Based on horizontal continuous casting for “profiles of cast iron”(solid),we innovated “physics force field confinement and shaping continuous casting technology” independently in 2006,using this technology we manufactured a new product---Hollow Profiles of Cast Iron .Our products have been tested by china’s authority sector in mechanical industry and proved that the quality is much better than traditional sand-casting and centrifugal casting products .Our products can meet the requirement of high density ,zero deficiency and easy cutting”. It is also the only product with following appearance characters in china’s market of casting products: thin diameter, thin wall pipe and near net shape .it has been widely used in china’s mechanical industries, such as railway vehicle, oil machine, engineering machine, accessories of auto engine, compressor, hydraulic pressure, chemical pump, machine tool, metallurgical equipment and etc. Meantime, some samples are on trial in United States, Korea, Syria, and Denmark.

Application fields:

Field

Part name

machine tool

sleeve ,upright column ,clamp ring

Oil and Gas

guide sleeves ,sealing ring, sliding sleeve

Industrial machineries

axis sleeve, gear, kawa, wear-resistant sleeve, grinding sleeve

Oil drilling

drillable packers/drillable bridge plug, suction vitta

Railway vehicle

bogie bush, braking system bushing

Metallurgical equipment

casting lift tube ,suction tube, thermocouple protect tube

Air-condition compression machine

rolling piston ring

Automotive

dry cylinder liner, piston ring, steering pump stator, gear

Tractorshipping

dry cylinder liner, piston ring, steering pump stator, gear

Mine mechinanism

wear resist sleeve, engine cylinder

Advantages:

A: High density microstructure, outstanding comprehensive mechanical property

The cooling intensity provided by Continuous casting mold is the average of 30 times than sand casting, and is 5 times the average than centrifugal casting. Strong cooling bring strong phase change, so that increased the melt of austenite and graphite spherical nuclear number (400-600/ mm2, while the sand-cast 100 of the graphite / mm2), to ensure that the detailed metallographic Organization.

B: Pure chemical composition

Melted iron in the holding furnace, the dross floated will be removed artificially, the high-density molten iron will sink, and then through U type channel bottom-up into the mold, so there is no impurity and gas come coercively.

C: Adequate and timely feeding function

When the molten iron concreting in the mold, the volumetric shrinkage arising from liquid / solid phase transition was fed in time by the center of the liquid feeding, so shrinkage situation won’t arise, thus it has excellent mechanical properties.

D: Compared with the centrifugal cast pipe

There is no concentration gradient of alloying element distribution between the inside and outside layer of the wall;carbon, sulfur, phosphorus and other elements of light metal will not aggregate to the inner wall layer to form a black spot, White Spot, cloud spot abnormal Microstructure; and the wall cavity center does not exist osteoporosis, trachoma, porosity and other casting defects.

E: Compared with sand casting

There is no slag, clamping sand, porosity, shrinkage defects, ideal graphite morphology, finer microstructure, in the same conditions of alloy composition, mechanical properties is higher than the grades 1-2.

F:For gray cast iron and gray iron alloy materials, we can get uniform structure composition, and avoid the horizontal continuous casting bar always exist soft liquid core problem eccentric, and ensure the production of wear-resistant ring hole on the inner parts have high hardness.

G: Compared with casting sand-cast semi-pipe, horizontal continuous casting cast ring sets,cylinder parts can get 30-70% material savings.

H: Providing the best original organizations for Isothermal quenching ductile iron (that is, the well-known foundry industry ADI)

Microstructure:

Gray iron: Small flake graphite (external layer is small D-type graphite, internal is small A-type graphite small)

Matrix structure: ferrite + pearlite

Mechanical Properties:σb = 150-380Μpa, HB = 150-350, E = 1.1-1.7 * 105Mpa

Ductile Iron profiles: the ball of the rate 1-2 class, more than 7 class for the ball diameter, ball number 400-600/ mm2

Compared with sand casting, when the same strength, elongation increased by 50 - 100%.

Austempered Ductile Iron (ADI): σb ≥ 1200Μpa, δ ≥ 2%, AK ≥ 45J/mm2

The products are successfully developed by Xi’an University of technology and Shaanxi Tongxin Continuous Cast Tube Tech Co., Ltd. That is to fill the market gap profiles of continuous casting of cast iron profile at home and abroad, if they are used to make ring sets, sleeves ,cylinder with high-performance machine parts, and under the premise of mechanical property equivalent to or better than the Horizontal Continuous Casting of solid material, will save materials 30 - 70%.