TWI761253B - High-strength maraging steel plate and method for manufacturing the same - Google Patents

Abstract

A method for manufacturing a maraging steel plate includes: performing a smelting process; performing a forging process; performing a rolling process; and performing a solution treatment, a cryogenic treatment, and an aging treatment on the plate after the rolling process to complete a stainless steel plate; wherein the stainless steel plate includes: 16~19wt% nickel, 8~10wt% cobalt, 5.5~7.0wt% molybdenum, 0.4~1.4wt% titanium, 0.05~0.3wt% chromium, 0.05~0.2wt% aluminum, 0.05~0.1wt% silicon, balance iron, and unavoidable impurities. The advantage of the stainless steel sheet of the present invention is a new low-cost hemp-aged steel alloy. After proper solution, cryogenic and aging environment, the tensile strength is 275~320 KSI and the yield strength is 264~315 KSI. It has good comprehensive mechanical properties and can be used as a structural material for golf club heads.

Description

High-strength hemp-aged steel sheet and its manufacturing method

The present invention relates to a hemp-aging steel sheet and a manufacturing method thereof, and in particular, to a high-strength hemp-aging steel sheet for golf club heads and a manufacturing method thereof.

During the development of golf club heads, from the early solid wood to the current hollow heads using metal materials, the overall strength is getting higher and higher and the weight can be reduced, and even the pursuit of high moment of inertia (MOI, moment of inertia) and high coefficient of restitution (COR, coefficient of restitution), to improve the success rate of hitting the ball and the distance the ball flies. Today's mainstream metal materials can be combined with different processing methods and alloying elements to create the best ball with more control, precision, long distance and higher error tolerance.

On the other hand, iron-based alloys are also used in the field of golf club heads. In recent years, the design of iron alloy golf club heads has gradually emphasized the development and design of golf club heads with high characteristic time (CT, characteristic time), mainly to increase the spring effect of the hitting surface as the main design concept to increase the hitting distance.

However, regarding the material of the existing iron-based alloy club head, a suitable material composition has not been found to increase the spring effect of the striking surface, thereby increasing the hitting distance. There are many ways to increase the spring effect of the striking surface. Among them, reducing the thickness of the striking surface is a common method in the industry. This method requires the striking surface to be matched with high strength, wear resistance and ductility.

Existing composition alloys for making golf club heads, such as patent application No. TW200630141 (stainless steel alloy for golf club heads), discloses an alloy comprising 0.08-0.15% carbon, 0.5-1.5% silicon, 0.4% manganese in weight percentages. ~1.2%, copper below 0.55%, nickel 3.5~6.0%, chromium 13.5~17.0%, molybdenum 1.5~2.6%, nitrogen 0.07~0.13%, and the rest are iron alloy materials (hereinafter referred to as existing stainless steel alloys). According to the description on page 9 of the specification of the golf club head made by the above alloy ratio, its tensile strength is about 216.8~219.1KSI (1495.8~1511.7MPa), and its yield strength is about 175.7~180.7KSI (1212.36~1247MPa). Its overall strength is still insufficient, which in turn causes the golf club head to have the disadvantage of being easily deformed.

Therefore, there is a need to provide a high-strength hemp-aging steel sheet for golf club heads and a manufacturing method thereof to solve the problems existing in the prior art.

One object of the present invention is to provide a high-strength hemp-aging steel sheet and a manufacturing method thereof.

According to the above-mentioned purpose, the present invention provides a method for manufacturing a hemp-aging steel sheet, comprising the following steps: ), aluminum (Al), and silicon (Si) materials are subjected to a smelting process to form an ingot; a forging process is performed on the ingot to form a slab; a rolling process is performed on the slab to form a sheet; and performing a solution treatment, a cryogenic treatment and an aging treatment on the sheet after the rolling process to complete a hemp-aging steel sheet: wherein the hemp-aging steel sheet includes the following components: 16-19wt% nickel ( Ni), 8~10wt% cobalt (Co), 5.5~7.0wt% molybdenum (Mo), 0.4~1.4wt% titanium (Ti), 0.05~0.3wt% chromium (Cr), 0.05~0.2wt% % aluminum (Al), 0.05~0.1wt% silicon (Si), balanced amount of iron (Fe), and inevitable impurities.

