Study on Forming Mechanism of Surface Hardening in Two-Pass Grinding 40Cr Steel

2006 ◽  
Vol 304-305 ◽  
pp. 588-592 ◽  
Author(s):  
Gui Cheng Wang ◽  
Ju Dong Liu ◽  
Hong Jie Pei ◽  
Z.H. Jia ◽  
Li Jie Ma
Keyword(s):  
Hardened Layer ◽  
Grinding Wheel ◽  
Forming Mechanism ◽  
Creep Feed ◽  
Grind Hardening ◽  
Quenched Steel ◽  
And Performance ◽  
Grinding Temperature Field ◽  
40Cr Steel ◽  
Martensite Structure

We had done the two-pass grind-hardening experiment on 40Cr steel using the conventional aluminum grinding wheel on a surface grinder, compared the structure and performance of the hardened layer of one-pass grinding with those of two-pass grinding and analyzed the forming mechanism of two-pass grinding hardened layers. The results show that there are a similar martensite structure and change rules of hardened layer of one-pass grinding and two-pass grinding in spite of the different of initial structures, for martensite has tempered by the action of the creep feed grinding temperature field. The depths of hardened layer, microhardness and wear resistance have further improved, but the maximal compressive residual stress and its influencing depth of hardened layer have decreased. The forming mechanism of the two-pass grinding hardened layer is the same as that of the grinding hardened layer of quenched steel.

Research of Surface Hardening Based on Transverse Feed Grinding

2006 ◽  
Vol 532-533 ◽  
pp. 584-587 ◽  
Author(s):  
Ju Dong Liu ◽  
Gui Cheng Wang ◽  
Qin Feng Li ◽  
Hong Jie Pei ◽  
Zhi Hong Jia ◽  
...  
Keyword(s):  
Surface Hardening ◽  
Hardened Layer ◽  
Grinding Temperature ◽  
Micro Hardness ◽  
Transitional Area ◽  
And Performance ◽  
Grinding Machine ◽  
Grinding Temperature Field ◽  
40Cr Steel

The structure and performance of the hardened layer in this paper has been researched by means of transverse feed grinding 40Cr steel on a plane grinding machine, the result shows that under the action of the grinding temperature field, there are different structural change rules and distributing characteristics of micro-hardness. Although there is always a softened band, which is made up of a transitional area and an unhardened area or a temper area in the hardened layer, the reasonable softened band is conducive to the improvement of wear-resistant quality of a hardened layer under the condition of oil lubrication.

Study on the Formation of Grind-Hardening of Steel AISI 1066

2007 ◽  
Vol 329 ◽  
pp. 57-62 ◽  
Author(s):  
Ju Dong Liu ◽  
Gui Cheng Wang ◽  
B.L. Wang ◽  
K.M. Chen
Keyword(s):  
Hardened Layer ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Micro Hardness ◽  
Cooling Conditions ◽  
Dry Grinding ◽  
Structures And Properties ◽  
Grind Hardening ◽  
Steel Aisi ◽  
Grinding Technique

Grind-hardening was done on Steel AISI 1066 with a conventional surface grinder and a corundum grinding wheel, and research was conducted to probe into structures and properties of the hardened layer under varied depth of cut and cooling conditions. Results show that the hardened layer do not change noticeably in their martensitic structures and micro-hardness, which is ranged between 810870HV; But when the depth of cut increased or the dry grinding technique is adopted, the concentration of martensites and carbonides becomes lower, while the amount of residual austenites increases, and the completely hardened zone gets thicker. This conclusion serves as an experimental basis for the active control of properties of the grind-hardened layer of Steel AISI 1066.

Experiments and Regression Analysis of Grinding Hardened Layer Depth Based on Transverse Feed

2019 ◽  
Vol 814 ◽  
pp. 190-195
Author(s):  
Shun Xing Gao ◽  
Ju Dong Liu ◽  
Zhi Long Xu ◽  
Xiao Fan Yang
Keyword(s):  
Process Parameters ◽  
Optimization Design ◽  
Hardened Layer ◽  
Depth Of Cut ◽  
Grinding Process ◽  
Layer Depth ◽  
Hardening Process ◽  
Orthogonal Experiments ◽  
Grind Hardening ◽  
40Cr Steel

