CN102560273A - Low-alloy seamless steel pipe for supporting crane cantilever - Google Patents

Abstract

The invention provides a low-alloy seamless steel pipe for supporting a crane cantilever. The seamless steel pipe comprises the following components in percentage by weight: 0.10 to 0.20 percent of C, 0.2 to 0.8 percent of Si, 0.6 to 1.5 percent of Mn, 0.3 to 0.8 percent of Cr, 0.2 to 0.6 percent of Mo, 0.001 to 0.050 percent of Ti, 0.02 to 0.06 percent of Al, 0.2 to 0.8 percent of Ni, 0.01 to 0.10 percent of V, 0.01 to 0.08 percent of Nb and the balance of Fe. The low-alloy seamless steel pipe has the advantages of lower carbon equivalent and the mechanical properties of similar products; a heavy-duty machinery manufacturing enterprise more easily obtains high-quality welded joints on the premise of a welding process, and the production efficiency of on-site welding is improved; and the using amount of precious metal alloy elements such as W, Ni, Mo and the like is reduced, resources are saved, and the production cost of the seamless pipe is reduced.

Description

Jib boom supports uses the low-alloy weldless steel tube

Technical field

The invention belongs to and be used for the heavy-duty machinery process industry in the metallic substance industry and use the weldless steel tube manufacturing technology, particularly a kind of jib boom supports uses the low-alloy weldless steel tube.

Background technology

It is shorter that China produces crawler crane history, compares with external advanced products such as special rex, De Mage, Manitowocs, in design and manufacturing, also has a certain distance.Domestic in recent years crawler crane develops rapidly, and product line is constantly perfect, has developed the complete series product of different model between the 35t-3600t, and more the large-tonnage crawler crane also is in the development phase.

Crawler crane mainly is applied to engineering projects such as petrochemical industry, oil, chemical industry, the energy, iron and steel, large-scale urban construction, and along with increasing of Chinese large-sized hoisting engineering, China's crawler mounted crane is just welcoming a new development climax.

According to statistics, from 2002-2008 crawler cranes occupation rate in four big types of walking crane markets, China crawler crane market demonstrates the paces of quick growth, by the less than 1% of calendar year 2001, rise to 2008 years 5.98%.2009, influenced by global financial crisis, the ratio that crawler crane accounts for walking crane descends to some extent, just maintains the ratio about 4% afterwards.Simultaneously, domestic crawler crane enterprise also begins to develop rapidly, constantly makes a breakthrough technically, and the trend of home products import substitutes progressively embodies, and domestic enterprise's crawler crane sales volume is soaring fast.Crawler mounted crane sales volume in 2008 is up to 1678, and the crawler mounted crane sales volume had downslide by a relatively large margin than previous year in 2009, especially is embodied on the little tonnage crawler-type crane, and the large-tonnage performance is better relatively, the situation that occurs increasing by on a year-on-year basis.2010, the crawler crane sales volume increased by 48% on a year-on-year basis, and sales volume reaches 1749.2011, construction machinery industry obviously demonstrated under the low big situation in preceding high back at home, and the first quarter, crawler crane continued high growth situation in 2010, and sales volume slightly glides for the second quarter, the third quater occurs small size bounce-back, and preceding 9 month to dates are sold 1485.

In the face of big good market development prospect; Not only external large-scale crawler crane lands China again and again; Domestic crawler crane manufacturing firm also accelerates the research and development paces of large-scale crawler crane one after another, with middle heavy section, 31 science and technology, comfort and dig heavy industry and Xu worker to build machine be that the domestic leading enterprise of representative has begun to initiate surging attack to middle large tonnage crawler crane:

