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In the article the results of study of the structure and micro-hardness of the surface layer of 38Cr2MoAl steel after volumetric quenching and high tempering, followed by ion-plasma nitriding, in comparison with electromechanical surface hardening (EMSH) are presented. Experimentally confirmed, that after the EMSH of 38Cr2MoAl steel, a gradient microstructure of finely dispersed martensite, bainite and austenite with a residual hardness of up to 8100 HV MPa and a depth of up to 0.8 mm is formed in the surface layer. At the same time, the maximum microhardness of the surface layer is not on the surface, but at a depth of 0.1 mm. The EMSH is formed by gradient surface layers of metal of high hardness on the surface of products. For a wide range of machine parts, EMSH can be used as a finishing treatment, since it is not accompanied by the presence of defects in the decarburization of the surface layer and deterioration of roughness. After ion-plasma nitriding for 8 hours, the microhardness of the surface layer of 38X2MYA steel was 9030 HV MPa at a depth of 0.1 mm and 8650 HV MPa at a depth of 0.2 mm. At a depth of 0.3 mm, the microhardness of the surface after nitriding and EMP are almost equal, respectively 7230 and 7170 HV MPa. The results of wear tests according to the “rubber roller — fixed sample” scheme and the American Society for Testing and Materials (ASTM G65) “Standard Method for Measuring Abrasive Abrasion using the “Dry Sand” Installation/Rubber wheel” showed high wear resistance of nitrided samples. However, with the continuation of the tests, due to the shallow depth of the nitrided layer (up to 0.3 mm), the wear resistance of the nitrided and hardened samples is leveled. The practical significance of the study is associated with the possibility of reducing the cost of manufacturing parts from nitrided steels by hardening the executive surfaces of the products of the EMSH. In addition, the EMSH allows steel 38Cr2MoAl for surface hardening and subsequent finishing by finishing turning on metal-cutting machines.

Aim. To analyze the first experience of administering polatu-zumab vedotin combined with bendamustine and rituximab (Pola-BR) in clinical practice at some specialized institutions in the Russian Federation. Materials & Methods. The prospective multi-center study enrolled 39 patients with relapsed/refractory aggressive В-cell non-Hodgkin’s lymphomas (B-NHLs): 31 (79 %) patients with diffuse large B-cell lymphoma, 7 (18 %) patients with primary mediastinal (thymic) large B-cell lymphoma, and 1 (3 %) patient with gray zone lymphoma. There were 20 men and 19 women aged 19-69 years (median 43 years). All the patients were treated with Pola-BR protocol: bendamustine 90 mg/m2 on Days 1 and 2, rituximab 375 mg/m2 on Day 1, and polatuzumab vedotin 1.8 mg/kg on Day 1 of each 21-day cycle. Full treatment with 6 cycles was completed by 19 patients. PET-CT was performed prior to therapy and after the 2nd, 4th, and 6th Pola-BR cycles. The tumor response was evaluated according to the Lugano 2014 criteria. The toxicity profile was assessed by means of reporting adverse events according to the NCI CTCAE, version 5.0. Results. Objective response to the therapy, according to the Lugano 2014 criteria, was identified in 24 (61.5 %) patients: 19 (48.7 %) of them showed the complete response, and 5 (12.8 %) of them showed the partial one. Stable disease as best response to the therapy was reported in 3 (7.7 %) patients, disease progression was observed in 12 (30.8 %) patients. By the time of data analysis, the median follow-up duration was 16.8 months (range 5.3-24.2 months). The 2-year overall survival (OS) was 44 % (95% confidence interval [95% CI] 24-62 %), the median OS was 20.8 months. The 2-year progression-free survival (PFS) was 27 % (95% CI 12-43 %), the median PFS was 7.3 months. Adverse events of grade 3/4 included anemia (n = 4; 10.3 %), neutropenia (n = 15; 38.5 %), thrombocytopenia (n = 3; 7.7 %), and febrile neutropenia (n = 2; 5.1 %). In 2 patients with history of hepatitis B, the virus reactivation was identified on Pola-BR therapy. No cases of peripheral neuropathy were observed. Conclusion. Results obtained in real-world clinical practice correspond to the previously published data and demonstrate that polatuzumab vedotin therapy (Pola-BR protocol) has a controllable toxicity profile and is, therefore, a promising chemotherapy method of relapsed/refractory aggressive B-NHL treatment.

The researching results of the structure and microhardness of the surface layer of steel 20 after vacuum cementation of cylindrical samples to a depth of 1,0 mm and their hardening by volumetric heat treatment in comparison with electromechanical surface hardening are presented. The maximum microhardness of the surface layer of cemented steel 20 is at a depth of 0,05 mm and corresponds to 9650 HV MPa, and gradually decreases within the hardened layer to 8190 HV MPa at a depth of up to 0,75 mm after electromechanical surface hardening has been experimentally established. There isn’t decarbonized layer after the electromechanical surface hardening of cemented steel samples 20. The reaserch practical significance is associated with the possibility of improving the quality and reducing the cost of parts producting from cemented steels by replacing heat treatment after cementation with the technology of hardening the working surfaces by electromechanical surface hardening.

The article is devoted to the founder and author of the electromechanical processing method Askinazi B.M. and prepared for the 110-th anniversary of his birth. The developed and researched method determines the ways of a new direction of scientific and technical policy in the field of improving the service life and reliability of machines, reducing the complexity of manufacturing and restoring parts, improving the efficiency of enterprises and organizations, protecting the environment and creating competitive products.