Effect of Postweld Heat Treatment on Microstructure and Properties of Thick S11306 Ferritic Stainless Welded Joints

Round 1

Reviewer 1 Report

This paper presented the effect Effect of Post weld Heat Treatment on Microstructure and Properties of Thick S11306 Ferritic Stainless Welded Joints. The abstract summarises all the key findings considering the context. However, it can be improved. A wide range of literature has been reviewed to justify the need for this research. The experimental section is ok, but can be improved. It was concluded that the composite phase of lower bainite and martensite is the weld zone is low for the as weld joint. When the heat treatment temperature is between 770℃ and 820℃  the composite phase of lower bainite and martensite is the weld zone increases. The conclusion is drawn based on the experimental observations. The manuscript definitely increases the current knowledge on this topic and the reviewer recommend to accept this article after revision. The following needs to be addressed:

1. A lot of redundancies are in abstract. Lines 9-14 is redundant. Please remove them and start from This study investigates.....Also include the different groups of PWHT in the abstract.

 

2. Table 3 line 114: s is missing for welding speed.

3. Line 107: Five groups of test plates are welded by the same welding process. Please make a clear statement. It appears that there are 20 weld beds and they are composed of 3 different welding parameters. Do you mean 5 repetitions?

 

4. Line 133: Please include how many points were tested for the hardness.

5. Table 5: What happened at 720 degree for the base metal zone? Please also add the error/standard deviation of the grain size. Please also include the units; Average size of ferrite grains in different regions (μ m).

 

6.  Table 7: Please include what was the temperature for those different holding times. Did you test only for one temperature for those different holding times? Also include the units as mentioned before. At what temperature complete crystallization occurred? The same for Table 8.

 

7. Figure 17: At what temperature those different heat treatment time was tested? I think it would be best to clearly mention in the experimental section, how many different temperature was tested and how many different holding time were tested for each of the different temperatures in a separate table.

8. Figure 22: Sample number does not make sense. What are the difference parameters of those samples? Again these condition should be clearly mentioned in the experimental section.

Overall, the manuscript has good contents. However, the organization of the manuscript was poor. Especially the experimental section should be rewritten completely to clearly mention all the experimental conditions.

Author Response

Detailed Response to First Reviewers' Comments

Title: Effect of Postweld Heat Treatment on Microstructure and Properties of Thick S11306 Ferritic Stainless Welded Joints

Manuscript ID: metals-2097464 

Reviewer Comments

Reviewer #1 

This paper presented the effect Effect of Post weld Heat Treatment on Microstructure and Properties of Thick S11306 Ferritic Stainless Welded Joints. The abstract summarises all the key findings considering the context. However, it can be improved. A wide range of literature has been reviewed to justify the need for this research. The experimental section is ok, but can be improved. It was concluded that the composite phase of lower bainite and martensite is the weld zone is low for the as weld joint. When the heat treatment temperature is between 770℃ and 820℃  the composite phase of lower bainite and martensite is the weld zone increases. The conclusion is drawn based on the experimental observations. The manuscript definitely increases the current knowledge on this topic and the reviewer recommend to accept this article after revision. The following needs to be addressed:

1.A lot of redundancies are in abstract. Lines 9-14 is redundant. Please remove them and start from This study investigates.....Also include the different groups of PWHT in the abstract.

R: Thanks for the expert's professional advice, the expert's professional advice is very important.

Abstract has been removed as recommended by the experts. And changed the content of the abstract,the altered abstract summarizes the different post-welding heat treatment processes. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

2.Table 3 line 114: s is missing for welding speed.

R: Thanks for the expert's professional advice, the expert's professional advice is very important.

This is a spelling error, the peed has been changed to speed. The welding speed is described in Table 3, as 4 mm/s. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

3.Line 107: Five groups of test plates are welded by the same welding process. Please make a clear statement. It appears that there are 20 weld beds and they are composed of 3 different welding parameters. Do you mean 5 repetitions?

R: Thanks for the expert's professional advice, the expert's professional advice is very important.

Five groups of test plates were welded in the test, and Chapter 2.1 of the article describes that the five groups of test plates all use the same welding process. Each group of test plates has 20 welds, as shown in Table 3. The welding parameters of the 1st, 19th and 20th passes are the same, and the welding parameters of the 2nd to 18th passes are the same.

