X80管道钢氢致附加应力的试验测定

Experimental Measurement on Hydrogen-induced Additive Stress for X80 Pipeline Steel.

X80管道钢在空气中拉伸至塑性变形大于1％后卸载,充氢至饱和再空拉,其屈服应力小于卸载前的流变应力,该差值就是氢引起的附加应力。试验表明,氢致附加应力随氢浓度的升高而线性升高。氢致附加应力能协助外应力促进塑性变形。

Tensile specimen of X80 pipeline steel was strained to over 1% plastic deformation in air. The flow stress of a X80 linepipe steel extended over yield is larger than the yield stress of the same sample extended in' air after unloading and charging with hydrogen. The difference is the hydrogen-induced additive stress, which can help the external stress to enhance the plastic deformation. The hydrogen-induced additive stress,σad,increases linearly with the increase of the hydrogen concentration,i. e.σad=- 14. 1 + 3.89 C0.