Microstructural and mechanical characterisation of laser-welded high-carbon and stainless steel

The final publication is available at Springer via http://dx.doi.org/10.1007/s00170-015-7111-5Laser welding is becoming an important joining technique for welding of stainless steel to carbon steel and is extensively used across various sectors, including aerospace, transportation, power plants, electronics and other industries. However, welding of stainless steel to high-carbon steel is still at its early stage, predominantly due to the formation of hard brittle phases, which undermine the mechanical strength of the joint. This study reports a scientific investigation on controlling the brittle phase formation during laser dissimilar welding of high-carbon steel to stainless steel. Attempts have been made to tailor the microstructure and phase composition of the fusion zone through influencing the alloying composition and the cooling rate. Results show that the heat-affected zone (HAZ) within the high-carbon steel has significantly higher hardness than the weld area, which severely undermines the weld quality. To reduce the hardness of the HAZ, a new heat treatment strategy was proposed and evaluated using a finite element analysis-based numerical simulation model. A series of experiments has been performed to verify the developed thermo-metallurgical finite element analysis (FEA) model, and a qualitative agreement of predicted martensitic phase distribution is shown to exist

Prevalence of Echinococcus spp. Infection Using Coproantigen ELISA among Canids of Moghan Plain, Iran

"nBackground: Echinococcosis is one of the most important helminthic zoonotic diseases in Iran. Intestinal Scraping Tech­nique (IST), the traditional method for diagnosis of the infection in definitive hosts, has many disadvantages including low sus­ceptibil­ity and being expensive, hazardous and laborious. Detection of coproantigens in fecal samples by enzyme-linked immu­nosorbent assay (CA-ELISA) is known as a useful tool for intravital mass-screening of definitive host populations. This study was performed to determine the prevalence of Echinococcus spp. infection among canids in Moghan plain, the only area in Iran known to be endemic for E. multilocularis."nMethods: One hundred thirty eight fecal samples were collected from red foxes and domestic dogs in three counties of Moghan plain namely Pars Abad, Bileh Savar and Germi. The samples were examined using an ELISA, designed for the detec­tion of Echinococcus-specific coproantigen and the formalin-ether concentration method as well."nResults: Totally, out of 138 fecal samples, 27 (21.6%) turned positive for Echinococcus. Coproantigen was de­tected in 16.7% and 27.1% of red foxes and domestic dogs, respectively. Formalin-ether concentration method revealed that 43 (31.2%) of samples harbored at least one parasitic helminth, but Taenia eggs were detected only in 3 fecal samples. Since coproan­tigen presence reflects current intestinal infection with adult worms, CA-ELISA can be regarded as one of the most use­ful immunological tools for diagnosis of Echinococcus infection. Besides, the high susceptibility, low cost and rapid­it