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Research on the Near Net Shape Hollow Forging Technology for CAP 1400 Main Pipe
Wang Baozhong,
Liu Ying,
Guo Yi,
Nie Yihong
Issue:
Volume 6, Issue 2, April 2018
Pages:
18-22
Received:
19 March 2018
Accepted:
9 April 2018
Published:
8 May 2018
Abstract: It has been widely focused because of its complex integral-structure and strict technical requirement since AP1000 main pipe appeared, which is made by 316LN stainless steel. After ten years of effort and exploring, excellent forging suppliers from all over the world agree that 316LN heavy forgings including AP1000 only can be formed by relatively simple solid forging technology though the grain size cannot meet the initial design requirement of ASTM level-4. The design concept of CAP1400 main pipe is the same as AP1000, in which the straight part, curving part and two supper-long asymmetrical nozzles should be an integrated structure manufactured by 316LN steel. But due to larger dimension and higher requirement for technology, the manufacturing of CAP1400 is more difficult. In order to realize the near net shape manufacturing of CAP1400 main pipe, we invent a green manufacturing technology with highly asymmetrical nozzle for stainless steel main pipe hollow forgings, We have successfully manufactured a stainless hollow forgings using a 78t ESR ingot with nozzle height of 400mm, wall thickness of 160mm, total length of 9000mm, and ASTM level 4-6 of grain size for each part.
Abstract: It has been widely focused because of its complex integral-structure and strict technical requirement since AP1000 main pipe appeared, which is made by 316LN stainless steel. After ten years of effort and exploring, excellent forging suppliers from all over the world agree that 316LN heavy forgings including AP1000 only can be formed by relatively ...
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An Improved Radar-Graph Method for Comprehensive Evaluation of Material Machinability
Tao Sun,
Jin Liang,
Dengwan Li,
Huizhong Wang,
Xinxing Li
Issue:
Volume 6, Issue 2, April 2018
Pages:
23-28
Received:
25 March 2018
Accepted:
18 April 2018
Published:
11 May 2018
Abstract: Material machinability evaluation is the basis of a reasonable manufacturing process. Material machinability can be evaluated qualitatively and quantitatively using the radar-graph method. However, two key questions remain unresolved, and these are indicator weight confirmation and effective evaluation. A comprehensive evaluation method is proposed to address the first question. A statistical method is used to compute the indicator weight, which is determined by a subjective or objective weighting method. An optimization model is established based on minimizing the total deviation between the original evaluation weight and the combination weight. As to the second question, a comprehensive evaluation index K, including the area vector and perimeter vector of a radar-graph, is defined to quantitatively evaluate material machinability. Machinability examples of Ti6Al4V titanium alloy, AISI316L stainless steel, P20 mold steel, 20 steel, and normalized 45 steel are provided. The results show that the method is feasible, reliable, and effective.
Abstract: Material machinability evaluation is the basis of a reasonable manufacturing process. Material machinability can be evaluated qualitatively and quantitatively using the radar-graph method. However, two key questions remain unresolved, and these are indicator weight confirmation and effective evaluation. A comprehensive evaluation method is proposed...
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A New Detection Method for Oxygen, Nitrogen and Hydrogen on Superalloy Milling Surfaces
Tao Sun,
Jin Liang,
Dengwan Li,
Ling Zhong,
Chunyuan Gong
Issue:
Volume 6, Issue 2, April 2018
Pages:
29-34
Received:
25 March 2018
Accepted:
18 April 2018
Published:
15 May 2018
Abstract: Oxygen, nitrogen and hydrogen from air greatly affect the surface quality of milled superalloys—a difficult-to-cut material. Here, we described a novel infrared-thermal conductivity method to measure oxygen, nitrogen and hydrogen on superalloy surfaces during milling. A milling experimental program was projected via the uniform design method—this contained a qualitative factor. The quadratic regression model of the superalloy was established using the best regression subset method. Here, the cutting speed, feed per tooth, axial cutting depth, radial cutting depth, and tool nose radius were the independent variables. The results were feasible with an acceptable regression effect.
Abstract: Oxygen, nitrogen and hydrogen from air greatly affect the surface quality of milled superalloys—a difficult-to-cut material. Here, we described a novel infrared-thermal conductivity method to measure oxygen, nitrogen and hydrogen on superalloy surfaces during milling. A milling experimental program was projected via the uniform design method—this c...
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Research and Development of the Wind Turbine Reliability
Yao Li,
Caichao Zhu,
Chaosheng Song,
Jianjun Tan
Issue:
Volume 6, Issue 2, April 2018
Pages:
35-45
Received:
19 March 2018
Accepted:
3 April 2018
Published:
18 May 2018
Abstract: With the rapid development of wind power industry, the wind turbine reliability has become a hotspot in wind power research. The failure modes and research progress of wind turbine reliability both at home and abroad were analyzed. The failure modes, failure causes and detection methods of some key components in the wind turbines were summarized. Also, the frequently used methods of reliability analysis and research status of wind turbine reliability were analyzed. Following this, research focuses, methods and measures to improve wind turbine reliability were presented. We also shed light on the condition monitoring and assessment process with condition monitoring system and supervisory control and data acquisition. It is of great significance to reduce the cost of operation and maintenance and to improve the safety of wind turbines.
Abstract: With the rapid development of wind power industry, the wind turbine reliability has become a hotspot in wind power research. The failure modes and research progress of wind turbine reliability both at home and abroad were analyzed. The failure modes, failure causes and detection methods of some key components in the wind turbines were summarized. A...
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