To upgrade the operational stability of the tool at LLC “Karbaz”, Sumy, Ukraine, carbonation of tools and samples for research in melts of salts of cyanates and carbonates of alkali metals at 570–580 °C was carried out to obtain a layer thickness of 0.15–0.25 mm and a hardness of 1000–1150 НV. Tests of the tool in real operating conditions were carried out at the press station at LLC “VO Oscar”, Dnipro, Ukraine. The purpose of the test is to evaluate the feasibility of carbonitriding of thermo-strengthened matrix rings and needle-mandrels to improve their stability, hardness, heat resistance, and endurance. If the stability of matrix rings after conventional heat setting varies around 4–6 presses, the rings additionally subjected to chemical-thermal treatment (carbonitration) demonstrated the stability of 7–9 presses due to higher hardness, heat resistance, the formation of a special structure on the surface due to carbonitration in salt melts cyanates and carbonates. Nitrogen and carbon present in the carbonitrided layer slowed down the processes of transformation of solid solutions and coagulation of carbonitride phases. The high hardness of the carbonitrified layer is maintained up to temperatures above 650 °C. If the stability of the needle-mandrels after conventional heat treatment varies between 50–80 presses, the needles, additionally subjected to chemical-thermal treatment (carbonitration) showed the stability of 100–130 presses due to higher hardness, wear resistance, heat resistance, the formation of a special surface structure due to carbonitration in melts of salts of cyanates and carbonates. Keywords: needle-mandrel, matrix ring, pressing, heat treatment, carbonitration.

The aim: We studied prevalence, intensity and predictors of fatigue in patient with episodic migraine (EM). Materials and methods: We enrolled in the study 85 patients with EM and 88 healthy subjects. Fatigue was identified according to Fatigue Severity Scale. We recorded socio-demographic factors: gender, age, marital status, formal education level, employment status, smoking. Anxiety and depression symptoms were assessed by Hospital Anxiety and Depression Scale, daytime sleepiness was measured by Epworth scale. The co-morbidities included history of low back pain during last year, arterial hypertension, diabetes mellitus and abdominal obesity. It was analyzed usage of non-steroidal anti-inflammatory drugs, combined analgesics, triptans for abortive migraine treatment. Results: Fatigue prevalence in patients with EM was 41,2%, which was significantly higher than in healthy controls (11,4%). Fatigue intensity in episodic migraineurs was 5,7 (4,9-6,8) and did not differ significantly from fatigue intensity in healthy individuals – 4,9 (4,5-5,8). In multivariate logistic regression analysis independent predictors of fatigue were only migraine-related factors (number of migraine headache days per month, headache severity and migraine prodrome presence). There was weak direct correlation between the number of headache migraine days per month and fatigue intensity. Conclusions: 1. Fatigue prevalence in patients with EM is significantly higher than in healthy controls. 2. In patients with EM fatigue has migraine-related predictors.

In the production of pipes from corrosion-resistant steels on pipe rolling plants, the current problem is the low stability of the pipe tool. Therefore, the creation of high-performance and durable tools is associated primarily with the production and processing of materials that could withstand harsh working conditions. The technology of heat hardening of the pipe tool for cold roller rolling of corrosion-resistant pipes (rollers and support laths of HPTR mills) from 4Х5МФ1С steel which excludes the third holiday and uses drawing of a covering from powders of amorphous alloys 100…150 µm thick is offered in the work. As a result of the offered technology durability, wear resistance, and also hardness to HV0.1 950–1050 (in comparison with HV 587–690 on existing technology of heat treatment in factory conditions) increases. A wide range of studies of the structure of the coating and industrial tests of rollers and support bars. It is shown that gas-plasma coating of amorphous alloy based on Fe–Si–B system increases the hardness of the tool surface by 1.3–1.6 times and their stability by ~ 30…50%.