Investigation of the Surface Layer Structure of High-Chromium and High-Strength Steels at the Variation of the Heating Temperature

2016 ◽  
Vol 870 ◽  
pp. 431-436 ◽  
Author(s):  
V.B. Dementyev ◽  
T.N. Ivanova
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Layer Structure ◽  
Heating Temperature ◽  
High Strength Steels ◽  
High Strength ◽  
Grinding Wheel ◽  
High Chromium ◽  
Cutting Surface ◽  
Grinding Tool

At present, hard-to-machine materials such as structural alloy steels with various chemical element additives – tungsten, chromium, etc. - are most widely used in engineering. When conventional finish methods are used for the treatment of hard-to-machine materials, the most important problems are the difficulty of obtaining work surfaces of a required quality in terms of accuracy, roughness and the physicochemical composition, and the low output. In the present paper, a finish method for metal treatment– grinding – is discussed. Zones of the formation of the surface stress state due to heating have been revealed: the zone of an insignificant increase in temperature in the contour of the contact of a grinding wheel and a work surface; the zone of the temperature intensive growth; and the zone of the temperature abrupt drop. The investigation has been conducted of the surface layer structure of high-strength and high-chromium steels during high-speed heating – grinding. The peculiarities of the change of the surface layer state of the above steels have been revealed after grinding with the use of conventional grinding wheels with a continuous cutting surface and a discontinuous cutting surface. Some recommendations are given for grinding of the high-strength 12Cr18Ni9 and high-chromium Cr12, Cr12Mo and Cr12V steels, taking into account the specific features of different technological situation characteristic of a specific grinding tool, a grinding tool grade, and conditions of grinding and cutting.

Study on Surface Integrity of an Ultra-High Strength Alloy in HSC Process

2006 ◽  
Vol 532-533 ◽  
pp. 241-244
Author(s):  
Zhen Hai Long ◽  
Xi Bin Wang ◽  
Wen Xiang Zhao
Keyword(s):  
Residual Stress ◽  
Surface Layer ◽  
Surface Integrity ◽  
High Speed ◽  
High Strength ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Cutting Condition ◽  
Tempered Martensite ◽  
Strength Alloy

Aiming to study the surface integrity of an ultra-high strength alloy in high speed milling process, 2K factorial design experiments were conducted to explore the effects of cutting parameters, such as cutting velocity, feed rate and depth of cut, on microstructure, microhardness and residual stress in the sub-surface layer. The following conclusions could be drawn from this paper within the range of cutting conditions: The cutting parameters could significantly influence the microstructure and microhardness in the surface and sub-surface layers, and the original fine martensite of the surface and sub-surface layer might be transformed into the over-tempered martensite, under-tempered martensite, secondary troostite, and tempered sorbite; Compressive residual stress distributions with different maximum stress values in the sub-surface layer of machined surfaces could emerge in high speed cutting process; the properly arranged cutting condition could achieve ideal surface characteristics and surface integrity.

scholarly journals Multi-cycle of AISI 5135 steel modification by irradiation of the “film (Si (0.2 μm) + Nb (0.2 μm))/(AISI 5135 steel) substrate” system with an intense pulsed electron beam

2021 ◽  
Vol 2064 (1) ◽  
pp. 012041
Author(s):  
N N Koval ◽  
Yu F Ivanov ◽  
V V Shugurov ◽  
A D Teresov ◽  
E A Petrikova
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Electron Beam ◽  
High Speed ◽  
Steel Substrate ◽  
High Hardness ◽  
High Strength ◽  
Pulsed Electron Beam ◽  
Impact Area ◽  
Steel Aisi

Abstract Steel AISI 5135 surface layer modification carried out by high-cycle high-speed melting of the “film (Si + Nb)/(steel AISI 5135) substrate” system with an intense pulsed electron beam with an impact area of several square centimeters, have been implemented in a single vacuum cycle on the “COMPLEX” setup. The regime of the system “film (Si (0.2 μm) + Nb (0.2 μm))/(steel AISI 5135) substrate” irradiation with an intense pulsed electron beam (20 J/cm2, 200 μs, 3 pulses, 3 cycles) which makes it possible to form a surface layer with high thermal stability have been revealed. This layer is characterized by high hardness, more than 3 times higher than the hardness of AISI 5135 steel in the original (ferrite-pearlite structure) and wear resistance, more than 90 times higher than the wear resistance of the initial AISI 5135 steel. It is shown that the high strength and tribological properties of steel are due to the formation of the hardening phase particles (niobium silicide of Nb5Si3 composition).

