EFFECT OF TEMPERATURE ON THE RESISTANCE TO TEARING OF TYPE 430 STAINLESS-STEEL SHEET

The effect of temperature and specimen orientation on the tearing of type 430 stainless-steel sheet was examined. Tests were conducted at temperatures between -50 and +150-degrees-C (223 to 423 K) on compact tension and conventional tensile specimens manufactured from 0.82 mm thick sheet. Tensile properties and K(R)-a R-curves were determined. Both the strength and the toughness of the material decreased as the temperature increased. This result for toughness is opposite in tendency to that found in plate and impact toughness specimens, but is explained by the observation that the sheet-metal specimens were in a state of plane stress. Under these conditions the toughness of the material is strongly influenced by its tensile properties, which declined as the temperature increased. Examination of the specimens in the scanning electron microscope indicated that the mechanism of tearing was ductile at all temperatures. The behaviour of blunt-notched and fatigue pre-cracked specimens was similar, confirming the sensitivity of these materials to notches.