Study on High Speed Milling of Steam Turbine Blade Materials - Difference in Cutting Characteristics by Alloying Elements of Stainless Steel

2016 ◽  
Vol 874 ◽  
pp. 439-444
Author(s):  
Tomonori Kimura ◽  
Takekazu Sawa ◽  
Tatsuyuki Kamijyo
Keyword(s):  
Stainless Steel ◽  
Steam Turbine ◽  
Tool Life ◽  
High Speed ◽  
Cutting Speed ◽  
End Mill ◽  
High Speed Milling ◽  
Point Temperature ◽  
Steam Turbine Blade ◽  
Cutting Point

In this study, high speed milling of stainless steel was tried for purpose of high efficiency cutting of a steam turbine blade. In the experiment, cutting tool used TiAlN coating radius solid end mill made of cemented carbide. Diameter of end mill is 5mm. Corner radius is 0.2mm. Cutting speed carried out at 100m/s~600m/s. Work pieces was used in the experiment are four kinds of stainless steel which alloy elements differ. Mainly, content of chromium and nickel is different. There are many researches about high speed milling [1, 2].However, the researches which examined relationship between alloy elements of stainless steel and cutting characteristics on high speed milling using small diameter endmill are few.As the results, in the case of stainless steel containing much nickel, tool life becomes short in high speed cutting area. This reason is nickel has low thermal conductivity. Because the cutting point temperature becomes higher. If the coating removes, wear becomes large rapidly. In other words, maximum limit value of cutting speed was found to be dependent on heat resistance temperature of the coating.On the other hand, Chromium has the effect of improving the abrasion resistant of the workpiece. However, Flank wear was not increased in a low cutting speed area. In the range of this experimental condition, chromium didn't influence tool life. When cutting point temperature is below heat resistant temperature of the coating, it is thought that effect of the coating is maintained. Namely, it was found that appropriate cutting speed followed heat resistant temperature of the coating.

Study on High Speed Milling of Steam Turbine Blade Materials - Differences in Cutting Characteristics of Titanium Alloy and Stainless Steel

2016 ◽  
Vol 874 ◽  
pp. 445-449
Author(s):  
Tomonori Kimura ◽  
Tatsuyuki Kamijo ◽  
Takekazu Sawa
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
Heat Resistance ◽  
Steam Turbine ◽  
High Speed ◽  
Cutting Speed ◽  
High Speed Milling ◽  
Point Temperature ◽  
Steam Turbine Blade ◽  
Cutting Point

Titanium alloy and stainless steel are used as steam turbine blade materials. However, their machining efficiency is low because they are difficult-to-cut materials. In particular, the high cutting point temperature and short tool life are major problems. Highspeed milling can reduce the cutting point temperature and tool wear. In this study, highspeed milling of a titanium alloy and stainless steel was investigated for the high-efficiency cutting of a steam turbine blade. In the experiment, workpieces were made of titanium alloy Ti-6Al-4V and stainless steel 13Cr. The experiment was conducted at cutting speeds from 100 m/min to 600 m/min. The flank wear increased rapidly with increase in the cutting speed. The loss of the coating on the flank of the end mill was confirmed via energy-dispersive Xray spectroscopy analysis. It was demonstrated that the cutting point temperature was higher than the heat resistance temperature of the coating. The cutting point temperature was analyzed using AdvantEdge FEM. It was found that the cutting point temperature at a cutting speed of 350 m/min or more was higher than the heat resistance temperature of the coating. On the other hand, in the case of the stainless steel 13Cr, the flank wear increased in proportion to the cutting speed, and the loss of the coating on the flank of the end mill was also confirmed. However, the loss of the coating was less than that in the case of the titanium alloy. It was found that the high-speed milling of the stainless steel did not reach the heat resistance temperature of the coating. The cutting characteristics of the high-speed milling of the titanium alloy and stainless steel differed, which was mainly attributed to the difference in the thermal conductivity. In the high-speed milling of the titanium alloy Ti-6Al-4V and stainless steel 13Cr, it was not possible to determine the factors that result in a low cutting point temperature. If the cutting point temperature is lower than the heat resistance temperature of the coating, high-speed milling may be possible. Therefore, the ways in which the cutting point temperature can be lowered will be examined in the future.

Study on High Speed Milling of Steam Turbine Blade Materials

2016 ◽  
Vol 1136 ◽  
pp. 251-256
Author(s):  
Tomonori Kimura ◽  
Takekazu Sawa ◽  
Tatsuyuki Kamijyo
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
Steam Turbine ◽  
Turbine Blade ◽  
Tool Life ◽  
High Speed ◽  
Cutting Speed ◽  
High Speed Milling ◽  
Steam Turbine Blade ◽  
Cutting Point

A titanium alloy and stainless steel is an excellent material having properties such as high intensity and high corrosion resistance. Therefore, a titanium alloy and a stainless steel are used as material of steam turbine blade. However, the machining efficiency of a titanium alloy and a stainless steel is a low because of difficult-to-cut materials. Especially, it is a major problem that the cutting point temperature is high and the tool life is short. In the conventional study, it is reported that the cutting point temperature is low and the tool life becomes long by cutting at the suitable cutting speed corresponding to material characteristics. This concept is known as high speed milling. In recent years, the high speed milling is actually used for the metal mold machining. In this study, the high speed milling of the titanium alloy and the stainless steel was tried for the purpose of high efficiency cutting of a steam turbine blade. In the experiment, the cutting tool used the TiAlN coating radius solid end mill made of micro grain cemented carbide. The diameter of endmill is 5mm. The corner radius is 0.2mm. And, the work piece is the titanium alloy Ti-6Al-4V and stainless steel 13Cr. The cutting speed carried out at 100m/min~600m/min. As the result, when the tool life and the surface roughness was a valuation basis, the optimum cutting speed of titanium alloy was 300m/min. On the other hand, In the case of the stainless steel, the flank wear becomes large in proportion to cutting speed. The feature of high speed milling was not able to be confirmed in the range of this experimental condition.

