Development Of Hardfacing Covered Electrode With High Strength And High Toughness

The high strength and high toughness hardfacing covered electrode to the medium-high carbon alloy steel surface' repair was put forward in this paper. Owing to the 9Cr2 cold roller high carbon equivalent, the weldability is not desirable . The key to repairing cold roller is to match high strength and high toughness for the all weld metal of covered electrode .It was made certain the primary abrasion mechanism by analyzed cold roller work condition that is adhesive wear and abrasive wear and contact fatigue wear. The composition of all weld is suitable with lathing martensite and remains austensite , rhythm distributing to a certainty quantity , size, shape and globularity carbide by right alloys accession of electrode coating. The hardness of all weld metal arrive at above Rockwell indentation hardness 55 and been provided with stated toughness.The crack shape , inclusion morphology, carbide shape and crystal bound morphology were observed by adopting the light microscope and scaned electron microscope (SEM) , and aided by energy compose test result and endure abrasion test. The investigation make know that right quantityrare earth magnesium alloy can improve weld toughness and amend shape of carbide and remains austensite , fining crystal bound and purifying weld , which improved all weld metal abrasion resistance.It is a new approach for the formula of covered electrode by introducing computer aid optimize design .