Possibilities of potentiometric methods of detection of cracks in forging tools at their renovation

Industrial production, which uses the forging tools constantly increases the requirements for the consumption of forging tools and the need for fast and flexible renovations of them. Forging tools made from special tool steels are highly cost-intensive. The main cost component is the price of the material, heat treatment and other chemi-cal-heat treatment surfaces. This is the main reason why it is necessary to think about renovation at the design stage, in case of the need for repairs. Main weaknesses of the renovations is the insufficient ability of identifica-tion of the cracks spreading from the surface towards the core of the basic components. An important factor in the renovation process is the optimal choice of technology to restore the mechanical and physical properties of tools at an acceptable price, of course. The main issue in the choice of the optimal technology is heat treatment to achieve a high hardness and surface of the die, which is nitrided to ensure wear resistance. This article deals with the application of non-destructive potentiometric detection technology when considering the size of die forging cracks that arise in the process of forming

Surface and Subsurface Residual Stresses after Machining and their Analysis by X-Ray Diffraction

Process specifications and working procedures widely used by the aerospace and automotive industries require surface analysis by machining and specify the process parameters such as type, destructive measuring or simulations. Destructive measuring or simulation carried out in order to optimise and later to verify the process parameters are a very indirect way of measurement. While they are performed on simulation only similar in composition and elastic properties to that of the actual part to be machined, they almost never match all the important conditions of the process such as the shape of the real part or the residual stress prior to the treatment. Consequently the residual stresses and their depth distribution after the machining may differ very significantly from those required by the technologist. The only reliable way to verify that the operation has produced the desired effect is to actually measure the stresses in the machined component

Studying of cutting conditions when hard turning and their impact on integrity of shaped-complex surfaces

This article deals with impact of cutting conditions when hard turning of shaped-complex surfaces which are concentration origin of cracks especially in the area of notches. These areas significantly reduce the lifetime and functionality of surface by degradation of surface integrity where are the significant number of destruction cracks. Actual experiments are focused on detection of impact of each individual cutting condition on the generation of residual stress and its impact in each surface and subsurface layer of material. Results and evaluations explain what way is necessary to design and apply cutting conditions when hard turning of shaped-complex surfaces

Studying of cutting conditions when hard turning and their impact on integrity of shaped-complex surfaces

This article deals with impact of cutting conditions when hard turning of shaped-complex surfaces which are concentration origin of cracks especially in the area of notches. These areas significantly reduce the lifetime and functionality of surface by degradation of surface integrity where are the significant number of destruction cracks. Actual experiments are focused on detection of impact of each individual cutting condition on the generation of residual stress and its impact in each surface and subsurface layer of material. Results and evaluations explain what way is necessary to design and apply cutting conditions when hard turning of shaped-complex surfaces

SURFACE INTEGRITY EVALUATION OF TURNING WITH AUTO-ROTATING TOOL

The technical practice requirements comes to have increased demands on higher productivity, speed and quality of the machining process of various materials. Hard to machine materials, whose machining led to the development of turning with rotating cutting edge are not an exception. The machining process of auto-rotating tool is more complicated than the conventional process of turning, especially for the process of reshaping cutting layers into chips. There is a significant load in the system, that may affect the life of the cutting edge of the tool as well as the whole system and also in the final extent of the qualitative parameters of the workpiece (product / product). The article specifies the knowledge and findings of measurement in machining material 100Cr6 with an auto-rotating tool. The measurements were conducted to evaluate the integrity of the surface (roughness) of the workpiece to the impacts of cutting conditions, in particular the feed and the cutting edge inclination. It also analyzes the presence (size, character, action) of residual stresses concentrated in the surface layers of the workpiece by changing the cutting conditions

Studying the Implementation of Potentiometric Methods for the Detection of Cracks in Renovation of Forging Tools

Mass production using forging tools leads to an enormous increase in the consumption of forging tools and the need for rapid and flexible tool renovations. A major shortcoming in the renovations is the failure to identify cracks propagating from the surface towards the core of the basic components. Forging tools made from special tool steels are highly cost-intensive. The main cost component is the price of the material, heat treatment and other chemical-heat treatment surfaces. This is the main reason why it is necessary to think about renovation at the design stage, in case of the need for repairs. An important factor in the renovation process is the optimal choice of technology to restore the mechanical and physical properties of tools at an acceptable price, of course. The main issue in the choice of the optimal technology is heat treatment to achieve a high hardness and surface of the die, which is nitrided to ensure wear resistance. This article deals with the application of non-destructive detection technology when considering the size of die forging defects that arise in the process of forming

Development and Applications of a Free Cutting by Nonconventional Tools

In publications concerning unconventional schemes can be seen working draft of different designs of rotation turning tools and tools with linear cutting edge. Sporadically, this tools has appeared in the specialized publications. So far its operational characteristics, mainly its considerable influence on machined surface quality, exceptional durability and possibility to be used to turn hard machinable and other materials. Some of its priorities are verified in this paper