CN102212752A - Low-temperature angle steel and manufacturing method thereof - Google Patents

Low-temperature angle steel and manufacturing method thereof Download PDF

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CN102212752A
CN102212752A CN2011101544127A CN201110154412A CN102212752A CN 102212752 A CN102212752 A CN 102212752A CN 2011101544127 A CN2011101544127 A CN 2011101544127A CN 201110154412 A CN201110154412 A CN 201110154412A CN 102212752 A CN102212752 A CN 102212752A
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angle steel
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杨富尧
李正
陈新
李现兵
韩钰
聂京凯
祝志祥
马光
朱全军
陈川
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State Grid Corp of China SGCC
China Electric Power Research Institute Co Ltd CEPRI
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Abstract

本发明涉及一种低温用热轧角钢及其制造方法,属于低温钢领域。所述角钢在-40℃以上具有优异的低温韧性,屈服强度达到350MPa,适合作为高寒地区低温条件下的输电铁塔塔材。所述角钢化学成分的重量百分配比为C:0.05~0.18%,Mn:0.5~1.7%,Si:0.01~0.55%,Ga:0.005~0.01%,V:0.01~0.08%,Nb:0.02~0.08%,Ca:0.001~0.005%;Ti:0.005~0.05%,Als:0.01~0.06%,Cu:0.15%~0.25%,B:0.0005~0.002%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的杂质。本发明具有工艺简单,钢质纯净,组织稳定、屈服强度大于350MPa、在-40℃以上具有优异低温韧性的优点,采用多元少量的合金化原则,高低温性能低成本。

Figure 201110154412

The invention relates to a hot-rolled angle steel for low temperature and a manufacturing method thereof, belonging to the field of low temperature steel. The angle steel has excellent low-temperature toughness above -40° C., and the yield strength reaches 350 MPa, and is suitable as a material for transmission iron towers under low-temperature conditions in alpine regions. The proportion by weight of the chemical composition of the angle steel is C: 0.05-0.18%, Mn: 0.5-1.7%, Si: 0.01-0.55%, Ga: 0.005-0.01%, V: 0.01-0.08%, Nb: 0.02-0.02%. 0.08%, Ca: 0.001-0.005%, Ti: 0.005-0.05%, Als: 0.01-0.06%, Cu: 0.15%-0.25%, B: 0.0005-0.002%, P: 0-0.01%, S: 0- 0.005%, the rest is Fe and unavoidable impurities. The invention has the advantages of simple process, pure steel quality, stable structure, yield strength greater than 350MPa, and excellent low-temperature toughness above -40°C, adopts the alloying principle of multiple elements and a small amount, and has low-cost high-low temperature performance.

Figure 201110154412

Description

一种低温用角钢及其制造方法A kind of angle steel for low temperature and its manufacturing method

技术领域technical field

本发明属于低温钢领域,具体讲涉及一种低温用热轧角钢及其制造方法。The invention belongs to the field of low-temperature steel, and in particular relates to a hot-rolled angle steel for low-temperature use and a manufacturing method thereof.

背景技术Background technique

材料的低温断裂问题是在上世纪三四十年代随着大型钢结构应用而生,上世纪30年代比利时哈塞尔特大桥在建成仅14个月后发生断裂坠毁,当时气温为-20℃。柏林附近跨越公路的桥梁,于1938年1月2日当温度急剧下降至-10℃时发生局部破坏,桥身上出现长达3m的裂缝。50年代,加拿大魁北克的一座桥梁,在通车27个月后发生断裂坠毁,当时气温为-35℃。1965年12月27日,北海气田“海宝”号海洋钻机井架倒塌下沉,时温为3℃。1984年1月4日,我国新疆发生一起工程起重机吊臂脆断事故,造成1人死亡,当时的工作环境温度为-15℃。研究表明,材料的应力低于屈服极限,也低于设计需用应力,钢材依然脆断失效,事故发生突然,过程短暂迅速,人们通过反思研究事故起因,确定低温是导致材料破坏的直接原因。The problem of low-temperature fracture of materials arose in the 1930s and 1940s with the application of large-scale steel structures. In the 1930s, the Belgian Hasselt Bridge broke and crashed only 14 months after it was built. The temperature at that time was -20°C. The bridge across the highway near Berlin was partially damaged on January 2, 1938 when the temperature dropped sharply to -10°C, and cracks as long as 3m appeared on the bridge. In the 1950s, a bridge in Quebec, Canada, broke and crashed 27 months after it was opened to traffic, when the temperature was -35°C. On December 27, 1965, the derrick of the "Haibao" marine drilling rig in the North Sea gas field collapsed and sank, and the hourly temperature was 3°C. On January 4, 1984, an engineering crane arm brittle fracture accident occurred in Xinjiang, my country, resulting in the death of one person. The working environment temperature at that time was -15°C. Studies have shown that the stress of the material is lower than the yield limit and the required stress of the design. The steel is still brittle and fails.

我国幅员辽阔,在北方很多地区冬季气温在-20℃以下,极限气温达-40℃以下,尤其是东北地区,属寒温带和寒带气候地区,具有气温低、温差大、降雪量大、空气密度大等特征,且持续得时间较长,低温出现时间一般3~6个月以上,在大、小兴安岭地区年平均气温都在0℃以下。东北地区最冷月温度大致在-10℃~-30℃之间,其中兴安岭地区各地极端最低温度的多年平均值大多在-40℃左右,而极值可达-45℃左右,随着近几年来,大气与自然环境的剧烈变化,极端天象出现频率增加,表1统计了我国部分地区的计算低温Tj(取自采暖规范,是50年中连续5天低温的平均值)和历史上出现的最低气温TzOur country has a vast territory. In many areas in the north, the temperature in winter is below -20°C, and the extreme temperature is below -40°C. Especially in the northeast region, it belongs to the cold temperate and frigid climate areas, with low temperature, large temperature difference, large snowfall, and air density. Large and other characteristics, and last for a long time, the low temperature generally occurs for more than 3 to 6 months, and the annual average temperature in the Greater and Lesser Khingan Mountains is below 0 °C. The temperature of the coldest month in Northeast China is roughly between -10°C and -30°C, and the multi-year average of the extreme minimum temperature in the Xing'an Mountains is mostly around -40°C, and the extreme value can reach around -45°C. In recent years, the atmosphere and natural environment have undergone drastic changes, and the frequency of extreme weather phenomena has increased. Table 1 shows the calculated low temperature T j in some areas of China (taken from the heating code, which is the average value of low temperature for 5 consecutive days in 50 years) and historical The lowest temperature T z that occurs.

表1我国部分地区的计算低温Tj和历史上出现过的最低气温Tz(℃)Table 1 The calculated low temperature T j and the lowest temperature T z in history in some regions of China (℃)

Figure BDA0000067236530000011
Figure BDA0000067236530000011

Figure BDA0000067236530000021
Figure BDA0000067236530000021

低温钢主要应具有如下的性能:①韧性-脆性转变温度低于使用温度;②满足设计要求的强度;③在使用温度下组织结构稳定;④良好的焊接性和加工成型性;关于低温用钢的专利技术如下:Low-temperature steel should mainly have the following properties: ①The ductile-brittle transition temperature is lower than the service temperature; ②The strength meets the design requirements; ③The structure is stable at the service temperature; The patented technology is as follows:

已经授权的公开号为CN101545077A、发明名称为《一种低温用钢及其制造方法》的发明专利,公开了一种低温钢板及制造方法,主要为针对低温钢板的开发,其低温钢在-80℃下具有优异的低温韧性,主要用于石油天然气管线、低温储气罐体LPG、LNG的低温钢板。该技术方案中贵金属Ni元素的含量为0.05-0.35%。The authorized publication number is CN101545077A, and the invention title is "a low-temperature steel and its manufacturing method", which discloses a low-temperature steel plate and its manufacturing method, mainly for the development of low-temperature steel plates. It has excellent low-temperature toughness at ℃, and is mainly used for low-temperature steel plates for oil and gas pipelines, low-temperature gas storage tanks for LPG and LNG. The content of noble metal Ni element in the technical scheme is 0.05-0.35%.

