The Effect of Workpiece Hardness and Cutting Speed on the Machinability of AISI H13 Hot Work Die Steel When Using PCBN Tooling

2002 ◽  
Vol 124 (3) ◽  
pp. 588-594 ◽  
Author(s):  
Eu-Gene Ng ◽  
David K. Aspinwall
Keyword(s):  
Flow Stress ◽  
Shear Flow ◽  
Shear Zone ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Die Steel ◽  
Aisi H13 ◽  
Hot Work Die ◽  
Cutting Speeds ◽  
Shear Flow Stress

When machining hardened steel (⩾45 HRC) with polycrystalline cubic boron nitride (PCBN) tooling, the cutting speeds used produce high temperatures in the primary shear zone, which are sufficient to plasticize the workpiece. The paper initially reviews the effect of workpiece hardness and cutting speed on chip formation, workpiece surface integrity and cutting forces. Equations are detailed for determining the primary shear zone temperature, the proportion of heat conducted into the workpiece and the shear flow stress. Following on from this, experimental work is presented involving the orthogonal machining of AISI H13 hot work die steel with PCBN tooling. Tests were carried out over a range of cutting speeds with workpieces of different hardness, in order to provide cutting force, shear angle, chip morphology and primary shear zone thickness data. The shear flow stress decreased with increasing cutting speed and/or workpiece hardness. With the AISI H13 heat treated to 49±1 HRC, the stress magnitude changed more significantly with cutting speed and the proportion of heat conducted away from the workpiece approached 99 percent at 200 m/min. Shear localized chips were produced with white unetched layers due to intense heat generation followed by rapid cooling.

The Effect of Workpiece Hardness and Cutting Speed on the Machinability of AISI H13 Hot Work Die Steel When Using PCBN Tooling

1999 ◽  
Author(s):  
Eu-Gene Ng ◽  
David K. Aspinwall
Keyword(s):  
Flow Stress ◽  
Shear Flow ◽  
Shear Zone ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Die Steel ◽  
Aisi H13 ◽  
Hot Work Die ◽  
Cutting Speeds ◽  
Shear Flow Stress

Abstract When machining hardened steel (≥ 45 HRC) with polycrystalline cubic boron nitride (PCBN) tooling, the cutting speeds used produce high temperatures in the primary shear zone, which are sufficient to plasticise the workpiece. The paper initially reviews the effect of workpiece hardness and cutting speed on chip formation, workpiece surface integrity and cutting forces. Equations are detailed for determining the primary shear zone temperature, the proportion of heat conducted into the workpiece and the shear flow stress. Following on from this, experimental work is presented involving the orthogonal machining of AISI H13 hot work die steel with PCBN tooling. Tests were carried out over a range of cutting speeds with workpieces of different hardness, in order to provide cutting force, shear angle, chip morphology and primary shear zone thickness data. The shear flow stress decreased with increasing cutting speed and/or workpiece hardness. With the AISI H13 heat treated to 49±1 HRC, the stress magnitude changed more significantly with cutting speed and the proportion of heat conducted away from the workpiece approached 99% at 200 m/min. Shear localised chips were produced with white unetched layers due to intense heat generation followed by rapid cooling.

Shear-Zone Size, Compressive Stress, and Shear Strain in Metal-Cutting and Their Effects on Mean Shear-Flow Stress

1960 ◽  
Vol 82 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Dimitri Kececioglu
Keyword(s):  
Flow Stress ◽  
Shear Flow ◽  
Size Effect ◽  
Shear Strain ◽  
Shear Zone ◽  
Compressive Stress ◽  
Metal Cutting ◽  
Zone Size ◽  
Wide Range ◽  
Shear Flow Stress

A relationship for the calculation of the shear-zone size is given. The shear-zone size, when machining SAE 1015, 118-Bhn seamless steel tubing under a wide range of cutting conditions, is found to vary from 0.95 × 10−6 in.3 to 61.5 × 10−6 in.3 The mean shear-flow stress is found to increase significantly with a decrease in the shear-zone size and with an increase in the compressive stress in the shear zone. It is concluded that the only size effect in metal-cutting is the shear-zone size effect, and that no separate depth-of-cut size effect should be sought. An apparent decrease in the shear-flow stress with an increase in the true, mean shear strain in the shear zone is observed, and this behavior is explained.

