Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C37/00—Cast-iron alloys

Definitions

• This invention relates to tough gray cast iron and particularly to tough gray cast iron having excellent tensile strength and impact modulus with higher manganese contents than heretofore believed acceptable.
• the instant invention is directed to an alloyed gray cast iron for use as a workpiece for east pieces having lamellar graphite formation, great toughness and high heat conductivity in cast condition, consist ing essentially of:
• the content of manganese is greater than 0.3% and up to 2.25%, preferably greater than 0.3% and up to 1.75% manganese. It was further determined that as the sulphur content becomes smaller within the range which is the subject of the instant application, the toughness increases with the manganese content being retained constant.
• compositions which were found to be particularly useful for this type of alloyed cast iron having lamellar graphite formation were such compositions which possess a manganese content of more than 0.3% and up to 1%, having high purity of the matrix.
• Cast pieces made of alloyed cast iron having manganese content within this range possess high mechanical properties concerning toughness and impact modulus. Especially favorable properties concerning toughness and impact modulus of cast pieces made from the inventive alloyed cast iron are obtained if the content of manganese is greater than 0.3% and up to 0.6%.
• the ratio of manganese to sulphur in the alloyed cast iron of the invention should be greater than 5 to 1. In general, this ratio is preferably greater than 10 to 1, but for practical purposes will not exceed 300 to l.
• the alloyed cast iron of this. invention possesses the good technical casting properties of normal gray cast iron and enables casting of pieces with attendant lamellar graphite formation having high values for toughness and elongation. Morevoer, it is possible to produce workpieces having high heat conductivity and increased toughness as compared with cast pieces made of normal gray cast iron. In addition thereto, the inventive alloyed cast iron enables production of work pieces having high wearability and improved toughness.
• the designation toughness (T) can be expressed as follows;
• a stands for impact modulus, measured in kp. cm./cm.
• 6 stands for tensile strength measured in kp./mm?
• the silicon content of the cast piece made from the alloyed cast iron of this invention is remarkably low and is considerably reduced as compared with cast pieces of the same wall thickness made from conventional gray cast iron.
• a cast piece formed of tough gray cast iron may be cast having a silicon value which is reduced by at least one half.
• the alloyed cast iron according to this invention can be produced by metallurgical processes which are known as such and are also mentioned in the aforesaid U.S. Letters Patent.
• Another object of this invention is to provide a gray cast iron of improved properties including good castability.
• EXAMPLE 2 After inoculation with the commercial inoculant of Example 1, a cast iron of the following final analysis was cast into 30 mm. test bars, and from tehse test bars test pieces were removed in order to determine tensile strength and impact modulus according to Example 1.
• Table IV lists the values derived from test bars of conventional gray cast iron. The 30 mm. test bars were cast under the same conditions as those in Examples 37 and then test pieces were prepared in order to determine the tensile strength and the impact modulus.
• An alloyed cast iron according to claim 1 containing preferably less than 0.03% sulphur.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
• Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
• Paper (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=5681499

Family Applications (1)

Country Status (4)

Cited By (4)

Families Citing this family (1)

• 1968
  • 1968-07-19 FR FR159882A patent/FR95256E/fr not_active Expired
  • 1968-07-24 US US747087A patent/US3591366A/en not_active Expired - Lifetime
  • 1968-07-29 CH CH930568A patent/CH539117A/de not_active IP Right Cessation
  • 1968-07-29 GB GB36145/68A patent/GB1176583A/en not_active Expired

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