申请号为201010157592.X、发明名称为《高强度低温韧性钢》的发明专利申请,其公开了一种鱼尾板钢技术方案,适用于作为高寒地区低温条件下使用的工程机械、铁路配件用钢,如铁路钢轨用接头夹板等,属于中炭低硅钢,其在-40℃冲击功为28.6-36J,屈服强度为680-780MPa,低温钢的化学成分中包含贵金属Ni元素和Mo元素,提高了低温钢的生产成本。The application number is 201010157592.X, and the invention title is "High-strength Low-Temperature Toughness Steel". It discloses a fishplate steel technical solution, which is suitable for construction machinery and railway fittings steel used under low-temperature conditions in alpine regions. , such as joint splints for railway rails, etc., are medium-carbon low-silicon steels, which have an impact energy of 28.6-36J at -40°C and a yield strength of 680-780MPa. The chemical composition of low-temperature steel contains precious metal Ni and Mo elements, which improves the Low temperature steel production costs.

申请号为200910019494.7、发明名称为《一种-40℃至-60℃低温冲击韧性热轧H型钢及其制备方法》的发明专利申请,其公开了一种适用于-40℃至-60℃低温下使用的热轧H型钢,其V型试样在-40℃至-60℃下冲击功超过27J。H型钢的化学成分中贵金属Ni元素的含量为0.30-0.90%。The application number is 200910019494.7, and the invention title is "a kind of -40 ℃ to -60 ℃ low temperature impact toughness hot-rolled H-shaped steel and its preparation method". For the hot-rolled H-shaped steel used under the conditions, the impact energy of the V-shaped sample exceeds 27J at -40°C to -60°C. The content of noble metal Ni element in the chemical composition of H-beam is 0.30-0.90%.

上述钢种均含有贵金属Ni元素。The above-mentioned steel grades all contain noble metal Ni.

近年来,我国输电铁塔在低温下的脆断引起了国内专家的广泛关注。按照我国电网规划,将在东北、华北、西北地区建设多条输电线路,这些地区冬季气温较低,最低温度将达-40℃以下,输电铁塔用材规格大、载荷大、施工条件恶劣,目前对现有角钢在不同低温情况下的性能差别缺乏试验研究,对高寒地区电网用钢应具有的性能,没有相关试验数据支撑。现有的钢种在-40℃低温条件下,韧性和塑性都大幅度的降低,现有技术标准能否满足恶劣低温条件下电网稳定运行要求还不清楚。In recent years, the brittle fracture of my country's transmission towers at low temperatures has aroused widespread concern from domestic experts. According to my country's power grid planning, multiple transmission lines will be built in Northeast China, North China, and Northwest China. The temperature in these areas is low in winter, and the lowest temperature will reach below -40°C. The transmission towers have large material specifications, heavy loads, and harsh construction conditions. There is a lack of experimental research on the performance difference of existing angle steels at different low temperatures, and there is no relevant experimental data to support the performance of steel used in power grids in alpine regions. The toughness and plasticity of the existing steel types are greatly reduced under the low temperature condition of -40°C. It is not clear whether the existing technical standards can meet the requirements for stable operation of the power grid under severe low temperature conditions.

输电线路铁塔用材主要以Q235和Q345热轧角钢型材为主,按照国家电网公司部署,近年来Q420B角钢在输电铁塔中得到了广泛应用,Q460C角钢也在部分试点工程中得到了应用。在北方很多地区冬季气温在-20℃以下,极限气温达-40℃以下,在这样的气温下,按照GB/50017-2003《钢结构设计规范》的要求,钢结构用钢选择,一般按工作温度T来选择其质量等级:-20℃≤T<0℃,选择C、D级钢;T<-20℃时,选择D、E级钢。依照以上规定,需要选用D级、甚至E级钢材,才能满足输电铁塔运行要求。Transmission line towers are mainly made of Q235 and Q345 hot-rolled angle steel profiles. According to the deployment of the State Grid Corporation of China, Q420B angle steel has been widely used in transmission towers in recent years, and Q460C angle steel has also been used in some pilot projects. In many areas in the north, the winter temperature is below -20°C, and the extreme temperature is below -40°C. The temperature T is used to select its quality grade: -20℃≤T<0℃, select C and D grade steel; when T<-20℃, select D and E grade steel. According to the above regulations, it is necessary to choose D-grade or even E-grade steel to meet the operation requirements of transmission towers.

由于我国钢材生产装备及技术水平的限制,现有的型材生产厂家均没有生产D级或E级角钢的实际生产经验,市场上无法大批供应廉价的低温用角钢,因此,在高寒地区曾经使用了大量的A级和B级钢,但随着近几年来,大气与自然环境的剧烈变化,极端气象出现频率增加,多次出现了塔材的低应力脆性断裂事故。典型事故为2010年3月12日长春供电公司66kV农开甲乙线铁塔主材断裂。Due to the limitation of my country's steel production equipment and technical level, the existing profile manufacturers have no actual production experience in producing D-grade or E-grade angle steel, and the market cannot supply a large number of cheap low-temperature angle steel. There are a large number of A-grade and B-grade steels, but with the drastic changes in the atmosphere and natural environment in recent years, the frequency of extreme weather has increased, and low-stress brittle fracture accidents of tower materials have occurred many times. A typical accident occurred on March 12, 2010, when the main material of the iron tower of Changchun Power Supply Company's 66kV Agricultural Development Line A and B broke.

人们的日常生活,国家的经济发展都离不开甚至严重依赖于钢材的使用,钢材的脆断失效将导致停水停电、交通阻塞、房屋和电塔倒塌等严重后果,人力物力损失惨重,其中被称为生命线工程的输电铁塔的倒塌,将直接导致供电系统瘫痪,引发火灾,影响国家的生产建设和人们的生命安全。因此,开发专门用于高寒地区输电铁塔用钢材具有非常的意义。众所周知,目前主要有两种途径来提高钢的低温韧性,一种是通过改变热轧工艺及热处理工艺实现细晶强化来提高低温韧性;另一种是添加一定量的Ni、Mo等合金成分达到低温韧性高的目的。一般实际生产往往同时采用这两种方法来提高钢材的低温韧性,但由于Ni、Mo成本太高,经济生产难以实现。因此寻求一种能满足在-40℃低温冲击韧性稳定而且生产成本低廉的输电铁塔用热轧角钢具有重大的经济和社会效益,对我国输电铁塔用热轧角钢钢种起到了十分积极的完善作用。People's daily life and the country's economic development are inseparable from or even heavily dependent on the use of steel. The brittle failure of steel will lead to serious consequences such as water and power outages, traffic jams, collapse of houses and towers, and heavy losses in manpower and material resources. The collapse of the transmission tower, known as the lifeline project, will directly lead to the paralysis of the power supply system, causing fires, and affecting the production and construction of the country and people's lives. Therefore, it is of great significance to develop steel materials specially used for transmission towers in alpine regions. As we all know, there are currently two ways to improve the low-temperature toughness of steel. One is to improve the low-temperature toughness by changing the hot rolling process and heat treatment process to achieve fine grain strengthening; the other is to add a certain amount of alloy components such as Ni and Mo to achieve The purpose of high low temperature toughness. Generally, these two methods are often used in actual production to improve the low temperature toughness of steel, but due to the high cost of Ni and Mo, economical production is difficult to achieve. Therefore, it is of great economic and social benefit to seek a hot-rolled angle steel for transmission towers that can meet the requirements of low-temperature impact toughness at -40°C and has low production costs. .

