Simulating the Climatic Impact on Vehicle Engine Function Parts

The paper describes the assessment of the influence of climatic conditions, temperature and relative humidity on the lifespan of the cylinder forming the functional part of the vehicle TATRA 815 6x6 VVN. Based on the measured notch-toughness value in the test temperature range -80 °C to +100 °C, the corrosion effect on specimens with and without corrosion protection was evaluated. A condensation chamber was used to simulate corrosion conditions which can cause corrosion and degradation process in the material leading to lifetime reduction and limit state development. The duration of the corrosion laboratory tests in the condensation chamber considered the real time when the TATRA 815 6x6 VVN vehicle is exposed to climate change on an open area in the fleet. There were three sets of samples for simulations with different number of cycles (9, 18 and 27 cycles).

The effect of consolidation treatment on selected mechanical properties of sandstone

An investigation was made into selected mechanical properties of sandstone of Božanov mining site in Czechia using both natural specimens of the sandstone and specimens impregnated with consolidants – liquid products aimed at improving strength and durability of degraded stones. Experiments in three-point bending of notched and cracked specimens made it possible to determine (i) the quasi-static notch toughness as well as the fracture toughness of specimens when they were subjected to static loading, and (ii) the impact fracture toughness and total energy of fracture when specimens were subjected to impact loading. The results of the tests are presented and are discussed with a view to the effects of consolidants.

Cold cracking, microstructure, notch toughness, transverse and longitudinal hardness to the weld joint of P460NL1 steel [Fisuracion en frio, microestructura, tenacidad a la entalla, dureza transversal y longitudinal a la union de soldadura del acero P460NL1]

Microstructural development, longitudinal HV10 hardness as transversal to the fusion zone and notch toughness in root and filling pass were evaluated at preheating temperatures of 100 °C, 140 °C, 180 °C, 220 °C and 260 °C in the weld joint of P460NL1 steel, by FCAW in root pass and for filling-finishing by means of the SAW process, the control of the start and interpass preheating temperatures was carried out by thermal blankets and digital pyrometer. The NDT of magnetic particles justify the acceptance or rejection of the specimens for the study. In selected points of the weld joint they showed the dependence of the hardness as a function of the microstructure. At room temperature, immediate cold cracking was observed. In the HAZ, the microconstituents generated areas of high hardness under the cord and areas of low hardness due to overturning, with the presence of Windmastatten ferrite, the increase in preheating determined the decrease and sometimes the absence of hardened structures. The profiles determined a decrease in hardness as the preheating temperature increased. Columnar grains with a high presence of WF ferrite in their different morphologies and FP (C) and refined areas with typical microconstituents were observed in the Fusion Zone. Homogeneity was evidenced with respect to notch toughness at all temperatures and the effect of passes on the longitudinal microstructure, which shows the benefit of the preheating temperature by reducing the hardness in critical areas and homogenizing the welded joint.

Microstructural Influence on Mechanical Properties of a Lightweight Ultrahigh Strength Fe-18Mn-10Al-0.9C-5Ni (wt%) Steel

This study evaluates the role of thermomechanical processing and heat treatment on the microstructure and mechanical properties of a hot rolled, annealed, and aged Fe-18Mn-10Al-0.9C-5Ni (wt%) steel. The steel exhibited rapid age hardening kinetics when aged in the temperature range of 500–600 °C for up to 50 h, which has been shown in other work to be the result of B2 ordering in the ferrite and κ-carbide precipitation within the austenite matrix. The ultimate tensile strength increased from 1120 MPa in the annealed condition to 1230 MPa after 2 h of aging at 570 °C. Charpy V-notch toughness was evaluated at −40 °C in sub-sized specimens with a maximum in the annealed and quenched condition of 28.5 J in the L-T orientation.

Review on different welding techniques of Titanium and its alloys

Titanium and its alloys are the most commonly and most widely used due to its significant properties like good biocompatibility , good tensile strength , low density , and good creep property up to 300 degrees centigrade .It is used in the major engineering fields like civil engineering , nuclear engineering , aerospace engineering etc., but the welding of titanium in industries has become a major challenging objective to the fabricators because, a lot of titanium alloys are found in the form of sheets , problem arises mainly while fabricating the space crafts , marine bodies , jet engine’s where the ends are need to be joined through welding with a similar or dissimilar metals and titanium possess to have a very high tendency to oxidize at higher temperatures .As Titanium becomes highly reactive to chemicals in its environment. In regular air, welding contaminates titanium with carbides, nitrides, and oxides that make the weld and HAZ (heat-affected zone) brittle, resulting in lower fatigue resistance and notch toughness. so, In order to get a perfect weld it is very important to avoid the molten metal to the exposure of atmospheric air , which will lead to porosity and results into a poor welding conditions or welding defects. This paper reviews the different methods of welding titanium and its alloys.