摘要：设计了一种新型65MnCr耐磨钢,并对其CCT曲线进行测定,研究该钢不同冷速下的组织变化及热处理后的组织性能。结果表明,65MnCr钢的临界冷却速度在1～3℃/s之间,Ms点184℃,具有很高的淬透性,完全淬透后,马氏体硬度达64 HRC,淬硬性好。130 mm柱状试样经水淬+自回火后,冲击吸收能量在15 J以上,从表面至心部,硬度分布均匀,均在48 HRC以上,组织依次为回火马氏体、马氏体+块状(马氏体+奥氏体)组织、马氏体+粒状贝氏体+块状(马氏体+奥氏体)组织,是一种理想的可供大尺寸构件用耐磨材料。

摘要：设计了一种9MnCr低合金磨球用钢,绘制了9MnCr钢的连续冷却转变曲线,并对其组织和硬度进行了分析。结果表明,当冷却速度小于2℃/s时,转变产物为片层状珠光体和沿晶界分布的二次碳化物;当冷却速度为2～5℃/s时,转变产物为片层状珠光体、马氏体和少量贝氏体;当冷却速度大于5℃/s时,转变产物为马氏体组织。硬度随冷却速度的增加而增加,当冷却速度大于5℃/s时,基本保持不变,为61 HRC。220℃等温30 min后,转变产物基本为马氏体组织,随着等温温度的升高,逐渐出现贝氏体,硬度呈下降趋势;在420℃等温过程中,初期贝氏体的转变速率较快,但转变一段时间后,贝氏体的转变速率减慢。

摘要：为了提高热成形钢的综合性能,设计了一种C-Si-Mn-Cr-B系热成形钢,采用热膨胀仪测定并研究了30SiMnCrB5热成形钢的连续冷却转变曲线和相变规律.分析了经轧制、退火及热成形模拟后钢板的微观组织形貌和力学性能,结合等密度线极图的方法,判定了热成形模拟后钢板中马氏体变体与母相的取向关系.30SiMnCrB5热成形钢具有较好的淬透性,临界冷速为5℃·s-1,有效抑制了珠光体和贝氏体的形成,完全马氏体组织的硬度可达600 HV以上.热成形模拟后的微观组织由板条马氏体和残余奥氏体构成,残余奥氏体主要以薄膜状分布在马氏体板条间,质量分数为6%~8%,抗拉强度为1800 Mpa左右,总伸长率可达10%以上,强度和塑性的匹配较好.热成形模拟后30SiMnCrB5热成形钢板中马氏体变体与母相的取向关系更接近N-W关系,12种变体没有都出现在原始奥氏体内.

摘要：WS2 nanomaterials have attracted great attention in the field of electromagnetic wave absorption due to their high specific surface area,layered structure,and peculiar electronic ***,further improvements on their limited electromagnetic absorbing(EMA)capacity and bandwidth are urgently required for their practical application as EMA *** this work,WS2/NiO hybrids with heterostructures are prepared by a hydrothermal method and developed into EMA *** maximum reflection loss of the hybrids with 20%NiO loading could reach-53.31 dB at a thickness of 4.30 mm;the bandwidth with a reflection loss value of less than-10 dB is determined to be13.46 GHz(4.54–18 GHz)when the thickness of the absorbent is between 3.5 and 5.5 *** is found that the enhanced EMA performance of WS2/NiO hybrids is caused by the addition of magnetic NiO,which could result in the interfaces between WS2 and NiO being responsible for the synergetic magnetic loss and dielectric loss in the *** work provides a new approach for the design of excellent EMA materials for practical applications.