Scholarlink

The carburizing process is used on steel parts that require high surface resistance. When carrying out this thermochemical treatment, quenching oils with suitable properties are used, which, by promoting high cooling rates, ensure martensitic structures. This paper presents an overview of the work developed to determine the influence of different quenching oils on the microstructure of carburizing steels. The main objective was determining the heat transfer coefficients of four oils, from now on referred to as A, B, C, and D, for data protection reasons. Small sheet specimens of AISI 304 austenitic stainless steel were quenched, and their temperature evolution was recorded during cooling. This data was used in the software Engineering Equation Solver to determine the heat transfer coefficient versus temperature, for each of the oils under analysis. To compare the accuracy of the obtained curves for larger bodies, the same experimental procedure was repeated for cylindrical samples of the same stainless steel. Their experimental temperature–time curves were compared to the corresponding numerical ones, obtained using the Abaqus software. The similarity between these two types of cooling curves indicated that the method used to determine the heat transfer coefficient of each of the oils is accurate and representative of the results obtained. To study the influence of the different quenching oils on the final properties, namely the hardness and microstructure, a hardness profile and microstructural analysis were performed on carburized and quenched samples of two different EN carburizing steels, 16MnCr5 and 18CrNiMo7-6. Moreover, cooling curves of the quenching of these parts on the four quenching oils were plotted into the CCT (Continuous Cooling Transformation) diagrams for comparison and prediction of the transformations occurred. Hardness, microstructure, and cooling curves analysis demonstrated that the oil known as “D” performs better in terms of the different steels’ hardenability and, as such, should be adopted in heat treatments.

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Study of the Influence of Different Quenching Oils on the Hardness and Microstructure of Carburizing Steels

  • 会议论文

  • 发表日期：

    2025年

查看全文
  • Maria Tavares,
  • Paulo Duarte,
  • Paulo Canhola,
  • Jorge Lino Alves

摘要

The carburizing process is used on steel parts that require high surface resistance. When carrying out this thermochemical treatment, quenching oils with suitable properties are used, which, by promoting high cooling rates, ensure martensitic structures. This paper presents an overview of the work developed to determine the influence of different quenching oils on the microstructure of carburizing steels. The main objective was determining the heat transfer coefficients of four oils, from now on referred to as A, B, C, and D, for data protection reasons. Small sheet specimens of AISI 304 austenitic stainless steel were quenched, and their temperature evolution was recorded during cooling. This data was used in the software Engineering Equation Solver to determine the heat transfer coefficient versus temperature, for each of the oils under analysis. To compare the accuracy of the obtained curves for larger bodies, the same experimental procedure was repeated for cylindrical samples of the same stainless steel. Their experimental temperature–time curves were compared to the corresponding numerical ones, obtained using the Abaqus software. The similarity between these two types of cooling curves indicated that the method used to determine the heat transfer coefficient of each of the oils is accurate and representative of the results obtained. To study the influence of the different quenching oils on the final properties, namely the hardness and microstructure, a hardness profile and microstructural analysis were performed on carburized and quenched samples of two different EN carburizing steels, 16MnCr5 and 18CrNiMo7-6. Moreover, cooling curves of the quenching of these parts on the four quenching oils were plotted into the CCT (Continuous Cooling Transformation) diagrams for comparison and prediction of the transformations occurred. Hardness, microstructure, and cooling curves analysis demonstrated that the oil known as “D” performs better in terms of the different steels’ hardenability and, as such, should be adopted in heat treatments.