ISO

P

Material Group - Tool Alloy Steel

Alloy steel contains mostly Iron but also have a variety of elements, other than carbon. These elements are deliberately added, in total amounts between 1.0% and 50% by weight to improve its mechanical properties.
Common alloyants include manganese (the most common one), nickel, chromium, molybdenum, vanadium, silicon, and boron

The common Improved properties in alloy steels:
strength, hardness, toughness, wear resistance, corrosion resistance hardenability, and hot hardness.
To achieve some of these improved properties the metal may require heat treating.

Material Group - Stainless steel – Ferritic and Martensitic

Stainless Steel is a steel alloy with a minimum of 10.5%[1] chromium content by mass.
Stainless steel is used where both the properties of steel and corrosion resistance are required and it differs from carbon steel by the amount of chromium present. Unprotected carbon steel rusts readily when exposed to air and moisture.

There are different types of ISO P stainless steels:
Significant quantities of manganese have been used in many stainless steel compositions. Manganese preserves an austenitic structure in the steel, similar to nickel, but at a lower cost.

Stainless steels ISO P materials are also classified by their crystalline structure:
• Ferritic stainless steels generally have better engineering properties than austenitic grades, but have reduced corrosion resistance,
   because of the lower chromium and nickel content. They are also usually less expensive.
• Martensitic stainless steels are not as corrosion-resistant as the other two classes but are extremely strong and tough,
   as well as highly machinable, and can be hardened by heat treatment. It is quenched and magnetic.

ISO

S

Material Group - Nickel based alloys

The excellent physical properties that characterize Nickel-based high temperature alloys make them ideal for use in the manufacture of aerospace components. Properties such as high yield strength and ultimate tensile strength, high fatigue strength, corrosion and oxidation resistance even at elevated temperatures, non-magnetic characteristics and low creep, enable the usage of Nickel-based high temperature alloys in many applications and over a very wide temperature spectrum. The aerospace industry accounts for about 80% of Nickel-based high temperature alloys which are used in rotating parts of gas turbines such as disks and blades, housing components such as turbine casing, engine mounts and in components for rocket motors and pumps. Nickel-based high temperature alloys, which contain 35-75% Ni and 15-22% Cr, constitute about 30% of the total material requirement in the manufacture of an aircraft engine, and are also used as structural material for various components in the main engine of space shuttles. With the introduction of Inconel 718 (which is one of the most common Nickel-based high temperature alloys in the aerospace industry) in the year 1960, its usage has seen a tremendous growth in the aircraft industry.

Machining Challenges:

The very same properties that make Nickel-based high temperature alloys such a great high temperature materials also cause high machining difficulties. Metallurgical characteristics like the hard abrasive particles in the materials’ microstructure and the high work hardening rates are primary reasons for the poor machinability.
The cutting forces and temperature at the cutting zone are extremely high due to the high shear stresses developed and the low thermal conductivity. This, coupled with the reactivity of Nickel-based high temperature alloys with the tool material, leads to galling and welding of the chips on the work piece surface and cause excessive tool wear, which can limit cutting speeds and reduce useful tool life. In addition, the high capacity of these materials for work hardening causes depth of cut notches on the tool.
All these characteristics contribute to low material removal rates and short tool life resulting in huge machining costs.
Over the past few years, ISCAR has invested a lot in R&D in order to investigate the machining of Nickel-based high temperature alloys. Our special improved cutting tools along with our unique grades have places ISCAR as a leading company in the area of machining Nickel-based high temperature alloys.
In addition to our standard pressure cooling solutions, the growing demands for high pressure machining solutions especially in the aerospace market, has led ISCAR to develop unique product lines suitable for high pressure cooling systems.
When machining Nickel-based high temperature alloys with standard pressure coolant, the recommended cutting speed is 30-35 m/min. The use of high pressure cooling system enables to increase the cutting speeds by 100-150% and significantly increase the productivity.

ISO

M

Material Group - Stainless steel –Austenitic

Stainless Steel is a steel alloy with a minimum of 10.5% chromium content by mass.

Stainless steel is used where both the properties of steel and corrosion resistance are required and it differs from carbon steel by the amount of chromium present. Unprotected carbon steel rusts readily when exposed to air and moisture.

Austenitic, or 200 and 300 series, stainless steels have an austenitic crystalline structure. Austenite steels make up over 70% of total stainless steel production. They contain a maximum of 0.15% carbon, a minimum of 16% chromium and sufficient nickel and/or manganese to retain an austenitic structure at all temperatures from the cryogenic region to the melting point of the alloy. when nickel is added, for instance, the austenite structure of iron is stabilized. This crystal structure makes such steels virtually non-magnetic and less brittle at low temperatures

•  200 Series—austenitic chromium-nickel-manganese alloys. Type 201 is hardenable through cold working;
   Type 202 is a general purpose stainless steel. Decreasing nickel content and increasing manganese results in weak corrosion resistance.

•  300 Series—The most widely used austenite steel is the 304, also known as 18/8 for its composition of 18% chromium and 8% nickel.
   The second most common austenite steel is the 316 grade, also called marine grade stainless, used primarily for its increased
   resistance to corrosion.