Havva Kazdal Zeytin
,
Hakan Yildirim
,
Banu Berme
,
Selim Duduolu
,
Gürkan Kazdal
,
Adem Deniz
钢铁研究学报(英文版)
Heat treatment methods were applied to white cast iron for improving the impact and wear resistance. Additionally, chemical composition optimization was made. Furthermore, the effect of boron addition on such applications was investigated. Samples were investigated by using optical and electron microscope methods. Hardness, wear and impact tests were conducted. The results showed that the secondary carbides in the standard alloy were iron-enriched, needle-like carbides M3C when the boron-added alloy contained Fe23(C,B)6 type, globular secondary carbides. It was concluded that heat treatment B provided higher wear and hardness properties, compared to the standard heat treatment. Optimum mechanical properties were obtained by lower destabilisation temperatures and increasing temperature reduced the wear resistance and hardness.
关键词:
white cast iron
,
mining application
,
impact resistance
,
wear
,
toughness
WEI Min-xian
,
WANG Shu-qi
,
WANG Lan
,
CHEN Kang-min
钢铁研究学报(英文版)
Elevated-temperature wear tests under atmospheric conditions at 400 ℃ were performed for a hot working die steel H21 on a pin-on-disk wear tester. The phase and morphology of worn surfaces were examined using XRD and SEM, and the relation of wear resistance to tempered microstructures was studied for H21 steel. XRD patterns exhibit that oxidative wear is a predominated wear mechanism with Fe3O4 and Fe2O3 on worn surfaces. It is found that with increasing normal load, obvious plastic deformation of substrate appears on worn surfaces. Microstructures start to affect apparently wear resistance of the steel with an increase of load. Under loads of 50-100 N, wear losses of steel retain low values and relatively approach for steels with various microstructures. As loads are increased to 150-200 N, wear losses of steel start to increase obviously and present apparent difference for steel with various microstructures. Wear resistance is found to increase in the sequence as follows: tempered sorbite, tempered martensite, tempered troostite without secondary hardening and tempered troostite with secondary hardening or upcoming one. Higher strength and microstructural stability are required for steels with excellent wear resistance.
关键词:
steel
,
heat treatment
,
microstructure
,
wear
,
wear resistance
陶红标，吕晓军，席常锁，张慧，吴夜明，干勇
钢铁
以提高结晶器使用寿命和铸坯表面质量为目标，通过建立漏斗区自有锥度、结晶器总锥度和结晶器局部锥度的计算模型，研究了漏斗区的宽度和深度、窄边铜板偏移量以及磨损对结晶器锥度沿高度方向分布的影响，提出了漏斗区自有锥度和局部锥度沿高度方向分布应与铸坯的凝固收缩相匹配的设计理念，对薄板坯连铸结晶器宽面铜板内腔形状及窄边锥度调控工艺进行了优化设计，为结晶器操作工艺及管理制度的优化提供了理论依据。基于上述研究工作，研发了适合于FTSC工艺的新型结晶器，进行了大量的工业生产试验。结果表明：在浇注宽度为1520mm的铸坯时，窄边附加偏移量可由12mm降低到7mm，窄边铜板的使用寿命得到了大幅度的提高，过钢量为2.25万t后，窄边铜板最大磨损量由5mm降低到2mm以下；新型结晶器有效控制了铸坯窄面凹陷和表面纵裂纹的发生。
关键词:
薄板坯
,
continuous casting
,
mould
,
taper
,
wear
,
crack
