CN102978554A - Titanium alloy valve rod preparation method of plug valve - Google Patents

Abstract

The invention discloses a titanium alloy valve rod preparation method of a plug valve. The process comprises a first step of choosing beta titanium alloy with titanium and the molybdenum as a cast object, wherein the content of molybdenum is from 6.5% to 18%. The beta alloy is fused under the temperature higher than 1550 DEG C, and the fused alloy is cast precisely into a valve rod blank piece. Hot isostatic pressure can be carried out when the highest temperature is equal to beta transformation temperature of the titanium and molybdenum alloy and the lowest temperature is 100 DEG C lower than beta transformation temperature. Solution annealing is carried out under the temperature from 700 DEG C to 900 DEG C. The alloy is heated to 650-760 DEG C. The process of heat preservation is carried out for 3-5 hours. When a furnace is cooled to 300 DEG C, the process of the heat preservation is carried out for 4 hours, and then the alloy is heated to 650-760 DEG C. The process of the heat preservation is carried out for 17 hours. The alloy is cooled to 450 DEG C at a speed of 50 DEG C per hour and then at a speed of 20 DEG C per hour, and the beta alloy is cooled to 140 DEG C. Heat treatment and subzero treatment have high production continuity. Material utilization rate is high. The beta alloy is suitable for mass production, and cost is reduced.

Description

A kind of titanium alloy valve rod preparation method of stopcock

Technical field

The present invention relates to a kind of preparation method of stopcock, specifically belong to a kind of titanium alloy valve rod preparation method of stopcock.

Background technology

Stopcock is the rotary valve of closuremember or plunger shape, makes porthole on the valve plug identical with the porthole on the valve body or separate by 90-degree rotation, realizes a kind of valve of opening or closing.

At present, preparation stopcock industry, domestic stopcock all adopts common rapid steel material, or the stainless steel material is by mach valve rod.Compare with powder metallurgy stopcock valve rod, the valve block process velocity that common rapid steel material or the machining of stainless steel material are made is slower, material use efficiency is not high, and powder metallurgical technique is made stopcock, not only material use efficiency is high, and be suitable for producing in enormous quantities, need the powder metallurgy valve rod is carried out a small amount of ground finish before assembling is used, crackle often appears in use procedure.

Summary of the invention

Technical problem to be solved by this invention is for stopcock valve rod Technology present situation, and the titanium alloy valve rod preparation method of a kind of stopcock that a kind of production efficiency is high, manufacturing cost is lower that provides.

The technical solution used in the present invention is as follows:

A kind of titanium alloy valve rod preparation method of stopcock includes following steps:

A, choose that to comprise titanium molybdenum and molybdenum content be that the beta-titanium alloy of 6.5-18% is cast object, at the temperature molten alloy that is higher than 1550 ℃, the valve rod blank is arrived in the molten alloy precision casting, carry out hot isostatic pressing at the most high β-transition temperature in titanium maxter alloy and minimum temperature than low 100 ℃ of β-transition temperature, carry out solution annealing 700-900 ℃ temperature, reheat to 650-760 ℃, be incubated 3-5 hour, stove is chilled to 300 ℃, is incubated 4 hours, reheats to 650-760 ℃, be incubated 17 hours, be cooled to 450 ℃ with 50 ℃/hour, again with 20 ℃/hour, be cooled to 140 ℃;

B, quench treatment: the stopcock valve rod sent into be heated to 850-890 ℃ in the heat treatment furnace, and insulation 2-3 hour; Then, cool off with quenching oil;

C, temper: the stopcock valve rod after will quenching is sent into and is heated to 300-400 ℃ in the tempering stove, insulation 50-70min;

D, sub-zero treatment: with the container of packing into of valve rod after the temper, add liquid nitrogen and carry out sub-zero treatment, the time is 10-12 hour;

E, bonderizing, be 180-200 ℃ with workpiece at showing tremendous enthusiasm closure temperature at normal temperatures, the employing pH value is 8 surface conditioner processing 1min, after dripping most 1-2min, adopt phosphorization agent to process 15-20min, after dripping most 1-2min, adopt clear water to clean 1-2min again, after dripping again most 1-2min, process 0.5-1min valve rod is placed 78-100 ℃ hot water.

In step c, temper: the stopcock valve rod after will quenching is sent into and is heated to 350 ℃ in the tempering stove, insulation 60min.

