Thermophysical Properties of Stainless Steel Containing 5 mass % B₄C in the Solid Phase

Thermophysical properties of austenitic stainless steel containing boron carbide in a solid state

“…As thermophysical properties in the solid state, density, specific heat, and thermal conductivity were measured using four SS-B4C samples mentioned in section 2.1 and 316L SS as a reference, only an outline will be described here. The detail of the measurement method has been described in the previous article (Takai et al, 2019).…”

“…This study aims to measure the thermophysical properties of the eutectic mixture in a solid state with a wide temperature range. To date, the thermophysical property measurements of the eutectic mixture from the solid to liquid state (Takai et al, 2019;Fukuyama et al, 2019;Ohta et al, 2019) and physical model development for the eutectic melting reaction (Liu et al, 2018) were conducted together with research institutes in our project (Yamano et al, 2019). As mentioned above, the SS-B4C produced by contact between SS and B4C is considered microscopically inhomogeneous from place to place.…”

“…Hence, pre-alloyed SS-B4C samples of the prescribed B4C concentration and as homogeneous as possible were utilized as common samples for the thermophysical measurements in both solid and liquid states to reduce the uncertainty of samples and achieve accurate measurement. The thermophysical property measurements in a solid state were started from the SS-5mass%B4C, which is considered as close to the eutectic composition of SS and B4C, and density, specific heat, and thermal conductivity of SS-B4C were evaluated and reported in the previous article (Takai et al, 2019). As SS-B4C samples synthesized at the early stage of the research were synthesized by the solid-phase reaction, it was reported that approximately 2% of voids remained in the sample structure and there was concern about the impact of thermophysical properties, especially density, on evaluation results (Takai et al, 2019).…”

“…The thermophysical property measurements in a solid state were started from the SS-5mass%B4C, which is considered as close to the eutectic composition of SS and B4C, and density, specific heat, and thermal conductivity of SS-B4C were evaluated and reported in the previous article (Takai et al, 2019). As SS-B4C samples synthesized at the early stage of the research were synthesized by the solid-phase reaction, it was reported that approximately 2% of voids remained in the sample structure and there was concern about the impact of thermophysical properties, especially density, on evaluation results (Takai et al, 2019). Based on this result, the purpose of this study is to evaluate the thermophysical properties of SS containing from 5mass% to 17mass% B4C without voids that were newly synthesized.…”

Post-test material analysis of eutectic melting reaction of boron carbide and stainless steel

“…60 mm) within about 10 min. which corresponded to SS freezing time.る結晶相と一致しており(Takai et al, 2019)，試料上段では，共晶溶融反応が進んでいると考えられる．一方，試 料中段の不定形の組織部や，粒状化があまり進んでいない試料底面の主たる結晶相はγ鉄であり，明確なほう素 との反応は確認できなかった．また，B4C と反応させた後の SS 試料上部に残っていた B4C ペレットの縦断面か らは，接触界面からの距離によらず SS 成分が全く検知されないことから，B4C と SS の反応は B4C が SS 側に溶 け出す方向に進んでいると考えられる． 次に，B4C と SS 接触部付近の状況を詳しく調べるため，SS 試料側表面について透過型電子顕微鏡(TEM：日 本電子製 JEM-2100F 型，EDX: 日本電子製 JED-2300T 型)を用いて詳細分析を実施した結果を図 14 に示す．…”