CAJ | 학술논문

讨论55SiMnMo 钎钢在正火（连续空冷）和等温条件下所转变的贝氏体，分析这两种贝氏体的形貌和形态差异。研究结果表明：55SiMnMo 钢加热（超过 AC3点）奥氏体化后，正火（连续空冷）获得的金相组织是B4型无碳化物上贝氏体（铁素体＋富碳奥氏体）；在等温条件下：等温的温度达到或超过400℃，长时间等温的金相组织是 B2型，B4型混合贝氏体，B2型的比例多过 B4型（以 B2型为主），短时间的等温则是以 B4型为主；等温的温度低过400℃，即使长时间等温，其金相组织仍是 B4型贝氏体。
토론55SiMnMo 천강재정화（련속공랭）화등온조건하소전변적패씨체，분석저량충패씨체적형모화형태차이。연구결과표명：55SiMnMo 강가열（초과 AC3점）오씨체화후，정화（련속공랭）획득적금상조직시B4형무탄화물상패씨체（철소체＋부탄오씨체）；재등온조건하：등온적온도체도혹초과400℃，장시간등온적금상조직시 B2형，B4형혼합패씨체，B2형적비례다과 B4형（이 B2형위주），단시간적등온칙시이 B4형위주；등온적온도저과400℃，즉사장시간등온，기금상조직잉시 B4형패씨체。
This paper discusses bainite of 55SiMnMo rock-drill steel,transformed under normalization (continuous cool-ing)and isothermal condition by analyzing the topography and morphology disparity of the two types of bainite.The research results demonstrate that the metallographic structure,gotten by normalization (continuous cooling),is B4 type no-carbide-bainite (ferrite and carbon-rich austenite)after heating (over AC3 point)and austenitizing 55SiMnMo steel. Under isothermy condition,the metallographic structure,gotten by long-time isothermy,is B2 type and B4 type mixed bainite with the temperature of or over 400 ℃.The proportion of B2 type is higher than B4 type (mainly B2 type).And B4 type is mainly gotten with the short isothermy time.While the isothermy is below 400 ℃,the metallographic structure is still B2 type bainite even though the isothermal time is long.