Abstract：The Vickers micro- harnesses of X42 expandable convoluted tube after rolling, annealing process were studied. It was found that the hardness in the middle region of the tube after rolling and annealing was lower than that in the regions of inner and outer surfaces; the annealing process of factory reduces and evens the hardness of the whole tube; for the rolling tube, the residual stress are compressive in inner surface while tensile in outer surface; the annealing process of factory makes the residual stress uneven. On these bases, the feasibility of micro- hardness to revealing the residual stress was confirmed, which is helpful to the control in the shape stability of expandable convoluted tube.
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2018, Vol. 25 
