US3634074A - Free cutting steels - Google Patents

Free cutting steels Download PDF

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US3634074A
US3634074A US781520A US3634074DA US3634074A US 3634074 A US3634074 A US 3634074A US 781520 A US781520 A US 781520A US 3634074D A US3634074D A US 3634074DA US 3634074 A US3634074 A US 3634074A
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steels
steel
cutting
tool
cut
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Tetsuro Ito
Goshi Kato
Atsuyoshi Kimura
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Daido Steel Co Ltd
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Daido Steel Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur

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  • This invention relates to free cutting steels containing in combination calcium and at least one member selected from the group consisting of lead, sulfur and tellurium.
  • the cutting technique and workability of the steels are recognized to be of great importance in order to meet the increased production of the steel articles and various kinds of free cutting steels have been developed by incorporating one or more members, in combination, selected from the group consisting of sulfur, lead, selenium, tellurium, bismuth, phosphorus and nitrogen with steels.
  • free cutting steels containing calcium have come to draw the attention of those in the art due to the facts that they produce a deposition layer on a cutting tool for preventing the abrasion of tool and improve the life of tool.
  • the copending Japanese Pat. application No. 14,630 filed on Mar. 3, 1968 discloses the free cutting stainless steels containing calcium in an amount varying from 100 p.p.m. to 600 p.p.m. (0.01 to 0.06 percent by weight).
  • the base steels contain Cr or Cr and Ni or Cr and Mn or Cr, Ni and Mn as the principal alloying elements.
  • the object of this invention is to provide free cutting steels without the above-mentioned defects as inherent to the conventional free cutting steels.
  • the object of this invention can be achieved by providing the free cutting steels containing in combination calcium and at least one member selected from the group consisting of Pb, S and Te.
  • the free cutting steels in accordance with this invention are remarkably improved in their mechanical properties, workability and etc., as compared with the free cutting steels containing Ca or Pb or Pb, S and Te when they are cut under low or medium or high speed, and also that the free cutting steels in accordance with this invention have the abrasion resistance, hardenability, cold and hot workability similar to those of the base steels.
  • the base steels used in this invention have the following chemical compositions.
  • the base steels must contain as the free cutting elements calcium in an amount of from 0 0.0010 to 0.030 percent by weight and at least one member selected from lead in an amount of from 0.03 to 0.35 percent by weight, sulfur in an amount of below 0.5 percent by weight and tellurium in an amount of from 0.01 to 0.10 percent by weight for producing the subject free cutting steels having the improved cutting property and workability.
  • the inventors have found that the free cutting steels are not improved in their workability when they contain calcium in an amount outside the range as defined above. Also, the inventors have found that the free cutting steels are decreased or not imiproved in their workability when they contain Pb, S and Te in an amount outside the range as defined above.
  • the lower limit of carbon is defined to 0.05 percent by weight for obtaining the necessary strength for the steels.
  • the upper limit of carbon, silicon or manganese is defined to 0.30, 2.0 or 4.0 percent by weight for obtaining the necessary tenacity and workability for the steels.
  • Phosphorus is an additive for increasing the workability of the steels but the amount of phosphorus is defined to the upper limit of a 1.0 percent by weight because the tenacity and ductility of the steels are affected as the phosphorus content increases.
  • the upper limit of nickel, chromium or molybdenum is defined to 5.0, 6.0 or 1.0
  • Tungsten is harmful to workability; copper causes brittleness; titanium, vanadium and niobium are harmful to hardenability; and foron is harmful to workability of the steels as the content thereof increases and thus their upper limit is defined to 1.0, 0.5, 0.5, 0.5 and 0.01 percent by weight respectively.
  • FIG. 1 shows curves illustrating the relationship between the flank wear width and the cutting period of time when SZOCN, SZOCF, S20CY and SZOCYF steels were normalized and then cut at the feed of 0.2 mm./rev., the depth of cut of 2.0 mm. and the cutting speed of 200 m./min. by using the cutting tool P 10 having the back rake angle of -5, the side rake angle of 5, the end relief angle of 5, the side relief angle of 5, the cutting angle of 30, the side cutting angle of and the l nose radium of 0.4 mm. It can be seen from the curves as indicated in FIG.
  • H indicates the initial height of the test piece and h indicates the final height of the test piece after it was compressed.
  • the above-mentioned steels were tested for hot workability.
  • the test pieces having the size of 8 mm. 30 mm. were made of the steels and the test pieces were tested for the torsion value for initiating the breaking of them at the strain speed of 2 sec. at l,l00 C. by using the high temperaturetorsion test machine.
  • the results of the tests are shown in FIG. 3.
  • the SZOCYF steel of this invention has the hot workability similar to that of the S20CN steel but higher hot workability than that of the S20CF steel containing Pb alone.
  • Free cutting steels were produced by incorporating various amounts of calcium and lead with SSOCN steel and then they were normalized.
  • the normalized free cutting steels were cut at the feed of 0.20 mm./rev. and the depth of cut of 2.0 mm. under high cutting speed by using a cutting oil and the cutting tool P 10" having the back rake angle of 5, the side rake angle of 5, the end relief angle of 5, the side relief angle of 5, the end cutting angle of 30, the side cutting angle of 0 and the nose radium of 0.4 mm.
  • the life of tool was evaluated at the flank wear width of 0.3 mm. The results of the tests are shown in FIG. 4. In FIG.
  • the life of tool is indicated by using the abbreviation (T) of the multiple number calculated by assuming that the life of tool is 1.0 when the SSOCN steel was cut.
  • T the abbreviation of the multiple number calculated by assuming that the life of tool is 1.0 when the SSOCN steel was cut.
  • the life of tool is remarkably improved as the amount of Ca and Pb contained in the free cutting steels increase and also the life of tool is improved by increasing the amount of Ca even if the amount of Pb is decreased.
  • FIG. 5 shows the life of tool when the SZOCN, SSOCY. SCF and SSOCYF steels were normalized and cut under low speed.
  • the normalized base steel and the free cutting steels were cut at the feed of 0.12 mm./rev. and the depth of cut of 1.0 mm. under high cutting speed of 50 m./min. by using a cutting oil and the cutting tool SKH4" having the back rake angle of 0, the side rake angle of 15, the end relief angle of 7, the side relief angle of 7, the end cutting angle of 10, the side cutting angle of 0 and the nose radius of 0.5 mm.
  • the life of tool was evaluated until the tool becomes to have no ability for cutting the test samples. As it is obvious from FIG.
  • the free cutting steel designated as SSOCY steel which contains calcium alone, is not improved in its workability as compared with the base steel designated as SSOCN steel butthe free cutting steel designated as SCSOCYF, which contains calcium and lead in combination, is remarkably improved in its workability as compared with the base steel.
  • FIG. 6 shows curves illustrating the relationship between the cutting speed and the roughness of the finished surface of each of SSOCN, SSOCY, SSOCF and SSOCYF steels when they were normalized and cut.
