CAJ | 학술논문

采用NETZSCH DIL 402C高温热膨胀仪对三种不同化学成分的钢种在30~1150℃温度范围内的热膨胀特性进行了测量，得到线性热膨胀和瞬时线膨胀系数随温度的变化曲线。对实测的热膨胀值进行定量计算和对比分析后发现，钢在加热过程中的线性热膨胀及瞬时线膨胀系数随温度的变化过程可分为室温至相变区、固态相变区和高温奥氏体区三个阶段，每个阶段碳含量对热膨胀的影响程度不同。在整个升温过程中，物理热效应引起的热膨胀占主导作用，不同钢种的物理热膨胀总量基本相同，而相变引起的收缩量大约占整个膨胀绝对变化量的16%，且收缩总量随碳含量的增加而减少，导致最终不同钢种试样的膨胀量不同。
채용NETZSCH DIL 402C고온열팽창의대삼충불동화학성분적강충재30~1150℃온도범위내적열팽창특성진행료측량，득도선성열팽창화순시선팽창계수수온도적변화곡선。대실측적열팽창치진행정량계산화대비분석후발현，강재가열과정중적선성열팽창급순시선팽창계수수온도적변화과정가분위실온지상변구、고태상변구화고온오씨체구삼개계단，매개계단탄함량대열팽창적영향정도불동。재정개승온과정중，물리열효응인기적열팽창점주도작용，불동강충적물리열팽창총량기본상동，이상변인기적수축량대약점정개팽창절대변화량적16%，차수축총량수탄함량적증가이감소，도치최종불동강충시양적팽창량불동。
ABSTRACT The thermal expansion properties of steels with different chemical compositions were precisely measured at temperatures from 30 to 1150℃ with a NETZSCH DIL 402C dilatometer. The curves of thermal linear expansion and instant linear expansion coeffi-cient versus temperature were plotted from measured data. Quantitative analysis and comparison results show that carbon content has different influences on the thermal linear expansion and instant linear expansion coefficient of steels in the three temperature ranges of low temperature, solid phase transformation and austenite phase. Thermal expansion caused by the heat effect, which is basically the same for different steels, is dominant in the whole temperature range. The shrinkage of samples caused by phase transformation, which decreases with increasing carbon content, accounts for about 16% of the total absolute amount of thermal expansion, leading to the different expansions for the three steels.