经过电镀后，可以提高产品表面的抗腐蚀能力，并能延缓疲劳裂纹的产生扩大，有效延长产品使用寿命。

After electroplating, can improve the corrosion resistance of the surface of the product, and can delay the expansion of fatigue crack, effectively prolong the service life of the product.

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在裂纹扩展试验中，试样切口后使其弯曲并产生微小裂纹，在试件上继续加力直到裂纹扩大为止。

For crack-opening displacement tests, a specimen is notched and then fatigued by flexing to obtain a fine crack. Force is then applied until the crack begins to grow.

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