The paper presents rezults of microstructure (LM, TEM) investigation and hardness measurments of welded joints in martensitic precipitation hardened stainless steel containing copper, subjected to heat treatment. For the aging temperature up to 540• C even for the very long times, the microstructure of the welded joints is similar to this one at lower temerature aging. After aging at 620• C a distinct change of the microstructure was observed. Non-equilibrium solidification conditions of the weld metal, segregation and the diffusion of copper and the elements stablilizing the austenite cause the occurrence of the reverse transformation of the martensite into austenite as fast as just 1 hour at 620• C. TEM investigations revealed the differences in dispersion of hardening copper precipitates after aging at temperature 620• C for 1 and 4 hours. Keywords: Weld metal, heat treatment, martensitic PH stainless steels , 17-4PH steel W artykule przedstawiono wyniki badań mikrostruktury (LM, TEM) oraz twardości złącz spawanych stali nierdzewnej martenzytycznej utwardzanej wydzieleniowo miedzią po obróbce cieplnej. Aż do temperatury starzenia 540• C mikrostruktura spoin nie wykazuje istotnych różnic niezależnie od czasu wytrzymania w porównaniu do tej obserwowanej w niższych temperaturach. Po starzeniu w temperaturze 620• C zaobserwowano wyraźne różnice w mikrostrukturze spoin. Nierównowagowe warunki krzepnięcia metalu spoiny, występowanie segregacji oraz procesy dyfuzji miedzi i pierwiastków stabilizujących austenit powodują wystąpienie przemiany odwrotnej martenzytu w austenit już po 1 godzinie starzenia w 620• C. Badania TEM wykazały, różnice w dyspersji cząstek umacniających w temperaturze starzenia 620• C przez 1 i 4 godziny.

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The aim of the work was to investigate the influence of the processing on the final microstructure of the melt-spun Ni-Fe-P ribbons. The melt-spinning was carried out in two ways. For the first one the alloy was molten in a simple single-chamber crucible and for the second one double-chamber crucible was used. The chemical composition of the alloy molten in the single chamber was Ni40Fe40P20. The two component melt-spinning was made starting from the Ni80P20 and Fe80P20 alloys. All of the three alloys were molten in titanium gettered argon atmosphere starting from 99.95 wt % Ni, 99.95 wt % Fe, Ni-P and Fe-P master alloys in the arc melting furnace. The alloys were melt-spun in helium. The phase composition and the microstructure of the melt-spun ribbons were investigated by X-ray diffraction (XRD), a transmission electron microscope (TEM), respectively. The fracture of the specimens were observed with use of scanning electron microscope (SEM). SEM observations of the fracture surfaces show different character of the fractured samples.

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Microstructure and mechanical properties of amorphous/crystalline ductile liquid immiscible Fe-Si-B-In alloy produced by two-component melt-spinning Mikrostruktura i właściwości mechaniczne ciągliwego stopu amorficzno-krystalicznego na osnowie Fe-Si-B-In wytworzonego przez odlewanie na wirujący walec z tygla dzielonego AbstractThe two-component melt-spun (TCMS) Fe 71.25 Si 9.5 B 14.25 In 5 alloy was produced from Fe 75 Si 10 B 15 and Fe 67.5 Si 9 B 13.5 In 10 alloys. The microstructure of the TCMS alloy was investigated by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). A tensile test of the alloy resulted in a tensile strength of R m = 1040 MPa, yield strength R e = 919 MPa, total plastic elongation e tot = 3.29%, and traces of plastic deformation on the surface of the Fe-Si-B-In TCMS sample. Microstructural analysis of the amorphous/crystalline composite and tensile sample free surface show the reason for the ductility of the sample in relation to the Fe 75 Si 10 B 15 alloy. Keywords: metallic glasses, X-ray diffraction (XRD), scanning electron microscopy (SEM), tensile test, ductility