Table 3. Welding process parameters

Weld bead	U/(V)	I/(A)	Welding speed(mm/s)	Heat input(kJ/mm)
1	23~25	149	4	0.857~0.931
2~18		155		0.891~0.969
19~20		149		0.857~0.931

Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

4.Line 133: Please include how many points were tested for the hardness. 

R:Thanks for the expert's professional advice, the expert's professional advice is very important. 

There are 20 hardness test points, which have been described in chapter 2.3. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

5.Table 5: What happened at 720 degree for the base metal zone? Please also add the error/standard deviation of the grain size. Please also include the units; Average size of ferrite grains in different regions (μ m).

R:Thanks for the expert's professional advice, the expert's professional advice is very important. 

The grain size of the base metal zone at 720℃ is supplemented in the text. At 720℃, the average grain size of ferrite is about 97μm. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

6.Table 7: Please include what was the temperature for those different holding times. Did you test only for one temperature for those different holding times? Also include the units as mentioned before. At what temperature complete crystallization occurred? The same for Table 8.

R:Thanks for the expert's professional advice, the expert's professional advice is very important. 

Since 820℃ is the recrystallization temperature of S11306 ferrite stainless steel, the heat treatment temperature was fixed at 820℃ at different holding times. Only tests with different holding time at 820℃ were conducted. The temperature for complete recrystallization is 870℃. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

7.Figure 17: At what temperature those different heat treatment time was tested? I think it would be best to clearly mention in the experimental section, how many different temperature was tested and how many different holding time were tested for each of the different temperatures in a separate table.

R:Thanks for your professional advice, and your professional advice is very important. 

The hardness change of the welded joints from 30s to 1h were tested at 820℃, and he hardness changes under complete recrystallization was tested at 870℃. The hardness distribution of the welded joints after 2h of holding time at five different heat treatment temperatures were tested. And this has been supplemented in the manuscript according to the experts' suggestions. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

8.Figure 22: Sample number does not make sense. What are the difference parameters of those samples? Again these condition should be clearly mentioned in the experimental section.

8.Figure 22: Sample number does not make sense. What are the difference parameters of those samples? Again these condition should be clearly mentioned in the experimental section.

R:Thanks for your professional advice, and your professional advice is very important.

The difference parameters of those samples is temperature, with 1 for as-welded, 2 for 720℃, 3 for 770℃, 4 for 820℃, and 5 for 870℃. And this has been supplemented in the manuscript according to the experts' suggestions.

Figure 22. Tensile test results:1.as-welded, 2.720℃ 3.770℃ 4.820℃ 5.870℃

Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

9.Overall, the manuscript has good contents. However, the organization of the manuscript was poor. Especially the experimental section should be rewritten completely to clearly mention all the experimental conditions.

R:Thanks for your professional advice, and your professional advice is very important.

The author modified the experimental section, put all the discussion about pictures in Chapter 3.1 before the pictures, improved the resolution of the pictures, and put the text labels in the pictures into transparent text boxes. The redundant tables are deleted, and the data in the tables are stated in the corresponding positions. All test conditions after modification are mentioned in the manuscript. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

Thanks again for your advice, and I hope I can learn more from you.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper presents the influence of the Post Weld Heat Treatment (PWHT) on the microstructure and properties of thick S11306 Ferritic Stainless welded joints. Many weaknesses have been noticed, as follows:

1. Abstract (L 18-22): The content of the composite phase of lower bainite and martensite in the as-welded samples is smaller in comparison with the content measured in the samples subjected to heat treatment. If the content of LB/M is increasing after the PWHT, how do you explain the embrittlement phenomenon and the inacceptable results of bending test in the case of as-welded samples?

2. The subject, the research methodology and the welding technique are not innovative. Consequently, the authors must clearly justify and highlight the novelty of their research.

3. The SMAW process is an unproductive technique to join such thick plates. There are more efficient welding procedures that are recommended for joining sheets with thickness of 25 mm.

4. To control the embrittlement phenomenon, did you try to modify the process parameters, instead of increasing the cost by applying PWHT, or better to change the welding method? Because of the large number of passes, the microstructure in WZ and HZ is subjected to consecutive heating and cooling cycles that obviously affect the metallurgical structure. This effect is not sufficiently presented and discussed.

