Investigation of quenching effect on mechanical property and abrasive wear behaviour of high boron cast steel

Abstract

The effect of quenching temperature from 900 to 1050°C on the microstructures, mechanical properties and abrasion resistance of modified high born cast steel containing 0·3 wt-%C and 3·0 wt-%B was studied by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, tensile tester, impact tester, hardness tester and abrasion tester. Quenching at 900°C resulted in structures containing a small amount of pearlite. The existence of pearlite led to poor hardness and wear resistance of modified high born cast steel. Quenching at temperatures between 900 and 950°C resulted in the decrease in pearlite and the increase in hardness and abrasion resistance in comparison with 900°C quenching. The metallic matrix all transformed into the martensite quenching at 1000°C; the modified high born cast steel had high hardness, tensile strength, impact toughness and excellent abrasion resistance. The hardness, tensile strength and impact toughness of modified high born cast steel had no obvious change quenching over 1000°C. The increase in quenching temperature also led to the transformation of boride from continuous shape to isolated shape and promoted the coarsening of boride.