Effect of cobalt-based coating microstructure on the thermal fatigue performance of AISI H13 hot work die steel

2020 ◽  
Vol 521 ◽  
pp. 146360 ◽  
Author(s):  
Xudong Yang ◽  
Chuanwei Li ◽  
Ziyang Zhang ◽  
Xinyu Zhang ◽  
Jianfeng Gu
Keyword(s):  
Thermal Fatigue ◽  
Fatigue Performance ◽  
Die Steel ◽  
Aisi H13 ◽  
Coating Microstructure ◽  
Hot Work Die

Theoretical and Experimental Investigation of Machining of AISI H13 Steel

2013 ◽  
Vol 818 ◽  
pp. 187-192
Author(s):  
Takács Márton ◽  
Farkas Balázs Zsolt
Keyword(s):  
Experimental Investigation ◽  
Finite Element ◽  
Cutting Speed ◽  
Chip Morphology ◽  
H13 Steel ◽  
Research Activity ◽  
Workpiece Material ◽  
Aisi H13 ◽  
Cutting Processes ◽  
Chip Removal

Main aim of our recent research activity is the theoretical and experimental investigation of hard turning of AISI H13 (52 HRC) hot work tool steel. Chip removal processes are of essential importance in modern manufacturing technology. The demand for higher accuracy, better surface roughness, more economical production, and miniaturization are constantly growing. This determines continuous research and development of cutting processes under special circumstances. Numerical simulation plays an important role in evaluating of the cutting processes, and in prediction of forces, chip formation, distribution of strain, strain rate, stresses, and temperature. Cutting experiments with varying feed rate and cutting speed were carried out to determine their effect on surface components of resultant force. 3D finite element model was proposed to simulate the chip removal process during turning of workpiece material AISI H13 (52 HRC). This paper gives a summary about the comparison of theoretical and experimental results. It was found that boundary conditions, such as finite element size, mesh density, material separation method has significant influence on chip morphology and value of cutting force, too.

FEM Prediction of Chip Morphology during the Machining of Particulates Reinforced Al Matrix Composites

2011 ◽  
Vol 188 ◽  
pp. 220-223 ◽  
Author(s):  
H. Guo ◽  
Dong Wang ◽  
Li Zhou
Keyword(s):  
Shear Failure ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Element Model ◽  
Matrix Composites ◽  
Segmented Chip ◽  
Sic Particulates ◽  
Al Matrix Composites ◽  
Cutting Speeds ◽  
Al Matrix

Chip morphology and segmentation play a predominant role in determining the machinability and tool wear during the machining of SiC particulates reinforced Al matrix composites. In this paper, a 2D coupled thermo-mechanical finite element model was used for simulating the segmented chip formation at different cutting conditions. The generation of segmentation is achieved by element erase and the shear failure, as well as the continuous adaptive remeshing technical. The results show that the chip is often discontinuous at lower cutting speeds, and with the increasing of the cutting speed, the chip becomes serrated. Fundamental observations from the simulations are concluded and a guideline for further research is proposed.

The Effect of Build Up Edge Formation on the Machining Characteristics in Austempered Ferritic Ductile Iron

2013 ◽  
Author(s):  
Şakir Yazman ◽  
Ahmet Akdemir ◽  
Mesut Uyaner ◽  
Barış Bakırcıoğlu
Keyword(s):  
Surface Roughness ◽  
Ductile Iron ◽  
Cutting Forces ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Salt Bath ◽  
Chip Formation Mechanism ◽  
Machining Properties ◽  
Machining Characteristics ◽  
Cutting Speeds

In this study, chip formation mechanism during the machining of austempered ferritic DI and the effect of the emerging chip morphology on such machining properties as surface roughness and cutting forces has been scrutinized. After austenitizing at 900 °C for 90 min, DI specimens were austempered in a salt bath at 380 °C for 90 min. Chip roots were produced by using a quick stop device during the machining of austempered specimens in different cutting speeds. The metallographies of these specimens were performed and chip morphologies were examined. The fact that the cutting speed increased led to a decrease in built-up edge formation. Depending on this fact, it was detected that the change in built-up edge thickness substantially affected the surface roughness and cutting forces. It was also detected that during the machining, with the effect of cutting forces and stress, spheroidal graphites were broken off in the chip and lost their sphericity and so that the chip became fragile and unstable and grafites here displayed a lubricant feature.