5. L108-109: For more clarity of the text, the sentence “Welded joints are not defects by X-ray detection” must be reformulated.

6. Tables 1 and 2: Please, mention the standards that provide the chemical composition and mechanical properties. Also, the mechanical properties of filler material must be added.

7. Table 3: The parameter “welding speed” must be corrected.

8. The filler material diameter of 4mm is too large to be used for depositing material by welding in the root gap. In practice, it is employed a coated electrode with diameter of 2.5 …. 3.25 mm to correctly and completely fill the root gap.

9. Fig. 3: “Weld bond” must be replaced with “Fusion line” which is the right technical term.

10. Figure 4 (Hardness test): The hardness profile must be plotted based on the hardness measurements on at least 3 lines (bottom, middle and top) that cross all regions of the welded joint (BM – HAZ – Weld – HAZ – BM).

11. Figures 5 and 6, Table 4 should be removed because they do not bring any scientific value to the manuscript.

12. The chapter 3.1 cannot start with figures. The discussion on results presented in figures and tables must be moved before them.

13. It is not sufficient to present the effects of the heat treatment time and temperature on the microstructure evolution. The discussion on the results must be supported by scientific arguments, so that the cause-effect be clearly explained and adequately justified.

14: All optical microstructures: The acronyms of phases (M, F) and especially the numbers (1, 2, 3….) must be written in transparent text boxes in order to see the complete images. The resolution of microstructures must be improved. The images size is too large and should be adapted to the paper content and font.

15. L 173: “alway” is the archaic form of “always”. Please correct it.

16. L 406-407: How do you explain that “the corrosion resistance of ferritic stainless steel can be effectively improved when the heat treatment temperature is in the range of 770℃~820℃.” Additional investigation on corrosion is needed to support this statement.

15. Lack of verb-subject agreement (i.e. L101) and more errors of grammar have been noticed. The translation into English language must be revised by a native speaker.

Author Response

Detailed Response to Second Reviewers' Comments

Title: Effect of Postweld Heat Treatment on Microstructure and Properties of Thick S11306 Ferritic Stainless Welded Joints

Manuscript ID: metals-2097464 

Reviewer Comments

Reviewer #2 

The paper presents the influence of the Post Weld Heat Treatment (PWHT) on the microstructure and properties of thick S11306 Ferritic Stainless welded joints. Many weaknesses have been noticed, as follows:

1.Abstract (L 18-22): The content of the composite phase of lower bainite and martensite in the as-welded samples is smaller in comparison with the content measured in the samples subjected to heat treatment. If the content of LB/M is increasing after the PWHT, how do you explain the embrittlement phenomenon and the inacceptable results of bending test in the case of as-welded samples?

R: Thanks for the expert's professional advice, the expert's professional advice is very important.

At as-welded, the content of the LB/M in the weld zone is less, and there is martensite, so the toughness of the welded joint is poor, and embrittlement is easy to occur. After heat treatment, the content of the LB / M increases. Due to the high strength and excellent toughness of the lower bainite , the toughness of the welded joints after heat treatment is improved, and no embrittlement occurs. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

2.The subject, the research methodology and the welding technique are not innovative. Consequently, the authors must clearly justify and highlight the novelty of their research.

R: Thanks for the expert's professional advice, the expert's professional advice is very important.

This article is mainly to solve the serious embrittlement problem of 25mm-thick S11306 ferrite stainless steel welded joints. At present, there are few reports on the post-welding heat treatment process of this material, and most scholars have studied the welding of S11306 and other metals' composite materials, and the thickness is about 10mm. This article mainly solves the embrittlement problem of welded joints through post-welding heat treatment, the microstructure, hardness and mechanical properties of the welded joints were tested, and finally obtained a reasonable heat treatment process, and the embrittlement problem of the welded joints with 25mm thick plate was solved. The innovation of the subject is addressed at the end of both sections 1 and 3. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

3.The SMAW process is an unproductive technique to join such thick plates. There are more efficient welding procedures that are recommended for joining sheets with thickness of 25 mm.

R: Thanks for the expert's professional advice, the expert's professional advice is very important.

