| 摘要 |
<p>A method consisting essentially of three steps, each of which may be subdivided. The steps include (a) forming a ductile metal (steel, aluminium or titanium) connecting rod (10) in one piece having an annular wall (22) defining a crankshaft opening (23) with preformed surface crevices (20) for guiding the initiation of a cracking plane that extends across the crank opening (23), (b) charging (i.e., for about 40 seconds) the region of such wall (22) along at least one portion of the cracking plane with hydrogen by means of an electrolytic cell or by means of reacting the metal rod with a strong acid to cause hydrogen to dissolve in the metal to facilitate hydrogen stress cracking thereat, with or without the imposition of static mechanical tensile loading at such crevices (i.e., for about 40 seconds) of a magnitude insufficient to cause yielding of the metal; and (c) prolonging, increasing, or imposing the static mechanical loading at the crevices (20) to effect fracture across the entire cracking plane (21) and thereby separate the connecting rod (10) into a cap and body with rough, fractured mating surfaces. <IMAGE></p> |