Trimming of Flat and Tubular Components by High Speed Impact Cutting (HSIC)

2017 ◽  
Author(s):  
Dirk Landgrebe ◽  
Tom Barthel ◽  
Frank Schieck
Keyword(s):  
High Speed ◽  
Construction Materials ◽  
High Strength ◽  
Lightweight Construction ◽  
Cycle Times ◽  
Reinforced Plastics ◽  
High Speed Impact ◽  
Cutting Surface ◽  
Impact Cutting ◽  
High Flexibility

The trend for lightweight construction, especially in the automotive industry, leads to increased use of corresponding lightweight materials. In addition to novel construction materials such as fiber-reinforced plastics, established materials such as steel or aluminum are continuously being further developed, which is usually accompanied by a distinct increase in their strength. Beside material-related lightweight construction, new designs are applied such as the profile design. The disadvantage of this development is that established forming processes such as deep drawing, profile bending, hydroforming but also shearing of high-strength components increasingly reach their process limits. Particularly, in the case of trimming of high-strength components such as press-hardened components, it is hard to present conventional shearing processes in serial processes due to low tool life and deficient cutting surface quality. For this reason the laser cutting technology is often used. It is characterized by high flexibility and can largely meet the requirements regarding component quality. In contrast to shearing, however, it requires very long process cycle times due to its process rate, which makes it significantly less productive. High speed impact cutting offers an alternative. By exploiting high speed effects in the material, which leads to adiabatic heating of the shearing zone and a related significant reduction in strength, even ultra-high strength steel materials with tensile strengths of above 1500 MPa can be cut at high quality and with a short cycle time. In order to transfer this technology to serial applications and to develop process limits, extensive investigations were carried out using high-strength sheet metal materials and tube materials. The results are presented in this paper.

scholarly journals Surface Layer Properties of Low-Alloy High-Speed Steel after Grinding

2016 ◽  
Vol 10 (4) ◽  
pp. 275-279
Author(s):  
Jan Jaworski ◽  
Tomasz Trzepieciński
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
High Speed Steel ◽  
Grinding Wheel ◽  
Grinding Temperature ◽  
Grinding Parameters ◽  
Micro Cracks ◽  
Secondary Austenite ◽  
Grinding Efficiency

AbstractInvestigations of the surface layer characteristics of selected kinds of low-alloy high-speed steel after grinding were carried out. They were carried out on the flat-surface grinder with a 95A24K grinding wheel without cooling. The influence of grinding parameters was defined especially for: the quantity of secondary austenite, surface roughness, microhardness and grinding efficiency with a large range of grinding parameters: grinding depth 0.005–0.035 mm, lengthwise feed 2–6 m/min, without a cross-feed on the whole width of the sample. It was found that improvement of grinding properties of low-alloy high-speed steels is possible by efficient selection of their chemical composition. The value of the grinding efficiency is conditioned by grinding forces, whose value has an impact on the grinding temperature. To ensure high quality of the tool surface layer (i.e. a smaller amount of secondary austenite, lack of wheel burn and micro-cracks) in the case of sharpening of tools made of low-alloy high-speed steel, the grinding temperature should be as low as possible.