SMAW process is the welding process used by the company. Thanks for your suggestion, due to your suggestion, I have found the shortcomings of my current work. In the later work, I will focus on the choice of welding process according to your suggestion. Thanks to your valuable advice, the level of the article has been improved.

4.To control the embrittlement phenomenon, did you try to modify the process parameters, instead of increasing the cost by applying PWHT, or better to change the welding method? Because of the large number of passes, the microstructure in WZ and HZ is subjected to consecutive heating and cooling cycles that obviously affect the metallurgical structure. This effect is not sufficiently presented and discussed.

R:Thanks for the expert's professional advice, the expert's professional advice is very important. 

The welding parameters used in the test are based on the requirements of the company, and the post weld heat treatment process has not been solved, so this paper mainly studies the influence of the post weld heat treatment process on the embrittlement of welded joints. Thanks for your suggestion, due to your suggestion, I have found the shortcomings of my current work. In the later work, I will focus on the choice of welding parameters according to your suggestion. After several times of heating, the weld bead does affect the microstructure of the welded joint, I did not consider this aspect in my study, Thank you for your suggestion. In the later work, I will focus on strengthening the research and discussion on this aspect. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

5. L108-109: For more clarity of the text, the sentence “Welded joints are not defects by X-ray detection” must be reformulated.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.  

In the manuscript, “The welded joints are not defects by X-ray detection ”has been corrected to “All the test samples have passed the nondestructive test”. And the nondestructive testing of the test plate is mainly used to check whether there are cracks in the welded joint after welding, thus affecting the accuracy of the mechanical test. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

6.Tables 1 and 2: Please, mention the standards that provide the chemical composition and mechanical properties. Also, the mechanical properties of filler material must be added.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

S11306 is based on NB/T47010-2010, and G2O7 is based on NB/T47018.2. The mechanical properties of the electrode G207 have been added in Table 2.

Table 2. Mechanical properties of S11306 ferrite stainless steel

Material	Tensile strength (MPa)	Yield strength (MPa)	Elongation (%)
S11306	410	205	20
G207	450	-	20

Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

7.Table 3: The parameter “welding speed” must be corrected.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

This is a spelling error, the peed has been changed to speed.

Table 3. Welding process parameters

Weld bead	U/(V)	I/(A)	Welding speed(mm/s)	Heat input(kJ/mm)
1	23~25	149	4	0.857~0.931
2~18		155		0.891~0.969
19~20		149		0.857~0.931

Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

8.The filler material diameter of 4mm is too large to be used for depositing material by welding in the root gap. In practice, it is employed a coated electrode with diameter of 2.5 …. 3.25 mm to correctly and completely fill the root gap.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

The diameter of electrode used by the company in actual work is 4mm, The 19th and 20th welding is to fill the root gap. Thanks for the experts' suggestions, In the later scientific research works, I will use the electrode with the diameter of 2.5~3.25mm mentioned by the experts for welding. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

9.Fig. 3: “Weld bond” must be replaced with “Fusion line” which is the right technical term.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

The Weld bond in Figures 3 and 4 have been replaced with the Fusion line.

 

Figure 3. Sampling diagram of metallographic specimen of welded joint

 

Figure 4. Sampling diagram of hardness test point of welded joint

Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

10.Figure 4 (Hardness test): The hardness profile must be plotted based on the hardness measurements on at least 3 lines (bottom, middle and top) that cross all regions of the welded joint (BM – HAZ – Weld – HAZ – BM).

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

In the manuscript, the hardness change test of the hardness samples obtained under each group of heat treatment processes under the fixed position is conducted, and the suggestions put forward by experts were not taken into account in the process of planning the test. Due to irresistible factors, I cannot return to the school for experiment in the next few months, and I hope the expert understand. Thanks for your suggestion, it is very important, because of your suggestions, I have found the shortcomings in my current works, I will improve the scientific research level according to your suggestions in the future work, and make more achievements. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

11.Figures 5 and 6, Table 4 should be removed because they do not bring any scientific value to the manuscript.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

Figure 5 and Figure 6 are two-dimensional drawings drawn to more clearly explain the dimensions taken by the stretching and bending tests in mechanical tests. Table 4 is to illustrate the test parameters used in the bending test. If the experts think it must be deleted, then I will delete them in later modifications. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