The present invention further provides a hemp-aging steel sheet, calculated with a total weight of 100wt%, the hemp-aging steel sheet includes the following components: 16-19wt% of nickel (Ni), 8-10wt% of cobalt (Co), 5.5-7.0 wt% molybdenum (Mo), 0.4~1.4wt% titanium (Ti), 0.05~0.3wt% chromium (Cr), 0.05~0.2wt% aluminum (Al), 0.05~0.1wt% silicon (Si) ), a balanced amount of iron (Fe), and unavoidable impurities.

The advantage of the hemp-aged steel sheet of the present invention is that it is a new low-cost hemp-aged steel alloy, which has good comprehensive mechanical properties after proper solution, cryogenic and aging environments, and can be used as a structural material for golf club heads. , and can be processed by hot and cold; it has good corrosion resistance in high chlorine environment, and is the best material for golf club heads.

S100: Steps

S200: Steps

S210: First forging step

S220: Second forging step

S230: The third forging step

S240: Fourth forging step

S250: Steps

S300: Steps

S310: The first hot rolling step

S320: Second hot rolling step

S330: The third hot rolling step

S340: Fourth hot rolling step

FIG. 1 is a schematic flow chart of a method for manufacturing an aged steel sheet according to an embodiment of the present invention.

FIG. 2 is a schematic flow chart of the forging process of the present invention.

FIG. 3 is a schematic flow chart of the rolling process of the present invention.

Figures 4a and 4b are metallographic images of the hemp-aging steel sheet after solution treatment + cryogenic treatment + aging treatment according to an embodiment of the present invention (SEM photos - 500 and 1000 times).

Figures 5a and 5b are metallographic images (SEM scanning electron micrograph - 5000 times) of an aged steel sheet according to an embodiment of the present invention, which show Ni3Ti precipitates.

FIG. 6 is a metallographic diagram (SEM scanning electron microscope photo-5000 times) of a hemp-aging steel sheet according to an embodiment of the present invention, which shows Ni ₃ Mo precipitates.

In order to make the above objects, features and characteristics of the present invention more obvious and easy to understand, the relevant embodiments of the present invention are described in detail as follows in conjunction with the drawings.

FIG. 1 is a schematic flowchart of a method for manufacturing a titanium alloy sheet according to an embodiment of the present invention. The manufacturing method of the titanium alloy plate comprises the following steps:

FIG. 1 is a schematic flowchart of a method for manufacturing a hemp-aged steel sheet for golf club heads according to an embodiment of the present invention. The hemp-aging steel sheet is a high-strength Fe-Ni-based maraging steel. The method for manufacturing the hemp-aging steel sheet comprises the following steps:

In step S100, a material containing iron (Fe), nickel (Ni), cobalt (Co), molybdenum (Mo), titanium (Ti), chromium (Cr), aluminum (Al), and silicon (Si) is subjected to a Melting process to form a hemp-aged steel ingot. For example, vacuum arc consumable smelting using industrial pure iron, electrolytic nickel, electrolytic cobalt, ferromolybdenum, pure aluminum bar, sponge titanium, ferrochrome alloy, and ferrosilicon as raw materials. The smelting adopts a vacuum induction furnace, and materials containing silicon (Si), iron (Fe), cobalt (Co), nickel (Ni) and molybdenum (Mo) are added to the crucible, and materials containing aluminum (Al), titanium (Ti) and chromium ( Cr) material is put into the hopper and smelted by the usual smelting process, but at the end of the refining period, after alloying, it is filled with argon (Ar) gas, and then stirred with electricity and evacuated for 1~2 minutes, and the vacuum degree reaches 10 ^-2 mmHg Above, the temperature reaches about 1600 ℃, and the power is cut to tap. Oxides, sulfides and oxysulfides float to the surface of molten steel or adhere to the crucible wall in the form of slag, and are removed during tapping, thus achieving the purpose of purifying steel. Add 0.1% of ferrovanadium and ferroniobium, so that vanadium (V) and niobium (Nb) finally remain in the steel alloy, accounting for 0.003~0.08%, and they are fine compound particles, which have the effect of refining grains, and the results are greatly improved. The impact toughness, strength and fatigue limit of hemp-aging steel alloys are also improved. After the refining period, a small amount of carbon (C) is added to the crucible, and the carbon has a strong affinity with oxygen (O 2 ) and sulfur (S) in the molten steel to further remove oxygen (O ₂ ) and sulfur (S) in the steel alloy. Sulfur (S), purification of molten steel, steel purification. At the same time, control the way of adding it, power supply stirring, power failure and other processes, so that 0.0035~0.03% of carbon (C) remains in the steel alloy, which increases the fluidity and subcooling of the molten steel, increases the non-spontaneous core during ingot casting, and makes the steel ingot. grain refinement. The low content of solid solution supersaturated carbon with moderate lattice distortion results in maintaining high tensile strength while increasing the impact toughness and fatigue strength limit of the steel alloy.

