CVN(Charpy V-notch) toughness and grainsizenumber of J55 grade oil casings produced by Baotou Iron and Steel Company did not meet the reiative standards in the past.
本文针对包钢原来生产的J55石油套管冲击韧性不足，晶粒粗大的问题开展研究。
2
The height of the Ke peak is independent of the grainsize while that of this peak is proportional to the number of the bamboo boundary containing in the specimen.
例如，葛峰的高度不随晶粒尺寸而变，而竹节峰的高度则与试样中所含的竹节晶界的数目成正比。
3
Then the morphology was observed by optical microscope and SEM. The grainsize of austenite, the number of martensite in austenite grains and the spacing of the lath martensite were measured.