  • the tests were conducted by cutting the normalized steels at the feed of 0.25 mm./rev. or 0.35 mm./rev. and the depth of cut of 2.0 mm. under the indicated cutting speed by using the cutting tool P 10" having the back rake angle of 5, the side rake angle of 5 the end relief angle of 5, the side relief angle of 5, the end cutting angle of 30, the side cutting angle of 0 and the nose radius of 4 mm.
  • the free cutting steel (SSOCYF steel) of this invention indicates to to have the good finished surface.
  • the normalized steels as mentioned above were cut at the feed of 0.18 to 0.48 mm./rev. and the depth of cut of L0 mm. by using the cutting tool P 10" having the back rake angle of 0, the side rake angle of 6, the end relief angle of 7, the side relief angle of 7, the end cutting angle of 10, the side cutting angle of 0 and the nose radius of 0.5 mm.
  • the cut scrap was crushed for testing its brittleness by using a chip breaker and it is found that the cut scrap obtained by cutting the SSOCYF steel of this invention can easily be crushed without the use of the chip breaker.
  • the results of tests are given in the following table 3.
  • FIG. 7 shows the microphotographs illustrating the fatigue state of the rake face and the relief face of the tool when S50CN, SSOCY, SSOCF and SSOCYF steels were cut with the cutting tool.
  • the rake face and the relief face of the tool were abraded when the SSOCN steel was cut.
  • the abrasion of the rake face and the relief face of the tool was considerably prevented due to the presence of the layer deposited on the rake and relief faces when the S50CY and S50CF steels were cut. Further, it is observed that the tool was not obraded when the SSOCYF steel was cut.
  • FIG. 8 shows curves illustrating the relationship between tensile strength and proof stress or elongation or a 0.2 percent reduction of area when SSOCN, SSOCYN, SSOCNF and SSOCYF steels were tested. As you see from the curves, the steels have the similar mechanical properties in the proof stress, elongation and the reduction of area and therefore it is understood that the mechanical properties of the SSOCYF steel are not affected by the presence of calcium and lead.
  • FIG. 9 shows a curve illustrating the relationship between Charpy impact strength and hardness of SSOCN, SSOCY, S50CF and S50CYF steels when they were heated at 800 C. and annealed at 550 600 or 650 C. As you see from the curve, the mechanical properties of the SSOCYF steel are not affected by the presence of calcium and lead.
  • FIG. 10 shows curves illustrating the change of fatigue strength affected by the presence of calcium and lead contained in S50CN steel. The test was conducted for three times in each of the test steels and their fatigue strength are given as the average value. In FIG. 10, it is noted that the fatigue strength is indicated by the multiple number calculated by assuming that the SSOCN steel has the fatigue strength of 1.0.
  • the following table 4 shows the relationship between the life of the cutting tool and the fatigue strength of the three types free cutting steels designated as S50CY, SSOCF and SSOCYF steels.
  • the life of tool and the fatigue strength of steels are indicated by the multiple number using the abbreviation (T).
  • SSOCY-l steel, S50C2 steel or S50CY3 steel contains 0.002% Ca, 0.005% Ca or from 0.007 to 0.016% Ca
  • S50CF-1 steel or S50CF-2 steel contains 0.15% Pb or 0.20% Pb
  • SSOCF-l steel, S50CYF-2 steel, SSOCYF-3 steel or SSOCYF-4 ste el contain 0.001% Ca plus 0.05% Pb, 0.001% Ca plus 0.10% Pb, 0.002% Ca plus 0.05% Pb or 0.004% Ca plus 0.05% Pb.
  • the following table 5 shows the relationship between the life of the cutting tool and the fatigue strength of the three types free cutting steels designated as S50CY, SSOCF and S50CYF steels.
  • the life of tool and the fatigue strength are indicated by using the multiple number.
  • S5OCY4 or SSOCY-S steel contains 0.010% Ca or 0.016% Ca
  • S50CF-2 or S50CF-3 steel contains 0.20% Pb or 0.25% Pb
  • SSOCYF-S or S50CYF-6 steel contains 0.005% Ca plus 0.05% Pb or 0.006% Ca plus 0.10% Pb.
  • FIG. 11 shows the cold workability of each of the steels designated as SSOCN, S50CY, SSOCF and SSOCYF.
  • the steels were normalized to have the hardness (HB) of 135 and 20 test pieces were made of the normalized steels.
  • the test pieces have the size of 6 mm. 12 mm. and they were tested for the critical reduction in height (L).
  • the S50CYF steel of this invention indicates substantially the same critical reduction in height as that of the base SSOCN steel and eliminates the defect of the SSOCF steel containing Pb alone as the free cutting element.
  • FIG. 12 shows the hot workability of each of the steels as mentioned in FIG. 11.
  • the test pieces have the size of 8 mm. 30 mm. and they were tested for the torsion value for initiating the breaking of them at the strain speed of 5 sec. at 1,100 C. by using the high temperature-torsion test machine.
  • the S50CYF steel of this invention indicates the torsion value for initiating the breaking of its similar to that of the base SSOCN steel and eliminates the defect of the SSOCF steel containing Pb alone as the free cutting element.
  • FIG. 13 shows the abrasion resistance of each of the steels as mentioned in FIGS. 11 and 12.
  • the steels were normalized s, HRClQ ?F t e srt wf -75 "I t-an test pieces were made of the normalized steels.
  • the test pieces have the size of 30 mm. in the outside diameter and the contact surface of 5 mm. in width. They were tested for their abrasion resistance.
  • the test was conducted at 1,000 r.p.m. under the surface pressure of 200 kg./mm. by using the abrasion test machine and the number of abrasion cycle for growing the pit was recorded.
  • the results of tests are shown in FIG. 13.
  • the SSOCYF steel of this invention indicates substantially the same abrasion resistance as that of the base SSOCN steel.
  • the steels as mentioned in FIGS. ll, 12 and 13 were tested for their crack at surface or root or in depth and it was found that the SSOCYF steel of this invention indicates good resistance against such a surface or root or depth crack as compared with that of the base SSOCN steel and the such crack resistance of the SSOCYF is measured as in the middle value of the S50CY steel containing Ca alone and the SSOCF steel containing Pb alone as the free cutting elements.
  • FIG. 14 shows curves illustrating the relationship between the life of tool and the cutting speed when the free cutting steels designated as SFC3F steel containing S and Pb, and SFC3FY steel containing S, Pb and Ca were cut.
  • the steels were normalized and the normalized steels were cut at the feed of0.l mm./rev. and the depth ofcut of0.5 mm. under the indicated cutting speed by using the cutting tool K 10' having the back rake angle of 0, the side rake angle of 6, the end relief angle of 7, the side relief angle of 7, the end cutting angle of 10, the side cutting angle of 0 and the nose radius of 0.5 mm.
  • the life of tool was evaluated at the flank wear width of 0.2 mm.
