Mechanical properties

Strength
The nominal yield strength shall be in the range of 235 N/mm2 to 690 N/mm2. The nominal tensile strength shall be in the range of 300 N/mm2 to 1000 N/mm2.

Ductility
The elongation after fracture on proportional gauge length shall be at least 15 %, for nominal yield strength not greater than 460 N/mm2; and shall be at least 10 % for nominal yield strength greater than 460 N/mm2.
The tensile strength to yield strength ratio shall be at least 1.2 based on nominal values, or at least 1.1 based on actual values, for nominal yield strength not greater than 460 N/mm2.
NOTE Conversion of elongation values measured not based on proportional gauge length is necessary and shall be performed according to BS EN ISO 2566-1.

Impact toughness
As a minimum, the product shall be able to absorb at least 27 J of impact energy at 20 °C.
NOTE Depending on other factors including the thickness and minimum service temperature, the impact toughness should also conform to the appropriate requirements as given in BS 5950-1.

Through thickness deformation properties
Where appropriate, through thickness deformation properties shall be specified to guarantee adequate
deformation capacity perpendicular to the surface to provide ductility and toughness against lamellar tearing.
NOTE Specification of through thickness deformation properties can be referred to BS EN 10164.




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    • Design Guide on Use of
    Alternative
    Steel
    Materials
    to BS 5950
    a touche design production @ 6743 5450
    BCA Sustainable Construction
    Series – 3
    200 Braddell Road Singapore 579700

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    Cold runner

    Expenditures runner of the mold.
    Way of the runner of the mold usually closely related to the type of gate is used. From this emerged a two plate mold design and three-plate mold. Gate Mold type: strip gate, tunnel gate and gate flash,
    if there is no requirement or a specific form of the product, mold will be designed with two plates.

    At the time of mold starts to open, regardless of the sprue runner R for pin carried by runners who have undercut at the edges.Meanwhile, the gate tunnel cavity disconnected from the product because it was interrupted by the lip of the pit gate. At the opening of the next runner mold and product driven by the stripper plate, the runner forcibly detached from the undercut at the end of the  runner-pin, then fell with the product. Here can be seen, that the mold with a tunnel gate will produce a product that has been separated from the runner. Being a product with a strip gate still hung with runnernya, to require additional work to cut the tow runner from the product.



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    Design tasks

    The design tasks of this particular project were a bit unusual. The contracting utility had already built the reactor and the buildings to house the control room. The control room designers, therefore, had to design a control room for an already existing plant, with consideration of the sensors and actuators that were present. Functional
    information, however, was largely lacking. For example, it would be known from plant drawings that a certain feedwater stream had x number of valves of which some
    were manually controllable. Functionally, however, it would not be known what purpose that feedwater stream served. In many cases, engineers had to infer design purposes from the drawings. For the most part, the plant was `wired already, meaning that sensors and their signals already existed. In particular, the level of automation of plant systems was pre-determined. In addition, the control room itself had to "t within the existing space allotted for the control room, with walls, doors, and basic wiring in fixed locations.



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    • A participant-observer study of ergonomics in engineering design:
    how constraints drive design process
    Catherine M. Burns*,1, Kim J. Vicente
    Cognitive Engineering Laboratory, Department of Mechanical & Industrial Engineering, University of Toronto, Canada
    www.elsevier.com
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    Feed gearbox Lathe

    The feed gearbox or quick-change gearbox is fitted directly below the head stock assembly. Power from the lathe spindle is transmitted through gears to the quick-change gearbox. This gear box contains a number of different sizes of gear which provides a means to change the rate of the feed, and the ratio between the revolutions of the head stock spindle and the movement of the carriage for thread cutting by altering the speed of motion of feed rod or lead screw.
    The arrangement which are employed in feed gear boxes to obtain multiple speeds and different rates of feed are:
    1.Sliding gear mechanism
    2.Sliding clutch mechanism
    3.Gear cone and tumbler gear mechanism
    4.Sliding key mechanism
    5.Combination of any two or more of the above

    Feed rod
    The feed rod is a long shaft that has the key way extending from the feed box across and in front of the bed. The power is transmitted from the lathe spindle to the apron gears through a feed rod via large number of gears. The feed rod is used to move the carriage or cross-slide for turning, boring, facing and all other operations except thread cutting.

    Lead screw
    The lead screw is a long threaded shaft used as a master screw, and is brought into operation only when threads have to be cut. In all other times the lead screw is disengaged from the gear box and remains stationary, but this ma be used to provide motion for turning, boring, etc. in lathes that are not equipped with a feed rod.

    Apron Mechanism
    The apron mechanism is used for transforming rotary motion of the feed rod and the lead screw into feed motion of the carriage. The mechanism also ensures that when the half nut is engaged with the lead screw the worm drops down disconnecting the feed motion. This arrangement is called foolproof arrangement and saves the machine from any damage.


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    • fr. NTTF ( NETTUR TECHNICAL TRAINING FOUNDATION)

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