Evaluation of the level of fatigue damage cumulation in the surface layer of high-strength steels

1987 ◽  
Vol 19 (6) ◽  
pp. 817-820
Author(s):  
V. V. Pleshakov ◽  
V. V. Filinov ◽  
A. I. Sokolik
Keyword(s):  
Surface Layer ◽  
Fatigue Damage ◽  
High Strength Steels ◽  
High Strength ◽  
Damage Cumulation

scholarly journals Surface microgeometry treated with a precast textured grinding wheel

2020 ◽  
Vol 329 ◽  
pp. 03019
Author(s):  
Vladimir Gusev
Keyword(s):  
Surface Layer ◽  
Thermal Damage ◽  
Transverse Plane ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Geometric Errors ◽  
Time Process ◽  
Cutting Surface ◽  
Surface Microgeometry ◽  
Textured Grinding Wheel

The article considers the formation of the geometry of internal cylindrical surfaces when grinding with a precast textured wheel, which is under the influence of the unbalances main vector and a variable cutting force caused by the discreteness of the cutting surface (texture). Under the influence of these factors, each point of the axis of the textured tool makes vibrations in the transverse plane in the form of a wavelike sinusoid consisting of two sinusoids. The Space-time process of forming the processed surface is mathematically described. It is in applying wavelike sinusoids to the workpiece, taking into account their phase shift at each revolution of the workpiece. To ensure minimal geometric errors at the maximum possible productivity of the grinding process, phase shifts φf = (0.07–0.12)π and φf = (0.88–0.93)π are recommended. The results of the study are recommended for use in the production of high-precision details, primarily from materials that are prone to thermal damage to the surface layer under the influence of high temperature in the grinding zone.

Appearances and Formation Mechanism of Welds in High-Strength Steels by High Speed Laser-Arc Hybrid Welding

2018 ◽  
Vol 45 (12) ◽  
pp. 1202007
Author(s):  
顾思远 Gu Siyuan ◽  
刘政君 Liu Zhengjun ◽  
张培磊 Zhang Peilei ◽  
于治水 Yu Zhishui ◽  
叶欣 Ye Xin ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
High Speed ◽  
High Strength Steels ◽  
High Strength ◽  
Hybrid Welding

New Insights on Recovery and Early Recrystallization of Ferrite-Pearlite Banded Cold Rolled High Strength Steels by High Speed Nanoindentation Mapping

2020 ◽  
Author(s):  
S. Janakiram ◽  
J. Gautam ◽  
P. Sudharshan Phani ◽  
Sairam K. Malladi ◽  
Govind Ummethala ◽  
...  
Keyword(s):  
High Speed ◽  
High Strength Steels ◽  
High Strength ◽  
Cold Rolled

Study of the surface layer of ground high strength steels

Wear ◽  
1975 ◽  
Vol 35 (1) ◽  
pp. 41-52 ◽  
Author(s):  
B. Srinivasa Bairi ◽  
V. Radhakrishnan
Keyword(s):  
Surface Layer ◽  
High Strength Steels ◽  
High Strength

Compression Tests of High Strength Steels

2008 ◽  
Vol 59 ◽  
pp. 293-298
Author(s):  
Vaclav Mentl ◽  
Josef Bystricky
Keyword(s):  
Mechanical Properties ◽  
Mechanical Testing ◽  
High Speed ◽  
Dynamic Compression ◽  
Testing Machine ◽  
High Strength Steels ◽  
High Strength ◽  
Strain Rates ◽  
Compression Tests ◽  
Impact Compression

Mathematical modelling and virtual testing of components and structures represent a useful and economic tool for design and safety assessment. The basic mechanical properties which can be found in material standards are not relevant in cases where the real service conditions differ from those applied during standardised testing. Thus e.g. mechanical behaviour at higher strain rates can be interesting for the car components when the simulation of crash situations is used during structure development. The dynamic compression tests are usually performed by means of drop towers, by means of high speed hydraulic testing machines or Hopkinson bar method. At the Mechanical Testing Laboratory of the SKODA Research Inst. in Pilsen, Czech Republic, an instrumentation of Charpy pendulum testing machine was realised in order that it was possible to perfom dynamic compression tests, [1], and the compatibility of obtained results in comparison with traditional impact compression tests was verified within the round–robin carried out by TC5 ESIS Sub-Committee on “Mechanical Testing at Intermediate Strain Rates“, [2]. A new striking tup and load measurement system were designed and callibrated. At the same time, a new software was developed which makes it possible to evaluate the test force-deformation record. The goal of this study was 1. to check the possibility of compression testing of high strength materilas by mens of Charpy pendulum, and 2. to study the strain rate influence on basic mechanical properties.

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