Wyniki wyszukiwania - BazTech

1

The Effect of Heat Treatment of Forgings Directly from the Forging Temperature on their Properties

Gronostajski Z., Hawryluk M., Jabłoński P., Zwierzchowski M., Barelkowski A., Widomski P.

Archives of Metallurgy and Materials

|

2020

|

Vol. 65, iss. 2

685--696

EN

The paper presents a prototype semi-industrial cooling line developed by the authors, which makes it possible to design a thermal treatment of forgings with the use of the forging heat, together with exemplary test results for forgings forked type. The proposed method of heat treatment dedicated to these forgings was described and compared to traditionally used heat treatment method in chamber furnaces. Next, the original research stand was presented, which performs mechanical fatigue test on final products – forked-type forgings. Forgings after heat treatment and cooling on the prototype line were tested on this stand in condition of cyclically variable mechanical loads in order to resistance to mechanical fatigue was analyzed and the influence of performed exemplary heat treatment on mechanical properties. The presented preliminary investigations performed on the designed combined research standing, consisting of: the prototype controlled cooling line, as well as mechanical fatigue stand point to the possibility of implementing thermal treatment with the use of the heat generated during the forging process and determining its impact on the mechanical properties of forgings.

2

Zastosowanie wyników symulacji numerycznej do analizy i poprawy przemysłowego procesu wytwarzania odkuwki zaworu

Hawryluk Marek, Krawczyk Jakub, Zwierzchowski Maciej, Janik Marta, Jaruzel Jerzy

Obróbka Plastyczna Metali

|

2019

|

T. 30, nr 4

291--306

PL

Artykuł dotyczy wykorzystania wyników modelowania numerycznego do wielowariantowej symulacji procesu wytwarzania odkuwki zaworu ze stali chromowo-niklowej przeznaczonej dla silników samochodów ciężarowych. Odkuwka tego typu wytwarza-na jest w dwóch operacjach: wyciskania współbieżnego długiego trzonka, a następnie kucia wykańczającego głowy zaworu. Głównym problemem w tym procesie jest stosunkowo niska trwałość narzędzi; w pierwszej operacji wyciskania obserwowane jest przedwczesne zużycie matrycy, a w drugiej operacji niska trwałość stempla, co związane jest z intensywnym zużyciem ściernym oraz adhezją materiału odkuwki do narzędzi. Modelowanie numeryczne przeprowadzono przy użyciu pakietu obliczeniowego Forge 2.0, w celu analizy wpływu zmian warunków temperaturowych oraz tarcia. Szczegółowej analizie poddano drugą operację kształtowania – kucie na gorąco głowy zaworu, gdyż w przemysłowym procesie, ze względu na niewystarczającą kontrolę kluczowych parametrów technologicznych, mogą wystąpić niewielkie zmiany warunków tribologicznych, co wpływa na poprawność całego procesu. Przeprowadzona wielowariantowa analiza procesu kucia z wykorzystaniem modelowania numerycznego do-starczyła wielu cennych informacji dotyczących zmian kluczowych parametrów trudnych do uzyskania podczas analizy procesu przemysłowego oraz ich wzajemnego wpływu na siebie, takich jak: rozkłady pól temperatury, nacisków oraz parametrów określających zużycie, a także przebiegów sił kucia. Na tej podstawie możliwe jest wprowadzenie bez większych obaw istotnych zmian w procesie przemysłowym, w celu uzyskania jego stabilności i powtarzalności oraz zwiększeniu trwałości oprzyrządowania kuźniczego.

EN

The article discusses the application of the results of numerical modelling for a multi-variant simulation of the process of producing a chromium-nickel steel valve forging designed for truck engines. A forging of this type is manufactured in two operations: coextrusion of a long shaft, followed by finishing forging of the valve head. The main problem in this process is a relatively low tool durability; in the first extrusion operation, we observe premature wear of the die, whereas in the second operation, a low durability of the punch can be noticed, which is connected with the intense abrasive wear as well as adhesion of the material of the forging to the tools. The numerical modelling was carried out with the use of the Forge 2.0 calculation packet in order to analyze the effect of the temperature conditions and friction. A detailed analysis was performed on the second forming operation – hot forging of a head valve, as, in the industrial process, due to insufficient control of the key technological parameters, slight changes of the tribological conditions might occur, which affect the properness of the whole process. The multi-variant analysis of the forging process with the use of numerical modeling provided a lot of valuable information regarding changes in key parameters difficult to obtain during the analysis of the industrial process and their mutual influence on each other, such as: distribution of tem-perature fields, pressures and parameters determining wear, as well as forging force courses. On this basis, it is possible to introduce without major worry significant changes in the in-dustrial process in order to obtain its stability and repeatability, and increase the durability of forging equipment.

3

Impact of Tool Magnetization on Changes in the Surface Layer of Forging Tools

Zwierzchowski M.

Archives of Metallurgy and Materials

|

2019

|

Vol. 64, iss. 1

317--324

EN

The paper presents a description of the phenomena occurring on the surface of the forging dies. A detailed analysis was made of 24 pre-forging dies due to the most intensive wear in this operation. To compare the results, new tools were also analysed. The research described in the study showed that the most dangerous factor for the hot forging process analysed is thermal-mechanical fatigue, which causes small cracks, which in turn quickly leads to the formation of a crack network on the entire contact surface of the tool with forged material. The second phenomenon is the tempering of the surface of the material for a long-term temperature effect. The presence of hard iron oxides in the form of scale from forging material is the accompanying phenomenon that intensifies the processes of tool wear. The paper presents the results of the analysis of the presence of residual magnetic field for forging tools and the results of laboratory tests of wear processes of tool steels for hot work in the presence of a magnetic field and in the presence of scale.

