Abstract:
The thermal fatigue resistances of a high Cr cast iron and of an AISI D2 steel were evaluated by means of a test apparatus comprising inductive heating and water cooling. Due to the complexity of the phenomena involved, a FEM study was performed for solving the temperatures and surface stresses fields. The results of the computational simulations guided the design of the geometry of the test pieces selected to perform the thermal fatigue tests in order to obtain stress levels comparable to the ones observed in practical applications. The matrix microstructure, carbide contents and microhardness of the test pieces were evaluated before the tests. After the tests the amount and depth of the thermal fatigue cracks were measured. The paths of the cracks were analyzed in relation to the microstructure features. At the surface of the test pieces, the crack propagation was mainly by interconnection of fractured carbides, while in the inner volume the paths of the cracks were predominantly by the carbide/matrix interfaces. The results obtained showed good adherence between the tests and the numerical model. Based on these results, a methodology is proposed for the evaluation of wear resistant alloys subjected to thermal cycles.
Reference:
MATSUMOTO, Marcos Machado; ALBERTIN, Eduardo; GOLDENSTEIN, Hélio. Evaluation of the thermal fatigue resistance of a high Cr cast iron and a D2 steel. In: CONFERENCE ON ABRASION WEAR RESISTANE CAST IRON AND FORGED STEEL FOR REOLLING AND PULVERIZING MILLS, 5., 2014, Stockholm. Proceedings… 14 p.
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The thermal fatigue resistances of a high Cr cast iron and of an AISI D2 steel were evaluated by means of a test apparatus comprising inductive heating and water cooling. Due to the complexity of the phenomena involved, a FEM study was performed for solving the temperatures and surface stresses fields. The results of the computational simulations guided the design of the geometry of the test pieces selected to perform the thermal fatigue tests in order to obtain stress levels comparable to the ones observed in practical applications. The matrix microstructure, carbide contents and microhardness of the test pieces were evaluated before the tests. After the tests the amount and depth of the thermal fatigue cracks were measured. The paths of the cracks were analyzed in relation to the microstructure features. At the surface of the test pieces, the crack propagation was mainly by interconnection of fractured carbides, while in the inner volume the paths of the cracks were predominantly by the carbide/matrix interfaces. The results obtained showed good adherence between the tests and the numerical model. Based on these results, a methodology is proposed for the evaluation of wear resistant alloys subjected to thermal cycles.
Reference:
MATSUMOTO, Marcos Machado; ALBERTIN, Eduardo; GOLDENSTEIN, Hélio. Evaluation of the thermal fatigue resistance of a high Cr cast iron and a D2 steel. In: CONFERENCE ON ABRASION WEAR RESISTANE CAST IRON AND FORGED STEEL FOR REOLLING AND PULVERIZING MILLS, 5., 2014, Stockholm. Proceedings… 14 p.
Log into BiblioInfo/IPT-DAIT to access the PDF text. Document is password protected, ask Customer Service/Library-DAIT/IPT:
escriba.ipt.br/pdf_restrito/172550.pdf