Based on orthogonal experiments, the influences of grinding process parameters including depth of cut (ap), workpiece infeed velocity (vw) and transverse regrinding value (Cr) on hardened layer depth (HLD) of 40Cr steel are studied in the grind-hardening process. The grind-hardening orthogonal experiments of 3-factors are performed on the 40Cr steel with the L16 (45) orthogonal table and the experimental optimization design theory. To understand quantitatively the effects of three grinding process parameters, the experimental data are modeled by regression. Among three grinding process parameters, the most important parameter is ap, followed by vw and Cr respectively. The experimental results indicate that HLD would increase with the increasing of the depth of cut and the decreasing of the workpiece infeed velocity in grind-hardening process, but HLD would decrease with the increasing of the interaction between the depth of cut and workpiece infeed velocity.

Experimental Research on Grind-Hardening of 65Mn Steel

2006 ◽  
Vol 505-507 ◽  
pp. 787-792 ◽  
Author(s):  
Ju Dong Liu ◽  
Gui Cheng Wang ◽  
Zhi Wang ◽  
Shu Tian Fan
Keyword(s):  
Surface Modification ◽  
Hardened Layer ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Micro Hardness ◽  
Layer Depth ◽  
Cooling Conditions ◽  
Dry Grinding ◽  
Grind Hardening ◽  
Grinding Technique

Grind-hardening was done on 65Mn steel with a conventional surface grinder and a corundum-grinding wheel. Research was conducted to probe into microstructures and properties of the hardened layer under varied depth of cut and cooling conditions. Results show that the hardened layer does not change noticeably in their martensitic structures and micro-hardness, which is ranged between 810-870HV. When the depth of cut increases or the dry grinding technique is adopted, the hardened layer becomes thicker accordingly. Under the condition of dry grinding with the depth of cut 1.0mm, the hardened layer depth reaches 2.0mm. It can find applications in grinding and metal surface modification field.

Research on Grind-Hardening Temperature and Cooling Rate of 48MnV Microalloyed Steel

2007 ◽  
Vol 359-360 ◽  
pp. 148-152 ◽  
Author(s):  
Bing Xiao ◽  
Hong Hua Su ◽  
Shu Sheng Li ◽  
Hong Jun Xu
Keyword(s):  
Cooling Rate ◽  
High Frequency ◽  
Microalloyed Steel ◽  
Hardened Layer ◽  
Processing Parameters ◽  
Transitional Region ◽  
Forming Mechanism ◽  
Hardened Zone ◽  
Grind Hardening ◽  
High Frequency Induction

The temperature, time and cooling rate are key factors in the hardening process using the grinding heat instead of the high frequency induction heat source. Thus, this paper established the mathematical model estimating the grind-hardening temperature, experimentally determined the grinding temperature and the cooling rate of different grinding parameters for 48MnV microalloyed steel using the conventional aluminum grinding wheel on a surface grinder, and investigated the grind-hardening effects and the forming mechanism of grind-hardening layer. The results show that the estimating temperatures are comparatively close to the measuring ones and hence the model could be utilized to optimize the processing parameters, and the satisfactory grind-hardening temperature and cooling rate could be achieved under the optimized processing parameters. The microstructure of the grind-hardening layer, the fine needlelike martensite in the entirely hardened zone, the martensite and ferrite in the transitional region is similar to that acquired through the high frequency induction technique. Especially, the average hardness of the entirely hardened zone is 740HV and the depth of the hardened layer is adjacent to 1.5mm, which indicate that the grind-hardening effects are very excellent. Different from the forming mechanism of the high frequency induction hardened layer, higher grind-hardening temperature is needed to compensate shorter time austenitization, and because of thermo-mechanical loading induced during grinding, from surface to inside, the morphology of martensite changes from fine to thicker, then to finer, other than from thick to finer.