发明内容Contents of the invention

本发明的目的在于提供一种具有优异低温韧性的输电铁塔用Q350MPa热轧角钢及其制造方法。本发明主要采用多元少量的合金化原则,结合多道次热轧及热处理工艺,开发出Q350MPa热轧角钢,所述角钢在-40℃以上具有优异低温韧性,适应于我国高寒地区低温条件下使用的输电铁塔。The object of the present invention is to provide a Q350MPa hot-rolled angle steel with excellent low-temperature toughness for power transmission towers and a manufacturing method thereof. The invention mainly adopts the alloying principle of multiple elements and a small amount, combined with multi-pass hot rolling and heat treatment processes, to develop Q350MPa hot-rolled angle steel. The angle steel has excellent low-temperature toughness above -40°C, and is suitable for use under low-temperature conditions in my country's alpine regions. transmission tower.

为实现上述发明目的,本发明所采取的技术方案如下:For realizing above-mentioned purpose of the invention, the technical scheme that the present invention takes is as follows:

一种低温用角钢,其改进之处在于所述角钢化学成分的重量百分配比为:C:0.05~0.18%,Mn:0.5~1.70%,Si:0.01~0.55%,Ga:0.005~0.01%,V:0.01~0.08%,Nb:0.02~0.08%,Ca:0.001~0.005%;Ti:0.005~0.05%,Als:0.01~0.06%,Cu:0.15%~0.25%,B:0.0005~0.002%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的杂质。An angle steel for low temperature, which is improved in that the weight percent distribution ratio of the chemical components of the angle steel is: C: 0.05-0.18%, Mn: 0.5-1.70%, Si: 0.01-0.55%, Ga: 0.005-0.01% , V: 0.01-0.08%, Nb: 0.02-0.08%, Ca: 0.001-0.005%, Ti: 0.005-0.05%, Als: 0.01-0.06%, Cu: 0.15%-0.25%, B: 0.0005-0.002% , P: 0-0.01%, S: 0-0.005%, and the rest are Fe and unavoidable impurities.

本发明的另一优选技术方案为:所述角钢化学成分的重量百分配比为:C:0.05~0.18%,Mn:0.65~1.70%,Si:0.01~0.55%,Ga:0.005~0.01%,V:0.01~0.08%,Nb:0.02~0.08%,Ca:0.001~0.005%;Ti:0.005~0.05%,Als:0.01~0.06%,Cu:0.15%~0.25%,B:0.0005~0.002%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的杂质。Another preferred technical solution of the present invention is: the weight percent distribution ratio of the chemical components of the angle steel is: C: 0.05-0.18%, Mn: 0.65-1.70%, Si: 0.01-0.55%, Ga: 0.005-0.01%, V: 0.01-0.08%, Nb: 0.02-0.08%, Ca: 0.001-0.005%, Ti: 0.005-0.05%, Als: 0.01-0.06%, Cu: 0.15%-0.25%, B: 0.0005-0.002%, P: 0 to 0.01%, S: 0 to 0.005%, and the rest are Fe and unavoidable impurities.

本发明的又一优选技术方案为:所述角钢中至少添加V和Nb中的一种,V和Nb总含量不超过0.12%。Another preferred technical solution of the present invention is: at least one of V and Nb is added to the angle steel, and the total content of V and Nb does not exceed 0.12%.

本发明的又一优选技术方案为:所述制造方法包括以下步骤:Another preferred technical solution of the present invention is: the manufacturing method includes the following steps:

1)按照化学成分的重量百分配比,C:0.05~0.18%,Mn:0.5~1.70%,Si:0.01~0.55%,Ga:0.005~0.01%,V:0.01~0.08%,Nb:0.02~0.08%,Ca:0.001~0.005%;Ti:0.005~0.05%,Als:0.01~0.06%,Cu:0.15%~0.25%,B:0.0005~0.002%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的杂质,其中V和Nb总含量不超过0.12%;1) According to the weight percent distribution of chemical components, C: 0.05-0.18%, Mn: 0.5-1.70%, Si: 0.01-0.55%, Ga: 0.005-0.01%, V: 0.01-0.08%, Nb: 0.02- 0.08%, Ca: 0.001-0.005%, Ti: 0.005-0.05%, Als: 0.01-0.06%, Cu: 0.15%-0.25%, B: 0.0005-0.002%, P: 0-0.01%, S: 0- 0.005%, the rest is Fe and unavoidable impurities, of which the total content of V and Nb does not exceed 0.12%;

2)初炼:控制其出钢温度在1630~1660℃;2) Initial refining: control the tapping temperature at 1630-1660°C;

3)进行转炉精炼,控制精炼时间在15~30min;3) Carry out converter refining, and control the refining time at 15-30 minutes;

4)进行真空脱氧后进行铸造,得到钢坯;4) casting after vacuum deoxidation to obtain a billet;

5)将步骤4所述钢坯加热到1190~1290℃进行多道次热轧得到角钢,终轧温度在860~940℃之间,空冷;5) Heating the steel billet described in step 4 to 1190-1290°C for multi-pass hot rolling to obtain angle steel, the final rolling temperature is between 860-940°C, and air-cooled;

本发明的又一优选技术方案为:于轧制开始,随着钢坯温度的降低,在钢坯的奥氏体区及铁素体再结晶温度区连续轧制,热轧道次为10次。Another preferred technical solution of the present invention is: at the beginning of rolling, as the temperature of the billet decreases, the billet is continuously rolled in the austenite zone and ferrite recrystallization temperature zone, with 10 hot rolling passes.

本发明的又一优选技术方案为:所述角钢为等边或不等边热轧角钢。Another preferred technical solution of the present invention is: the angle steel is an equilateral or unequal side hot-rolled angle steel.

本发明的又一优选技术方案为:正火后所述角钢的铁素体晶粒度不低于8级。Another preferred technical solution of the present invention is: the ferrite grain size of the angle steel after normalizing is not lower than grade 8.

各合金元素的作用及机理如下:The role and mechanism of each alloying element are as follows:

C:在钢中以间隙原子存在,也可以与钢种的强碳化合物元素相结合如Ti、Nb、V、W等相结合,形成细小弥散的碳化物,起到抑制晶粒长大和析出强化的作用,是最有效的强化元素之一。但是随着C含量的增加,钢材的硬度虽有所提高,延伸率和冲击韧性却下降很大,其中低温韧性下降的幅度更大。兼顾到钢的强度和低温韧性,本发明中采用的C含量范围将为0.05~0.18%。C: It exists as interstitial atoms in steel, and can also be combined with strong carbon compound elements of steel such as Ti, Nb, V, W, etc. to form fine and dispersed carbides, which can inhibit grain growth and precipitation strengthening It is one of the most effective strengthening elements. However, with the increase of C content, although the hardness of the steel increases, the elongation and impact toughness decrease greatly, and the low temperature toughness decreases even more. Considering the strength and low temperature toughness of the steel, the C content used in the present invention will be in the range of 0.05-0.18%.