Flow stress of AISI H13 die steel in hard machining

2007 ◽  
Vol 28 (1) ◽  
pp. 272-277 ◽  
Author(s):  
Hong Yan ◽  
J. Hua ◽  
R. Shivpuri
Keyword(s):  
Flow Stress ◽  
Hard Machining ◽  
Die Steel ◽  
Aisi H13 ◽  
H13 Die Steel

Effects of Accelerated Tests on Shear Flow Stress in Machining

1987 ◽  
Vol 109 (3) ◽  
pp. 206-212 ◽  
Author(s):  
V. K. Jain ◽  
B. K. Gupta
Keyword(s):  
Flow Stress ◽  
Shear Flow ◽  
Shear Strain ◽  
Tool Material ◽  
Interface Temperature ◽  
Accelerated Tests ◽  
Instantaneous Values ◽  
Longitudinal Turning ◽  
Materials Behavior ◽  
Shear Flow Stress

Facing and taper turning tests (also known as accelerated cutting tests) are commonly used for the evaluation of machinability of materials. Of late, it has been reported that instantaneous values of tool-chip interface temperature, tool wear, shear angle, etc, in longitudinal turning are different from the corresponding values in accelerated cutting. This effect has been attributed to shear strain acceleration phenomenon. Materials behavior during accelerated cutting changes in a manner different than that in longitudinal turning. To test this hypothesis, experiments have been conducted using HSS as tool material and mild steel as work material. It has been concluded that shear flow stress during accelerated cutting is governed by shear strain acceleration and its governing parameters. Shear flow stress value is highest during facing, lowest in taper turning and in between the two during longitudinal turning.

Influence of nickel on secondary hardening of a modified AISI H13 hot work die steel

2019 ◽  
Vol 50 (2) ◽  
pp. 197-203
Author(s):  
S.W. Xia ◽  
P. Zuo ◽  
Y. Zeng ◽  
X. Wu
Keyword(s):  
Secondary Hardening ◽  
Die Steel ◽  
Aisi H13 ◽  
Hot Work Die

scholarly journals Effect of cutting speed on chip formation and wear mechanisms of coated carbide tools when ultra-high-speed face milling titanium alloy Ti-6Al-4V

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771370 ◽  
Author(s):  
Anhai Li ◽  
Jun Zhao ◽  
Guanming Hou
Keyword(s):  
Tool Wear ◽  
Chip Formation ◽  
Wear Mechanisms ◽  
Failure Mechanisms ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Face Milling ◽  
Formation Mechanisms ◽  
Tool Wear Mechanisms ◽  
Cutting Speeds

Chip morphology and its formation mechanisms, cutting force, cutting power, specific cutting energy, tool wear, and tool wear mechanisms at different cutting speeds of 100–3000 m/min during dry face milling of Ti-6Al-4V alloy using physical vapor deposition-(Ti,Al)N-TiN-coated cemented carbide tools were investigated. The cutting speed was linked to the chip formation process and tool failure mechanisms of the coated cemented cutting tools. Results revealed that the machined chips exhibited clear saw-tooth profile and were almost segmented at high cutting speeds, and apparent degree of saw-tooth chip morphology occurred as cutting speed increased. Abrasion in the flank face, the adhered chips on the wear surface, and even melt chips were the most typical wear forms. Complex and synergistic interactions among abrasive wear, coating delamination, adhesive wear, oxidation wear, and thermal mechanical–mechanical impacts were the main wear or failure mechanisms. As the cutting speed was very high (>2000 m/min), discontinuous or fragment chips and even melt chips were produced, but few chips can be collected because the chips easily burned under the extremely high cutting temperature. Large area flaking, extreme abrasion, and serious adhesion dominated the wear patterns, and the tool wear mechanisms were the interaction of thermal wear and mechanical wear or failure under the ultra-high frequency and strong impact thermo-mechanical loads.

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