7/29/2019 hardfacing

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Abstract

This paper is a study on the shaft behavior of BTA deep hole drilling tool. The dynamics of tool

shaft are often taken to be that of a second order lumped mass system for other cutting processes.This simplification does not apply for deep hole drilling because of its shaft length and the fact

of fluid coupling. This paper constructed the general equations of motion for the pipe-like fluidconveying tool shaft of deep hole drill. The proposed general equations can be reduced todifferent specific forms of former works. Solutions for lateral and longitudinal motions were

given. Series of experiments were designed and performed. Comparisons between theoretical

and experimental results confirmed the validity of the constructed equations. The studies

disclosed build the knowledge about the tool shaft and pave the way for future researchconcerning the correlation between the tool shaft and cutting process taking place on the cutting

head.

Abstract

Solidification microstructure of a cast stainlesssteel containing 1.52.5 wt.%B has been

examined by means of the optical microscopy (OM), the scanning electron microscopy (SEM),

the electron probe microanalyzer (EPMA), energy dispersive X-ray spectrometry (EDS), X-raydiffraction (XRD) and Vickers microhardness. The as-cast microstructure consists of the

M2(B,C) borocarbide and the austenite. The borocarbide is continuously distributed over theaustenite. There are some broken-networks in the local location of borocarbide. Moreover, thedistribution of alloy elements is not homogeneous in the cast B-bearing stainlesssteel. Boron

element is mainly distributed over the borocarbide, carbon element is mainly distributed over the

matrix. Chromium element is mainly distributed over the borocarbide, and there are also some

chromium elements in the matrix. Nickel element is mainly distributed over the matrix andsilicon is insoluble in the borocarbide.