STRUCTURE AND PROPERTIES OF ROLLED STEEL AFTER SKIN-ROLLING ACCORDING TO DIFFERENT TECHNOLOGICAL PRODUCTION SCHEMES

Problem statement. Development of an effective technology for the skin-rolling will allow the production of hot-rolled sheet products with quality indicators that meet the requirements of standards for cold-rolled sheets. Consumers with significant economic benefits will be able to use relatively inexpensive hot-rolled sheets instead of expensive cold-rolled sheets. The purpose of the article: establishment of the effect of skin-rolling to various technological schemes for the production of hot rolled fine and thickness rolled for cold stamping on the structure and properties of the metal. Conclusion. The patterns of the formation of the structure and properties after skin-rolling of hot rolling sheet steel and plate steel for cold stamping are established. It is shown that with an increase in the degree of deformation during skin-rolling in the unit cutting unit, there is a decrease in the plasticity of hot-rolled plate steel strips of low carbon steels. As a result of heat treatment and skin-rolling on a separately located mill of hot rolled, thin-sheet low carbon steel, the plasticity of the metal rises and a homogeneous structure is formed in accordance with the requirements of ДСТУ 2834-94. Obtaining hot-rolled thin-sheet steel with quality indicators at the level of requirements for cold-rolled metal will allow the use of hot-rolled steel instead of cold-rolled one, which will ensure an increase in labor productivity and savings electricity.

Development of health massage to improve working productivity with Daksa disabilities

This development research by modifying the form of massage. The phase being developed is related to health massage which is expected to increase productivity and provide suitable techniques for disabled persons with lower limbs. The research objective is to develop a form of health massage so that it can increase work productivity for persons with disabilities. The specific target in the research is to find the right health massage techniques and patterns for people with disabilities in increasing work productivity. The target of this research is designed through three stages, namely survey research, development research, and experimental research. The subjects of the study were persons with disabilities with monoplegia disabilities in Yogyakarta Special Region. Based on the research results, it can be concluded that the perception of the form of health massage is very good and feasible to be applied. In addition, massage is effective for dealing with health and overcoming complaints of pain. The specifications for the form of health massage are body position consisting of three positions, namely face down on your back and sitting. In a prone position starting from the left starting from the bottom, namely the left leg. In the supine position massage starts from the left foot and toes. In a sitting position massage starts from the right shoulder. The techniques used from these three positions use friction, petrisage, tapotement, walken, skin rolling and effleurage. In addition, the massage applied is safe for persons with disabilities, safe in dealing with health and safe for increasing work productivity which consists of motivation, knowledge, skills, and attitudes. Pengembangan masase kesehatan untuk meningkatkan produktivitas kerja disabilitas Tuna Daksa Penelitian pengembangan ini dengan memodifikasi bentuk masase. Masase yang dikembangan berkaitan dengan masase kesehatan yang diharapkan dapat meningkatkan produktivitas dan memberikan teknik yang sesuai untuk disabilitas tuna daksa yang mengalami cacat bagian bawah. Tujuan penelitian untuk mengembangkan bentuk masase kesehatan sehingga dapat meningkatkan produktivitas kerja bagi penyandang disabiliatas tuna daksa. Target khusus dalam penelitian menemukan teknik dan pola masase kesehatan yang tepat bagi para disabiliatas tuna daksa dalam meningkatkan produktivitas kerja. Target penelitian ini dirancang melalui tiga tahap yaitu penelitian survey, penelitian pengembangan, dan penelitian eksperimental. Subyek penelitian penyandang disabilitas tuna daksa monoplegia di Daerah Istimewa Yogyakarta. Berdasarkan hasil penelitian dapat disimpulkan bahwa persepsi bentuk masase kesehatan sangat baik dan layak untuk diterapkan. Selain itu masase yang diterapkan efektif untuk mengatasi kesehatan serta mengatasi keluhan rasa sakit. Spesifikasi bentuk masase kesehatan yaitu posisi badan terdiri dari tiga posisi, yaitu telungkup terlentang dan duduk. Pada posisi telungkup dimulai dari sebelah kiri diawali dari bawah yaitu bagian kaki kiri. Pada posisi terlentang masase diawali dari kaki dan jari-jari kaki sebelah kiri. Pada posisi duduk masase diawali dari bahu sebelah kanan. Teknik yang dipakai dari ketiga posisi tersebut menggunakan friction, petrisase, tapotement, walken, skin rolling dan effleurage. Selain itu masase yang diterapkan aman untuk penyandang disabilitas tuna daksa, aman dalam mengatasi kesehatan dan aman untuk meningkatkan produktifitas kerja yang teridiri dari motivasi, pengetahuan, keterampilan, dan sikap.

Analysis of Orange Peel Defects on Hot-Dip Galvanized High Strength Low Alloy Steel

The surface of hot-dip galvanized high strength low alloy (HSLA) steel easily occurs orange peel in the deformation process. On the other hand, the defects possess a specific directivity and sits at approximately a 45-degree angle to the sheet steel rolling direction. The microstructures and properties of steel specimens with the orange peel defects and the normal were analyzed, which results showed that their microstructures consist of ferrite and few granular pearlite. The yield point elongation of the HSLA steel resulted in the orange peel defects on the surface of sheet stamping and it is associated with skin rolling and stretch rolling process. Further studied on the fine microstructures by means of SEM and electron back scatter diffraction (EBSD) techniques, which was apparent for the defect steel that the orange peel defects were resulted from weak favorable {111} texture might be the key factors aggravating the formation of orange peel defects. It can be concluded that the formation of Cottrell atmospheres caused the yield point elongation by the interaction between dislocation and diffusive solute atoms as basic reason and the directivity of the orange peel defects was related with the LUDERS slip forming. The yield point elongation can be eliminated to avoid the orange peel defects beyond to 1.8% skin-rolling and stretch rolling method with an appropriate annealing technology.

Preparation and Characterization of Anti-Oxidation Coatings for Sliding Plates

High-temperature anti-oxidation coating was prepared by a milling process, which mainly composed of flake graphite and hexagonal BN (hBN). The coating was brushed on the sliding plate surface and dried in air for 24 h, The surface of the sliding plate painted was smooth and without peeling, suggesting a strong bonding strength. The samples were heated at 1200 °C for 20 min to evaluate the mass-loss rate. The mass-loss rate of the slide gate painted is 3.7%, less than the un-painted 5.1%. XRD and SEM techniques were used to characterize the as-heated samples. The results showed that the surface of the slide plate painted was skin rolling. And the graphite reacted with oxygen at an elevated temperature to reduce oxygen concentration. In addition, hBN also reacted with oxygen to form B2O3, which also has an oxygen-resistant role in the sliding plates. These coatings exhibited unique oxidation-resistant properties, and the service life of the coated sliding plates was obviously improved.