Jan 11 2016 0
Jan 11, 2016

Milltech’s state-of-the art Heat Treatment facility produces straight, stress-free bars providing Australian Industry with uniform, reliable products. The continous heat treatment line quenches and tempers one bar at a time with all process variables closely controlled, resulting in bars which don’t require any straightening and exhibiting a uniform structure which machines easily and has very little scale, thus, SUPErior QUENCHed & Tempered product or SUPERQUENCH.

The products

Bar 19-150 mm Diameter solid bar and selected Hexagon sizes
Surface Black, peeled, precision ground, hard chromed (includes IH alloy)
Grades 4140, 4340, EN26 and other grades on enquiry
Length
5-6 mtrs with capability to 12 mtrs

The Process

The computer controlled induction quench and temper process has turned bar heat treatment from an art to a science. Individual bars proceed through the precision controlled heating coils while being rotated. Each bar enters the powerful quench where its temperature is rapidly decreased to transform the microstructure to the desired martensite structure. Next, it is tempered through more in-line coils to produce a tough custom-made product, superior in every aspect to the batch furnace product.

The results

Stress-free, straight bars so no stress inducing mechanical straightening is required.
Uniform Micro Structure
• Much improved surface finish with minimal scale.
Straightness deviation of better than 1 in 500.
Saw cut bar ends means optimal use of products with less preparation required before machining.
• Less than one half commercial heat treatment tolerance for tensile strength.
• Brinell hardness spread of less than 50 points.
• Orders can be custom made to very tight specifications.
• Products that are well within the specifications of the various international standards.

User Benefits

Improved machinability
Cost savings on materials
Improved tool life on machine operations
No distortion during machining
Tougher product: Longer life
• The above add up to BETTER VALUE FOR YOUR MONEY

Application

Mining Pins, picks, digging tools, hydraulic cylinder rods
Construction Hold down bolts and threaded bar
Engineering Motor shafting, axles and gears
Energy Hold down bolts for wind powered electricity generators
Automotive Drivetrain/steering components, king pins, stabiliser bars
Defence Track pins, rifle barrels
Oil and Gas Down hole retrieving equipment and fasteners
The ability to closely control its physical properties make it particularly suitable for oil and gas industry ‘sour’ gas applications due to its ability to resist corrosion, which seriously affects components exhibiting residual stress.

QUENCHED AND TEMPERED BAR MECHANICAL PROPERTY SPECIFICATIONS AS 1444 - 2007

Mechanical
Property
Designation
Tensile Strength MPA
0.2% proof Stress Mpa
elongation %
Brinell Hardness
HB
Minimum
Maximum
Minimum
Maximum
Minimum
Maximum
R 700 850 480 15 201 255
S 770 930 540 13 223 277
T 850 1000 665 13 248 302
U 930 1080 740 12 269 331
V 1000 1150 835 12 293 352
W 1080 1230 925 12 311 375