  • the SFC3F Y steel of this invention gives a longer life of tool as compared with the SFC3F steel.
  • FIG. 15 shows the hot workability of the steels as shown in FIG. 14.
  • the test pieces have the size of 8 mm.X30 mm.
  • the SFC3FY steel is improved in the torsion value as compared with the base SFC3F steel.
  • FIG. 16 shows curves illustrating the relationship between the life of tool and the cutting speed when the free cutting steels designated as SFC3FT steel and SFC3FI Y steel were cut.
  • the SFC3FT steel contains sulfur, lead and teliurium
  • the SFC3FT Y steel contains sulfur, lead, tellurium and calcium as the free cutting elements.
  • the steels were normalized and the normalized steels were cut at the feed of 0.1 mm./rev. and the depth of cut of 0.5 mm. under the indicated cutting speed by using the cutting tool K having the back rake angle of 0, the side rake angle of 6, the end relief angle of 7, the side relief angle of 7, the end cutting angle of 10, the side cutting angle of0 and the nose radius of 0.5 mm.
  • the life of tool was evaluated at the flank wear width of 0.2 mm.
  • the SFC3FT Y of this invention gives a longer life of tool as compared with the base SFC3F'I steel.
  • FIG. '17 shows curves illustrating the relationship between the life of tool and the cutting speed when the free cutting steels designated as SUMIB steel and SUMIBY steel were cut.
  • the SUMIB steel contains sulfur and the SU- M IBY steel contains sulfur and calcium as the free cutting elements.
  • the steels were normalized and the normalized steels were cut in the same manner as in the tests conducted and explained in FIG. 16.
  • the life of tool was evaluated at the flank wear width of 0.2 mm.
  • the SUMIBY steel of this invention gives a longer life of tool as compared with the base SUMIB steel.
  • FIGS. 18 and 19 show distribution of the characteristic X- ray emission density emitted from sulfur and iron contained in the deposited layer on the rake face of tool after the tool was used for cutting the steels designated as SUMIB steel and SU- MIBY steel. Both the steels were cut at the feed of 0.1 mm./rev., at the depth of cut of 0.5 mm. and at the cutting speed of 180 meters per minute for 20 minutes by using a cutting oil and the cutting tool K 10" as explained in the above mentioned tests.
  • FIG. 18 shows the results of test when the tool is used for cutting the SUMIB steel and a considerable amount of Fe is observed over the range varying from the end of the tool to about 250;4..
  • FIG. 19 shows the results of test when the tool is used for cutting the SUMIBY steel and a considerable amount ofS (or CaS) is observed all over the tool but Fe is not observed over the range varying from the end of the tool to about 5011.. This proves that the rake face of the tool was coated with the thin layer containing sulfur and the tool was prevented from abrasion.
  • FIG. 20 shows curves illustrating the relationship between the flank wear width and the cutting speed when Cr-Mo alloy steel designated as SCM3N and free cutting steels designated as SCMBY, SCM3F and SCM3YF steels were cut with tool.
  • SCM3Y steel contains calcium
  • SCM3F steel contains lead
  • SCM3YF steel contains calcium and lead as the free cutting elements.
  • the SCM3YF steel of this invention is less abrasion than the other steels.
  • all the steels were normalized and the normalized steels were cut at the feed of 0.2 mm./rev. and the depth of cut of 2.0 mm. under the cutting speed of 200 meters per minute by using the cutting tool P 10'' as mentioned in FIG. 6.
  • FIG. 21 shows curves illustrating the hardenability of the steels as shown in FIG. 20.
  • the SCM3YF steel of this invention has better hardenability than that of the SCM3N steel.
  • FIG. 22 shows curves illustrating the relationship between tensile strength and elongation (percent) or 0.2 percent yield strength or reduction of area when the steels designated as SCM3N, SCM3Y, SCM3F and SCM3YF were tested.
  • SCM3N steel is indicated by the marks 0"
  • SCMBY steel is indicated by the marks
  • SCM3F steel is indicated by the marks A
  • t e SCM3YF steel is indicated by the marks A
  • the SCM3YF steel of this invention has the mechanical properties similar to those of the other steels.
  • FIG. 23 shows a curve illustrating the relationship between hardness (HB) and Charpy impact strength when the steels designated as SCM3N, SCM3Y, SCM3F and SCM3YF were tested. It is noted that all the steels are indicated in the same marks as in FIG. 22 respectively. The steels were normalized at 860 C. and then annealed at 500, 550, 600 and 650 C. As it is obvious from the curves as shown in FIG. 23, the SCM3YF steel of this invention has the Charpy impact strength similar to those of the other steels.
  • FIG. 24 shows the cold workability of the steels designated as SCM3N, SCM3Y, SCM3F and SCM3FY when they were tested for critical reduction in height (L). All the steels were normalized to have the hardness (HB) of I and test pieces were made of the normalized steels. The test pieces have the size of 6mm.Xl2mm.
  • the SCM3YF steel of this invention indicates substantially the same critical reduction in height as that of the SCM3N steel and also indicates better critical reduction in height than that of the SCM3F steel containing Pb alone.
  • this invention provides the calcium composite free cutting steels which are manufactured by incorporating calcium and at least one member selected from the group consisting of Pb, S and Te with the carbon steels or the alloy steels.
  • Such composite free cutting steels are improved in their cutting property as compared with the free cutting steels which are manufactured by incorporating calcium alone or at least one member selected from the group consisting of Pb, S and Te with the carbon steels or alloy steels.
  • such composite free cutting steels have the mechanical properties, cold and hot workability, hardenability, abrasion resistance and weldability similar to those of the original carbon steels or the original alloy steels.
  • Free cutting carbon steel and alloy steel having improved cutting properties such that it may be cut at low or high speeds with an improved life to the cutting too], said steel being characterized by containing as the free cutting elements calcium in an amount of from 0.0010 to 0.020 percent by weight and lead in an amount of from 0.03 to 0.35 percent by weight.

Abstract

This invention relates to free cutting steels containing in combination calcium and at least one free cutting element selected from the group consisting of lead, sulfur and tellurium. Such free cutting steels are characterized by their cutting property.

Description

United States Patent [72] Inventors Tetsuro Ito Nagoya; Goshi Kato, Tsushima; Atsuyoshi Kimura, Chita-gun, all of Japan [2]] Appl. No. 781,520
[22] Filed Dec. 5, 1968 [45] Patented Jan. 1 1, 1972 [73] Assignee Daido Seiko Kabushiki Kaisha Minami-ku, Nagoya, Aichi, Japan [32] Priority Apr. 3, 1968 [3 3 Japan [54] FREE CUTTING STEELS 1 Claim, 24 Drawing Figs.
