【Mechanical Equipment Technology Exchange Edition】Mechanical Equipment 【Daily Question】20190716
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Question: What is thermal fatigue in metal materials? There are no answers provided for this series of posts; fellow netizens are free to share their own opinions – just reply with what you understand. Replies earn rewards ranging from 5 to 15 points; all forum members are welcome to participate actively and support the development of the forum! ! ! Chemical Equipment and Machinery
The fatigue failure of metal materials caused by thermal stress cycles (or thermal strain cycles) resulting from temperature gradient cycles is known as thermal fatigue. Features: (1) Typical surface fatigue cracks appear in a cracked pattern. (2) The crack direction can be along the grain boundary or through the grain ； Generally, the ends of cracks are sharp, and the cracks contain or are filled with oxides. (3) The macroscopic fracture surface is gray and covered with oxides. (4) The cracks originate from the surface, and the depth of crack propagation corresponds to changes in stress, time, and temperature differences. Factors affecting it: (1) The greater the temperature gradient in the environment and the higher the frequency of changes, the more likely heat fatigue will occur. (2) When materials with different coefficients of thermal expansion are combined, thermal fatigue is likely to occur. (3) The grains are coarse and uneven, making it prone to thermal fatigue. (4) The second-phase particles distributed at the grain boundaries contribute to the occurrence of thermal fatigue. (5) The material has poor plasticity and is prone to thermal fatigue. (6) The geometric structure of the parts exerts a strong constraint on the expansion and contraction of the metal, making thermal fatigue likely to occur.
The fatigue failure of metal materials caused by thermal stress cycles (or thermal strain cycles) resulting from temperature gradient cycles is known as thermal fatigue. Features: (1) Typical surface fatigue cracks appear in a cracked pattern. (2) The crack direction can be along the grain boundary or through the grain ； Generally, the ends of cracks are sharp, and the cracks contain or are filled with oxides. (3) The macroscopic fracture surface is gray and covered with oxides. (4) The cracks originate from the surface, and the depth of crack propagation corresponds to changes in stress, time, and temperature differences. Factors affecting it: (1) The greater the temperature gradient in the environment and the higher the frequency of changes, the more likely heat fatigue will occur. (2) When materials with different coefficients of thermal expansion are combined, thermal fatigue is likely to occur. (3) The grains are coarse and uneven, making it prone to thermal fatigue. (4) The second-phase particles distributed at the grain boundaries contribute to the occurrence of thermal fatigue. (5) The material has poor plasticity and is prone to thermal fatigue. (6) The geometric structure of the parts exerts a strong constraint on the expansion and contraction of the metal, making thermal fatigue likely to occur.
The fatigue failure of metal materials caused by thermal stress cycles (or thermal strain cycles) resulting from temperature gradient cycles is known as thermal fatigue. Features: (1) Typical surface fatigue cracks appear in a cracked pattern. (2) The crack direction can be along the grain boundary or through the grain ； Generally, the ends of cracks are sharp, and the cracks contain or are filled with oxides. (3) The macroscopic fracture surface is gray and covered with oxides. (4) The cracks originate from the surface, and the depth of crack propagation corresponds to changes in stress, time, and temperature differences. Factors affecting it: (1) The greater the temperature gradient in the environment and the higher the frequency of changes, the more likely heat fatigue will occur. (2) When materials with different coefficients of thermal expansion are combined, thermal fatigue is likely to occur. (3) The grains are coarse and uneven, making it prone to thermal fatigue. (4) The second-phase particles distributed at the grain boundaries contribute to the occurrence of thermal fatigue. (5) The material has poor plasticity and is prone to thermal fatigue. (6) The geometric structure of the parts exerts a strong constraint on the expansion and contraction of the metal, making thermal fatigue likely to occur.
When metal materials are subjected to alternating stresses over a long period of time, they can fracture even when the maximum stress is well below the material’s strength limit; this phenomenon is known as fatigue failure of metal materials
The fatigue failure of metal materials caused by thermal stress cycles (or thermal strain cycles) resulting from temperature gradient cycles is known as thermal fatigue. Features: (1) Typical surface fatigue cracks appear in a cracked pattern. (2) The crack direction can be along the grain boundary or through the grain ； Generally, the ends of cracks are sharp, and the cracks contain or are filled with oxides. (3) The macroscopic fracture surface is gray and covered with oxides. (4) The cracks originate from the surface, and the depth of crack propagation corresponds to changes in stress, time, and temperature differences. Factors affecting it: (1) The greater the temperature gradient in the environment and the higher the frequency of changes, the more likely heat fatigue will occur. (2) When materials with different coefficients of thermal expansion are combined, thermal fatigue is likely to occur. (3) The grains are coarse and uneven, making it prone to thermal fatigue. (4) The second-phase particles distributed at the grain boundaries contribute to the occurrence of thermal fatigue. (5) The material has poor plasticity and is prone to thermal fatigue. (6) The geometric structure of the parts exerts a strong constraint on the expansion and contraction of the metal, making thermal fatigue likely to occur.
The fatigue failure of metal materials caused by thermal stress cycles (or thermal strain cycles) resulting from temperature gradient cycles is known as thermal fatigue.
The fatigue failure of metal materials caused by thermal stress cycles (or thermal strain cycles) resulting from temperature gradient cycles is known as thermal fatigue.
When metal materials are subjected to alternating stresses over a long period of time, they can fracture even when the maximum stress is well below the material’s strength limit; this phenomenon is known as fatigue failure of metal materials. Thermal fatigue refers to the phenomenon of fracture that occurs under the repeated action of alternating thermal stresses on metals.
When metal materials are subjected to alternating stresses over a long period of time, they can fracture even when the maximum stress is well below the material’s strength limit; this phenomenon is known as fatigue failure of metal materials.
The fatigue failure of metal materials caused by thermal stress cycles (or thermal strain cycles) resulting from temperature gradient cycles is known as thermal fatigue.