CN104131230A - Aging-resistant alloy steel for valves and manufacturing method thereof - Google Patents

Abstract

The invention discloses an aging-resistant alloy steel for valves and a manufacturing method thereof. The alloy steel comprises the following chemical elements by mass: 0.42 to 0.58% of carbon, 0.35 to 0.55% of silicon, 0.095 to 0.120% of manganese, 0.02 to 0.032% of nickel, 0.03 to 0.05% of chromium, 0.023 to 0.025% of rhodium, 0.056 to 0.068% of cerium, 0.035 to 0.04% of molybdenum, 0.1 to 0.25% of tungsten, 0.068 to 0.075% of molybdenum, 0.035 to 0.045% of sulfur and no more than 0.03% of phosphorus, with the balance being iron. According to the invention, based on the principles of low alloy and low carbon and through addition of metallic elements consisting of rhodium, cerium, molybdenum, tungsten, molybdenum, etc., combination of a plurality of other raw materials and reasonable setting of a ratio and production process, the formed alloy steel has good comprehensive mechanical properties; since a part of alloy blocks are prepared at first and then refining is carried out to prepare the alloy steel, the interior atomic structure of the alloy steel is enhanced, and the formed alloy steel has the characteristics of high strength, impact resistance, wear resistance and high hot strength; and the alloy steel is applicable to valves, pipelines and impellers of pumps working at high temperature.

Description

The ageing-resistant steel alloy of a kind of valve and manufacture method thereof

Technical field

The present invention relates to a kind of steel alloy and manufacture method thereof, particularly the manufacture method of the ageing-resistant steel alloy of a kind of valve.

Background technology

The environment of pump valve work is various, badly, very high to the requirement of material, the steel alloy that pump valve is used at present has varied, technology has very much progress, but still have a lot of problems to exist, as wear resistance, hardness, rustless property, corrosion resistance nature, high and low temperature resistance, fragility, toughness etc., in a lot of occasions, can't meet the requirement of production, also require further improvement, to enhance productivity, reduce costs, improve security, for high-quality precision and sophisticated technology development provides safeguard, for social development provides power, task is also very arduous.

Summary of the invention

The object of the present invention is to provide the manufacture method of the ageing-resistant steel alloy of a kind of valve.

The present invention adopts following technical scheme:

The ageing-resistant steel alloy of valve, chemical element composition and mass percent thereof that it contains are: carbon 0.42-0.58%, silicon 0.35-0.55%, manganese 0.095-0.120%, nickel 0.02-0.032%, chromium 0.03-0.05%, rhodium 0.023-0.025%, cerium 0.056-0.068%, molybdenum 0.035-0.04%, tungsten 0.1-0.25%, molybdenum 0.068-0.075%, sulphur 0.35-0.45%, phosphorus≤0.03%, surplus are iron.

The manufacture method of the ageing-resistant steel alloy of valve, comprises the following steps:

(1) by the mass percent of chemical element composition, take nickel powder, manganese powder and tungsten powder; Fully mix, add in appropriate kerosene, send into ball milling in ball mill, obtain 200-400 order powder, then, spraying is dry, oven dry, under 8-10Mpa pressure, be pressed into bulk, then under nitrogen protection atmosphere 550-600 ℃ carry out sintering 4-6 hour, by crossing 200-400 mesh sieve after the crushing material after sintering, standby;

(2) ferrochrome is pressed and waited 2:3 to mix with siliceous 50% ferrosilicon, then add steel scrap, be smelted into molten steel, at 1650 ℃-1680 ℃, adding successively weight is borax deoxidizer and the 0.03-0.05% Fluorspar Powder of the 0.5-1% of ferrosilicon total amount, is uniformly mixed;

(3) in step (2), add the standby material of step (1), after melting is uniformly mixed, by constitutive material mass percent, add other residue alloying elements, insulation 20-30 minute, then sampling wherein again, after analysis ingredient, adjusting component, fusing 25-35min, casting, tapping temperature is 1340-1480 ℃, is cooled to room temperature.