[52] US. Cl 75/125,
75/123 AA, 75/123 F, 75/126 C, 75/126 G, 75/126 M [51] Int. Cl
C22c 39/54 [50] Field ofSearch ..75/l23, 123 R, [23 AA, l23 F, 125, 1266, 126M [5 6] References Cited UNITED STATES PATENTS Primary Examiner- L.-Dewayne Rutledge Assistant Examiner-Joseph E. Legru Attorney-Wenderoth, Lind & Ponack Gagnebin ABSTRACT: This invention relates to free cutting steels containing in combination calcium and at least one free cutting element selected from the group consisting of lead, sulfur and tellurium. Such free cutting steels are characterized by their cutting property.
PATENIEDJAIII 1 I972 3.634.074
SHEET um 12 FLANK WEAR WIDTH CUTTING TIME (M IN.)
CRITICAL REDUCTION IN HEIGHT ILI INVENTORS TETSURO ITO FIG. 2 GOSHI KATO ATSUYOSHI KIMURA PATEF: 1511 1 :11 1 2912 E? Q 834 0174 RAKE FACE OF TOOLAFTER TI-IE RAKE FACE OF TOOL AFTER SSOCN STEEL WAS CUT THE S50 CY STEEL WAS CUT RELIEF FACE OF TOOL AFTER RELIEF FACE OF TOOLAFTER THE QOCN STEEL WAS CUT TI-IE S5OCY STEEL WA CUT FIG.7
RAKE FACE OF TOOL AFTER RAKE FACE OF TOOL AFTER THE SSOCF STEELWAS CUT THE SSOCYF STEELWAS CUT FIO.7
RELIEF FACE OF TOOL AFTER RELIEF FACE OF TOOL AFTER THE S5OCF STEEL WAS CUT TI-IE S50 CYF STEELWAS CUT //vI/EN 70R$ TETSURO ITO. GOSHI KATO.
ATSUYOSH KIMURA' ZMJQ-m A TTORNEVS PATENTEU JAN] 1 1972 3334074 SHEET can; 12
FIG. l5
. I I l 1 l l 1 1 1 1 I 20 40 a0|oo|so2oo3o04ooeoosoo9ooaoo20oo LIFE OF TOOL (MIN) FIG. l6
CUTTING SPEED INVENTOR5 TETSURO ITO 605 H I KATO ATSUYOSHI K IMU RA ATTORNEYS FIG.
PATENTED JAN] 1 I872 SHEET 09 0F 12 6O .1 1 I. LMIMLWL. .1. J
20 40 so I00 I50 200 300 400 600 LIFE OF TOOL (MINJ FIG. 7
500 200 0 THE END OF TOOL ll K'Oll DISTANCE FROM THE END OF TOOL (JJ-I THE END OF TOG.
L IIKIOU 500 400 300 200 I00 0 DISTANCE FROM THE END OF TOOL p) INVENTORS TETSURO no sosm KATO ATSUYOSHI K I MURA PATENTEI] m1 1 1972 3634074 SPEETv IUUF 12 l I 1 1 700 e00 500 400 300 200 I00 0 DISTANCE FROM THE END OF TOOL THE Tag TOOL FIG. I93 FE l I l l 700 600 500 400 300 200 I00 0 DISTANCE FROM THE END OF TOOL 11-) THE END O TOOL "mo" FLANK WEAR WIDTH CUTTING TIME (MIN.)
FIG. 20
INVENTORS TETSURO ITO GOSH! KATO ATSUYOSHI KIMURA ATTORNEYS PAIENTED mu 1 I372 ROCKWELL HARDNESS "c" SHEET 1 1 U? 1|||111||||||1411 24 68IOl2l4l6l820222426'28303234xfi" NORMILIZED AT THE INDICATED DISTANCE FROM THE END OF STEELS (INCH) FIG. 2!
I '20 E oSCM3N 5 I00 SCM3Y g ASCM3F 8o ASCM3YF N 60 (I g FIG. 22
e5 4 24 60 E 03 22 55 5 v g 5 I8 45 F 5 [6 E 3 l4 l2 J [INN/mo so [)0 no I20 I30 TETSURO To TENSILE STRENGTH 9 Mme) GOSH! KATO ATSUYOSHI KIMURA jZ/M4m%;/MM i/m/Mz ATTORNEYS FREE CUTTING STEELS This invention relates to free cutting steels containing in combination calcium and at least one member selected from the group consisting of lead, sulfur and tellurium.
The cutting technique and workability of the steels are recognized to be of great importance in order to meet the increased production of the steel articles and various kinds of free cutting steels have been developed by incorporating one or more members, in combination, selected from the group consisting of sulfur, lead, selenium, tellurium, bismuth, phosphorus and nitrogen with steels. Recently, free cutting steels containing calcium have come to draw the attention of those in the art due to the facts that they produce a deposition layer on a cutting tool for preventing the abrasion of tool and improve the life of tool.
The copending Japanese Pat. application No. 59,620 filed on Sept. 19, 1967 discloses the free cutting steels containing anorthite as the principal oxide inclusion. Such free cutting steels contain calcium in an amount varying from p.p.m. to 100 p.p.m. (0.002 to 0.01 percent by weight).
Also the copending Japanese Pat. application No. 14,630 filed on Mar. 3, 1968 discloses the free cutting stainless steels containing calcium in an amount varying from 100 p.p.m. to 600 p.p.m. (0.01 to 0.06 percent by weight). The base steels contain Cr or Cr and Ni or Cr and Mn or Cr, Ni and Mn as the principal alloying elements.
The inventors have found that such a Ca-containing free cutting steel improves the life of tool when it is cut under high speed but it does not improve the life of tool when it is out under low speed as compared with the life of tool when the base steel not containing the free cutting additive or additives is out under low speed. In this connection, it was reported and recognized in the art that the free cutting steels containing the single member or in combination, more members selected from the group consisting of Pb, S and Te remarkably improve the life of tool when they are cut under low or medium speed but that they slightly improve the life of tool when they are cut under high speed.
The object of this invention is to provide free cutting steels without the above-mentioned defects as inherent to the conventional free cutting steels. The object of this invention can be achieved by providing the free cutting steels containing in combination calcium and at least one member selected from the group consisting of Pb, S and Te.
The inventors have found that the free cutting steels in accordance with this invention are remarkably improved in their mechanical properties, workability and etc., as compared with the free cutting steels containing Ca or Pb or Pb, S and Te when they are cut under low or medium or high speed, and also that the free cutting steels in accordance with this invention have the abrasion resistance, hardenability, cold and hot workability similar to those of the base steels. It should be noted that the base steels used in this invention have the following chemical compositions.
in accordance with this invention, the base steels must contain as the free cutting elements calcium in an amount of from 0 0.0010 to 0.030 percent by weight and at least one member selected from lead in an amount of from 0.03 to 0.35 percent by weight, sulfur in an amount of below 0.5 percent by weight and tellurium in an amount of from 0.01 to 0.10 percent by weight for producing the subject free cutting steels having the improved cutting property and workability. The inventors have found that the free cutting steels are not improved in their workability when they contain calcium in an amount outside the range as defined above. Also, the inventors have found that the free cutting steels are decreased or not imiproved in their workability when they contain Pb, S and Te in an amount outside the range as defined above.