4

Analysis of the Industrial Process of Producing a Lever-Type Forging Used in Motorcycles

Hawryluk M., Zwierzchowski M., Rychlik M., Gronostajski Z.

Archives of Metallurgy and Materials

|

2019

|

Vol. 64, iss. 4

1421--1432

EN

The article presents an analysis of the multi-operation hot die forging process, performed on a press, of producing a lever forging used in the motorcycles of a renowned producer by means of numerical simulations. The investigations were carried out in order to improve (perfect) the currently applied production technology, mainly due to the presence of forging defects during the industrial production process. The defects result mainly from the complicated shape of the forging (bent main axis, deep and thin protrusions, high surface diversity in the cross section along the length of the detail), which, during the filling of the die by the deformed material, causes the presence of laps, wraps and underfills on the forging. Through the determination of the key parameters/quantities during the forging process, which are difficult to establish directly during the industrial process or experimentally, a detailed and complex analysis was performed with the use of FEM as well as through microstructure examinations. The results of the performed numerical modelling made it possible to determine: the manner of the material flow and the correctness of the impression filling, as well as the distributions of temperature fields and plastic deformations in the forging, and also to detect the forging defects often observed in the industrial process. On this basis, changes into the process were introduced, making it possible to improve the currently realized technology and obtain forgings of the proper quality as well as shape and dimensions.

5

Analysis of the influence of lubrication conditions on tool wear used in hot die forging processes

Hawryluk M., Gronostajski Z., Ziemba J., Dworzak Ł., Jabłoński P., Rychlik M.

Eksploatacja i Niezawodność

|

2018

|

Vol. 20, no. 2

169--176

EN

The study discusses the subject of lubrication in the processes of hot die forging with the consideration of the durability of forging tools and instrumentation. It presents a literature research as well as the authors’ own investigations of the effect of the use of cooling and lubrication agents, the amount of the dosage as well as the direction of its application, and also the factors influencing the tribological conditions. The lubrication devices and systems currently applied in the industry have been analyzed as well. On this basis, making use of their knowledge and experience, the authors have developed and constructed a lubricating device. The elaborated system, implemented into the industrial process, makes it possible to select and ensure the optimal tribological conditions of the process by way of controlling the amount and frequency of the applied lubricant dosage. It can constitute an alternative for the manual method of lubricant application, which is dependent on the human factor, or the fully automated, yet expensive, lubrication systems. The obtained test results point to potential possibilities of a permanent introduction of the constructed device also into other forging processes, through its integration with a manipulator. The proposed solution ensures more stability and higher repeatability of the lubrication conditions as well as increases the efficiency of the production process, thus significantly reducing the unit costs of the production of forgings.

PL

Praca dotyczy problematyki smarowania w procesach kucia matrycowego na gorąco z uwzględnieniem trwałości narzędzi i oprzyrządowania kuźniczego. Przedstawiono badania literaturowe oraz własne autorów dotyczące wpływu zastosowania środków smarno-chłodzących, ilości dawki i kierunku jej podawania oraz innych czynników wpływających na warunki tribologiczne. Przeanalizowano także obecnie stosowane w przemyśle urządzenie i systemy smarowania. Na tej podstawie autorzy w oparciu o wiedzę i doświadczenie opracowali i zbudowali urządzenie smarujące. Opracowany system, zaimplementowany do przemysłowego procesu pozwala na dobór i zapewnienie optymalnych warunków tribologicznych w procesie poprzez sterowanie ilością i częstotliwością podawanej dawki środka smarnego. Może być ono alternatywą dla manualnej metody nanoszenia środka smarnego, zależnej od czynnika ludzkiego lub w pełni zautomatyzowanych, lecz drogich systemów smarowania. Uzyskane wyniki badań wskazują na potencjalne możliwości wprowadzenia na stałe do pracy zbudowanego urządzenia także do innych procesów kucia poprzez integrację z manipulatorem. Zaproponowane rozwiązanie zapewnia większą stabilność i powtarzalność warunków smarowania oraz pozytywnie wpływa na zwiększenie wydajności procesu wytwarzania, a tym samym znacząco obniża jednostkowe koszty produkcji odkuwek.

6

Factors Affecting the Wear Resistance of Forging Tools

Zwierzchowski M.

Archives of Metallurgy and Materials

|

2017

|

Vol. 62, iss. 3

1567--1576

EN

The durability of forging tools is a function of many variables: tool heat treatment, surface quality, temperature, pressure, number of forgings, diffusion layers (nitriding) and many others. The objective of study was to analyze and compare the working conditions of forging tools. For the analysis of selected flat surfaces of tools. Analyzed forging dies subjected to normal use. Presented results of laboratory tests . The effect of temperature and time on the properties of the surface layer of forging tools. The results were compared with the literature data. This article shows the results of microhardness tests for forging dies which have forged the corresponding number of forgings. The results of laboratory studies on microhardness of hot working steel 1.2344 in the furnace at various temperatures and time are also presented. The working conditions of the forging tools are very complex. The most often described in the literature are: thermal fatigue, abrasive wear, mechanical fatigue and cracks. The article discusses the effects of increased temperature on the surface properties of forging tools. Forging dies were made of hot work tool steel 1.2344. FEM modeling of changes in the surface layer should take into account changes in tool hardness as a function of time (number of forgings).