A study of high-strength bolts after dephosphoring

作者:Hsia Shao Yi; Chou Yu Tuan*; Chao Jung Chi
来源:Advances in Mechanical Engineering, 2016, 8(3): 168781401663731.
DOI:10.1177/1687814016637317

摘要

A wide variety of fasteners are produced, including those for the automobile industry, household electrical appliances industry, architectural engineering, and even the aviation industry. The effects of the high-tensile bolt dephosphoring process on the entire fastener manufacturing process and its organizational characteristics and mechanical properties are analyzed and discussed in this study. Our experimental results reveal that the bolt dephosphoring process must be completed before heat treatment, which can be confirmed with a dephosphoring reagent or metallographic observation. Once bolt heat treatment is completed, bolts without dephosphoring appear to be coated with delta ferrite (delta ferrite) composed of a phosphate coating and a phosphatizing coating, which are not easily removed. Heat treatment with phosphorus results in grain boundary segregation, causing embrittlement and a reduction in lattice bonding forces and resulting in a high risk of fracturing when bolts are used in high-temperature environments or undergo multiaxial stresses.

  • 出版日期2016-3

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