Further there are explained hereinafter the reasons why the amount of the components contained in the base steels is defined within the range as mentioned above.
The lower limit of carbon is defined to 0.05 percent by weight for obtaining the necessary strength for the steels. The upper limit of carbon, silicon or manganese is defined to 0.30, 2.0 or 4.0 percent by weight for obtaining the necessary tenacity and workability for the steels. Phosphorus is an additive for increasing the workability of the steels but the amount of phosphorus is defined to the upper limit of a 1.0 percent by weight because the tenacity and ductility of the steels are affected as the phosphorus content increases. The upper limit of nickel, chromium or molybdenum is defined to 5.0, 6.0 or 1.0
percent by weight because the workability of the steels are decreased when the steels contain Ni, Cr or M0 in a larger amount over the upper limit thereof. Tungsten is harmful to workability; copper causes brittleness; titanium, vanadium and niobium are harmful to hardenability; and foron is harmful to workability of the steels as the content thereof increases and thus their upper limit is defined to 1.0, 0.5, 0.5, 0.5 and 0.01 percent by weight respectively.
Examples of the free cutting steels in accordance with this invention as well as the base steels and control steels are listed in the following table 1 TABLE 1 Chemical components Hardgrmss Steels C Si Mn P S Cu Cr Mo Pb Te Ga normalized ZO N base 0.21 0.24 0.38 0.018 0.012 .13 0.08 151 20UF 0.20 0.31 0.40 0.018 0.015 3.12 0.11 160 S20CY 0.21 0.31 0.50 0.021 0.016 0.12 0.10 153 S20CY 0.20 0.28 0.88 0.019 0.016 0.12 0.10 151 SEOCN (b 0.51 0.28 0.75 0.014 0.018 0.11 0.10 215 S5001 0.50 0.29 0.78 0.016 0.019 0.16 0.14 213 S500 0.51 0.30 0.74 0.014 0.020 0.10 0.13 215 S50CYF 0.50 "0,27 0.68 0.016 -0.020 0.16 0.12 214 SFCBF..- 0.08 0.10 0.99 0.068 0.318 0.12 0.16 124 SFC3YF- 0.00 0.09 1.01 0.071 0.321 0.11 0.16 123 SFC3FT 0.07 0105 0.99 0.075 0.321 0.13 0.16 126 SFO3FTY 0.08 0.06 0.98 0.075 0.316 0.13 0.15 124 SUM1B(b8S9) 0.11 0.18 0.78 0.014 0.183 0.23 0.10 lBY 0.10 0.20 0.76 0.015 0.181 0.20 0.11 122 SCM3N (bBSe) 0.35 0.29 0.69 0.018 0.012 0.14 1.00 269 CM3Y 0.36 0.28 0.69 0.016 0.013 0.12 0.98 269 SCMBF.-- 0.35 0.31 0.71 0.017 0.013 0.12 0.98 270 a F 0.35 0.30 0.70 0.018 0.011 0.12 1.00 270 In table I, it is noted that the base steels are S20CN, S50CN, SUMIB and SCM3N as designated in the Japanese Industrial Standards, and F-type, Y-type and YF-type steels contain lead, calcium and lead plus calcium respectively.
Now, this invention is fully explained by referring to the accompanying drawings in which:
FIG. 1 shows curves illustrating the relationship between the flank wear width and the cutting period of time when SZOCN, SZOCF, S20CY and SZOCYF steels were normalized and then cut at the feed of 0.2 mm./rev., the depth of cut of 2.0 mm. and the cutting speed of 200 m./min. by using the cutting tool P 10 having the back rake angle of -5, the side rake angle of 5, the end relief angle of 5, the side relief angle of 5, the cutting angle of 30, the side cutting angle of and the l nose radium of 0.4 mm. It can be seen from the curves as indicated in FIG. 1 that the S20CYF steel of this invention which contains 0.18 percent of Pb and 0.0051 percent of Ca is remarkably improved as compared with the S20CF steel and the SZOCY steel. When the steels were cut for 60 minutes, the flank wear width of the tool is given in the following table 2.
The above-mentioned steels were normalized to have the hardness (I-IB) of 135 and test pieces were madeof the normalized steels. The test pieces have the size of 6 mm.Xl2 mm. and they were tested for the critical reduction in height. The test was condueed for 20 times in each of the steels. The results of the test are shown in FIG. 2. As it is obvious from FIG. 2, the S20CYF steel of this invention has the cold workability similar to that of the S2OCN steel but higher cold workability than that of the S20CF steel containing Pb alone. It should be understood that the critical reduction in height (11L) is indicated by the following equation.
wherein, H indicates the initial height of the test piece and h indicates the final height of the test piece after it was compressed.
Also the above-mentioned steels were tested for hot workability. The test pieces having the size of 8 mm. 30 mm. were made of the steels and the test pieces were tested for the torsion value for initiating the breaking of them at the strain speed of 2 sec. at l,l00 C. by using the high temperaturetorsion test machine. The results of the tests are shown in FIG. 3. As it is obvious from FIG. 3', the SZOCYF steel of this invention has the hot workability similar to that of the S20CN steel but higher hot workability than that of the S20CF steel containing Pb alone.
Free cutting steels were produced by incorporating various amounts of calcium and lead with SSOCN steel and then they were normalized. The normalized free cutting steels were cut at the feed of 0.20 mm./rev. and the depth of cut of 2.0 mm. under high cutting speed by using a cutting oil and the cutting tool P 10" having the back rake angle of 5, the side rake angle of 5, the end relief angle of 5, the side relief angle of 5, the end cutting angle of 30, the side cutting angle of 0 and the nose radium of 0.4 mm. The life of tool was evaluated at the flank wear width of 0.3 mm. The results of the tests are shown in FIG. 4. In FIG. 4, the life of tool is indicated by using the abbreviation (T) of the multiple number calculated by assuming that the life of tool is 1.0 when the SSOCN steel was cut. As it is obvious from FIG. 4, the life of tool is remarkably improved as the amount of Ca and Pb contained in the free cutting steels increase and also the life of tool is improved by increasing the amount of Ca even if the amount of Pb is decreased.
FIG. 5 shows the life of tool when the SZOCN, SSOCY. SCF and SSOCYF steels were normalized and cut under low speed. The normalized base steel and the free cutting steels were cut at the feed of 0.12 mm./rev. and the depth of cut of 1.0 mm. under high cutting speed of 50 m./min. by using a cutting oil and the cutting tool SKH4" having the back rake angle of 0, the side rake angle of 15, the end relief angle of 7, the side relief angle of 7, the end cutting angle of 10, the side cutting angle of 0 and the nose radius of 0.5 mm. The life of tool was evaluated until the tool becomes to have no ability for cutting the test samples. As it is obvious from FIG. 5, the free cutting steel designated as SSOCY steel, which contains calcium alone, is not improved in its workability as compared with the base steel designated as SSOCN steel butthe free cutting steel designated as SCSOCYF, which contains calcium and lead in combination, is remarkably improved in its workability as compared with the base steel.
