60Si2Mn钢盘条断裂原因

某60Si2Mn钢盘条在卷簧过程中发生断裂。采用宏观观察、化学成分分析、金相检验、夹杂物分析、扫描电镜分析等方法对该盘条的断裂原因进行分析。结果表明:在卷簧前及卷簧初期的拉拔过程中,盘条表面受到了严重的挤压或擦蹭,使组织变形,并形成了隐晶马氏体;在后续的拉拔过程中,盘条内部应力集中处萌生了微裂纹,裂纹不断扩展,最终导致盘条断裂。

Effects of deep cryogenic treatment on microstructure and properties of WC-11Co cemented carbides with various carbon contents

The effects of deep cryogenic treatment on the microstructure and properties of WC-11 Co cemented carbides with various carbon contents were investigated.The results show that after deep cryogenic treatment,WC grains are refined into triangular prism with sound edges via the process of spheroidization,but WC grain size has no evident change compared with that of untreated alloys.The phase transformation of Co phase from α-Co（FCC） to ε-Co（HCP） is observed in the cryogenically treated alloys,which is attributed to the decrease of W solubility in the binder（Co）.Deep cryogenic treatment enhances the hardness and bending strength of the alloys,while it has no significant effects on the density and cobalt magnetic performance.

控轧型Q420C钢板延伸率不合原因分析

通过对控轧型Q420C钢板延伸率不合原因进行分析,发现混晶和硬相组织是造成钢板延伸率不合的主要原因,针对上述原因,对≤40 mm控轧型Q420C钢板提出了改进工艺措施,有效地解决了控轧型Q420C钢板延伸率不合问题。

Effects of solid solution treatment and cooling on morphology of LPSO phase and precipitation hardening behavior of Mg-Dy-Ni alloy

Effects of solid solution treatment and cooling on the morphology of long period stacking order(LPSO)phase and precipitation hardening behavior of Mg?2Dy?0.5Ni(molar fraction,%)alloy were investigated.Microstructures of the as-cast alloy mainly consisted ofα-Mg phase,bamboo-like Mg12DyNi phase with LPSO structure distributed between dendrites and small amounts of cubic Dy phases.During solid solution treatment at565oC for12h and subsequent different cooling conditions,dot-shaped,block,fine lamellar and rod-shaped LPSO phases precipitate in Mg matrix,respectively.For continuous cooling conditions(furnace and air cooling),the fine lamellar LPSO phase generally forms in grain interior and its volume fraction increases and block LPSO phase coarsens with increasing cooling time.For discontinuous cooling conditions(air cooling after furnace cooling to415and265°C),the dot-shaped LPSO grows into the rod-shaped phase,which results in an decrease of cooling hardening behavior of alloy.

Effect of hot deformation on α→β phase transformation in 47Zr-45Ti-5Al-3V alloy

The effect of strain rate and deformation temperature on theα→βphase transformation in 47Zr-45Ti-5Al-3V alloy with an initial widmanstattenαstructure was investigated.At the deformation temperature of 550°C,the volume fraction ofαphase decreased with increasing strain rate.At 600 and 650°C,the volume fraction ofαphase firstly increased to a maximum value with increasing strain rate from 1×10-3 to 1×10-2 s-1,and then decreased.At 700°C,the microstructure consisted of singleβphase.At a given strain rate,the volume fraction ofαphase decreased with increasing deformation temperature.With decreasing strain rate and increasing deformation temperature,the volume fraction and size of globularαphase increased.At 650°C and 1×10-3 s-1,the lamellarαphase was fully globularized.The variation in the volume fraction and morphology ofαphase with strain rate and deformation temperature significantly affected the hardness of 47Zr-45Ti-5Al-3V alloy.

Advances in the diagnosis and treatment of Ig G4-related sclerosing cholangitis: a review

Immunoglobulin G4-related sclerosing cholangitis （IgG4-SC） is an IgG4-related disease characterized by bile duct fibroinflammatory wall-thickening and stenosis, resulting in obstruction jaundice, weight loss. Dif- ferent regions of the bile duct can be involved, with the distal region being the most common. IgG4-SC can also have other organ involvement, such as the pancreas, urinary tract, salivary glands and lacrimal glands. In clinical practice, the manifestation of IgG4-SC is very similar to cholangiocarcinoma （CC） and primary sclerosing cholangiUs （PSC）, as well as pancreatic malignancies, while the treatment and prognosis are totally different. Japanese researchers ever established the clinical diagnostic criteria in 2012： （1） charac- teristic biliary imaging findings; （2） elevated serum IgG4 concentrations; （3） the coexistence of IgG4-related diseases except those of the biliary tract; and （4） characteristic histopathological features. According to our observations, IgG4-SC can be distinguished from CC with 100% specificity only at a cutoff of six times the upper normal limit. Imaging findings have low specificity for diagnosis, with the exception of intraductal ultrasonography, which can reflect the lesion with relatively high specificity. IgG4 plasma cell infiltration can be found in bile duct biopsy tissue, although this procedure is difficult. According to recent studies, the treatment of IgG4-SC relies mainly on corticosteroids. Following steroid treatment, most IgG4-SC patients can recover and their symptoms are resolved although a few patients relapse after steroid withdrawal. Maintenance of steroid therapy or alternative drugs is necessary in such cases. There is, however, no stronq evidence for malignant transformation in I qG4-SC.