Method for manufacturing superior 13Cr tool coupler

Abstract

The present invention discloses a method for manufacturing a superior 13Cr tool coupler, which method comprises the following steps: manufacturing a blank; forging the blank; heating the forged blank to 600-700° C. for a stress-relief annealing; quenching; and tempering. The present technical solution can produce a superior 13Cr tool coupler which achieves a mechanic feature of 110 ksi.

Claims

1. A method for manufacturing a 13Cr tool coupler, wherein the 13Cr tool coupler consists essentially of 0.01-0.05 wt % carbon, 0.25-0.42 wt % silicon, 0.2-1.0 wt % manganese, 12-14 wt % chromium, 1-3 wt % molybdenum, 4-6 wt % nickel, and a balance of iron and inevitable impurities, the method consisting of: (1) manufacturing a blank; (2) forging the blank and cooling the blank after forging; (3) annealing the forged blank at 600-700° C. to relieve stress; (4) rough machining the blank; (5) heating the rough machined blank, and then quenching the same in an oil tank; and (6) tempering the quenched blank; wherefrom the 13Cr tool coupler is manufactured, wherein the manufactured 13Cr tool coupler has a yield strength from 835 MPa to 915 MPa and a tensile strength from 928 MPa to 1020 MPa, and wherein the manufactured 13Cr tool coupler has a tempered martensitic structure.

2. The method of claim 1, wherein the manufactured blank is forged at a temperature ranging from 1150-1200° C.

3. The method of claim 1, wherein the rough machined blank is heated to a temperature ranging from 950-1000° C.

4. The method of claim 1, wherein the quenched blank is tempered at a temperature ranging from 600-650° C.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) The method for manufacturing a superior 13Cr tool coupler according to the present invention is described below in more details, in conjunction with particular embodiments.

Embodiments 1-5

(2) A superior 13Cr tool coupler is manufactured in the following steps:

(3) (1) obtaining a blank, with the chemical composition thereof in percentage by weight being controlled to be: C 0.01-0.05%, Si≤0.5%, Mn 0.2-1.0%, Cr 12-14%, Mo 1-3%, Ni 4-6%, and a balance of Fe and inevitable impurities;

(4) (2) forging the blank at 1150-1200° C.;

(5) (3) heating the forged blank to 600-700° C. for a stress-relief annealing;

(6) (4) rough machining the blank;

(7) (5) after heating the rough machined blank to 950-1000° C., quenching and cooling same in an oil tank; and

(8) (6) tempering, with the tempering temperature being controlled at 600-650° C.

(9) The composition formulations of the tool couplers in embodiments 1-5 of the present application are shown in table 1.

(10) Table 1 (wt %, with a balance of Fe and other inevitable impurities)

(11) TABLE-US-00001 TABLE 1 Type of Steel C Si Mn Cr Mo Ni Embodiment 1 0.04 0.27 0.92 13.9 1.8 5.8 Embodiment 2 0.03 0.28 0.70 12.8 2.7 4.1 Embodiment 3 0.02 0.34 0.40 12.3 1.1 4.9 Embodiment 4 0.03 0.42 0.52 12.5 1.9 5.5 Embodiment 5 0.04 0.25 0.65 13.7 2.5 4.5

(12) Process parameters of the steps and mechanic performance of the tool couplers in embodiments 1-5 of the present application are listed in table 2.

(13) TABLE-US-00002 TABLE 2 Heating Stress-relief temperature annealing Quenching Tempering Yield Tensile for forging, temperature, temperature, temperature, strength, strength, Type of Steel ° C. ° C. ° C. ° C. MPa MPa Embodiment 1 1160 680 960 640 835 928 Embodiment 2 1180 650 970 630 851 939 Embodiment 3 1190 620 980 620 883 965 Embodiment 4 1175 660 975 610 915 1020 Embodiment 5 1170 640 990 632 845 938

(14) It can be seen from table 2 that the superior 13Cr tool coupler manufactured by the method according to the present technical solution can achieve a mechanic feature of above 110 ksi.

(15) It should be noted that what are set forth above are only particular embodiments of the present invention, and that clearly the present invention is not to be limited to these embodiments, but covers many similar variations thereof. All of the variations either directly derived from or associated with the disclosure of the present invention by those skilled in the art will fall into the protective scope of the present invention.