12.The chapter 3.1 cannot start with figures. The discussion on results presented in figures and tables must be moved before them.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

All the discussions in Chapter 3.1 are placed before the picture. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

13.It is not sufficient to present the effects of the heat treatment time and temperature on the microstructure evolution. The discussion on the results must be supported by scientific arguments, so that the cause-effect be clearly explained and adequately justified.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

The article first analyzes the evolution of the microstructure of the welded joints under different heat treatment processes, and then makes the hardness test, tensile test and bending test of the welding joint under different heat treatment temperatures, through the microstructure evolution, To explain why the welded joints exhibit different mechanical properties. Finally, the best heat treatment process was obtained to solve the embrittlement problem of welded joints of 25 mm-thick S11306 ferrite stainless steel. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

14.All optical microstructures: The acronyms of phases (M, F) and especially the numbers (1, 2, 3….) must be written in transparent text boxes in order to see the complete images. The resolution of microstructures must be improved. The images size is too large and should be adapted to the paper content and font.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

All the text in the graphic images were written in transparent text boxes, and the image size and resolution were improved. For example:

Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

15.L 173: “alway” is the archaic form of “always”. Please correct it.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

In the manuscript, “alway” has been corrected to “always”. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

16.L 406-407: How do you explain that “the corrosion resistance of ferritic stainless steel can be effectively improved when the heat treatment temperature is in the range of 770℃~820℃.” Additional investigation on corrosion is needed to support this statement.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

According to reference 27, heat treatment at 770 ℃~820 ℃ can improve the corrosion resistance of ferritic stainless steel. Since this paper mainly studies the embrittlement of welded joints, no test on the corrosion resistance of ferrite stainless steel has been conducted, this has been deleted during modification. Thanks for the advice of the experts, this suggestion is very important. In the later scientific research works, I will strengthen the research of the corrosion resistance of stainless steel. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

17.Lack of verb-subject agreement (i.e. L101) and more errors of grammar have been noticed. The translation into English language must be revised by a native speaker.

R:Thanks for the expert's professional advice, the expert's professional advice is very important.

The whole article has been carefully revised by my colleagues majoring in English. The syntax errors in L101 and elsewhere in the article have been corrected, and the word order problems existing in some places are corrected. This has resulted in some changes, that has also helped boost consistency across the text as a whole. Thanks again for the expert's advice. Thanks to your valuable advice, the level of the article has been improved.

Thanks again for your advice, and I hope I can learn more from you.

 

 

 

 

 

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear authors,

I have read your article with interest.

The topic is devoted to the issue known for years and quite well described in the literature about 25 years ago in general.

The weldability of steels (including corrosion-resistant ferritic chromium) is referenced in the standards of quality assurance systems in welding, e.g. EN-ISO 3834.

However, there are some newsworthy news in your article.

Detailed comments are provided below:

-Keywords:
There no justify to repeat "S11306 ferritic stainless steel" in keywords. In this way you will not increase visibility of you paper in internet browser. Metadata words should be different.

-Introduction 
Line 32 "excellent corrosion resistance" is jargon. Corrosion resistance is relative.

Line 42 "... few literature reports on different post-welding heat treatment processes". This is not true, I suggest toning down the statement.

Line 45 I suggest to mention about different welding methods dedicated to welding of thick joints as PTA-MAG hybrid

DOI: 10.1016/j.jajp.2022.100111

Line 74 HIC abbreviation is not expanded.

-Materials

S11306 by what standard?
Line 100 "electrode arc welding" What kind of welding method it means?

Line 104 "ZX7-500S" is very mysterious designation, I suggest supplementing the manufacturer's name and country. 

Tab. 3 "welding peed";  "cm" seems to be unsuitable unit for scientific papers

Line 117 "Wire cut" is jargon.

- Result and discussion
Line 187 (and many other places) In your work you refer to different grain sizes, but there is no description of how the grain size was measured and which standard was used. Without this description, there is concern that the grain size measurement is not statistically reliable.

Line 231 "completely soft microstructure" What does it mean?

Line 237 "the content of LB/M" How it was measured?

Line 287 "After complete recrystallisation" What does it mean?

Figure 16 and 17 Hardness measurement without showing the mean value and standard deviation is statistically unreliable. A single measurement may be random (especially for a complex phase structure).

