【Daily Question】Chemical Engineering Principles 349: Caustic Embrittlement (March 28)
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This post was last edited by Zaihui Kangqiao on 2016-4-8 at 16:29. The Chemical Engineering Theory section is now launching a \"One Question per Day\" initiative to help everyone reinforce their basic knowledge in chemical engineering. Subsequent series will include those on \"Principles of Chemical Engineering\", \"Mass Transfer and Separation\", \"Thermodynamics in Chemical Engineering\", and \"Chemical Process Engineering\". We hope you will give it your active support! Wishing everyone a happy Christmas! Answers to the questions in the \"One Question per Day\" initiative can be viewed directly, and the thread will be closed after 1 day ! To encourage continued participation from everyone this year! You get 3 wealth rewards just for participating, and an additional 4 wealth points for correct answers~~~ Short answer question: What are the three factors that cause caustic embrittlement in boilers? Answer: 1) The boiler water contains a certain amount of free alkali, which gives it corrosive properties ； 2) The boiler is riveted or expanded, and there are gaps in these areas, which lead to localized concentration of water quality ； 3) There is high stress in the metal.
1) The boiler water contains a certain amount of free alkali, which gives it corrosive properties； 2) The boiler is riveted or expanded, and there are gaps in these areas, which lead to localized concentration of water quality ； 3) There is high stress in the metal.
Answer: 1) The boiler water contains a certain amount of free alkali, which gives it corrosive properties； 2) The boiler is riveted or expanded, and there are gaps in these areas, which lead to localized concentration of water quality ； 3) There is high stress in the metal.
1. Boiler water is corrosive, meaning it contains a certain amount of free alkalis. 2. The boiler has riveted or expansion-jointed areas, and there are gaps or leaks in these parts, resulting in localized concentration of water quality and high alkalinity. 3. The metal has extremely high stresses, close to the yield point, with a high degree of stress concentration.
1. The furnace water contains a high concentration of caustic soda, NaOH. 2. The boiler is riveted or expanded, and there are gaps at these connection points, resulting in localized concentration of boiler water. 3. Metals have tensile stress approaching their yield point.
①The furnace water contains a high concentration of caustic soda, NaOH. ②The boiler is riveted or expanded, and there are gaps at these joints, resulting in localized concentration of boiler water. ③Metals have tensile stress near their yield point
1\ The boiler water contains a certain amount of free alkali, which gives it corrosive properties; 2\ The boiler is riveted or expanded, and there are gaps in these areas, leading to localized concentration of water quality; 3\ High stresses exist in the metal.
1 The boiler water contains a certain amount of free alkali, which is aggressive. The 2 boilers are riveted or expanded, and there are gaps in these areas, which leads to localized concentration of water quality. There is high stress in the 3 metals.
1) The boiler water contains a certain amount of free alkali, which gives it corrosive properties; 2) The boiler is riveted or expanded, and there are gaps in these areas, leading to localized concentration of water quality; 3) There are tensile stresses in the metal that are close to its yield point.
What are the three factors that cause caustic embrittlement in boilers? Answer: The three factors that cause caustic embrittlement in boilers are: 1) The boiler water contains a certain amount of free alkalis, which are corrosive ； 2) The boiler is riveted or expanded, and there are gaps in these areas, which lead to localized concentration of water quality ； 3) There is high stress in the metal.
Caustic embrittlement is a type of corrosion that affects specific areas of boiler metal; it is caused by the concentration of free alkalis in the boiler water along with high stresses within the metal. This corrosion occurs along the interfaces between the metal’s crystalline grains and progresses inward, resulting in the formation of fine cracks, which can develop into penetrating cracks under the effect of stress. The main causes of caustic embrittlement include: (1) stresses within the metal that exceed its yield limit; (2) a high concentration of sodium hydroxide in the boiler water, which is highly corrosive; (3) areas in the boiler structure where the boiler water may become concentrated, leading to very high concentrations in those local areas.