Precision, Power, and Flexibility in Closed-Die Forging

Jan. 10, 2020
A new clutch-operated screw press will expand forger's product volume and portfolio to supply aircraft structural parts and turbine blades.

Closed-die forging technology represents a steady pursuit of dimensional precision, but in practical terms it is also the effort to deliver higher and higher volumes of force effectively, to produce forgings efficiently, reliably, and flexibly. AVIC Shaanxi Hongyuan Aviation Forging Co. Ltd. recently started the latest example of this — a 2,900-metric ton clutch-operated screw press designed and built by SMS group.

AVIC Shaanxi Hongyuan Aviation Forging Co. Ltd. is a subsidiary of AVIC Heavy Machinery Co. Ltd., itself a holding of Aviation Industry Corp. of China, the state-owned developer, designer, and manufacturer of civilian and military aircraft systems.

The forging operation at Xi’an, Shaanxi Province, is one of China's largest manufacturers of structural components, aviation discs, and turbine blades for Chinese aviation manufacturing. The new press is part of the forger's plan to increase its production volume and expand its component portfolio, specifically by supplying high-alloy steel, titanium, and nickel-based alloys to the domestic aircraft market.

The type SPKA, clutch-operated screw press, has a screw diameter of 1,330 millimeters; a "hard-on- hard blow" force of 365 MN; and a gross power of 27,000 kJ. It is the third, clutch-operated screw press of this size supplied by SMS, exceeding the performance data the two previous units.

Screw-press design combines high forming force with high forging precision, according to SMS, and the incorporation of the flywheel and integral clutch mean that high forming energy is available even at reduced ram speeds. More than this, the configuration makes it possible to minimize workpiece contact times. Clutch disengagement can be force- or stroke-controlled, and all functions are controlled electronically.

The mechanical design of the machine includes pneumatic weight balancing, a spindle brake, and hydraulic flywheel bearings. Low accelerated masses, short acceleration distances, and stroke rate preselection are further benefits of this machine type, according to SMS.

For forging operators, the SMS clutch-operated screw press offers flexibility for process optimization, requiring less stroke to achieve a preset ram speed than a conventional slipping-wheel screw press. The maximum ram speed is attained after just 10% of the ram stroke, and remains at a constant level until the ram hits the part being forged. These types of presses are particularly well-suited for high-energy forging typified by the production of turbine blades or structural aircraft components.