Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Archives of Materials Science and Engineering

1 2015

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: maraging alloy

Sortuj według:

Ogranicz wyniki do:

Fractographic and structural peculiarities of laser weld-on layers with a maraging alloy

Shtarbakov V., Stavrev D.

Archives of Materials Science and Engineering

2015

Vol. 75, nr 1

12--17

Purpose: Purpose of the present paper is to investigate the fractographical peculiarities of the layers welded-on the surface of 30CrMoV12-28 (DIN) tool steel by laser with additional material of marraging alloy. Design/methodology/approach: The operation was accomplished on an AL 200 automatic weld-on machine with an Nd:YAG pulse resonator providing a beam of 1064 nm wavelength. The mean power output of the pulse was 200 W and the maximum peak power output was 10 kW. The operating frequency was 20 Hz. The diameter of the laser beam focused on the sample surface was 0.6 mm. The weld-on maraging alloy featured contents of 0.02C - 0.2Si - 0.2Mn - 2Cr - 19.3Ni - 0.4V - 4.7Mo - 14.5Co - 0.25Al, wt%. Studied were the fractures obtained at three - point bending of the layer upon weld-on followed by two - hour age hardening at temperatures of 550 and 600°C. Findings: The nature of deformation along the weld-on layer under tensile impact strains was studied, the destruction being trans-crystalline determined by the prevailing plastic deformation.The destruction after age hardening at temperatures of 550 and 600°C was of the mixed and trans-crystalline type. The results of the processes of dispersion hardening and those of the beginning of coherent phase formation were connected with the main matrix of the inter-metallic compounds based on NiAl and NiMo. The condition of the structure was characterized by the so called “pit” curved surface of the destruction. The analysis of the fractures along with the EDS analysis showed that the inter-metallic phases formed in the process of secondary hardening of the material in the weld-on layer were of the NiAl, NiMo and Ni3Mo type. Research limitations/implications: For more correct determination of phase contents in depth of hardened layers have to be used XRD techniques. Practical implications: Taking into account the high value of the materials used for producing press-forming dies it is of vital importance to find possibilities for considerable increase of the lifecycle of casting moulds. Laser surface welding-on by using of maraging alloy as additional material is cost effective technology for repairing of press-forming dies.