The TEM study of structure of 1H18N9T stainless steel buildups

Purpose: The reason of investigation was finding the answer of the question what was the reason of extreme hardness of build-ups created during bulk metal forming processes of austenitic stainless steel. Design/methodology/approach: The studies were conducted using transmission electron microscopy (TEM). Since very specific specimens special method for thin foil preparation were elaborated. Thin foil method was chose because it was only one which supply both structure and diffraction information. Findings: On the basis of careful analysis structural and electron diffraction pattern it was proposed that simultaneously to very well known strengthening mechanisms like grain refinement and dislocation density increase, the additional mechanism can not be excluded. Based mostly on the electron diffraction pattern (appearance of forbidden reflexes for FCC) it is proposed that this additional mechanism could be the marthensitic transformation caused by very high plastic deformation. Practical implications: At this moment it is difficult to point out the practical implications of the result however the mechanism proposed in this elaboration might be used in design of high strength materials. Originality/value: The main achievement of this investigation is TEM results which analysis allow to propose that an extra-mechanism for strengthening of 1H18N9 stainless steel is marthensitic transformation involved with high plastic deformation in build-ups. Additionally the special method of thin foils preparation was elaborated.