US1515244A - Method of producing chilled-iron-alloy castings - Google Patents

Description

Patented Nov. 11, 1924.

JOHN N. EAFRLY, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO W. J. EARLY SONS FOUNDRY CORPORATION, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF DELAWARE.

I METHOD OF PRODUCING CHILLED-IRON-ALLOY CASTINGS.

No Drawing.

To all whom it may concern Be it known that I, JOHN H. EARLY, a citizen of the United States, and resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Methods of Producing Chilled-Iron-Alloy Castings,.of which the following is a specification.

This invention relates to a method of producing a chilled iron alloy casting, and has for its principal object the rovision of a novel method of controlling the chill depth on the finished casting.

The main constituents of which are iron, silicon, sulfur, phosphorus, manganesavand carbon, with or without small quantities of nickel and chromium. v

This alloy is characterized by having great strength and a very hard chill surface; also by the fact that the chill depth may be readily controlled by the operator, either in a sand or chill mold.

Heretofore, in casting iron alloys the chill depth has been uncontrollable, except by the use of chill pieces or chill molds, and even then has been more or less of an uncertain matter, while the present alloy permits of positive control of the chill depth at all times.

Generically, the invention consists in castings containing the elements and the percentages thereof, following- Per cent.

Silicon .75 to 1.50 Sulfur .05 to .25 Phosphorus .25 to .75 Manganese .20 to .70 Total carbon 2.25 to 3.75 Combined carbon 1.00 to 2.2 Iron, approximately sufiicient to make 100 Such castings show remarkable results in tensile strength and in wearing and abrasive qualities, and in the resistance to the action of heat. p

A specific analysis .of one of the char-- acteristic castings made under my method and of my new alloy is silicon 1.21%, sulfur 14%, phosphorus .57 manganese 21%, free carbon 1.76%, and combined carbon 1.54%. l

:I have discovered that the combined carbon varies more or less in proportion with Application filed January 10, 1924. Serial No. 685,423.

. chill in either a sand mold or chill mol'dji} Rolls for rolling mills, crusher rolls grid other castings in'which it is desired to have a very hard wear resisting surface may readily be cast in sand molds when formed from my novel alloy and will come out of the mold with a uniform depth of chill of such hardness that they will outwear ordinary cast rolls from 'four to five times.

The depth of chill on castings formed from my novel alloy is readily controlled when they are cast in either sand or chill moldsby varying the sulfur content and by varying the heat at which the metal is poured into the molds.

Alloys having a high content of combined carbon have been made heretofore, but all of such alloys, such as the Well known adamite, and similar alloys have depended upon the high chromium content to cause the combining of the carbon, while the present alloyhas a high combined carbon with or without the use of chromium or nickel.

It will. also be noted that due to the peculiar characteristics of adamite and similar high chromium alloys, they can not be produced commercially in a cupola, while the present alloy may readily be produced in a cupola, electric furnace, or other smelting furnace. In fact, for several months past the alloy of this invention has been commercially produced in a cupola.

When it is desired to increase the tensile strength and toughness of the castings, I

.may add a relatively small amount of centage of combined carbon remains substantially the same. l I

In producing my novel alloy, the following method is carried out I first charge a cunola or other smelting furnace with suitable scrap, pigs, or ores, of

the proper analysis to enable me to secure the proper proportion of silicon, sulfur, phosphorus, manganese, and carbon and if chromium and nickel are to be included in the alloy suitable pigs containing these ingredients are also added. After the mix is made up it is heated to form 2500 degrees to 2700 degrees Fahrenheit to melt the metals. That is, the mix is raised to a heat materially above the melting temperature so as to obtain a good pouring temperature. After the min has been melted it is tapped and then poured in the molds at a temperature of from 2300 degrees to 2500 degrees Fahren- 5101i The depth of chill on the finished casting is controlled primarily by the pouring temperature. That is, the hotter the pouring temperature the deeper will be the chill; also the depth of chill can be controlled somewhat by the sulfur content of the'mix, that is, the greater the sulfur content the greater the chill. However, the sulfur content is known and when it is slightly higher or lower than necessary to produce the cor rect depth of chill, the pouring temperature may be increased or lowered accordlngly to give the correct depth of chill.

For instance, if the sulfur content were such that it would tend to cause too great a depth of chill, then the pouring temperature would be lowered to lessen the chilling effect of the casting heat while if the sulfur content was slightly lower than necessary to give the desired depth of chill, the pourin heat would be increased.

This alloy is peculiar to itself in that it will form a uniform depth of chill over the entire surface of a casting'in a sand mold, and the depth of such chill can be varied or controlled by the pouring temperature, so that an operator may readily produce castingssuch as crusher rolls, dies, rolling mill rolls, rolling mill guides, etc, with definite de ths of chill over their entire surface.

Experience has shown that crusher rolls, rolling mill guides, dies and other castings formed from my alloy will outlast as many as-four or five similar articles made from ordinary cast iron alloys or steels. 'lhe chilled surfaces of articles made from my alloy are very hard and will outwear any coercial steel or iron alloy lmown at this time. In fact, in most cases it is so hard that it will withstand any of the no forms of tool steel and can not be turned on a lathe, but must be around to finish, I

The method of producing a chilled iron alley casting comprising silicon ,75% to I, ercial 1.50%; sulfur 05% to 25% phosphorus 25% to .75% manganese 20% to 30% combined carbon of from'l.00% to 2.25%; some free carbon; and approximately sulficient iron to complete 100%; which consists in mixing suitable quantities of the diderent metals to form the alloy, melting the metals at a temperature of from approximately 2500 degrees to 2700 degrees Fahrenheit, and pouring the molten alloy to form the casting at approximately 2300 degrees to 2500 degrees Fahrenheit, and varying the depth of the chill on said casting by varying the term perature at which the molten metal is poured within the above limits of pouring temperature.

2. The method of producing a chilled iron alloy casting comprising silicon T55 to 1.50% sulfur 05% to 25%; phosphorus 25% to 175%; manganese 20% to YO/0;

combined carbon of from 1.00% to metals at a temperature of from ELPPK'QXZ- mately 2500 degrees to 27 00 degrees Fahrenheit, and pouringthe molten alloy to the casting at approximately 2300 de -lees to 2500 degrees Fahrenheit, and varying the depth of the chill on said casting by varying thetemperature at which the molten metal is pbured within the above limits of pouring temperature and by varying the sulfur content in said alloy. 5

- 3, The method of producing a chilled iron alloy casting having a relatively large sulfur content and a high combined carbon contentgswnich consists in mixin melting the difierent metals to form t' e al loy, melting the metals at a temperature of from 2500 degrees to 2700 degrees F ahrenheit, and pouring the molten mloy to form the casting at from 2300 degrees to 2500 degrees Fahreeit. 4:. The method of producing a chilled iron alloy casting having a relatively large sulfur content, and a high combined carbon tent and the pouring temperature.

In testimony wheneof, l have hereunto signed my name 'JQHN N. EARLY.