CN104131242A - Low-carbon low-alloy steel material and manufacturing method thereof - Google Patents

Abstract

The invention discloses a low-carbon low-alloy steel material and a manufacturing method thereof. The low-carbon low-alloy steel material comprises the following chemical elements by mass: 0.23 to 0.35% of carbon, 0.2 to 0.5% of silicon, 0.08 to 0.085% of manganese, 0.03 to 0.04% of cobalt, 0.25 to 0.3% of copper, 0.35 to 0.4% of molybdenum, 0.003 to 0.004% of cerium, 0.05 to 0.06% of boron, 0.02 to 0.04% of titanium, 0.8 to 0.9% of aluminum, 0.07 to 0.075% of sulfur and 0.06 to 0.08% of phosphorus, with the balance being iron. According to the invention, requirements of alloy steel for impact force and toughness are met through usage of low carbon and low alloying components; the steel material has high hardness, and toughness of the steel material is improved through addition and content controlling of silicon, manganese, cobalt, molybdenum, cerium and titanium so as to prevent generation of cracks and brittle failure of the material during working. Raw materials used in the invention are simple, and cost is low.

Description

A kind of low-carbon and low-alloy steel and manufacture method thereof

Technical field

The present invention relates to a kind of steel alloy and manufacture method thereof, particularly a kind of manufacture method of low-carbon and low-alloy steel.

Background technology

In industries such as mining, metallurgy, cement, potteries, the ore that frequent contact is hard or the equipment of other hard things can be worn, if the contact surface with these ores adopts common iron, will inevitably there is heavy wear, user need often be safeguarded and exchange device more, reduce production efficiency, increased production cost; If adopt high hardness wear-resisting steel alloy, although overcome wear-out defect, its fragility is too strong, be easy to be hit and breakage, and this material is expensive, makes this equipment be difficult to be accepted by factories and miness.

Summary of the invention

The object of the present invention is to provide a kind of manufacture method of low-carbon and low-alloy steel.

The present invention adopts following technical scheme:

Low-carbon and low-alloy steel, chemical element composition and mass percent thereof that it contains are: carbon 0.23-0.35%, silicon 0.2-0.5%, manganese 0.08-0.085%, cobalt 0.03-0.04%, copper 0.25-0.3%, molybdenum 0.35-0.4%, cerium 0.003-0.004%, boron 0.05-0.06%, titanium 0.02-0.04%, aluminium 0.8-0.9%, sulphur 0.07-0.075%, phosphorus 0.06-0.08%, surplus are iron.

The manufacture method of low-carbon and low-alloy steel, comprises the following steps:

(1) batching: in steel alloy mass percent, by following chemical composition batching, cobalt 0.03-0.04%, molybdenum 0.35-0.4%, cerium 0.003-0.004%, boron 0.05-0.06%, titanium 0.02-0.04%, put into smelting furnace melting, be incubated after 20-30 minute, add by mass percentage copper powder and aluminium powder, continue melting 1-2h, tapping temperature is 1240 ℃-1520 ℃; Then pour into alloy block, take out air cooling standby;

(2) ferromanganese and the pig iron are dropped in vacuum induction furnace and melted in 1:3-4 ratio, then add steel scrap, as ferrous substrate, originate; Carry out desulfurization, deoxidation; Then the alloy block that adds step (1), after melting is uniformly mixed, by constitutive material mass percent, add other residue alloying elements wherein again, insulation 20-30 minute, at 1500-1600 ℃ of refining 50-60min, after insulation 20-30min, sample, after analysis ingredient, adjusting component, fusing 15-25min, casting, tapping temperature is 1480-1580 ℃;

(3) thermal treatment: the foundry goods of step (2) casting is first cooled to 600-650 ℃ with 180-200 ℃/h of speed, then is cooled to 480-500 ℃ with 80-100 ℃/h of speed, insulation 70-80 minute; Then carry out quench treatment, the formula of hardening liquid is sodium carbonate 8-10%, saltpetre 1.5-2%, potassium hydroxide 1.5-3%, all the other are distilled water; Quenching temperature is 600-720 ℃, and the cool time is 4-6s.

Beneficial effect of the present invention:

The present invention is by adopting low-carbon (LC) and low alloying composition to guarantee the requirement of steel alloy to anti-impact force and toughness, steel hardness of the present invention is high, simultaneously by adding and the content of controlling silicon, manganese, cobalt, molybdenum, cerium and titanium, improve its toughness, the generation of brittle failure situation when the generation of Crack prevention and work; Raw material of the present invention is simple, and cost is low.