Mn:是很重要的有益合金元素,主要固溶于铁素体中,起到固溶强化的效果,可提高钢的强度和硬度。其又是良好的脱氧剂和脱硫剂,含有一定量的锰可以消除或减弱钢因硫而引起的脆性,从而改善钢在低温下的韧性。Mn属于FCC稳定化元素,能够扩大奥氏体区域,使A1和A3温度降低,A4点升高。由于A3点温度下降,使先共析铁素体在更低的温度下析出,从而抑制了晶粒的长大,细化了组织。且同时也抑制了碳化物在过冷奥氏体的晶界处析出,起到降低DBTT的作用,因此,Mn是低温钢中的主要合金元素;但当其含量高时因钢的过热敏感性增大,在稍微过热的情况下,晶粒就发生粗化,且产生回火脆性,所以本发明中采用的Mn含量在0.50~1.70%范围。Mn: It is a very important beneficial alloying element, which is mainly dissolved in ferrite and has the effect of solid solution strengthening, which can improve the strength and hardness of steel. It is also a good deoxidizer and desulfurizer, containing a certain amount of manganese can eliminate or weaken the brittleness of steel caused by sulfur, thereby improving the toughness of steel at low temperature. Mn is an FCC stabilizing element, which can expand the austenite region, reduce the temperature of A 1 and A 3 , and increase the temperature of A 4 . As the temperature at point A3 drops, the pro-eutectoid ferrite precipitates at a lower temperature, thereby inhibiting the growth of grains and refining the structure. And at the same time, it also inhibits the precipitation of carbides at the grain boundaries of supercooled austenite, which plays a role in reducing DBTT. Therefore, Mn is the main alloying element in low temperature steel; but when its content is high, due to the superheat sensitivity of steel Increase, in the case of slight overheating, the crystal grains will coarsen and temper brittleness will occur, so the Mn content used in the present invention is in the range of 0.50% to 1.70%.

其中:in:

Ac1:加热时珠光体向奥氏体转变的温度;Ac 1 : the temperature at which pearlite transforms to austenite when heated;

Ar1:冷却时奥氏体向珠光体转变的温度;Ar 1 : the temperature at which austenite transforms to pearlite during cooling;

Ac3:加热时先共析铁素体全部转变为奥氏体的终了温度;Ac 3 : the final temperature at which proeutectoid ferrite transforms into austenite when heated;

Ar3:冷却时奥氏体向铁素体转变的开始温度;Ar 3 : the starting temperature of austenite to ferrite transformation during cooling;

Ac4:加热时二次渗碳体全部溶入奥氏体的终了温度;Ac 4 : the final temperature at which the secondary cementite is completely dissolved into austenite during heating;

Ar4:冷却时从奥氏体中开始析出二次渗碳体的温度。Ar 4 : The temperature at which secondary cementite begins to precipitate from austenite during cooling.

Si:常添加在钢中用于脱氧,不形成碳化物但固溶于铁素体中,固溶效果强,是很强的BCC稳定元素,因此会使DBTT升高,而且也会降低钢的韧性,所以本发明将Si元素含量范围严格规定在0.01~0.55%内。Si: It is often added in steel for deoxidation, does not form carbide but dissolves in ferrite, has a strong solid solution effect, and is a strong BCC stabilizing element, so it will increase DBTT and reduce steel Toughness, so the present invention strictly regulates the content of Si element within 0.01-0.55%.

Ga:一般以廉价的粗镓或铁-镓化合物的形式添加镓元素,研究表明,微量的镓元素可大幅度提高钢材的淬透性;但含量稍高时易引起冷脆现象,故本发明中采用的Ga元素范围为0.005~0.01%。Ga: Gallium is generally added in the form of cheap coarse gallium or iron-gallium compounds. Studies have shown that a small amount of gallium can greatly improve the hardenability of steel; The range of Ga element used in is 0.005-0.01%.

V、Nb:均为强碳化合物形成元素,在钢中形成的VC、NbC等第二相质点可阻碍钢在加热时的奥氏体晶粒长大,并能够抑制轧制后的再结晶及再结晶后的晶粒长大,起到细化晶粒的作用,进而提高钢材的强度和低温韧性;但当Nb、V过量时易产生晶间裂纹,并降低钢的可焊性,所以两者的含量之和不应超过1.2%。V and Nb: Both are strong carbon compound forming elements. The second phase particles such as VC and NbC formed in the steel can hinder the austenite grain growth of the steel when it is heated, and can inhibit the recrystallization and After recrystallization, the grain grows, which plays the role of refining the grain, thereby improving the strength and low-temperature toughness of the steel; but when Nb and V are excessive, it is easy to generate intergranular cracks and reduce the weldability of the steel, so the two The sum of their content should not exceed 1.2%.

Ca:作为脱氧去硫的净化剂,可以净化钢液,提高钢的纯净度,可改善非金属夹杂物的形态,使钢中的MnS球化,发挥材料的潜能,其含量过高时,易形成粗大的非金属夹杂物。固Ca含量控制在0.001~0.005%范围内。Ca: As a purifying agent for deoxidation and desulfurization, it can purify molten steel, improve the purity of steel, improve the shape of non-metallic inclusions, make MnS in steel spheroidize, and exert the potential of the material. When its content is too high, it is easy to Coarse non-metallic inclusions are formed. The solid Ca content is controlled within the range of 0.001-0.005%.

Ti:是一种强烈的碳化物和氮化物形成元素,易形成细小的TiC和TiN等粒子,TiC和TiN非常稳定,能够有效的钉扎晶界,细化晶粒,并具有稳定再次加热的组织的作用。少量的Ti元素使钢材的强度和低温韧性得以改善;但由于Ti是很强的BCC(体心立方晶体)稳定元素,因此添加Ti会使DBTT提高,且过量的Ti易形成粗大的TiN或TiC,使钉扎作用减弱,对钢的韧性会造成损害。所以本发明规定Ti含量为0.005~0.05%。Ti: is a strong carbide and nitride forming element, easy to form fine particles such as TiC and TiN, TiC and TiN are very stable, can effectively pin the grain boundary, refine the grain, and have stable reheating the role of the organization. A small amount of Ti element can improve the strength and low temperature toughness of steel; but because Ti is a strong BCC (body-centered cubic crystal) stable element, adding Ti will increase DBTT, and excessive Ti will easily form coarse TiN or TiC , so that the pinning effect is weakened, and the toughness of the steel will be damaged. Therefore, the present invention stipulates that the Ti content is 0.005-0.05%.

Al:该元素主要脱氧元素,一定含量的Al可与钢中的N形成细小难溶的AlN质点,弥散分布起到细化晶粒的作用,提高钢材的强度和韧性,但铝量过高易导致夹杂物过多,对钢材的低温韧性不利。因此本发明Al的含量范围为0.01~0.06%。Al: This element is the main deoxidizing element. A certain amount of Al can form fine and insoluble AlN particles with N in the steel. The dispersed distribution plays a role in refining the grains and improving the strength and toughness of the steel. However, if the amount of aluminum is too high, it is easy to Lead to too many inclusions, which is not good for the low temperature toughness of steel. Therefore, the content range of Al in the present invention is 0.01-0.06%.

