Wear, corrosion and cracking resistance of some W- or Mo-containing Stellite hardfacing alloys

Traditional Stellite hardfacing materials are Co-Cr-W-C type of alloys. A series of new Stellite alloys are developed based on Co-Cr-Mo-C system. Immersion-corrosion test is conducted in 10% HNO3 oxidizing acid at boiling temperature, in 10% H2SO4 reducing acid at 66 °C and in 5% HCl reducing acid at 40 °C to evaluate the general corrosion resistance of the Stellite alloys. The abrasive, adhesive and erosive wear resistance is investigated on these two types of Stellite alloys. Critical plastic shear strain is obtained by conducting scratch test to evaluate the resistance to cracking. The W-containing Stellite alloys have better corrosion resistance in oxidizing acid. The Mo-containing Stellite alloys exhibit unusual combination of excellent wear resistance and corrosion resistance in reducing environments. Mo-containing Stellite alloys also have adequate cracking resistance compared with the W-containing Stellite alloys.