Novel steel material for automobile rotation shaft

Abstract

Compared with domestic steel W6Mo5Cr4V2, the steel material of the present invention replaces a large amount of molybdenum with chromium, which saves the usage of molybdenum, and also reduces the usage of vanadium and tungsten, thereby reducing the production cost of alloy steel; adding non-carbide elements Nickel improves the strength of steel through solid solution strengthening, and at the same time has high plasticity and toughness, and strongly increases the hardenability of steel, and the addition of cobalt greatly improves the hot hardness and cutting performance of alloy steel; adding The carbide forming element niobium increases the toughness of the steel and improves the processability of hot working. The content of P and S in the present invention is very low (especially P), so the purity of the steel is particularly good, and it plays a role in guaranteeing various properties of the steel. The annealed Brinell hardness of the steel reaches HB250. Therefore, the steel of the invention has high thermal hardness and cutting performance, and also has high toughness and wear resistance. However, the material cost is much lower than the domestic steel W6Mo5Cr4V2, which is suitable for making various vehicle shafts.

Description

technical field

[0001] The invention relates to a new type of steel used for the rotating shaft of automobiles. Background technique

[0002] The existing steel materials used for the rotating shaft of automobiles are generally made of domestic steel W6Mo5Cr4V2. The chemical composition of the alloy is (weight%): C0.80%~0.90%, Si≤0.45%, Mn≤0.40%, W5.50%~6.75 %, Mo4.50%~5.50%, Cr3.80%~4.40%, V1.75%~2.15%, S≤0.03%, P≤0.03%, and the rest is Fe. This steel contains a relatively high content of Mo. Now due to the lack of Mo in the international market, the price is relatively expensive, and the content of tungsten and vanadium in this steel is also high, so the cost of producing the alloy is also greatly increased. The Chinese invention patent (the notification number is CN1014081) discloses low-alloy high-performance steel, which is characterized in that the specific chemical composition of the steel is (weight %) C0.85% ~ 1.05%, W3.0% ~ 5.0%, Mo2. 0%~3.5%, Cr3.5%~5.0%, V1.15%...

Examples

Embodiment 1

[0019] A new type of steel used for the rotating shaft of automobiles, the steel includes: carbon C0.9%-1.2%, silicon Si0.21%-0.5%, manganese Mn0.18%-0.3%, chromium Cr9.5 %~12.0%, tungsten W4%~4.8%, molybdenum Mo0.55%~2.2%, vanadium V0.5%~2.2%, nickel Ni0.05%~0.2%, cobalt Co0.25%~4.0%, niobium Nb0 .7~2%, sulfur S≤0.01%, phosphorus P≤0.01%, and the balance is iron Fe.

[0020] The heat treatment process for the above-mentioned novel chromium steel series steel includes the following steps:

[0021] (1), the first preheating, the temperature is 600 ℃, and the preheating time is 60 minutes;

[0022] (2), the second preheating, the temperature is 900 ℃, and the preheating time is 45 minutes;

[0023] (3) Quenching heating, the quenching heating temperature is 1150°C-1240°C, the quenching time is: (25+material thickness / 2) minutes, and then oil-cooled to 250°C-270°C;

[0024] (4) For the first tempering, the tempering temperature is 500°C to 550°C, the tempering time is 110 minu...

Embodiment 2

[0028] A new type of steel used for the rotating shaft of automobiles. The steel includes: carbon C0.95%~1.0%, silicon Si0.25%~0.35%, manganese Mn0.22%~0.3%, chromium Cr10%~ 11%, tungsten W4%~4.3%, molybdenum Mo0.6%~1%, vanadium V0.6%~1.5%, nickel Ni0.1%~0.15%, cobalt Co1%~1.4%, niobium Nb0.9~1.5% %, sulfur S≤0.005%, phosphorus P≤0.005%, and the balance is iron Fe.