Cu:是一种FCC(面心立方晶体)稳定元素,通过回火期间析出第二相起到沉淀强化的作用,少量Cu元素可使DBTT下降,提高钢材的低温韧性、抗疲劳裂纹扩展能力;当Cu含量较高时,会由于析出的第二相量大且不可控直接导致钢材的韧性下降及DBTT的升高,而且过量的Cu也会导致钢坯铸造及热轧期间变脆,因此本发明Cu的含量控制范围在0.15%~0.25%。Cu: It is a stable element of FCC (face-centered cubic crystal), which plays a role of precipitation strengthening through the precipitation of the second phase during tempering. A small amount of Cu element can reduce DBTT and improve the low-temperature toughness and fatigue crack growth resistance of steel; When the Cu content is high, the toughness of the steel will decrease and the DBTT will directly increase due to the large and uncontrollable second phase amount of precipitation, and excessive Cu will also cause the slab to become brittle during casting and hot rolling, so the present invention The content control range of Cu is 0.15%-0.25%.

B:添加极少量的硼元素能够显著的改善钢材的性能,微量的硼可抑制磷、硫有害元素的偏析及沿晶断裂,沿晶偏析的硼能降低磷、硫在晶界的偏析及引起的沿晶断裂,从而显著提高钢材的低温韧性。硼元素可以改善夹杂物得形态和分布,加硼处理后,由于硼的表面活性高,可吸附在硫化物和氧化物表面,阻止夹杂物进一步长大,使夹杂物变得细小、圆整、均匀分布于晶界,强化晶界,减小局部应力集中,抑制裂纹萌生降低裂纹扩展速率,使材料的韧性提高。当硼加入铌钢中,硼和铌可形成复合物起到细化晶粒的作用;且微量的硼元素可大幅度提高钢的淬透性,通过获得均匀的具有良好的综合力学性能的组织(下贝氏体或回火索氏体)来提高钢的韧性;但硼元素必须维持在微量范围,随着硼元素的含量增加,将形成粗大的夹杂物,对钢的性能有不利的作用。B: Adding a very small amount of boron can significantly improve the performance of steel. A small amount of boron can inhibit the segregation and intergranular fracture of harmful elements of phosphorus and sulfur. intergranular fracture, thereby significantly improving the low temperature toughness of steel. Boron can improve the shape and distribution of inclusions. After boron treatment, due to the high surface activity of boron, it can be adsorbed on the surface of sulfides and oxides, preventing further growth of inclusions, making inclusions small, round, Evenly distributed in the grain boundary, strengthen the grain boundary, reduce local stress concentration, inhibit crack initiation and reduce crack growth rate, so as to improve the toughness of the material. When boron is added to niobium steel, boron and niobium can form a compound to refine the grain; and a small amount of boron can greatly improve the hardenability of the steel, and obtain a uniform structure with good comprehensive mechanical properties (lower bainite or tempered sorbite) to improve the toughness of steel; but the boron element must be maintained in a trace range, as the content of boron element increases, coarse inclusions will be formed, which will have an adverse effect on the performance of the steel .

P:是钢中的有害元素,由于其偏析倾向严重,形成带状组织,使钢的力学性能不均匀,一般认为,磷是引起钢铁材料在低温下发生脆断的主要原因。所以其含量越少越好,本发明将磷含量控制到0.01%以下。P: It is a harmful element in steel. Due to its serious segregation tendency, it forms a banded structure, which makes the mechanical properties of steel uneven. It is generally believed that phosphorus is the main cause of brittle fracture of steel materials at low temperatures. Therefore, the less the content, the better, and the present invention controls the phosphorus content to below 0.01%.

S:是大多数钢种中的有害元素,偏析倾向严重,易引起钢材低温沿晶断裂和高温脆化,并能导致钢材具有各向异性韧性低等缺点。故应严格控制其含量,本发明将硫含量控制在0.005%以下。S: It is a harmful element in most steel types, and has a serious segregation tendency, which can easily cause low-temperature intergranular fracture and high-temperature embrittlement of the steel, and can lead to the disadvantages of low anisotropy and toughness of the steel. Therefore, its content should be strictly controlled, and the present invention controls the sulfur content below 0.005%.

由于采用了上述技术方案,与现有技术相比,本发明所取得的有益效果包括:Owing to adopting above-mentioned technical scheme, compared with prior art, the beneficial effect that the present invention obtains comprises:

1)在-40℃具有优异低温韧性1) Excellent low temperature toughness at -40°C

按我国对钢材的低温冲击韧性的要求,在相应的温度下冲击功Akv大于27J即满足低温冲击性能指标,本发明所述热轧角钢在-40℃下的冲击功为60-88J,可知本发明的热轧角钢满足在-40℃的冲击韧性指标;According to the requirements of my country on the low-temperature impact toughness of steel products, the impact energy Akv at the corresponding temperature is greater than 27J to meet the low-temperature impact performance index. The impact energy of the hot-rolled angle steel in the present invention is 60-88J at -40°C. It can be seen that this The invented hot-rolled angle steel meets the index of impact toughness at -40°C;

2)屈服强度大于350MPa2) Yield strength greater than 350MPa

采用GB/T13239-2006低温拉伸试验方法进行低温拉伸性能测试,结果表明热轧角钢的屈服强度大于350MPa,具有优异低温韧性与良好力学性能的匹配;The low-temperature tensile performance test was carried out using the GB/T13239-2006 low-temperature tensile test method. The results showed that the yield strength of the hot-rolled angle steel was greater than 350MPa, and it had excellent low-temperature toughness and good mechanical properties;

3)成本低3) Low cost

所述低温用角钢以锰和镓代镍、采用多元少量的合金化原则;同时,冶炼的过程中通过添加廉价的硼铁来改变钢中B元素的含量;在提高角钢低温性能的同时大大降低了成本,适合作为高寒地区低温条件下的输电铁塔塔材;The low-temperature angle steel uses manganese and gallium instead of nickel, and adopts the principle of alloying with a small amount of multiple elements; at the same time, the content of B element in the steel is changed by adding cheap iron boron during the smelting process; while improving the low-temperature performance of the angle steel, it is greatly reduced. It reduces the cost and is suitable as a transmission tower material under low temperature conditions in alpine regions;

4)工艺简单,钢质纯净,组织稳定4) The process is simple, the steel is pure, and the structure is stable

其发明的工艺特点在于:先进行初炼,控制钢坯在较高的温度然后转炉精炼,降低S、P含量,控制钢中气体含量并进行真空脱氮脱氧,真空脱氧后,将钢坯进行10道次热轧,在奥氏体区及再结晶温度区连续热轧。钢坯在奥氏体区较软,具有优异的可塑性,通过4道次热轧后使钢坯具有角钢的形状,并使奥氏体晶粒破碎,形核后成为多个细小的亚晶,随着钢坯温度的降低,在铁素体再结晶温度区连续热轧成等边或不等边角钢,大量的变形使晶粒变形产生形变强化,并通过空冷使晶粒来不及长大,最后得到铁素体晶粒度高于8的热轧角钢。本发明所述的热轧角钢的制造方法工艺简单,所得角钢组织稳定,力学性能稳定,适用于大规模的工业化生产。The characteristics of the process of its invention are as follows: the primary refining is carried out first, the billet is controlled at a higher temperature and then refined in a converter, the content of S and P is reduced, the gas content in the steel is controlled, and vacuum denitrification and deoxidation are carried out. After vacuum deoxidation, the billet is subjected to 10 passes Secondary hot rolling, continuous hot rolling in the austenite zone and recrystallization temperature zone. The steel billet is soft in the austenite zone and has excellent plasticity. After 4 passes of hot rolling, the steel billet has the shape of an angle steel, and the austenite grains are broken, and after nucleation, they become many fine subgrains. The temperature of the steel billet is lowered, and it is continuously hot-rolled into equilateral or unequal angle steel in the ferrite recrystallization temperature zone. A large amount of deformation causes the deformation of the grain to produce deformation strengthening, and the grain is too late to grow through air cooling, and finally ferrite is obtained. Hot-rolled angle steel with bulk grain size higher than 8. The manufacturing method of the hot-rolled angle steel of the present invention has simple process, and the obtained angle steel has stable structure and stable mechanical properties, and is suitable for large-scale industrial production.

