In the paper, it is studied the effects of alloy elements on microstructure, mechanical properties and resistance to scute burst of high strength enamel steel for inside liner of water heater as well as analyzed the mechanism of action of hot rolling process such as finish rolling temperature, coiling temperature and continuous annealing process of cold rolling on microstructure and mechanical properties. The trial production results showed that the yield strength was 245~272 MPa, tensile strength was 362~386 MPa and elongation was 39.0%~41.0% for the cold rolled high strength enamel steel, which could meet the production requirements of inside liner of water heater. Its microstructure is mainly composed of ferrite and pearlite as well as a little MnS and TiN particles were with dispersed distribution. It is further verified that the developed high strength enamel steel is with good resistance to scute burst through the sensitivity test of anti scute burst and test of end user.

In this paper, the chemical composition and production process are designed according to the technical requirements of 420 MPa grade high-strength weather-resistant H beam for residential building as well as the performances of test steel are studied by observing the microstructure with metalloscope and transmission electron microscopy (TEM), room temperature mechanical properties and periodic immersion corrosion tests. The results showed that the fluctuation of impact toughness at room temperature for test steel was small and its toughness was good. The yield strength of three test steels with different specifications was higher than 420 MPa and corrosion resistance index (I) was 6.15~6.45, which showed good resistance to atmospheric corrosion. The microstructure of test steels was mainly consisted of ferrite and pearlite as well as the average grain size of ferrite was 25.73 μm and there was nanoscale (Cu, Cr) C precipitated phases in grain.

In this paper, the 390 MPa grade test steel for offshore platform is obtained with the component system of low C, high Mn and Nb-Ti microalloying and reasonable adding sequence of alloys during smelting as well as the controlled rolling and controlled cooling process. The test results showed that the upper yield strength was 488 MPa, tensile strength was 550 MPa, elongation after fracture was 30%, longitudinal and transverse impact energies at -20 ℃ were 242 J and 155 J; the microstructure was fine ferrite and pearlite as well as the inclusions were fine and with the size of 2~3 μm; after the welding thermal simulation test with welding heat input of 100 kJ/cm for test steel, the mechanical property test and metallographic structure were with the basic characteristics of steel with large heat input welding as well as the products are verified to be with good low-temperature impact toughness and welding performances.

The comparison tests for corrosion resistances of samples with and without black spots on the surface of Zn-Al-Mg coating as well as the pure Zn coating are carried out with the neutral salt spray tests. There was not red rust for the samples with and without black spots on the surface of Zn-Al-Mg coating with the neutral salt spray tests of 2 000 h and 4 000 h, while there was obvious red rust for the sample with pure Zn coating with the test of 2 000 h and it was increased obviously with the test of 4 000 h. The positions with and without black spots of Zn-Al-Mg coating are analyzed with the scanning electron microscope and energy disperse spectroscopy. The results showed that many fine magnesium-rich eutectic structures were enriched at the position with black spots. There were differences for reflection of light between them and stripy eutectic structure at the position without black spots as well as the magnesium-rich eutectic structures were easily to be oxidized by the oxygen in the air so as to form black oxide so that the visual differences appear black spots. The salt spray test results showed that the corrosion resistance at the position with black spots didn’t deteriorate as well as the corrosion resistances of samples with and without black spots on the surface of Zn-Al-Mg coating were the same good.

The physical archives are archives in physical forms with important preservation significance and collection value formed in various work activities and outside communications of colleges and universities. They are the important components of archives and important supplement to documentary archives of colleges and universities. They concentrate the essence of school development as well as they are the powerful proof of historical development of colleges and universities and the crystallization of practical experiences and wisdom for teachers and students. They are with relatively obvious characteristics and are different from the traditional archives so that they are with important significances and values. In this paper, the current situation of physical archives in colleges and universities is analyzed starting from the work experiences of managing them as well as the management of them is discussed from such aspects as collection, arrangement and utilization of them. Moreover, their outlook is proposed.

In this article, the problem of high scrap rate caused by surface defects of a batch of seamless steel pipes for high strength hydraulic cylinders produced on site is analyzed and studied. There are mainly three categories of surface defects, they are rolling skin, pits and pitted surface by analyzing their morphology. The defects are detected and analyzed with such analytical methods as metallographic examination and scanning electron microscope. The results showed that rolling skin and pits were caused by the existing surface cracks of billet before rolling as well as pitted surface was caused due to the roll compacting of surface scale onto pipe body in the process of hot rolling. In order to eliminate the above defects, the corresponding rectification measures are taken as well as the continuous casting and rolling processes are optimized. As a result, the surface quality of products is greatly improved and scrap rate is decreased from 30.6% to 1.7%.

The IS350 rail is medium strength rail in the American AREMA—2019 standard, which is mostly used for laying busy freight railways in North America and with a broad application prospect. Its industrial trial production is carried out combining with the requirements of American standard and the equipment conditions of universal rolling mill of rail. The results of trial production showed that its composition design was reasonable, the smelting, external refining, rolling and online heat treatment processes were proper as well as its general and special performances were in line with the requirements of American AREMA—2019 standard and with sufficient surplus so that a new way was explored for adjusting the product mix of rail of Baotou Steel and developing new markets.

The axle housing is one of the main components of traveling system for vehicle. The 650QK steel developed in laborotary is with the component design of medium carbon as well as trace amount of Nb, Ti and V alloy elements are added, the microstructure is fine and even ferrite, pearlite and bainite, grain size is grade 12~13, yield strength is 664~671 MPa, tensile strength is 762~794 MPa, elongation is 20.0%~21.5%, cold bending property and low temperature impact toughness are good, low temperature impact toughness at -60 ℃ reaches 127 J, ductile-brittle transition temperature is lower than -60 ℃, ultimate fatigue strength is 270 MPa as well as synthesized mechanical properties of material are good, which could provide the technical index of basic performances of material for industrial production.

The stability of rock slopes is mainly controlled by the spatial composing relations between the developmental structural plane in slope rock mass and slope. The stereographic projection is to project the interaction cutting relation of slopes and structural plane space onto a plane, with which the failure types and stability of rock slopes could be intuitively and preliminarily analyzed to provide support for the subsequent treatment of rock slopes. The analysis and determination for failure types and stability of rock slopes with polar stereographic projection are introduced by taking the stability evaluation of rock slope for 2^# open pit of Shuangli Iron Mine of Inner Mongolia Shuangli Mining Co. , Ltd. as an example as well as the prevention measures for unstable rock slope are proposed based on the failure types of slopes.

In this paper, the production technology process and technological parameters of spring steel plate 60Si2MnA are introduced as well as the microstructure that products need could be obtained through corresponding cooling technique (4~9 ℃/s) control, which guarantees the mechanical properties of products. The results showed that the spring steel plate 60Si2MnA with tensile strength not less than 1 050 MPa and elongation not less than 13% could be manufactured through choosing appropriate process parameters with the existing equipment and processes under appropriate conditions of liquid iron and other raw materials. Moreover, the thickness of decarburized layer on the surface of high carbon steel 60Si2MnA is controlled better, which is 18% of requirements of national standard GB/T 1222—2016 through controlling the atmosphere of heating furnace.