[0029] The heat treatment process for the above-mentioned novel chromium steel series steel includes the following steps:

[0030] (1), the first preheating, the temperature is 600 ℃, and the preheating time is 60 minutes;

[0031] (2), the second preheating, the temperature is 900 ℃, and the preheating time is 45 minutes;

[0032] (3) Quenching heating, the quenching heating temperature is 1150℃~1240℃, the quenching time is: (25+material thickness / 2) minutes, then cooling in salt bath, grading heat preservation at 650℃, and then salt bath to 250℃~270℃ ;

[0033] (4) For the first tempering, the tempering temp...

technical field

[0001] The invention relates to a new type of steel used for the rotating shaft of automobiles. Background technique

[0002] The existing steel materials used for the rotating shaft of automobiles are generally made of domestic steel W6Mo5Cr4V2. The chemical composition of the alloy is (weight%): C0.80%~0.90%, Si≤0.45%, Mn≤0.40%, W5.50%~6.75 %, Mo4.50%~5.50%, Cr3.80%~4.40%, V1.75%~2.15%, S≤0.03%, P≤0.03%, and the rest is Fe. This steel contains a relatively high content of Mo. Now due to the lack of Mo in the international market, the price is relatively expensive, and the content of tungsten and vanadium in this steel is also high, so the cost of producing the alloy is also greatly increased. The Chinese invention patent (the notification number is CN1014081) discloses low-alloy high-performance steel, which is characterized in that the specific chemical composition of the steel is (weight %) C0.85% ~ 1.05%, W3.0% ~ 5.0%, Mo2. 0%~3.5%, Cr3.5%~5.0%, V1.15%...

Examples

Embodiment 1

[0019] A new type of steel used for the rotating shaft of automobiles, the steel includes: carbon C0.9%-1.2%, silicon Si0.21%-0.5%, manganese Mn0.18%-0.3%, chromium Cr9.5 %~12.0%, tungsten W4%~4.8%, molybdenum Mo0.55%~2.2%, vanadium V0.5%~2.2%, nickel Ni0.05%~0.2%, cobalt Co0.25%~4.0%, niobium Nb0 .7~2%, sulfur S≤0.01%, phosphorus P≤0.01%, and the balance is iron Fe.

[0020] The heat treatment process for the above-mentioned novel chromium steel series steel includes the following steps:

[0021] (1), the first preheating, the temperature is 600 ℃, and the preheating time is 60 minutes;

[0022] (2), the second preheating, the temperature is 900 ℃, and the preheating time is 45 minutes;

[0023] (3) Quenching heating, the quenching heating temperature is 1150°C-1240°C, the quenching time is: (25+material thickness / 2) minutes, and then oil-cooled to 250°C-270°C;

[0024] (4) For the first tempering, the tempering temperature is 500°C to 550°C, the tempering time is 110 minu...

Embodiment 2

[0028] A new type of steel used for the rotating shaft of automobiles. The steel includes: carbon C0.95%~1.0%, silicon Si0.25%~0.35%, manganese Mn0.22%~0.3%, chromium Cr10%~ 11%, tungsten W4%~4.3%, molybdenum Mo0.6%~1%, vanadium V0.6%~1.5%, nickel Ni0.1%~0.15%, cobalt Co1%~1.4%, niobium Nb0.9~1.5% %, sulfur S≤0.005%, phosphorus P≤0.005%, and the balance is iron Fe.

[0029] The heat treatment process for the above-mentioned novel chromium steel series steel includes the following steps:

[0030] (1), the first preheating, the temperature is 600 ℃, and the preheating time is 60 minutes;

[0031] (2), the second preheating, the temperature is 900 ℃, and the preheating time is 45 minutes;

[0032] (3) Quenching heating, the quenching heating temperature is 1150℃~1240℃, the quenching time is: (25+material thickness / 2) minutes, then cooling in salt bath, grading heat preservation at 650℃, and then salt bath to 250℃~270℃ ;

[0033] (4) For the first tempering, the tempering temp...