附图说明Description of drawings

下面结合附图对本发明进一步说明。The present invention will be further described below in conjunction with the accompanying drawings.

图1是标准夏比V型缺口冲击试样;Figure 1 is a standard Charpy V-notch impact specimen;

图2是低温拉伸试样;Figure 2 is a low temperature tensile sample;

图中标记单位:mm。Marking unit in the figure: mm.

具体实施方式Detailed ways

下面结合实例对本发明进行详细的说明。Below in conjunction with example the present invention is described in detail.

所有实施方式都是采用常规冶炼及轧制设备,按照前面所叙述的步骤进行:All implementation modes are all to adopt conventional smelting and rolling equipment, carry out according to the steps described above:

实施例1:Example 1:

具有优异低温韧性输电铁塔用Q350MPa热轧角钢,其化学成分的重量百分配比为:C:0.145%,Mn:0.65%,Si:0.21%,Ga:0.005%,V:0.025%,Ca:0.001%;Ti:0.005%,Als:0.02%,Cu:0.16%,B:0.0005,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的微量杂质。Q350MPa hot-rolled angle steel for transmission towers with excellent low-temperature toughness, the weight percentage of its chemical composition is: C: 0.145%, Mn: 0.65%, Si: 0.21%, Ga: 0.005%, V: 0.025%, Ca: 0.001 %; Ti: 0.005%, Als: 0.02%, Cu: 0.16%, B: 0.0005, P: 0-0.01%, S: 0-0.005%, and the rest are Fe and unavoidable trace impurities.

一种生产低温韧性输电铁塔用Q350MPa热轧角钢的方法,其步骤:A method for producing Q350MPa hot-rolled angle steel for low-temperature ductile power transmission towers, the steps of which are:

(1)初炼:控制其出钢温度在1630~1640℃;(1) Primary refining: control the tapping temperature at 1630-1640°C;

(2)进行转炉精炼,控制精炼时间在15min,;(2) Carry out converter refining, control refining time at 15min;

(3)进行真空脱氧并进行铸造;(3) vacuum deoxidation and casting;

(4)将钢坯加热到1195~1130℃进行10道次热轧,终轧温度在860~940℃之间,空冷。(4) Heating the billet to 1195-1130°C for 10 passes of hot rolling, the final rolling temperature is between 860-940°C, and air-cooled.

实施例2:Example 2:

具有优异低温韧性输电铁塔用Q350MPa热轧角钢,其化学成分的重量百分配比为:C:0.16%,Mn:1.06%,Si:0.37%,Ga:0.006%,Nb:0.045%,Ca:0.002%;Ti:0.01%,Als:0.032%,Cu:0.18%,B:0.0007%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的微量杂质。Q350MPa hot-rolled angle steel for transmission towers with excellent low-temperature toughness, the weight percentage distribution of its chemical composition is: C: 0.16%, Mn: 1.06%, Si: 0.37%, Ga: 0.006%, Nb: 0.045%, Ca: 0.002 %; Ti: 0.01%, Als: 0.032%, Cu: 0.18%, B: 0.0007%, P: 0-0.01%, S: 0-0.005%, and the rest are Fe and unavoidable trace impurities.

一种生产低温韧性输电铁塔用Q350MPa热轧角钢的方法,其步骤:A method for producing Q350MPa hot-rolled angle steel for low-temperature ductile power transmission towers, the steps of which are:

(1)初炼:控制其出钢温度在1635~1645℃;(1) Initial refining: control the tapping temperature at 1635-1645°C;

(2)进行转炉精炼,控制精炼时间在18min,;(2) Carry out converter refining, control refining time at 18min;

(3)进行真空脱氧并进行铸造;(3) vacuum deoxidation and casting;

(4)将钢坯加热到1220~1245℃进行10道次热轧,终轧温度在860~940℃之间,空冷。(4) Heating the billet to 1220-1245°C for 10 passes of hot rolling, the final rolling temperature is between 860-940°C, and air cooling.

实施例3:Example 3:

具有优异低温韧性输电铁塔用Q350MPa热轧角钢,其化学成分得的重量百分配比为:C:0.16%,Mn:1.32%,Si:0.44%,Ga:0.008%,V:0.065%,Ca:0.003%;Ti:0.025%,Als:0.045%,Cu:0.19%,B:0.001%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的微量杂质。Q350MPa hot-rolled angle steel for transmission towers with excellent low-temperature toughness, the weight percentage distribution of its chemical composition is: C: 0.16%, Mn: 1.32%, Si: 0.44%, Ga: 0.008%, V: 0.065%, Ca: 0.003%; Ti: 0.025%, Als: 0.045%, Cu: 0.19%, B: 0.001%, P: 0-0.01%, S: 0-0.005%, and the rest is Fe and unavoidable trace impurities.

一种生产低温韧性输电铁塔用Q350MPa热轧角钢的方法,其步骤:A method for producing Q350MPa hot-rolled angle steel for low-temperature ductile power transmission towers, the steps of which are:

(1)初炼:控制其出钢温度在1640~1645℃;(1) Primary refining: control the tapping temperature at 1640-1645°C;

(2)进行转炉精炼,控制精炼时间在20min;(2) Carry out converter refining, control refining time at 20min;

(3)进行真空脱氧并进行铸造;(3) vacuum deoxidation and casting;

(4)将钢坯加热到1230~1250℃进行10道次热轧,终轧温度在860~940℃之间,空冷。(4) Heating the billet to 1230-1250°C for 10 passes of hot rolling, the final rolling temperature is between 860-940°C, and air cooling.

实施例4:Example 4:

具有优异低温韧性输电铁塔用Q350MPa热轧角钢,其化学成分的重量百分配比为:C:0.17%,Mn:1.58%,Si:0.55%,Ga:0.01%,Nb:0.08%,Ca:0.004%;Ti:0.033%,Als:0.43%,Cu:0.18%,B:0.0012%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的微量杂质。Q350MPa hot-rolled angle steel for transmission towers with excellent low-temperature toughness, the weight percentage of its chemical composition is: C: 0.17%, Mn: 1.58%, Si: 0.55%, Ga: 0.01%, Nb: 0.08%, Ca: 0.004 %; Ti: 0.033%, Als: 0.43%, Cu: 0.18%, B: 0.0012%, P: 0-0.01%, S: 0-0.005%, and the rest are Fe and unavoidable trace impurities.

