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1

Wojciech Gasparski's Praxiological View of Business

100%

Sojka J.

Zagadnienia Naukoznawstwa

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2006

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tom 42

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nr 4(170)

495-502

EN

This article describes the approach to business which can be found the work of Wojciech Gasparski. A special stress is put on the fact that professor Gasparski, himself a prominent representative of Polish praxiology, makes use of the basic praxiological premises. According to this theory business is seen as something performing its basic, 'technical' function which consists in the maximisation of so called owner's value. It does not mean that ethical aspects of business or the problem of social responsibility of companies are being neglected. The main purpose is rather to build a solid basis for an ethical reflection on business. Wojciech Gasparski builds a 'minimal business ethics', which does not create an Arcadian vision of business, but tends to propagate professional standards in this field, already accepted in many European countries.

2

Rekreacja w lasach szczecinskich

63%

Sojka J.

Las Polski

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2000

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nr 13-14

24-25

3

Influence of arsenic as a hydrogenation promoter during cathodic hydrogen charging of very high strength steels

45%

Sojka J. , Ly C. , Jérome M. , Ruscassier N. , Guillot J.

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2008

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tom z. 92

59-60

EN

Hydrogen embrittlement mechanisms of two very high strength steels (VHSS) with ultimate tensile strength reaching 1000 MPa were studied in severe hydrogen charging conditions. These VHSS were a TRIP steel (A) and a Cr-V alloyed high strength steel (B). They were submitted to cathodic charging in a sulfuric acid solution (0.1 N) with an addition of 5 nig L-1 of As2O3 as a promoter of hydrogen absorption. Electrochemical permeation technique and subsequent hydrogen dosage by thermal desorption tests provided values for hydrogen diffusion characteristics. A and B present diffusivity of respectively 2.6 10-11 nr s-1 and 2.2 10-10 m2 s-1. Blistering occurred at high charging currents, but residual hydrogen content appeared to be very low for both steels. The results can be attributed to the fine homogeneous microstructures with very few lattice defects like inclusions, impurities or microcracks that are the most potential sites for hydrogen trapping. Otherwise, tensile tests performed on hydrogenated steels showed higher loss of ductility in the presence of arsenic. Fracture surface observations suggest brittle fractures: transgranular brittle fracture for the steel A and intergranular brittle fracture for the steel B. Diffusible hydrogen is to be incriminated in the loss of plasticity since diffusion to crack tips is rather easy in these steels. All the results highlight the role of As2O3 in enhancing the steels susceptibility to hydrogen embrittlement.

4

Hydrogen diffusion in micro alloy steels

38%

Sojka J. , Jonšta P. , Rytířová L. , Jerome M. , Zajac J. , Sozanska M.

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2007

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tom Vol. 321, z. 89

121-122

EN

Petroleum and natural gas systems can be contaminated with wet H2S. This environment is very aggressive to the steels used in the transport and processing of these products and it can result in various forms of hydrogen embrittlement. The reaction between wet H2S and the steel generates atomic hydrogen, which can be, at least partially, absorbed into the steel. In the absence of applied stress, the diffused hydrogen can cause hydrogen induced cracking (HIC). The resistance of steels to HIC is closely related to the microstructure features: nonmetallic inclusions, hard phase constituents, banded structures etc. In the presence of applied or residual stress, the failure process can occur by sulphide stress cracking (SSC) or stress oriented hydrogen induced cracking (SOHIC). In the case of SSC, steel resistance is commonly derived from its strength level. It is generally accepted that steels having tensile strength less than 690 MPa approx. are resistant to SSC. The role of microstructure is not emphasized although there are some works showing that microstructure can also play an important role in the case of SSC. In the previous works, it was proved that even in case of SSC the resistance of the steels can be improved by the heat treatment – quenching and tempering, if the banded structure of ferrite and pearlite is replaced by the tempered martensite and/or bainite. The resistance of the steel to the hydrogen embrittlement is affected by both the microstructure and hydrogen concentration. To understand the hydrogen embrittlement it is necessary to characterize also the hydrogen transport – diffusion. In this work hydrogen diffusion coefficient in micro alloy X52 and X60 API steels (tubes), having different microstructures - banded ferrite and pearlite after hot rolling and the mixture of tempered bainite and martensite after quenching and tempering, are evaluated. The role of specimen orientation is also taken into account.