Formation and Control of 40Cr Grind-Hardening

2008 ◽  
Vol 373-374 ◽  
pp. 758-761 ◽  
Author(s):  
Gui Cheng Wang ◽  
Hong Jie Pei ◽  
Jin Yu Zhang ◽  
Chun Yan Zhang ◽  
Qin Feng Li
Keyword(s):  
Surface Layer ◽  
Thermal Effects ◽  
Hardened Layer ◽  
Experimental Conditions ◽  
Forming Mechanism ◽  
Hardening Process ◽  
Complex Process ◽  
Grind Hardening ◽  
Variation Characteristics ◽  
And Control

Grind-hardening machining is not only a complex process coupling mechanical, dynamical and thermal effects, but a process containing distinct changes of microstructure and properties of the workpiece grinded surface layer. Under the defined experimental conditions, an empirical formula was constituted to describe the relation between hardened layer depth and grinding parameter of grind-hardening layer, and the multi-parametric optimization was conducted. A commercial FEM software package was used to simulate the grind-hardening process. The distribution and variation characteristics of the temperature and microstructure in the grinded surface layer of workpiece were obtained and the forming mechanism of the grind-hardened layer is revealed.

Study on Depth and its Uniformity of 65Mn Steel Grind-Hardened Layer

2011 ◽  
Vol 487 ◽  
pp. 94-98 ◽  
Author(s):  
Jie Zhen Zhuang ◽  
Lian Fen Liu ◽  
Y.Z. Zhang
Keyword(s):  
Orthogonal Experiment ◽  
Hardened Layer ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Practical Applications ◽  
Grind Hardening ◽  
Grinding Conditions ◽  
Orthogonal Experiment Method ◽  
Table Speed ◽  
Significant Factors

On the basis of orthogonal experiment method, the grind-hardening of 65Mn steel had been carried out on a conventional surface grinder with alumina grinding wheel, the influence of depth of cutap, table speedvw, grinding modegm, and interaction between depth of cut and table speedavon depth and its uniformity of grind-hardened layer of 65Mn steel were investigated. The results show that, theapis the significant factor influences the average depth of grind-hardened layer and the significance ratio of experiment factors from most to least as followed:ap>vw>gm> av; thegmand thevware the significant factors influence the depth uniformity of grind-hardened layer and the significance ratio of experiment factors from most to least as followed: gm>vw>ap>av. The fairly uniformity of grind-hardened layer with good economy can be obtained when using grinding conditions that theap= 0.6mm, thevw= 0.4m/min, and thegm=up grinding + down grinding in practical applications.

Influence of Depth of Cut on Grind-Hardened Layer and Its Uniformity

2011 ◽  
Vol 109 ◽  
pp. 345-349 ◽  
Author(s):  
Lian Fen Liu ◽  
Jie Zhen Zhuang ◽  
Chao Liu
Keyword(s):  
Hardened Layer ◽  
Maximum Depth ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Hardened Zone ◽  
Grind Hardening

The grind-hardening of steel 65Mn had been carried out on a conventional surface grinder with alumina grinding wheel, the influence of depth of cut on the microstructure and the microhardness of workpiece, the depth and its uniformity of grind-hardened layer were studied. The results show that the completely hardened zone of grind-hardened layer is composed of fine acicular martensites, residual austenites and a little carbide. The variety of depth of cut has no obvious influence on the microstructure and the microhardness of completely hardened zone of grind-hardened layer. The maximum depth of grind-hardened layer and the depth uniformity of grind-hardened layer of workpiece increases with the increase of depth of cut ap.

Investigation on Simulation for Grind-Hardening Temperature Field of Non-Quenched and Tempered Steel

2008 ◽  
Vol 375-376 ◽  
pp. 520-524 ◽  
Author(s):  
Shu Sheng Li ◽  
Bing Xiao ◽  
Song Xiang Qin ◽  
Zheng He Song ◽  
Hong Hua Su ◽  
...  
Keyword(s):  
Temperature Field ◽  
Hardened Layer ◽  
Source Model ◽  
Grinding Temperature ◽  
Ansys Software ◽  
Heat Source Model ◽  
Grind Hardening ◽  
Variation Characteristics ◽  
Quenched And Tempered Steel ◽  
Grinding Temperature Field

This paper studies the grinding temperature field of non-quenched and tempered steels grind-hardening technology using experiments and finite simulation. A mathematical model of grind-hardening temperature field is established to investigate steel 48MnV which is used for making crankshaft. The grinding temperature field is simulated and the hardened depth is forecasted by finite-element method with the triangular shape of the heat source model based on the ANSYS software. The experimental results show that the simulative temperature and estimating hardened depth are comparatively close to the measuring ones. The model could be utilized to forecast the distribution and variation characteristics of the grinding temperature field and the hardened layer depth.

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