After the components of the steel alloy are proportioned according to the design quality, they are smelted in a vacuum consumable smelting furnace. The number of smelting is 3 times. is 220mm. The ingot production process is as follows: material picking → material mixing → cloth → pressing electrode → electrode group welding → smelting → ingot processing, analysis and inspection → storage. Ingots with a diameter of Φ220mm are smelted according to the determined process route, alloying method and the formulated trial production plan. After the surface contamination layer and subcutaneous pore defects are removed from the ingot, the chemical composition and gas analysis samples are taken at a distance of 50mm from the riser and bottom of the ingot. Using standard methods, component testing was completed, and the results are shown in Table 1. It can be seen that the main elements and impurity elements in the ingot meet the requirements of trial production, and the composition control has achieved the expected goal.

In step S200, a forging process is performed on the ingot to form a slab. For example, the forging equipment used is an 800-ton fast forging machine, and the temperature control accuracy of the heating furnace is ±10°C. FIG. 2 is a schematic flow chart of the forging process of the present invention. The forging process includes: performing a first forging step S210, billet opening: at a heating temperature of 1180±10°C, performing an upsetting process on the ingot Elongation, air cooling after forging, and grinding to remove surface oxide scale and cracks to form a blank; a second forging step S220 is performed, the blank is forged: at a heating temperature of 1000±10°C, the first forging is performed. After the forging step S210, the blank is subjected to one upsetting and one drawing, air cooling after forging, and grinding to remove the surface oxide scale and grinding to remove cracks; a third forging step S230 is performed, the blank is forged: the heating temperature is between 960±10°C , the blank after the second forging step S220 is subjected to one upsetting and one drawing, air cooling after forging, and grinding to remove the surface oxide scale and grinding cracks; a fourth forging step S240 is performed, the blank is forged: at a heating temperature of 900 ℃ Between ±10°C, the blank after the third forging step S230 is subjected to one upsetting and one drawing, and then returned to the furnace after forging; and in step S250, the blank after the fourth forging step is unidirectionally pressed and surrounded by Alternating operations for shaping and forging into slabs with dimensions of 400mmx300mmx60mm.

In step S300, a rolling process is performed on the slab to form a plate. For example, sheet rolling is done using a small rolling mill with a roll width of 400 mm. The slab is heated by a high-temperature box-type resistance furnace and rolled on the rolling mill of the hot-rolling test unit. Use a digital potentiometer to calibrate the temperature of the box-type resistance furnace to ensure that the temperature deviation is ±10°C.

