Steel 40Г17ХН2 (MML-1)
|Designation GOST Cyrillic||40Г17ХН2|
|Designation GOST Latin||40G17XH2|
|By chemical elements||40Mn17CrН2|
|Designation GOST Cyrillic||ММЛ-1|
|Designation GOST Latin||MML-1|
|By chemical elements||MoMoBe-1|
40Г17ХН2 steel is used: for the manufacture of castings by sand casting parts, buildings, machinery and equipment of the Navy ships of all classes, types and appointments, as well as ballast, which is required of namagnichennosti μ≤ 1,262·10-6 G/m (1,005 GS/e) group I (ballasts, keys, on-Board mooring fairleads, etc.), group II (mortars, bearing housings of the spindles, the hubs of rudder blades, covers, housings, levers, sprockets windlasses, the plates and drums are the base of the spires, etc.) and group III (propeller shaft brackets, stem, glasses of end and intermediate brackets, post rudder, spinners, anchors, mortars, etc.).
Vysokoorganizovannaja low austenitic steel.
Difficult the production of thin-walled complicated castings because of the tendency of steel to the formation of oxide captivity.
Magnetic permeability μ ≤ 1,005 GS/e and is almost constant in any thermal and thermomechanical processing. The magnetic field of the casting is increased in the presence of penetration and in particular the ferromagnetic oxides.
Do not use steel grades for cast metal parts, running on friction (bushings, worm wheels, gear) or requiring surface hardening by nitriding, as well as parts of valves and similar parts. Unacceptable use of steel for the manufacture of parts without cathodic protection, operating in seawater and other environments that cause intense General corrosion.
Steel has low frictional properties and surface hardening (nitriding and carburizing) is not exposed.
Steel is not prone to intergranular corrosion and acquires a tendency only after a long vacation at a temperature of 650−700° C and this is due to the precipitation of carbides along the grain boundaries of austenite. Steel is prone to General corrosion. Therefore, it is recommended to use protectors in conjunction with paint coatings.
|Castings, non-ferrous metals and alloys||В84||OST 9261-76, RD 9257-76|
According to OST 9261-76, when steel is smelted for ballast production, it is allowed to increase the carbon content to 0.75% and manganese to 19.0%, and to reduce the nickel content to zero.
|sT|s0,2, MPa||σU, MPa||d5, %||KCU, kJ/m2|
|Casting as supplied. Without heat treatment (thickness of wall up to 20 mm) or normalizing at 1100 °C (wall thickness > 20 mm)|
Description mechanical marks
|sT|s0,2||Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%|
|σU||Limit short-term strength|
|d5||Elongation after rupture|
|Temperature||Е, HPa||r, kg/m3||R, Mr. · m||С, J/(kg · °C)||l, W/(m · °C)||a, 10-6 1/°C|
A description of the physical symbols
|l||Coefficient of thermal conductivity|
|R||UD. the resistivity|
|Weldability||good weldability. The castings are subjected to welding, as between themselves, and with low sheet steel and other structural steels. It is also possible welding defects.|
|Machinability||reduced workability is close in parameters to the machinability of steel 45Г17Ю3 (Yu3).|