Embodiment

Embodiment 1: low-carbon and low-alloy steel, chemical element composition and mass percent thereof that it contains are: carbon 0.28%, silicon 0.4%, manganese 0.082%, cobalt 0.035%, copper 0.28%, molybdenum 0.38%, cerium 0.0035%, boron 0.055%, titanium 0.03%, aluminium 0.85%, sulphur 0.072%, phosphorus 0.07%, surplus are iron.

The manufacture method of low-carbon and low-alloy steel, comprises the following steps:

(1) batching: in steel alloy mass percent, by following chemical composition batching, cobalt 0.035%, molybdenum 0.38%, cerium 0.0035%, boron 0.055%, titanium 0.03%, put into smelting furnace melting, be incubated after 25 minutes, add by mass percentage copper powder and aluminium powder, continue melting 1-2h, tapping temperature is 1350 ℃; Then pour into alloy block, take out air cooling standby;

(2) ferromanganese and the pig iron are dropped in vacuum induction furnace and melted in 1:3.5 ratio, then add steel scrap, as ferrous substrate, originate; Carry out desulfurization, deoxidation; Then the alloy block that adds step (1), after melting is uniformly mixed, by constitutive material mass percent, add other residue alloying elements wherein again, be incubated 25 minutes, at 1550 ℃ of refining 55min, after insulation 25min, sample, after analysis ingredient, adjusting component, fusing 20min, casting, tapping temperature is 1480 ℃;

(3) thermal treatment: the foundry goods of step (2) casting is first cooled to 620 ℃ with 190 ℃/h of speed, then is cooled to 490 ℃ with 90 ℃/h of speed, be incubated 75 minutes; Then carry out quench treatment, the formula of hardening liquid is sodium carbonate 9%, saltpetre 1.8%, potassium hydroxide 1.8%, all the other are distilled water; Quenching temperature is 650 ℃, and the cool time is 5s.

The present invention manufacture alloy steel material testing data: tensile strength sigma b>=1330MPa; Yield strength σ 0.2>=1148MPa; Unit elongation δ 5 (‰)>=19; Relative reduction in area ψ (‰)>=24; Low-temperature impact toughness σ ku (40 ℃)>=37J/cm ²; Hardness HRC50-55.

Claims (2)

1. a low-carbon and low-alloy steel, is characterized in that: chemical element composition and mass percent thereof that it contains are: carbon 0.23-0.35%, silicon 0.2-0.5%, manganese 0.08-0.085%, cobalt 0.03-0.04%, copper 0.25-0.3%, molybdenum 0.35-0.4%, cerium 0.003-0.004%, boron 0.05-0.06%, titanium 0.02-0.04%, aluminium 0.8-0.9%, sulphur 0.07-0.075%, phosphorus 0.06-0.08%, surplus are iron.

2. a manufacture method for low-carbon and low-alloy steel as claimed in claim 1, is characterized in that comprising the following steps:

(1) batching: in steel alloy mass percent, by following chemical composition batching, cobalt 0.03-0.04%, molybdenum 0.35-0.4%, cerium 0.003-0.004%, boron 0.05-0.06%, titanium 0.02-0.04%, put into smelting furnace melting, be incubated after 20-30 minute, add by mass percentage copper powder and aluminium powder, continue melting 1-2h, tapping temperature is 1240 ℃-1520 ℃; Then pour into alloy block, take out air cooling standby;

(2) ferromanganese and the pig iron are dropped in vacuum induction furnace and melted in 1:3-4 ratio, then add steel scrap, as ferrous substrate, originate; Carry out desulfurization, deoxidation; Then the alloy block that adds step (1), after melting is uniformly mixed, by constitutive material mass percent, add other residue alloying elements wherein again, insulation 20-30 minute, at 1500-1600 ℃ of refining 50-60min, after insulation 20-30min, sample, after analysis ingredient, adjusting component, fusing 15-25min, casting, tapping temperature is 1480-1580 ℃;

(3) thermal treatment: the foundry goods of step (2) casting is first cooled to 600-650 ℃ with 180-200 ℃/h of speed, then is cooled to 480-500 ℃ with 80-100 ℃/h of speed, insulation 70-80 minute; Then carry out quench treatment, the formula of hardening liquid is sodium carbonate 8-10%, saltpetre 1.5-2%, potassium hydroxide 1.5-3%, all the other are distilled water; Quenching temperature is 600-720 ℃, and the cool time is 4-6s.