General information

The automat steels are divided in to two main groups as shown below:

a- Without heat treatment (soft automat steel)
b- Heat treated
b1) with enhancement process
b2) with case hardening ,

The automat steel and its variants produced by "Asil Çelik" according to the Turkish Standards and International Standards are given under 1, 2, 3, 4 and 5.

PROCESSES APPLIED

- As the surfaces that do not require machining have to possess precise measurement tolerances, the automat steels are used cold rolled mostly.
- At the same time, the steels types containing approximately 0.120% sulphur and low carbon, and called "semi-automat" steels are used for hot or cold forging and punching, in addition to their good manufacture qualities (example, nuts). The 9SMn 28 quality steel high sulphur steel is used successfully in the hot forging applications.
- In the meantime, various types of pipes are produced by pressing the semi weldable automat steels and extruding subsequently in the recent years. Such an application reduces production costs by machining and provides a large saving in the materials as well.

AREAS OF UTILIZATION

The automat steels display the following characteristics when used with the high-speed mass production machining applications;
- Long machining bit life suited to the machining speed of the lathe,
- Easy processing of the pars and a good chip brittleness that allows comfortable operation on the lathe,
- Very low cutting forces required,
- Good surface quality on the part machined, and
- Narrow measurement tolerances.

In short, as they provide good machineability, they are used;
- For manufacturing various types of fastening pieces for the automotive industry,
- In industry branches engaged in machinery and equipment manufacturing and the construction sector,
- Construction element manufacturing
- In industry branches engaged in the precision mechanical parts (optical equipment and measurement equipment components)
THE FACTORS THAT PROVIDE GOOD PROCESSIBILITY IN THE AUTOMAT STEELS

As known, the chips (shavings) produced during the machining of different steel types demonstrate typical characteristics. For example, the un-alloyed soft steels cause the formation of chip types that are not suitable for machining on the automated lathes.

Obtaining short and brittle chips possible by:
a- Ensuring the formation of homogenously distributed residue in the texture first,
b- By rendering the texture of the steel brittle

A short explanation about the issues discussed can be provided as follows:
Addition of lead (Pb) besides sulphur (S) increases the processing ease a little.
In the index given below in relation with this subject, the differences between the processibility characteristics of the leaded and unleaded automat steels are shown by comparison.

MACHINING INDEX

In spite of facilitating processibility, adding lead during steel production increases the production cost, and therefore, selling price of the steel exorbitantly as it requires special methods and is a very hazardous process for the health. However, because the lathes can operate at optimal capacity and speed with the sulphurous automat steels, the utilization of the leaded automat steels have become quite limited.
The leaded products are shown with the symbols 1 ILXX or 12LXX in the SAE/AISI standards
SAE J402 and DIN 1651 standards cover the automat steels.