Beneficial effect of the present invention:

The present invention is with low-alloy, low-carbon (LC) principle, by adding metallic element and multiple other material combination such as rhodium, cerium, molybdenum, tungsten, molybdenum, proportioning and production technique are rationally set, the alloy material forming has good comprehensive mechanical property, the present invention first makes alloy part piece, then makes steel alloy by refining, strengthens the inner atomic structure of steel alloy, the alloy forming has high strength, shock-resistant, wear-resisting, the strong high feature of heat, is applicable to valve, pipeline, the impeller of high-temperature service pump.

Embodiment

Embodiment 1: the ageing-resistant steel alloy of valve, chemical element composition and mass percent thereof that it contains are: carbon 0.55%, silicon 0.45%, manganese 0.098%, nickel 0.03%, chromium 0.04%, rhodium 0.024%, cerium 0.06%, molybdenum 0.038%, tungsten 0.15%, molybdenum 0.072%, sulphur 0.4%, phosphorus≤0.03%, surplus are iron.

The manufacture method of the ageing-resistant steel alloy of valve, comprises the following steps:

(1) by the mass percent of chemical element composition, take nickel powder, manganese powder and tungsten powder; Fully mix, add in appropriate kerosene, send into ball milling in ball mill, obtain 300 order powder, then, spraying is dry, oven dry, under 8-10Mpa pressure, be pressed into bulk, then under nitrogen protection atmosphere 580 ℃ carry out sintering 5 hours, by crossing 300 mesh sieves after the crushing material after sintering, standby;

(2) by ferrochrome and siliceous 50% ferrosilicon by waiting 2:3 to mix, then add steel scrap, be smelted into molten steel, at 1670 ℃, adding successively weight is 0.8% borax deoxidizer and 0.04% Fluorspar Powder of ferrosilicon total amount, is uniformly mixed;

(3) in step (2), add the standby material of step (1), after melting is uniformly mixed, by constitutive material mass percent, add other residue alloying elements wherein again, be incubated 25 minutes, then sampling, after analysis ingredient, adjusting component, fusing 30min, casting, tapping temperature is 1400 ℃, is cooled to room temperature.

The present invention manufacture alloy steel material testing data: tensile strength sigma b>=1328MPa; Yield strength σ _0.2>=1090MPa; Impact absorbing energy 61J, low-temperature impact toughness σ ku (40 ℃)>=43.2J/cm ²; Hardness HRC 54-58.

Claims (2)

1. the ageing-resistant steel alloy of valve, is characterized in that: chemical element composition and mass percent thereof that it contains are: carbon 0.42-0.58%, silicon 0.35-0.55%, manganese 0.095-0.120%, nickel 0.02-0.032%, chromium 0.03-0.05%, rhodium 0.023-0.025%, cerium 0.056-0.068%, molybdenum 0.035-0.04%, tungsten 0.1-0.25%, molybdenum 0.068-0.075%, sulphur 0.35-0.45%, phosphorus≤0.03%, surplus are iron.

2. a manufacture method for the ageing-resistant steel alloy of valve as claimed in claim 1, is characterized in that comprising the following steps:

(1) by the mass percent of chemical element composition, take nickel powder, manganese powder and tungsten powder; Fully mix, add in appropriate kerosene, send into ball milling in ball mill, obtain 200-400 order powder, then, spraying is dry, oven dry, under 8-10Mpa pressure, be pressed into bulk, then under nitrogen protection atmosphere 550-600 ℃ carry out sintering 4-6 hour, by crossing 200-400 mesh sieve after the crushing material after sintering, standby;

(2) ferrochrome is pressed and waited 2:3 to mix with siliceous 50% ferrosilicon, then add steel scrap, be smelted into molten steel, at 1650 ℃-1680 ℃, adding successively weight is borax deoxidizer and the 0.03-0.05% Fluorspar Powder of the 0.5-1% of ferrosilicon total amount, is uniformly mixed;

(3) in step (2), add the standby material of step (1), after melting is uniformly mixed, by constitutive material mass percent, add other residue alloying elements, insulation 20-30 minute, then sampling wherein again, after analysis ingredient, adjusting component, fusing 25-35min, casting, tapping temperature is 1340-1480 ℃, is cooled to room temperature.