FIG. 6 shows curves illustrating the relationship between the cutting speed and the roughness of the finished surface of each of SSOCN, SSOCY, SSOCF and SSOCYF steels when they were normalized and cut. The tests were conducted by cutting the normalized steels at the feed of 0.25 mm./rev. or 0.35 mm./rev. and the depth of cut of 2.0 mm. under the indicated cutting speed by using the cutting tool P 10" having the back rake angle of 5, the side rake angle of 5 the end relief angle of 5, the side relief angle of 5, the end cutting angle of 30, the side cutting angle of 0 and the nose radius of 4 mm. As it is obvious from FIG. 6, the free cutting steel (SSOCYF steel) of this invention indicates to to have the good finished surface.
Also, the normalized steels as mentioned above were cut at the feed of 0.18 to 0.48 mm./rev. and the depth of cut of L0 mm. by using the cutting tool P 10" having the back rake angle of 0, the side rake angle of 6, the end relief angle of 7, the side relief angle of 7, the end cutting angle of 10, the side cutting angle of 0 and the nose radius of 0.5 mm. The cut scrap was crushed for testing its brittleness by using a chip breaker and it is found that the cut scrap obtained by cutting the SSOCYF steel of this invention can easily be crushed without the use of the chip breaker. The results of tests are given in the following table 3.
TABLE 3 SSOCN SBOCY S50CF SHJCYF PPPPPPPPPPPPPPPPPPPP saeessesseaseseessee mqoexxooooxoooxw kww NN NMO O NM NNN NNN oooooooooooooooo o ooooooooooooooooxgm Note: The mark X indicates the use of the chip breaker for crushing the cut scrap and the mark 0 indicates that the chip breaker is not required for crushing the cut scrap.
FIG. 7 shows the microphotographs illustrating the fatigue state of the rake face and the relief face of the tool when S50CN, SSOCY, SSOCF and SSOCYF steels were cut with the cutting tool. As you see from the rnicrophctographs, it is observed that the rake face and the relief face of the tool were abraded when the SSOCN steel was cut. Also, it is observed that the abrasion of the rake face and the relief face of the tool was considerably prevented due to the presence of the layer deposited on the rake and relief faces when the S50CY and S50CF steels were cut. Further, it is observed that the tool was not obraded when the SSOCYF steel was cut.
FIG. 8 shows curves illustrating the relationship between tensile strength and proof stress or elongation or a 0.2 percent reduction of area when SSOCN, SSOCYN, SSOCNF and SSOCYF steels were tested. As you see from the curves, the steels have the similar mechanical properties in the proof stress, elongation and the reduction of area and therefore it is understood that the mechanical properties of the SSOCYF steel are not affected by the presence of calcium and lead.
FIG. 9 shows a curve illustrating the relationship between Charpy impact strength and hardness of SSOCN, SSOCY, S50CF and S50CYF steels when they were heated at 800 C. and annealed at 550 600 or 650 C. As you see from the curve, the mechanical properties of the SSOCYF steel are not affected by the presence of calcium and lead.
FIG. 10 shows curves illustrating the change of fatigue strength affected by the presence of calcium and lead contained in S50CN steel. The test was conducted for three times in each of the test steels and their fatigue strength are given as the average value. In FIG. 10, it is noted that the fatigue strength is indicated by the multiple number calculated by assuming that the SSOCN steel has the fatigue strength of 1.0.
The following table 4 shows the relationship between the life of the cutting tool and the fatigue strength of the three types free cutting steels designated as S50CY, SSOCF and SSOCYF steels. In table 4, it is noted that the life of tool and the fatigue strength of steels are indicated by the multiple number using the abbreviation (T). Also it is noted that SSOCY-l steel, S50C2 steel or S50CY3 steel contains 0.002% Ca, 0.005% Ca or from 0.007 to 0.016% Ca, S50CF-1 steel or S50CF-2 steel contains 0.15% Pb or 0.20% Pb, and SSOCF-l steel, S50CYF-2 steel, SSOCYF-3 steel or SSOCYF-4 ste el contain 0.001% Ca plus 0.05% Pb, 0.001% Ca plus 0.10% Pb, 0.002% Ca plus 0.05% Pb or 0.004% Ca plus 0.05% Pb.
It is understood from the data as shown in table 4 that the SSOCYF-type steels have the fatigue strength similar to or above the fatigue strength of the S50CY-type steels and also that the SSOCYF-type -type steels have the larger fatigue strength than that of the SSOCF-type steels.
Also, the following table 5 shows the relationship between the life of the cutting tool and the fatigue strength of the three types free cutting steels designated as S50CY, SSOCF and S50CYF steels. As in table 4, the life of tool and the fatigue strength are indicated by using the multiple number. Further, it is noted that S5OCY4 or SSOCY-S steel contains 0.010% Ca or 0.016% Ca; S50CF-2 or S50CF-3 steel contains 0.20% Pb or 0.25% Pb; and SSOCYF-S or S50CYF-6 steel contains 0.005% Ca plus 0.05% Pb or 0.006% Ca plus 0.10% Pb.
19 hav the ha n TABLE 5 Fatigue strength Steels Life of tool S50CY-4 5 T 0.94 T S50CF-2 4 T SSOCYF-S S T S50CY-5 5 T 0.89 T SSOCF-3 4 T SSOCYF-6 16 T As you see from the data as shown in table 5, the fatigue strength of the SSOCYF-type steels is not so much decreased in spite of the high increase of the life of the cutting tool.
FIG. 11 shows the cold workability of each of the steels designated as SSOCN, S50CY, SSOCF and SSOCYF. The steels were normalized to have the hardness (HB) of 135 and 20 test pieces were made of the normalized steels. The test pieces have the size of 6 mm. 12 mm. and they were tested for the critical reduction in height (L). As it is obvious from FIG. 11, the S50CYF steel of this invention indicates substantially the same critical reduction in height as that of the base SSOCN steel and eliminates the defect of the SSOCF steel containing Pb alone as the free cutting element.
FIG. 12 shows the hot workability of each of the steels as mentioned in FIG. 11. The test pieces have the size of 8 mm. 30 mm. and they were tested for the torsion value for initiating the breaking of them at the strain speed of 5 sec. at 1,100 C. by using the high temperature-torsion test machine. As it is obvious from FIG. 12, the S50CYF steel of this invention indicates the torsion value for initiating the breaking of its similar to that of the base SSOCN steel and eliminates the defect of the SSOCF steel containing Pb alone as the free cutting element.