Figure 18 has no description in the text.

Line 393 "the residual stress after welding was effectively eliminated" Please indicate proof of this claim.

Figure 22. The description of the chart needs improvement.

Figure 23 and 24 The pictures are too small, I can't see the details.

Conclusions 2; 3; 4 Based on statistically unreliable results. I suggest rewording.

Regards

 

 

Author Response

please see the response in the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The reviewer is satisfied with the response. It can be accepted now.

Author Response

Thank you very much for the expert on the valuable opinions put forward by the manuscript,I wish you a happy life, happy every day.

Reviewer 2 Report

The scientific content of the manuscript was improved according to the reviewers’ comments. However, in my opinion, there are still several technological issues in terms of the process and parameters employed to perform the welded joint.

1. The SMAW process is an unproductive and inappropriate technique to join such thick plates. There are other efficient welding procedures which are recommended for joining sheets with thickness of 25 mm.

2. The value of the welding speed is too high (4 mm/s). Usually, this parameter should be, for Shielded Metal Arc Welding (SMAW), in the range of 75 … 150 mm/min, meaning 1.25 …. 2.5 mm/s.

3. The filler material diameter of 4mm is too large to be used for depositing material by welding in the root gap. In practice, it is employed a coated electrode with diameter of 2.5 …. 3.25 mm to correctly fill the root gap.

Author Response

Detailed Response to Second Reviewers' Comments

Title: Effect of Postweld Heat Treatment on Microstructure and Properties of Thick S11306 Ferritic Stainless Welded Joints

Manuscript ID: metals-2097464 

Reviewer Comments

Reviewer #2 

The scientific content of the manuscript was improved according to the reviewers’ comments. However, in my opinion, there are still several technological issues in terms of the process and parameters employed to perform the welded joint.

1. TheSMAW process is an unproductive and inappropriate technique to join such thick plates. There are other efficient welding procedures which are recommended for joining sheets with thickness of 25 mm.

R: Thanks for the expert's professional advice, the expert's professional advice is very important.

The SMAW process refers to the current process used by the company for welding such stainless steel. Due to the limitations of welding environment, it is more convenient to use SMAW process and more flexible in actual operation. Thank you very much for the expert's valuable advice. In the future research work, I will focus on using other welding processes to explore the best welding process suitable for this kind of thick plate. Thanks again for the expert's advice. Your valuable suggestions will have a great inspiration to my future work.

2. The value of the welding speed is too high (4 mm/s). Usually, this parameter should be, for Shielded Metal Arc Welding (SMAW), in the range of 75 … 150 mm/min, meaning 1.25 …. 2.5 mm/s.

R: Thanks for the expert's professional advice, the expert's professional advice is very important.

The higher welding speed is to reduce the welding heat input as much as possible on the basis of meeting the welding requirements, so as to avoid the occurrence of unfavorable microstructure in the welded joints, which will affect the comprehensive mechanical properties of the welded joints. Thank you very much for the expert's valuable advice. In the future research work, I will focus on welding with the welding speed proposed by the expert, and study the changes in its mechanical properties and microstructure. Thanks again for the expert's advice. Your valuable suggestions will have a great inspiration to my future work.

3. The filler material diameter of 4mm is too large to be used for depositing material by welding in the root gap. In practice, it is employed a coated electrode with diameter of 2.5 …. 3.25 mm to correctly fill the root gap.

R: Thanks for the expert's professional advice, the expert's professional advice is very important.

During welding, in order to avoid the root gap cannot be filled or filling unqualified phenomenon, after the completion of 18 welding on the front side, the back of the test plate is welded twice, so as to realize the full filling of the root gap. Thank you very much for the expert's valuable advice. In the future research work, I will focus on using the welding rod of 2.5~3.25mm suggested by the expert to weld this material, and study the impact of different electrode diameters on the comprehensive performance of welding joints. Thanks again for the expert's advice. Your valuable suggestions will have a great inspiration to my future work.

Thanks again for your advice, and I hope I can learn more from you.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors,

I appreciate you deep rebuilding of the manuscript. I my opinion in present form it is good enough for publishing.

I have no more comments.

Regards

Author Response

Thank you very much for the expert on the valuable opinions put forward by the manuscript,I wish you a happy life, happy every day.