Study on High-Speed Milling of Steam Turbine Blade Materials - Differences in Cutting Characteristics of an Unforged Ingot and a Forged Part of Stainless Steel

2017 ◽  
Vol 749 ◽  
pp. 3-8
Author(s):  
Tomonori Kimura ◽  
Takekazu Sawa ◽  
Tatsuyuki Kamijyo
Keyword(s):  
Stainless Steel ◽  
Tool Wear ◽  
Steam Turbine ◽  
High Speed ◽  
Flank Wear ◽  
Turbine Blades ◽  
Cutting Speed ◽  
High Speed Milling ◽  
Finished Surface ◽  
Steam Turbine Blade

Stainless steel is an excellent material that has properties such as heat and corrosion resistance. Thus, stainless steel is used as a material in steam turbine blades. Steam turbine blades are mainly manufactured using two methods. One is the cutting of unforged metal ingots. Another is the cutting of forged parts. Small blades are made by cutting metal ingots. Large blades are made by cutting forged parts. The mechanical characteristics of a metal ingot and a forged part, such as hardness and toughness, are almost the same. There were not researches related to a relationship between “an unforged ingot and a forged part of stainless steel” and “the differences of the tool wear and the finished surface by high-speed milling”.In this study, the high-speed milling of stainless steel was attempted for high-efficiency cutting of a steam turbine blade. The differences of the tool wear and the finished surface in the cuttings of an unforged ingot and a forged part were investigated. In the experiment, the cutting tool was a TiAlN coating radius solid end mill made of cemented carbide. The diameter of the end mill was 5 mm, and the corner radius was 0.2 mm. The cutting speed were 100 m/min-600 m/min. The workpieces used were a metal ingot and a forged part of stainless steel. In the results, it was found that the differences of the tool wear and the finished surface in the cuttings of an unforged ingot and a forged part. In the case of the unforged ingot, the flank wear became large with increasing cutting speed. On the other hand, in the case of forged part, the flank wear rapidly increased at a cutting speed of 100 m/min. In addition, the flank wear became smaller than the cutting speed 100 m/min at the cutting speed 200 m/min. Further, the flank wear became large with increasing cutting speed at cutting speeds higher than 200 m/min. That is, the flank wear was at a minimum at a cutting speed of 200 m/min. Although it could not be confirmed the characteristic of high speed milling at an unforged ingot, it has been identified at a forged part.

Multi-Objective Optimization Using Box-Behken of Response Surface Methodology for High-Speed Machining of Inconel 718

2014 ◽  
Vol 629 ◽  
pp. 487-492 ◽  
Author(s):  
Mohd Shahir Kasim ◽  
Che Hassan Che Haron ◽  
Jaharah Abd Ghani ◽  
E. Mohamad ◽  
Raja Izamshah ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Response Surface Methodology ◽  
Cutting Force ◽  
Response Surface ◽  
Tool Life ◽  
Feed Rate ◽  
Inconel 718 ◽  
High Speed ◽  
Cutting Speed ◽  
High Speed Milling

This study was carried out to investigate how the high-speed milling of Inconel 718 using ball nose end mill could enhance the productivity and quality of the finish parts. The experimental work was carried out through Response Surface Methodology via Box-Behnken design. The effect of prominent milling parameters, namely cutting speed, feed rate, depth of cut (DOC), and width of cut (WOC) were studied to evaluate their effects on tool life, surface roughness and cutting force. In this study, the cutting speed, feed rate, DOC, and WOC were in the range of 100 - 140 m/min, 0.1 - 0.2 mm/tooth, 0.5 - 1.0 mm and 0.2 - 1.8 mm, respectively. In order to reduce the effect of heat generated during the high speed milling operation, minimum quantity lubrication of 50 ml/hr was used. The effect of input factors on the responds was identified by mean of ANOVA. The response of tool life, surface roughness and cutting force together with calculated material removal rate were then simultaneously optimized and further described by perturbation graph. Interaction between WOC with other factors was found to be the most dominating factor of all responds. The optimum cutting parameter which obtained the longest tool life of 60 mins, minimum surface roughness of 0.262 μm and resultant force of 221 N was at cutting speed of 100 m/min, feed rate of 0.15 mm/tooth, DOC 0.5 m and WOC 0.66 mm.

Tool-Life Optimization in High-Speed Milling of Aeronautical Aluminum Alloy 7050-T7451

2009 ◽  
Vol 626-627 ◽  
pp. 117-122
Author(s):  
Y.Z. Pan ◽  
Xing Ai ◽  
Jun Zhao ◽  
X.L. Fu
Keyword(s):  
Aluminum Alloy ◽  
Tool Life ◽  
High Speed ◽  
Metal Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Least Square ◽  
High Speed Milling ◽  
Solid Carbide ◽  
Multi Linear Regression

A new approach is presented to optimize the tool life of solid carbide end mill in high-speed milling of 7050-T7451 aeronautical aluminum alloy. In view of this, the multi-linear regression model for tool life has been developed in terms of cutting speed and feed per tooth by means of central composite design of experiment and least-square techniques. Variance analyses were applied to check the adequacy of the predictive model and the significances of the independent parameters. Response contours of tool life and metal removal rates were generated by using response surface methodology (RSM). The analysis results show that it is possible to select an optimum combination of cutting speed and feed per tooth that improves metal removal rate without any sacrifice in tool life.

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