UGIMA® 4005 QT650

Grade used in numerous applications where high machinability is necessary (i.e. for screw machining of very high number of parts), and when corrosion resistance is not a critical deciding factor.

Corrosion resistance properties of UGIMA® 4005 are globally the same as those of a standard UGI 4005. Therefore, storage in an area with low humidity is to be preferred.

Pitting corrosion: The following figure shows the pitting potential expressed in mV/SCE; it is measured in a saline environment with a pH of 6.6 at 23°C and a sodium chloride concentration of 0.002M (116 mg/l, i.e. 0.01%). This kind of measurement on resulphurised low chromium stainless steel is always highly dispersed and UGIMA® 4005 shows, in this test, dispersion slightly over that of a standard UGI 4005.

Thanks to its controlled oxide inclusions, UGIMA® 4005 presents an excellent machinability, significantly over that of a standard 1.4005 like UGI 4005. For identical cutting conditions, UGIMA® 4005 allows tool wear rates far below that of observed when cutting a standard 1.4005.

It allows significant productivity increases without decreasing the tool life duration. As examples, the following table shows for two different cutting tools the VB15/0.15 * measured in turning on UGIMA® 4005 and UGI 4005 hot rolled bars comparatively.

Annealing: To lower the mechanical properties of UGIMA® 4005, make a heat treatment of several hours between 745 and 825°C followed by a slow air cooling.

Quenching: To quench UGIMA® 4005, make a heat treatment between 950°C and 1000°C followed by air or oil cooling.

Tempering: The choice for the tempering temperature depends on the mechanical properties needed (see the graph hereunder). It is better to avoid temperatures between 400 and 550°C which induce a toughness decrease.

Forging: UGIMA® 4005 can be forged but it is not suited to severe upsetting operations. The following forging conditions are recommended:

Available products:

Other finishes, tolerances, sizes, profiles on request

The possible surface treatments are the same as those used for a standard 1.4005 such as UGI4005.

As a standard 1.4005 like UGI 4005, UGIMA® 4005 is weldable by most arc welding processes (GMAW, GTAW with or without filler wire, SMAW, SAW, ...), by laser, resistance welding (spot or seam welding), friction or electron beam welding processes, ...

Thanks to a “as welded” martensitic structure in Welded metal (WM) as well as in Heat Affected Zone (HAZ) [if welding without filler wire], UGIMA® 4005, as well as a standard 1.4005, is not subject to intergranular corrosion phenomenon due to chromium carbide precipitation and grain boundary déchromisation.

In GMAW and GTAW, the protection gas must be without nitrogen, nor hydrogen, in order to avoid an increasing risk of hydrogen embrittlement typical of martensitic grades. For the same reason, in SMAW, the electrodes must be oven-dried (in order to eliminate the residual water present in the coating of electrodes, which can increase the hydrogen content in the weld).

Because of its quite low carbon content, UGIMA® 4005 can be arc welded without pre-heating of parts to be welded. However, a tempering treatment between 200 and 300°C is needed most of the time to improve the toughness of the HAZ (and that of WM in case of welding without filler wire or with a homogeneous filler wire). With a homogeneous filler wire, heat treatments between 300 and 550°C are prohibited in order to avoid a fine carbide precipitation inducing embrittlement of the HAZ and WM.

In case of austenitic filler wire (309L, 308L, ...), a heat treatment between 200 and 300°C can also be used to improve the HAZ toughness. Heat treatments at higher temperature are prohibited in order to avoid risks of C migration from HAZ into the WM, which could induce corrosion resistance decrease of the WM.