一种生产低温韧性输电铁塔用Q350MPa热轧角钢的方法,其步骤:A method for producing Q350MPa hot-rolled angle steel for low-temperature ductile power transmission towers, the steps of which are:

(1)初炼:控制其出钢温度在1640~1650℃;(1) Initial refining: control the tapping temperature at 1640-1650°C;

(2)进行转炉精炼,控制精炼时间在15min,;(2) Carry out converter refining, control refining time at 15min;

(3)进行真空脱氧并进行铸造;(3) vacuum deoxidation and casting;

(4)将钢坯加热到1245~1265℃进行10道次热轧,终轧温度在860~940℃之间,空冷。(4) Heating the billet to 1245-1265°C for 10 passes of hot rolling, the final rolling temperature is between 860-940°C, and air-cooled.

实施例5:Example 5:

具有优异低温韧性输电铁塔用Q350MPa热轧角钢,其化学成分的重量百分配比为:C:0.175%,Mn:1.70%,Si:0.55%,Ga:0.01%,V:0.045%,Nb:0.043%,Ca:0.005%;Ti:0.042%,Als:0.51%,Cu:0.2%,B:0.0015%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的微量杂质。Q350MPa hot-rolled angle steel for transmission towers with excellent low-temperature toughness, the weight percentage of its chemical composition is: C: 0.175%, Mn: 1.70%, Si: 0.55%, Ga: 0.01%, V: 0.045%, Nb: 0.043 %, Ca: 0.005%; Ti: 0.042%, Als: 0.51%, Cu: 0.2%, B: 0.0015%, P: 0~0.01%, S: 0~0.005%, the rest is Fe and unavoidable trace impurities .

一种生产低温韧性输电铁塔用Q350MPa热轧角钢的方法,其步骤:A method for producing Q350MPa hot-rolled angle steel for low-temperature ductile power transmission towers, the steps of which are:

(1)初炼:控制其出钢温度在1640~1655℃;(1) Primary refining: control the tapping temperature at 1640-1655°C;

(2)进行转炉精炼,控制精炼时间在28min,;(2) carry out converter refining, control refining time at 28min;

(3)进行真空脱氧并进行铸造;(3) vacuum deoxidation and casting;

(4)将钢坯加热到1255~1285℃进行10道次热轧,终轧温度在860~940℃之间,空冷。(4) Heating the billet to 1255-1285°C for 10 passes of hot rolling, the final rolling temperature is between 860-940°C, and air-cooled.

沿热轧角钢纵向取拉伸及冲击试样,严格执行GB/T3808采用摆锤式冲击试验机,采用GB/T229-1994金属夏比缺口冲击试验方法中的V型缺口进行冲击试验。并采用GB/T13239-2006低温拉伸试验方法进行低温拉伸性能测试,试样尺寸如图1和图2,表1列出了各实例在-40℃温度下的力学性能。Tensile and impact samples are taken along the longitudinal direction of the hot-rolled angle steel, and GB/T3808 is strictly implemented using a pendulum impact testing machine, and the impact test is carried out using the V-shaped notch in the GB/T229-1994 metal Charpy notch impact test method. The low-temperature tensile performance test was carried out using the GB/T13239-2006 low-temperature tensile test method. The sample dimensions are shown in Figures 1 and 2. Table 1 lists the mechanical properties of each example at a temperature of -40°C.

表1试验钢材性能检验结果Table 1 Test results of steel performance inspection

 实例example   Rel(MPa)R el (MPa)  Rm(MPa)R m (MPa)   A(%)A(%)  Akv(-40℃)(J)纵向Akv(-40℃)(J)longitudinal  晶粒度(级)Grain size (level)  实施例1Example 1   355355  515515   3232  6060   8 8  实施例2Example 2   367367  522522   2929  7575   8 8  实施例3Example 3   382382  557557   3131  8585   9 9  实施例4Example 4   386386  566566   2727  8888   9.59.5  实施例5Example 5   353353  517517   3030  8080   8 8

按我国对钢材的低温冲击韧性的要求,在相应的温度下冲击功AKV大于27J即满足低温冲击性能指标,由表1可知本发明的热轧角钢满足在-40℃的冲击韧性指标。According to my country's requirements for low-temperature impact toughness of steel, the impact energy AKV greater than 27J at the corresponding temperature meets the low-temperature impact performance index. It can be seen from Table 1 that the hot-rolled angle steel of the present invention meets the impact toughness index at -40°C.

本发明具有工艺简单,钢质纯净,组织稳定、屈服强度大于350MPa、在-40℃以上具有优异低温韧性的优点,且以锰和镓代镍、采用多元少量的合金化原则,在提高角钢低温性能的同时大大降低了成本,适合作为高寒地区低温条件下的输电铁塔塔材。The invention has the advantages of simple process, pure steel, stable structure, yield strength greater than 350MPa, and excellent low-temperature toughness above -40°C, and uses manganese and gallium instead of nickel, and adopts the principle of alloying with a small amount of multiple elements to improve the low temperature of angle steel. The performance is greatly reduced at the same time, and it is suitable as a transmission tower material under low temperature conditions in alpine regions.

此处已经根据特定的示例性实施例对本发明进行了描述。对本领域的技术人员来说在不脱离本发明的范围下进行适当的替换或修改将是显而易见的。示例性的实施例仅仅是例证性的,而不是对本发明的范围的限制,本发明的范围由所附的权利要求定义。The invention has been described herein in terms of specific exemplary embodiments. Appropriate substitutions or modifications will be apparent to those skilled in the art without departing from the scope of the present invention. The exemplary embodiments are illustrative only, and not limiting of the scope of the invention, which is defined by the appended claims.

Claims (7)

