CHEN Ai-hua
,
XU Jian-qiu
,
LI Ran
,
LI Hua-long
钢铁研究学报(英文版)
The mechanical properties, corrosion resistance and microstructures of high performance steel (HPS) was investigated by tensile testing machine, Charpy V-Notch (CVN) testing machine, cyclic immersion corrosion tester, XRD, optical microscopy (OM), scanning electron microscopy (SEM), and electron probe micro-analyzer (EPMA). The results showed that significant differences existed in the tensile strength, yield strength and impact toughness between HPS and PCS. After 72 h cyclic immersion accelerated corrosion test, the inner rust layer on HPS was composed of α-FeOOH phase and denser than that on PCS that was a mixture of α-FeOOH and Fe3O4. The rust formed on HPS provides better protection and HPS has lower corrosion rates than PCS. Copper and chromium in HPS enrich in the rust layer and enhance the compactness of the rust layer. Based on the results of the accelerated corrosion tests and rust layer analysis, the roles of Cu and Cr against corrosion are discussed, providing HPS with chemical specification which has been industrially successful to produce weathering steel for bridge structure.
关键词:
HPS
,
corrosion resistance
,
microstructure
,
mechanical property
JIA Yue-cai
,
GUO Hai-rong
,
LI Ran
,
LI Hua-long
钢铁研究学报(英文版)
Deep drawing properties of hot rolled gas cylinder steel was investigated by using HP295 steel in terms of microstructure, texture, yield ratio, plastic strain ratio (r-value) and plastic anisotropy (Δr). The grains in the hot strip were largely equiaxed, and the texture was weak, containing α- and γ-fibre. Reheating temperature, finish rolling temperature and cooling rate after rolling influenced the ferrite-pearlite band formation significantly, and the yield ratio increased steeply with decreasing coiling temperature below 630 ℃. The anisotropy is relatively high due to retained severe ferrite-pearlite band. A mechanism of the band formation due to manganese segregation is elaborated and confirmed validly, from which the measures to avoid the band formation are worked out. Rolling parameters have been optimized by the measures, and industrial production of the gas cylinder steel has been made possible with much improved r-and Δr-values, while meeting other specifications.
关键词:
yield ratio
,
formability
,
ferrite-pearlite band
,
texture
,
plastic anisotropy
