Response 5：Current:120A Voltage:15V Speed:6.4cm/min Argon flow rate:10L/min and related content has been added to the paper.
Response 6：This part of the content has been supplemented in the paper.
Response 7：Corrections have been made in the paper.
Response 8：The purpose of the EBSD test is to analyze the changes in the orientation angle of grains and grain boundaries before and after laser shock strengthening. The specific analysis mainly uses SEM.
Response 9：Figure 4 shows a cross-sectional view of the 316l substrate away from the weld. Figure 5 shows the cross-sectional view of the 316l base at the weld. Corrections have been made in the paper.
Response 10：This paper studies 316L stainless steel instead of 316 stainless steel, 316L stainless steel can produce martensite and can be found in the literature.
DOI: 10.3390/met10070928
Response 11：This is a misrepresentation and has been corrected.
Reviewer 2 Report
The present paper includes interesting results regarding the microstructure and corrosion behavior of the diffusion bonding zone which is suitable for Journal of METALS. Anyhow, the reviewer would like to make the following comments.
1-How did the authors find the typical austenite structure in Fig.2? I suggest that XRD results can remove the issue.
2- In Fig.4b, the direction of one of the twins and the slip band are the same. However, the second twin (right position in the Fig) is perpendicular on the slip bands. It should be amended.
3-The twins are not observed with increasing the number of impacts. How to justify the matter?
4- The authors should list the data of XRD picks (Angles, full width at half maximum) in the table.
Author Response
Response 1：It is well known that 316l stainless steel contains austenite structure. Figure 2 only shows the phenomenon of grain refinement after laser shock strengthening, and there is no intention to find the location of austenite structure.
Response 2：Modifications have been made in Fig.4b.
Response 3：With the increase of the number of laser shocks, the single-system twins will gradually transition to multiple twins, the twins and dislocations will interact, and the grains show a clear tendency to refinement, so the twins in the figure are not represented.
Response 4：The radiation was Cu-Kα, the tube voltage 40 kV, the tube current 40 mA, the scanning angle ranged from 40° to 100°, the step size 0.01°, and the counting time 0.2 s.
Changed “impact” to “laser shock peening” in the whole paper.
Reviewer 3 Report
The authors have done a great and interesting scientific work. However, the welding experiment was described very poorly, the welding modes, the welding method are not indicated, the introduction does not contain articles on the features of welding this steel, but for some reason it is said about solid state welding (line 31). But well written about Laser Shock Peening. The welding experiment carried out by the authors is correctly called the Bead-on-plate test, when the plate is remelted by some source of energy (laser beam, electron beam, electric arc). In this case, as a rule, filler material is not used (lines 87 - 88). And the microstructure strongly depends on the level of heat input and welding regimes. I suggest to the authors to describe the experiment in more detail.
To other questions.
1 Lines 11 - 15. "And" is repeated 4 times, a lot for one sentence.
2 It is not customary to use "we" when writing scientific articles (lines 76, 80, 81, 82, 114, 119, 121, 127). You need to write in the third person.
3 There are some typos, lines 82, 118, 169; "different lasers" lines 191, 195.
4 Line 178, the microstructure shown in figure 5 cannot be called dendritic.
5 When welding this steel, the heat affected zone is very small, how the authors were able to get into it by laser shock peening, and most importantly, how they then made a sample for research.
6 Some references must be added to the text written on lines 203 - 213.
7 The title of section 3.3 is unclear.
8 The description of the experiment in Section 3.3 needs to be supplemented. It is not clear what "Wear" is in this context (figure 9). For the convenience of the reader, in figure 8, you need to add where the Base metal, Welding seam, Heat affected zone is located on the sample.
9 In figure 10, photos of the surface are visible, and not «diagram of the welded……».
10 In figure 12, it is need to add the thickness of the grain refinement zone for each laser shock peening treatment.
11 It is desirable to supplement the list of references with articles from the journals of the publishing house MDPI (Metals, Materials, Coatings).
Author Response
Response ：1. Welding experiments have been described in detail in the paper.
- The introduction was supplemented with articles on the characteristics of welding this steel.
- Because the research content of this paper does not include tensile tests, etc., the role of the welding filler is to weld on it and form a welded joint while maintaining the same composition as the 316l stainless steel plate.
Response 1：Modifications have been made to reduce the word “and”.
Response 2：Modifications have been made in the paper.
Response 3：Modifications have been made in the paper.
Response 4：Changed “dendritic” to “grain”.
Response 5：The welding zone is clear, but it is difficult to directly define the heat-affected zone and the base metal zone, so choose a larger area when performing laser shock hardening to ensure that the welding zone, heat-affected zone and base metal zone are covered.
Response 6：References [22-25] have been added.
Response 7：Changed to “Effect of Laser Shock Peening of Welded 316L Stainless Steel Joints”
Response 8：Because it is difficult to directly determine the boundary between the heat-affected zone and the matrix zone, considering that the width of the weld in this experiment is 5 mm (point 1 in Figure 8 is the center of the weld), point 2 is also located in the weld zone, and point 3 is located in the heat Affected zone, point 4 is in the transition between the heat-affected zone and the base metal zone, and point 5 is in the base metal zone.
Response 9：Corrections have been made in the paper.
Response 10：The thickness has been added in Figure 12.
Response 11：References [22-25] have been added.
Round 2
Reviewer 1 Report
The paper can be accepted in the Metal Journal
Author Response
Thank you very much!
Reviewer 3 Report
Line 271 - 272: incomprehensible phrase «….and the filler metal placed in the middle of the melt by arc heating, so as to form a 5 mm welded joint at the center of the weldment».
Line 54 - "We" is remained.
Author Response
Response 1：It has changed to "Using WS-300 argon tungsten arc welding equipment to melt the base plate and the filler metal which was placed in the middle of the base plate, so as to form a 5 mm welded joint at the center of the weldment in Figure 1."
Response 2：It has been modified.