FIG. 3 is a schematic flow chart of the rolling process of the present invention. In this embodiment, the rolling process (ie, the rolling method) includes: performing a first hot rolling step S310 : rolling the slab at a heating temperature of 1000±100° C. to make the slab The original thickness is reduced to the first thickness, such as δ 60mm→δ 30mm; a second hot rolling step S320 is performed: at a heating temperature of 850±50°C, the slab after the first heat treatment step S310 is rolled, Reduce the first thickness of the slab to the second thickness, such as δ 30mm→δ 15mm; perform a third hot rolling step S330 : at a heating temperature of 1000±100° C., the plate after the second heat treatment step S320 Water quenching is performed on the blank, for example, water quenching for 30 minutes; and a fourth hot rolling step S340 is performed: at a heating temperature of 850±50° C., reverse rolling is performed on the blank after the third heat treatment step S330, so that the The second thickness of the slab is reduced to the first Three thicknesses, eg δ 15mm→δ 4±0.6mm, to form the sheet.

保溫時間

8小時，然後在空氣中升到室溫；時效處理(回火處理)：加熱到430~550℃，保溫2~5小時，空冷。除了鈷之外，加入的合金元素都降低Ms點，但可保持Mf點高於室溫，這樣固溶化後淬冷下來都能完全轉化為馬氏體。時效析出硬化相主要是小片狀Ni₃Mo，鈷的作用是加強Ni₃Mo引起析出硬化，鉬是主要時效硬化的主要元素。 In step S400, a solution treatment, a cryogenic treatment and an aging treatment are performed on the plate after the rolling process to complete a hemp-aged steel plate product. For example, the final heat treatment process after the rolling process includes solution treatment at a temperature of 800°C to 900°C for 1 to 2 hours, cryogenic treatment at a temperature of -40 to 80°C for 2 to 8 hours, and The aging treatment is performed at a temperature of 430-550° C. for 2-5 hours to complete the hemp-aged steel sheet product. In detail, solution treatment: heat to 830±15℃, hold for 1 hour after heat penetration, oil quenching; or air cooling, or vacuum heat treatment with inert gas, followed by cryogenic treatment, at -73℃, 2 hours

holding time

8 hours, then rise to room temperature in the air; aging treatment (tempering treatment): heat to 430~550℃, keep warm for 2~5 hours, and cool in air. Except for cobalt, the added alloying elements all reduce the Ms point, but can keep the Mf point higher than room temperature, so that it can be completely transformed into martensite after solid solution quenching. The aging precipitation hardening phase is mainly flake Ni ₃ Mo. The role of cobalt is to strengthen Ni ₃ Mo and cause precipitation hardening. Molybdenum is the main element of aging hardening.

The hemp-aging steel sheet includes the following components: 16-19wt% of nickel (Ni), 8-10wt% of cobalt (Co), 5.5-7.0wt% of molybdenum (Mo), 0.4-1.4wt% of titanium (Ti) , 0.05~0.3wt% of chromium (Cr), 0.05~0.2wt% of aluminum (Al), 0.05~0.1wt% of silicon (Si), balanced amount of iron (Fe), and inevitable impurities (such as O , N, S, C, etc.), as shown in Table 2.

As described above, the hemp-aging steel sheet of the present invention can further add 0.1% of V-iron and Nb-iron to various raw materials required for Fe-Ni-based maraging steel containing Co, Mo, Ti, Cr, Al, and Si , and 0.003~0.083% of Nb and V compounds remain in the alloy. Due to the high purity of the steel and the refinement of the grains, the tensile strength, fatigue strength, and especially the impact toughness are higher than those of the prior art. The hemp-aging steel sheet of the present invention obtains Fe-Ni-based maraging steel with tensile strength of 275-320 KSI and yield strength of 264-315 KSI, which meets the requirements of golf club heads, as shown in Table 3.

According to the third embodiment of the present invention, the material properties of the hemp-aging steel sheet are as follows: the final heat treatment process after the rolling process of the present invention is in a high-temperature vacuum environment of 830°C, and then after deep cooling to -73°C, by The aging effect at 480℃ makes the hemp-aging steel sheet reach the best strength index; the tensile strength TS is 320KSI, the yield strength YS is 315KSI, the elongation EL is 6.5%, and the hardness is HRC 56. Figures 4a and 4b are metallographic diagrams of the hemp-aging steel sheet after solution treatment + cryogenic treatment + aging treatment according to an embodiment of the present invention.