1.一种低温用角钢,其特征在于所述角钢化学成分的重量百分配比为:C:0.05~0.18%,Mn:0.5~1.70%,Si:0.01~0.55%,Ga:0.005~0.01%,V:0.01~0.08%,Nb:0.02~0.08%,Ca:0.001~0.005%;Ti:0.005~0.05%,Als:0.01~0.06%,Cu:0.15%~0.25%,B:0.0005~0.002%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的杂质。1. An angle steel for low temperature, characterized in that the weight percent distribution ratio of the chemical composition of the angle steel is: C: 0.05-0.18%, Mn: 0.5-1.70%, Si: 0.01-0.55%, Ga: 0.005-0.01% , V: 0.01-0.08%, Nb: 0.02-0.08%, Ca: 0.001-0.005%, Ti: 0.005-0.05%, Als: 0.01-0.06%, Cu: 0.15%-0.25%, B: 0.0005-0.002% , P: 0-0.01%, S: 0-0.005%, and the rest are Fe and unavoidable impurities. 2.如权利要求1所述的低温用钢,其特征在于所述角钢化学成分的重量百分配比为:C:0.05~0.18%,Mn:0.65~1.70%,Si:0.01~0.55%,Ga:0.005~0.01%,V:0.01~0.08%,Nb:0.02~0.08%,Ca:0.001~0.005%;Ti:0.005~0.05%,Als:0.01~0.06%,Cu:0.15%~0.25%,B:0.0005~0.002%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的杂质。2. The steel for low temperature according to claim 1, characterized in that the weight percent distribution ratio of the chemical components of the angle steel is: C: 0.05-0.18%, Mn: 0.65-1.70%, Si: 0.01-0.55%, Ga B : 0.0005-0.002%, P: 0-0.01%, S: 0-0.005%, and the rest are Fe and unavoidable impurities. 3.如权利要求1所述的低温用钢,其特征在于所述角钢中至少添加V和Nb中的一种,V和Nb总含量不超过0.12%。3. The steel for low temperature according to claim 1, characterized in that at least one of V and Nb is added to the angle steel, and the total content of V and Nb does not exceed 0.12%. 4.一种如权利要求1所述的低温用角钢的制造方法,其特征在于所述制造方法包括以下步骤:4. A method for manufacturing low temperature angle steel as claimed in claim 1, characterized in that said method for manufacturing comprises the following steps: 1)按照化学成分的重量百分配比,C:0.05~0.18%,Mn:0.5~1.70%,Si:0.01~0.55%,Ga:0.005~0.01%,V:0.01~0.08%,Nb:0.02~0.08%,Ca:0.001~0.005%;Ti:0.005~0.05%,Als:0.01~0.06%,Cu:0.15%~0.25%,B:0.0005~0.002%,P:0~0.01%,S:0~0.005%,其余为Fe和不可避免的杂质,其中V和Nb总含量不超过0.12%;1) According to the weight percent distribution of chemical components, C: 0.05-0.18%, Mn: 0.5-1.70%, Si: 0.01-0.55%, Ga: 0.005-0.01%, V: 0.01-0.08%, Nb: 0.02- 0.08%, Ca: 0.001-0.005%, Ti: 0.005-0.05%, Als: 0.01-0.06%, Cu: 0.15%-0.25%, B: 0.0005-0.002%, P: 0-0.01%, S: 0- 0.005%, the rest is Fe and unavoidable impurities, of which the total content of V and Nb does not exceed 0.12%; 2)初炼:控制出钢温度在1630~1660℃;2) Primary refining: control the tapping temperature at 1630-1660°C; 3)进行转炉精炼,控制精炼时间在15~30min;3) Carry out converter refining, and control the refining time at 15-30 minutes; 4)进行真空脱氧后进行铸造,得到钢坯;4) casting after vacuum deoxidation to obtain a billet; 5)将步骤4所述钢坯加热到1190~1290℃进行多道次热轧得到角钢,终轧温度在860~940℃之间,空冷。5) Heating the steel slab described in step 4 to 1190-1290° C. and performing multi-pass hot rolling to obtain angle steel, the final rolling temperature is between 860-940° C., and air-cooled. 5.如权利要求4所述的一种低温用角钢的制造方法,其特征在于轧制开始,随着钢坯温度的降低,在钢坯的奥氏体区及铁素体再结晶温度区连续轧制,热轧道次为10次。5. the manufacture method of a kind of low-temperature angle steel as claimed in claim 4, it is characterized in that rolling starts, along with the reduction of steel billet temperature, continuous rolling in the austenite zone and ferrite recrystallization temperature zone of steel billet , hot rolling pass is 10 times. 6.如权利要求4所述的一种低温用角钢的制造方法,其特征在于所述角钢为等边或不等边热轧角钢。6. A method for manufacturing low-temperature steel angles as claimed in claim 4, characterized in that said angle steels are equilateral or unequal-edge hot-rolled angle steels. 7.如权利要求4所述的一种低温用角钢的制造方法,其特征在于正火后所述角钢的铁素体晶粒度不低于8级。 7. The manufacturing method of a low temperature angle steel as claimed in claim 4, characterized in that the ferrite grain size of the angle steel after normalizing is not lower than grade 8. the
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CN102851584A (en) * 2012-04-20 2013-01-02 宿迁南钢金鑫轧钢有限公司 A kind of niobium-containing large-scale high-strength angle steel and its production process
CN103042028A (en) * 2012-12-21 2013-04-17 山西新泰钢铁有限公司 Method for rolling H-shaped steel with stable impact energy
CN103526120A (en) * 2013-09-25 2014-01-22 安徽宏源线路器材有限公司 Low-temperature impact resistant angle steel for power transmission iron tower
CN103938063A (en) * 2014-04-04 2014-07-23 北京国网富达科技发展有限责任公司 Preparation method of high-toughness Q345 grade hot-rolled equal angle steel for iron tower
CN103938075A (en) * 2014-04-04 2014-07-23 北京国网富达科技发展有限责任公司 Preparation method of high-toughness Q420 grade hot-rolled equal angle steel for iron tower
CN104018081A (en) * 2014-06-25 2014-09-03 武汉钢铁(集团)公司 Low-temperature resistant special steel bar and production method thereof
CN104087827A (en) * 2014-07-15 2014-10-08 武汉钢铁(集团)公司 Atmosphere-corrosion-resistant and low-temperature-impact-resistant high-specification angle steel and production method thereof
CN107502835A (en) * 2017-08-17 2017-12-22 北京国网富达科技发展有限责任公司 A kind of weather-proof angle steel of steel tower high-strength and high ductility and preparation method thereof
CN109425544A (en) * 2017-09-04 2019-03-05 中国电力科学研究院 Stretching device under a kind of low temperature environment
CN118422058A (en) * 2024-05-02 2024-08-02 新疆八一钢铁股份有限公司 A smelting method for high-toughness Q420MPa steel plate for wind power

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102851584A (en) * 2012-04-20 2013-01-02 宿迁南钢金鑫轧钢有限公司 A kind of niobium-containing large-scale high-strength angle steel and its production process
CN103042028A (en) * 2012-12-21 2013-04-17 山西新泰钢铁有限公司 Method for rolling H-shaped steel with stable impact energy
CN103526120B (en) * 2013-09-25 2016-09-07 安徽宏源线路器材有限公司 Low-temperature impact resistant angle steel for power transmission iron tower
CN103526120A (en) * 2013-09-25 2014-01-22 安徽宏源线路器材有限公司 Low-temperature impact resistant angle steel for power transmission iron tower
CN103938063A (en) * 2014-04-04 2014-07-23 北京国网富达科技发展有限责任公司 Preparation method of high-toughness Q345 grade hot-rolled equal angle steel for iron tower
CN103938063B (en) * 2014-04-04 2016-03-30 北京国网富达科技发展有限责任公司 A kind of preparation method of steel tower high tenacity Q345 level hot rolling equal angle steel
CN103938075A (en) * 2014-04-04 2014-07-23 北京国网富达科技发展有限责任公司 Preparation method of high-toughness Q420 grade hot-rolled equal angle steel for iron tower
CN104018081A (en) * 2014-06-25 2014-09-03 武汉钢铁(集团)公司 Low-temperature resistant special steel bar and production method thereof
CN104018081B (en) * 2014-06-25 2016-07-13 武汉钢铁(集团)公司 A kind of low temperature resistant special reinforced and production method
CN104087827A (en) * 2014-07-15 2014-10-08 武汉钢铁(集团)公司 Atmosphere-corrosion-resistant and low-temperature-impact-resistant high-specification angle steel and production method thereof
CN107502835A (en) * 2017-08-17 2017-12-22 北京国网富达科技发展有限责任公司 A kind of weather-proof angle steel of steel tower high-strength and high ductility and preparation method thereof
CN109425544A (en) * 2017-09-04 2019-03-05 中国电力科学研究院 Stretching device under a kind of low temperature environment
CN118422058A (en) * 2024-05-02 2024-08-02 新疆八一钢铁股份有限公司 A smelting method for high-toughness Q420MPa steel plate for wind power

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