Vpliv umetnih površinskih napak na dinamično trdnost materiala na prehodu temena vara

Abstract

Dinamično obremenjeni kakovostni soležni zvarni spoji se porušijo zaradi utrujenosti materiala na prehodu temena vara v osnovni material. Pri tem je pomembna tudi prisotnost inicialnih mikro napak. Vzorce materiala TVP smo pripravili na simulatorju termičnega cikla. Iz njih smo izdelali preizkušance z žlebom in umetnimi površinskimi inicialnimi mikronapakami. Na dnu žleba je bila koncentracija napetosti približno takšna kot pri zvarnih spojih. Inicialne mikronapake so bili posamični odtisi in nizi odtisov Vickersove piramide. Pri analizi rezultatov smo upoštevali termične parametre pri varjenju in mehanske lastnosti. Rezultate sme primerjali z dinamičnimi lastnostmi, ko ni vpliva inicialnih mikro napak. Z manjšanjem hitrosti ohlajanja, ki je posledica večjega vnosa toplote pri varjenju, dinamična trdnost materiala z inicialnimi mikronapakami pada, ob tem pa linearno raste s statično trdnostjo.

Keywords

varjenje;soležni zvarni spoji;dinamične obremenitve;utrujenost materiala;trdnost;mikro napaka;odtis Vickersove piramide;prehod temena vara;produktivno varjenje;

Data

Language:	Slovenian
Year of publishing:	2001
Typology:	1.01 - Original Scientific Article
Organization:	UM FS - Faculty of Mechanical Engineering
Publisher:	Inštitut za kovinske materiale in tehnologije Ljubljana
UDC:	621.791.05:669.14.018.298:620.178.3
COBISS:	6213142
ISSN:	1580-2949
Parent publication:	Materiali in tehnologije
Views:	1757
Downloads:	77
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	ǂThe ǂinfluence of artificial surface defects on the fatigue strength of material at the weld toe
Secondary abstract:	Dynamically loaded high-quality butt-weld joints fail due to fatigue of the material at the weld toe. Initial microdefects present in that material are important too. Samples of HAZ materials were prepared on the therml cycle simulator. Specimens with a groove and an artificial surface of initial microdefects were made from these samples. Stress concentration at the bottom of the groove was approximately the same as at the actual welded joints. Initial micro-defects were single and series indentations of the Vickers pyramid. In the analysis of results, parameters of the welding and mechanical properties were taken into account. Results were compared with those from samples without any influence of initial microdefects. The decreasing cooling rate that is a consequence of the higher heat input by welding fatigue strength of material with initial micro defects is decreasing while the fatiguestrength is linearly increasing with ultimate tensile strength.
Secondary keywords:	welding;butt welded joint;dynamic loads;material fatigue;strength;micro defects;Vickers pyramid indentation;weld toe;productive welding;
URN:	URN:NBN:SI
Type (COBISS):	Scientific work
Pages:	str. 55-59
Volume:	ǂLetn. ǂ35
Issue:	ǂšt. ǂ1/2
Chronology:	2001
ID:	1748169