Adding 16.0-19.0wt% nickel to the steel alloy material can increase the corrosion resistance and oxidation resistance of the alloy material, and stabilize the FCC phase of the alloy material. Nickel has a positive effect on improving the toughness of steel. The nickel in Matian loose iron aging steel can promote the aging precipitation of Ni ₃ . When the nickel content is low, Ni ₃ Ti is confined to grain boundaries and laths only. At 18%, Ni ₃ Ti can be found on grain boundaries and laths. Figures 5a and 5b are metallographic images of an aged steel sheet according to an embodiment of the present invention, which show Ni3Ti precipitates.

Adding 8~10wt% of cobalt to the steel alloy material makes the hemp-aging steel alloy obtain higher tensile strength and yield strength.

Adding 5.5-7.0wt% molybdenum to the steel alloy material can further improve the high temperature strength, creep strength and high temperature hardness of the hemp-aging steel alloy, and relatively increase the wear resistance and strength of the golf club head produced. The addition of molybdenum may cause the precipitation of Fe ₂ Mo and Ni ₃ Mo, which can increase the strength without reducing the toughness. Molybdenum can form Ni ₃ Mo intermetallic compounds with nickel, strengthen the matrix, and inhibit P and S in the hemp-aging steel alloy. 6 is a metallographic diagram of a hemp-aging steel sheet according to an embodiment of the present invention, which shows Ni ₃ Mo precipitates.

Adding 0.4~1.4wt% of titanium to steel alloy material, titanium can improve the strength of hemp-aging steel alloy by forming Ni ₃ Ti, and the strength and toughness have a significant effect. When the titanium content exceeds 2.0%, the toughness drops sharply. If it does not reach 0.4%, not only the strength does not meet the requirements, but also the effect is reduced during the sintering process, thereby promoting the softening of timeliness (over-aging). Therefore, the titanium content is kept at 0.4~1.4%.

Add 0.05~0.3wt% of chromium to the steel alloy material to ensure the corrosion resistance of the hemp-aging steel alloy.

Adding 0.05-0.2wt% aluminum to the steel alloy material can form a dense Ai ₂ O ₃ oxide film on the surface of the steel, thereby improving the corrosion resistance of the hemp-aging steel alloy.

Adding 0.05~0.1wt% of silicon to the steel alloy material can prevent the formation of pores, enhance the shrinkage effect and increase the fluidity of the molten steel in the smelting process, which is helpful for the process of casting raw materials.

The hemp-aging steel sheet used for the golf club head of the present invention is composed of hemp-aging steel (C320) alloy, wherein the density of the hemp-aging steel alloy is 7.9-8.1 g/cm ³ . Compared with the prior art, the hemp-aged steel sheet of the present invention has excellent comprehensive properties, has the advantages of higher strength and good plastic toughness, and has good stress corrosion resistance at the same time.

The advantage of the hemp-aged steel sheet of the present invention is that it is a new low-cost hemp-aged steel alloy, which can obtain a tensile strength of 275-320KSI and a yield strength of 264-315KSI after proper solution, cryogenic and aging environments. With good comprehensive mechanical properties, it can be used as a structural material for golf club heads, and can be processed by cold and hot; it has good corrosion resistance in high chloride environments, making it the best material for golf club heads.

To sum up, the present invention merely describes the preferred embodiments or examples of the technical means adopted by the present invention to solve the problem, and is not intended to limit the scope of the patent implementation of the present invention. That is, all the equivalent changes and modifications that are consistent with the context of the scope of the patent application of the present invention, or made in accordance with the scope of the patent of the present invention, are all covered by the scope of the patent of the present invention.