Compared with prior art, the invention has the advantages that:

Compared with prior art, the inventive method is by the cast operation, and by quenching, tempering, phosphatization, sub-zero treatment, the tensile strength sigma b (MPa) of the stopcock valve rod that obtains: 〉=780, yield strength σ s (MPa): 〉=655, elongation δ 5 (%): 〉=12, relative reduction in area ψ (%): 〉=45, Impact energy Ak v (J): 〉=63, notched bar impact strength α kv (J/cm2): 〉=78 make blank obtain rational distribution, thereby reduced the size of overlap, so that material use efficiency has brought up to 70% from original about 30%, improved 40%, because blank reduces, the equipment hitting power also reduces accordingly, and the life-span that causes mould is brought up to 9000 from original 5000, improves nearly about one times.After the blank properly distributed, because the minimizing of overlap, metal reflow causes the phenomenons such as the sufficient and part of folder dirt and forging part is inabundant to improve.

Embodiment

A kind of titanium alloy valve rod preparation method of stopcock includes following steps:

A, choose that to comprise titanium molybdenum and molybdenum content be that the beta-titanium alloy of 6.5-18% is cast object, at the temperature molten alloy that is higher than 1550 ℃, the valve rod blank is arrived in the molten alloy precision casting, carry out hot isostatic pressing at the most high β-transition temperature in titanium maxter alloy and minimum temperature than low 100 ℃ of β-transition temperature, carry out solution annealing 700-900 ℃ temperature, reheat to 650-760 ℃, be incubated 3-5 hour, stove is chilled to 300 ℃, is incubated 4 hours, reheats to 650-760 ℃, be incubated 17 hours, be cooled to 450 ℃ with 50 ℃/hour, again with 20 ℃/hour, be cooled to 140 ℃;

B, quench treatment: the stopcock valve rod sent into be heated to 850-890 ℃ in the heat treatment furnace, and insulation 2-3 hour; Then, cool off with quenching oil;

C, temper: the stopcock valve rod after will quenching is sent into and is heated to 350 ℃ in the tempering stove, insulation 60min;

D, sub-zero treatment: with the container of packing into of valve rod after the temper, add liquid nitrogen and carry out sub-zero treatment, the time is 10-12 hour;

E, bonderizing, be 180-200 ℃ with workpiece at showing tremendous enthusiasm closure temperature at normal temperatures, the employing pH value is 8 surface conditioner processing 1min, after dripping most 1-2min, adopt phosphorization agent to process 15-20min, after dripping most 1-2min, adopt clear water to clean 1-2min again, after dripping again most 1-2min, process 0.5-1min valve rod is placed 78-100 ℃ hot water.

Claims (2)

1. the titanium alloy valve rod preparation method of a stopcock is characterized in that including following steps:

A, choose that to comprise titanium molybdenum and molybdenum content be that the beta-titanium alloy of 6.5-18% is cast object, at the temperature molten alloy that is higher than 1550 ℃, the valve rod blank is arrived in the molten alloy precision casting, carry out hot isostatic pressing at the most high β-transition temperature in titanium maxter alloy and minimum temperature than low 100 ℃ of β-transition temperature, carry out solution annealing 700-900 ℃ temperature, reheat to 650-760 ℃, be incubated 3-5 hour, stove is chilled to 300 ℃, is incubated 4 hours, reheats to 650-760 ℃, be incubated 17 hours, be cooled to 450 ℃ with 50 ℃/hour, again with 20 ℃/hour, be cooled to 140 ℃;

B, quench treatment: the stopcock valve rod sent into be heated to 850-890 ℃ in the heat treatment furnace, and insulation 2-3 hour; Then, cool off with quenching oil;

C, temper: the stopcock valve rod after will quenching is sent into and is heated to 300-400 ℃ in the tempering stove, insulation 50-70min;

D, sub-zero treatment: with the container of packing into of valve rod after the temper, add liquid nitrogen and carry out sub-zero treatment, the time is 10-12 hour;

E, bonderizing, be 180-200 ℃ with workpiece at showing tremendous enthusiasm closure temperature at normal temperatures, the employing pH value is 8 surface conditioner processing 1min, after dripping most 1-2min, adopt phosphorization agent to process 15-20min, after dripping most 1-2min, adopt clear water to clean 1-2min again, after dripping again most 1-2min, process 0.5-1min valve rod is placed 78-100 ℃ hot water.

2. the titanium alloy valve rod preparation method of stopcock according to claim 1 is characterized in that:

In step c, temper: the stopcock valve rod after will quenching is sent into and is heated to 350 ℃ in the tempering stove, insulation 60min.