FIG. 13 shows the abrasion resistance of each of the steels as mentioned in FIGS. 11 and 12. The steels were normalized s, HRClQ ?F t e srt wf -75 "I t-an test pieces were made of the normalized steels. The test pieces have the size of 30 mm. in the outside diameter and the contact surface of 5 mm. in width. They were tested for their abrasion resistance. The test was conducted at 1,000 r.p.m. under the surface pressure of 200 kg./mm. by using the abrasion test machine and the number of abrasion cycle for growing the pit was recorded. The results of tests are shown in FIG. 13. As it is obvious from FIG. 13, the SSOCYF steel of this invention indicates substantially the same abrasion resistance as that of the base SSOCN steel.
Further, the steels as mentioned in FIGS. ll, 12 and 13 were tested for their crack at surface or root or in depth and it was found that the SSOCYF steel of this invention indicates good resistance against such a surface or root or depth crack as compared with that of the base SSOCN steel and the such crack resistance of the SSOCYF is measured as in the middle value of the S50CY steel containing Ca alone and the SSOCF steel containing Pb alone as the free cutting elements.
FIG. 14 shows curves illustrating the relationship between the life of tool and the cutting speed when the free cutting steels designated as SFC3F steel containing S and Pb, and SFC3FY steel containing S, Pb and Ca were cut. The steels were normalized and the normalized steels were cut at the feed of0.l mm./rev. and the depth ofcut of0.5 mm. under the indicated cutting speed by using the cutting tool K 10' having the back rake angle of 0, the side rake angle of 6, the end relief angle of 7, the side relief angle of 7, the end cutting angle of 10, the side cutting angle of 0 and the nose radius of 0.5 mm. The life of tool was evaluated at the flank wear width of 0.2 mm. As it is obvious from the curves shown in FIG. 14, the SFC3F Y steel of this invention gives a longer life of tool as compared with the SFC3F steel.
FIG. 15 shows the hot workability of the steels as shown in FIG. 14. The test pieces have the size of 8 mm.X30 mm. and
they were tested for the torsion value for initiating the breaking of them at the strain speed of 3 sec. at l,l50 C. by using the high temperature-torsion test machine. As it is obvious from FIG. 15, the SFC3FY steel is improved in the torsion value as compared with the base SFC3F steel.
FIG. 16 shows curves illustrating the relationship between the life of tool and the cutting speed when the free cutting steels designated as SFC3FT steel and SFC3FI Y steel were cut. It is noted that the SFC3FT steel contains sulfur, lead and teliurium, and the SFC3FT Y steel contains sulfur, lead, tellurium and calcium as the free cutting elements. The steels were normalized and the normalized steels were cut at the feed of 0.1 mm./rev. and the depth of cut of 0.5 mm. under the indicated cutting speed by using the cutting tool K having the back rake angle of 0, the side rake angle of 6, the end relief angle of 7, the side relief angle of 7, the end cutting angle of 10, the side cutting angle of0 and the nose radius of 0.5 mm. The life of tool was evaluated at the flank wear width of 0.2 mm. As it is obvious from the curves shown in FIG. 16, the SFC3FT Y of this invention gives a longer life of tool as compared with the base SFC3F'I steel.
FIG. '17 shows curves illustrating the relationship between the life of tool and the cutting speed when the free cutting steels designated as SUMIB steel and SUMIBY steel were cut. It is noted that the SUMIB steel contains sulfur and the SU- M IBY steel contains sulfur and calcium as the free cutting elements. The steels were normalized and the normalized steels were cut in the same manner as in the tests conducted and explained in FIG. 16. The life of tool was evaluated at the flank wear width of 0.2 mm. As it is obvious from the curves shown in FIG. 17, the SUMIBY steel of this invention gives a longer life of tool as compared with the base SUMIB steel.
FIGS. 18 and 19 show distribution of the characteristic X- ray emission density emitted from sulfur and iron contained in the deposited layer on the rake face of tool after the tool was used for cutting the steels designated as SUMIB steel and SU- MIBY steel. Both the steels were cut at the feed of 0.1 mm./rev., at the depth of cut of 0.5 mm. and at the cutting speed of 180 meters per minute for 20 minutes by using a cutting oil and the cutting tool K 10" as explained in the above mentioned tests. FIG. 18 shows the results of test when the tool is used for cutting the SUMIB steel and a considerable amount of Fe is observed over the range varying from the end of the tool to about 250;4.. This proves that the rake face of the tool was directly contacted with the scraps of the steel. FIG. 19 shows the results of test when the tool is used for cutting the SUMIBY steel and a considerable amount ofS (or CaS) is observed all over the tool but Fe is not observed over the range varying from the end of the tool to about 5011.. This proves that the rake face of the tool was coated with the thin layer containing sulfur and the tool was prevented from abrasion.
FIG. 20 shows curves illustrating the relationship between the flank wear width and the cutting speed when Cr-Mo alloy steel designated as SCM3N and free cutting steels designated as SCMBY, SCM3F and SCM3YF steels were cut with tool. It is noted that the SCM3Y steel contains calcium, the SCM3F steel contains lead and the SCM3YF steel contains calcium and lead as the free cutting elements. As it is obvious from the curves shown in FIG. 20, the SCM3YF steel of this invention is less abrasion than the other steels. Also, it is noted that all the steels were normalized and the normalized steels were cut at the feed of 0.2 mm./rev. and the depth of cut of 2.0 mm. under the cutting speed of 200 meters per minute by using the cutting tool P 10'' as mentioned in FIG. 6.
Also the steels were tested for time in minutes until the flank wear width of the tool reached 0.30 mm. when the steels were cut with the cutting tool P 10 the results of tests are given in the following table 6.
FIG. 21 shows curves illustrating the hardenability of the steels as shown in FIG. 20. As it is obvious from the curves as shown in FIG. 21, the SCM3YF steel of this invention has better hardenability than that of the SCM3N steel.
FIG. 22 shows curves illustrating the relationship between tensile strength and elongation (percent) or 0.2 percent yield strength or reduction of area when the steels designated as SCM3N, SCM3Y, SCM3F and SCM3YF were tested. In FIG. 22, it should be noted that the SCM3N steel is indicated by the marks 0" and the SCMBY steel is indicated by the marks Also, the SCM3F steel is indicated by the marks A and t e SCM3YF steel is indicated by the marks A As it is obvious from the curves as shown in FIG. 22, the SCM3YF steel of this invention has the mechanical properties similar to those of the other steels.
FIG. 23 shows a curve illustrating the relationship between hardness (HB) and Charpy impact strength when the steels designated as SCM3N, SCM3Y, SCM3F and SCM3YF were tested. It is noted that all the steels are indicated in the same marks as in FIG. 22 respectively. The steels were normalized at 860 C. and then annealed at 500, 550, 600 and 650 C. As it is obvious from the curves as shown in FIG. 23, the SCM3YF steel of this invention has the Charpy impact strength similar to those of the other steels.