S100: Steps

S200: Steps

S300: Steps

S400: Steps

Claims (7)

A method for manufacturing a hemp-aging steel sheet, comprising the steps of: assembling iron (Fe), nickel (Ni), cobalt (Co), molybdenum (Mo), titanium (Ti), chromium (Cr), aluminum (Al), silicon (Si) material is subjected to a smelting process to form an ingot; a forging process to the ingot to form a slab; a rolling process to the slab to form a plate; and the rolling process After that, the plate is subjected to a solution treatment, a cryogenic treatment and an aging treatment to complete a hemp aging steel plate, wherein the solution treatment, the cryogenic treatment and the aging treatment refer to the solution treatment at a temperature of 800 ° C ~ 900 ° C. 1 to 2 hours, cryogenic treatment at a temperature of -40 to 80 ° C for 2 to 8 hours, and aging treatment at a temperature of 430 to 550 ° C for 2 to 5 hours; wherein the hemp aging steel sheet includes the following components: 16 to 19wt% of nickel ( Ni), 8~10wt% cobalt (Co), 5.5~7.0wt% molybdenum (Mo), 0.4~1.4wt% titanium (Ti), 0.05~0.3wt% chromium (Cr), 0.05~0.2wt% % aluminum (Al), 0.05~0.1wt% silicon (Si), balanced amount of iron (Fe), and inevitable impurities. According to the method for manufacturing a hemp-aged steel sheet according to item 1 of the patent application scope, the hemp-aged steel sheet further comprises 0.003-0.08% vanadium (V) and 0.003-0.08% niobium (Nb). According to the method for manufacturing an aged steel sheet according to item 1 of the scope of patent application, wherein the smelting process includes: using industrial pure iron, electrolytic nickel, electrolytic cobalt, ferromolybdenum, pure aluminum bar, sponge titanium, ferrochrome alloy, and ferrosilicon. Vacuum arc consumable melting. According to the method for manufacturing hemp-aged steel sheet according to item 1 of the scope of patent application, wherein the forging process includes: performing a first forging step: performing an upsetting and a drawing process on the ingot at a heating temperature of 1180±10°C long, air-cooled after forging, and ground to remove surface oxide scale and cracks to form a billet; carry out a second forging step: at a heating temperature of 1000 ± 10 ° C, the first forging After the forging step, the billet is subjected to one upsetting and one drawing, air cooling after forging, and grinding to remove the surface oxide scale and grinding to remove cracks; a third forging step is performed: the second forging is performed at a heating temperature of 960±10°C. After the step, the blank is subjected to one upsetting and one drawing, air cooling after forging, and grinding to remove the surface oxide scale and grinding to remove cracks; a fourth forging step is performed: at a heating temperature of 900±10°C, the third forging step is performed. After that, the blank is subjected to one upsetting and one drawing, and then returned to the furnace after forging; and the blank after the fourth forging step is subjected to alternate operations of unidirectional pressing and peripheral shaping to form the slab. According to the manufacturing method of the hemp-aged steel sheet according to item 1 of the scope of the patent application, wherein the rolling process comprises: performing a first hot rolling step: rolling the sheet blank at a heating temperature of 1000±50°C, The original thickness of the slab is reduced to the first thickness; a second hot rolling step is performed: at a heating temperature of 850±50° C., the slab after the first heat treatment step is rolled, so that the slab is The first thickness is reduced to the second thickness; a third hot rolling step is performed: at a heating temperature of 1000±50° C., water quenching is performed on the slab after the second heat treatment step; and a fourth hot rolling step is performed: At a heating temperature of 850±50° C., the slab after the third hot rolling step is reverse rolled to reduce the second thickness of the slab to the third thickness. A hemp-aging steel sheet manufactured by the method for manufacturing the hemp-aging steel sheet described in item 1 of the scope of the patent application, calculated with a total weight of 100wt%, the hemp-aging steel sheet comprises the following components of 16-19wt% of nickel (Ni (Ni) ), 8~10wt% cobalt (Co), 5.5~7.0wt% molybdenum (Mo), 0.4~1.4wt% titanium (Ti), 0.05~0.3wt% chromium (Cr), 0.05~0.2wt% of aluminum (Al), 0.05~0.1wt% of silicon (Si), a balanced amount of iron (Fe), and inevitable impurities. The hemp-aging steel sheet according to item 6 of the patent application scope, wherein the hemp-aging steel sheet further comprises 0.003-0.08% vanadium (V) and 0.003-0.08% niobium (Nb).

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