FIG. 24 shows the cold workability of the steels designated as SCM3N, SCM3Y, SCM3F and SCM3FY when they were tested for critical reduction in height (L). All the steels were normalized to have the hardness (HB) of I and test pieces were made of the normalized steels. The test pieces have the size of 6mm.Xl2mm. As it is obvious from FIG. 24, the SCM3YF steel of this invention indicates substantially the same critical reduction in height as that of the SCM3N steel and also indicates better critical reduction in height than that of the SCM3F steel containing Pb alone.
As stated in the foregoing, this invention provides the calcium composite free cutting steels which are manufactured by incorporating calcium and at least one member selected from the group consisting of Pb, S and Te with the carbon steels or the alloy steels. Such composite free cutting steels are improved in their cutting property as compared with the free cutting steels which are manufactured by incorporating calcium alone or at least one member selected from the group consisting of Pb, S and Te with the carbon steels or alloy steels. In addition such composite free cutting steels have the mechanical properties, cold and hot workability, hardenability, abrasion resistance and weldability similar to those of the original carbon steels or the original alloy steels.
What we claim is:
1. Free cutting carbon steel and alloy steel having improved cutting properties such that it may be cut at low or high speeds with an improved life to the cutting too], said steel being characterized by containing as the free cutting elements calcium in an amount of from 0.0010 to 0.020 percent by weight and lead in an amount of from 0.03 to 0.35 percent by weight.
zgz g UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,634 O74 Dated January 11 1972 lnventofls) Tetsuro ITO, Goshi KA'IO and Atsuyoshi KIMURA It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 2 line 37:
change "0.30" to Signed and sealed this 9th day of January 1973.
(SEAL) Attest:
EDWARD M.FLF,TCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents
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US3844773A (en) * 1972-05-10 1974-10-29 Kobe Steel Ltd Free cutting steel containing mullite
USB289883I5 (en) * 1972-09-18 1975-01-28
US3876422A (en) * 1972-05-25 1975-04-08 Inland Steel Co Elongated leaded steel casting
US3948649A (en) * 1971-08-04 1976-04-06 Daido Seiko Kabushiki Kaisha Free cutting steel
US3984238A (en) * 1975-05-14 1976-10-05 Nikolai Nikiforovich Vlasov Steel for metal cord
US4004922A (en) * 1974-10-11 1977-01-25 Ugine Aciers Free machining steel
US4020887A (en) * 1975-05-14 1977-05-03 Nikolai Nikiforovich Vlasov Tires reinforced with steel cord
US4056387A (en) * 1974-08-14 1977-11-01 Inland Steel Company Leaded steel bar free of lead macroinclusions
US4115111A (en) * 1973-11-13 1978-09-19 Daido Tokushuko Kabushiki Kaisha Free-cutting structural steel for machines
DE2824803A1 (en) * 1977-06-24 1979-01-18 Acieries De Pompey Neuilly Soc FINE GRAIN STEEL WITH IMPROVED MACHINABILITY
US4153454A (en) * 1977-08-12 1979-05-08 Kawasaki Steel Corporation Steel materials having an excellent hydrogen induced cracking resistance
US4247326A (en) * 1979-08-29 1981-01-27 Inland Steel Company Free machining steel with bismuth
US4255188A (en) * 1979-08-29 1981-03-10 Inland Steel Company Free machining steel with bismuth and manganese sulfide
US4255187A (en) * 1979-08-29 1981-03-10 Inland Steel Company Bismuth-containing steel
US4265660A (en) * 1979-07-03 1981-05-05 Henrik Giflo High-strength free-cutting steel able to support dynamic stresses
US4279646A (en) * 1978-12-25 1981-07-21 Daido Tokushuko Kabushiki Kaisha Free cutting steel containing sulfide inclusion particles with controlled aspect, size and distribution
US4326886A (en) * 1979-03-14 1982-04-27 Daido Tokushuko Kabushiki Kaisha Steel for cold forging having good machinability and the method of making the same
US4434006A (en) 1979-05-17 1984-02-28 Daido Tokushuko Kabushiki Kaisha Free cutting steel containing controlled inclusions and the method of making the same

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2258604A (en) * 1940-05-18 1941-10-14 Int Nickel Co Cast steel

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2258604A (en) * 1940-05-18 1941-10-14 Int Nickel Co Cast steel

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3948649A (en) * 1971-08-04 1976-04-06 Daido Seiko Kabushiki Kaisha Free cutting steel
US3844773A (en) * 1972-05-10 1974-10-29 Kobe Steel Ltd Free cutting steel containing mullite
US3876422A (en) * 1972-05-25 1975-04-08 Inland Steel Co Elongated leaded steel casting
USB289883I5 (en) * 1972-09-18 1975-01-28
US3925063A (en) * 1972-09-18 1975-12-09 Daido Steel Co Ltd Electromagnetic stainless steel having excellent machinability
US4115111A (en) * 1973-11-13 1978-09-19 Daido Tokushuko Kabushiki Kaisha Free-cutting structural steel for machines
US4056387A (en) * 1974-08-14 1977-11-01 Inland Steel Company Leaded steel bar free of lead macroinclusions
US4004922A (en) * 1974-10-11 1977-01-25 Ugine Aciers Free machining steel
US3984238A (en) * 1975-05-14 1976-10-05 Nikolai Nikiforovich Vlasov Steel for metal cord
US4020887A (en) * 1975-05-14 1977-05-03 Nikolai Nikiforovich Vlasov Tires reinforced with steel cord
DE2824803A1 (en) * 1977-06-24 1979-01-18 Acieries De Pompey Neuilly Soc FINE GRAIN STEEL WITH IMPROVED MACHINABILITY
US4210444A (en) * 1977-06-24 1980-07-01 Societe Nouvelle Des Acieries De Pompey Magnesium-free, fine-grained structural steel with improved machinability and workability
US4153454A (en) * 1977-08-12 1979-05-08 Kawasaki Steel Corporation Steel materials having an excellent hydrogen induced cracking resistance
US4279646A (en) * 1978-12-25 1981-07-21 Daido Tokushuko Kabushiki Kaisha Free cutting steel containing sulfide inclusion particles with controlled aspect, size and distribution
US4326886A (en) * 1979-03-14 1982-04-27 Daido Tokushuko Kabushiki Kaisha Steel for cold forging having good machinability and the method of making the same
US4434006A (en) 1979-05-17 1984-02-28 Daido Tokushuko Kabushiki Kaisha Free cutting steel containing controlled inclusions and the method of making the same
US4265660A (en) * 1979-07-03 1981-05-05 Henrik Giflo High-strength free-cutting steel able to support dynamic stresses
US4247326A (en) * 1979-08-29 1981-01-27 Inland Steel Company Free machining steel with bismuth
US4255188A (en) * 1979-08-29 1981-03-10 Inland Steel Company Free machining steel with bismuth and manganese sulfide
US4255187A (en) * 1979-08-29 1981-03-10 Inland Steel Company Bismuth-containing steel

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