In October, 2005, the Xuzhou heavy type took the lead in succeeding in developing first 300 tons of crawler crane in China; Mays 31 in 2006, science and technology rose to 400 tons with this record; Join heavy section in 2007 12 months and also released 600 tons of crawler cranes; Succeeded in developing 900 tons of crawler cranes again in November 31 in 2008; Join heavy section in 2009 9 months and held 1000 tons of ceremonies of rolling off the production line that crawler mounted crane is grand, indicate that homemade super-tonnage crawler crane strides into the kiloton epoch; In the BICES exhibition in 2009, when 31 science and technology have been released again 1180 tons of maximum crawler crane SCC11800 of Asia; After less than 1 year, to comfort QUY1250 that the biggest lifting capacity that digs the heavy industry research and development reaches 1250 tons and be pleasantly surprised on May 19th, 2010 and expose, another has refreshed the record of homemade super-tonnage crawler crane; In April, 2011, Xu worker two kiloton crawler crane XGC28000 were tested and appraised; May 28, join heavy section in the Changsha and release crawler mounted crane---ZCC3200NP the biggest in the world; And then the super-tonnage SCC86000TM crawler crane that was described as " hang in the whole world first " on May 29 has been held the ceremony of rolling off the production line in industrial park, 31 Kunshan, has refreshed the world record that middle heavy section only keeps a day once more.

China's crawler crane market development speed is surprising, can be rated as " at a tremendous pace ".Cut-throat competition between enterprise will make that Chinese crawler crane industry is more unusually brilliant.

Along with the fast development of all kinds of Mechanical Manufacturing Enterprises, the high-quality cantilever support becomes restraining factors with the supply of seamless tube.At present, the cantalever tube of the lifting-jack that exports to foreign countries mainly relies on the import seamless tube, does not only guarantee delivery date, and price also is very high.Therefore get into the world market for accelerating lifting machine, the starting material seamless tube that offers heavy-duty machinery manufacturing good quality, reasonable price is most important.

Summary of the invention

For solving the problem of above-mentioned existence; The purpose of this invention is to provide a kind of jib boom support and use the low-alloy weldless steel tube; Be beneficial to the weldless steel tube that production performance is qualified, have price competitiveness, reduce production costs, adapt to the fast-developing market requirement of heavy-duty machinery manufacturing.

For realizing above-mentioned purpose; Technical solution of the present invention provides a kind of jib boom support and uses the low-alloy weldless steel tube; Wherein: the moity of this weldless steel tube is %:C:0.10-0.20%, Si:0.2-0.8%, Mn:0.6-1.5%, Cr:0.3-0.8%, Mo:0.2-0.6%, Ti:0.001-0.050%, Al:0.02-0.06%, Ni:0.2-0.8%, V:0.01-0.10%, Nb:0.01-0.08% by weight, and all the other are Fe.The metallographic structure of this weldless steel tube after modifier treatment is tempered sorbite, and the control carbon equivalent is Ceq≤0.55;

The mechanical property of this weldless steel tube is:

When tube wall thickness t≤20mm, ys:>=890MPa, tensile strength: 940-1100MPa, longitudinal extension rate %:>=14%; Impact of collision value at-40 ℃ full-scale 10 * 10: one group of sample mean>=50J, single>=45J;

When tube wall thickness t >=20mm, ys: >=850MPa, tensile strength: 940-1050MPa, longitudinal extension rate (%): >=14%; Impact of collision value at-40 ℃ full-scale 10 * 10: one group of sample mean >=50J, single >=45J.

The invention has the beneficial effects as follows that the weldless steel tube of this component has reduced the use of precious metal alloys, cooperate the seamless tube production technique of TPCO simultaneously, thereby acquisition superior and price have more the product of advantage.Reduce the use of alloy in addition, make weldless steel tube be easy to welding more, thereby accelerate manufacturing concern's site welding production rate, improve the quality of welding joint, improve the production efficiency of lifting machine manufacturing concern.Simultaneously, adopt sophisticated rolling technology to guarantee that the surface quality of seamless tube is excellent.

Embodiment

In conjunction with embodiment jib boom is supported and to explain with the implementation process of low-alloy weldless steel tube.

Jib boom of the present invention supports uses the low-alloy weldless steel tube; The moity scope of design of this weldless steel tube is %:C:0.10-0.20%, Si:0.2-0.8%, Mn:0.6-1.5%, Cr:0.3-0.8%, Mo:0.2-0.6%, Ti:0.001-0.050%, Al:0.02-0.06%, Ni:0.2-0.8%, V:0.01-0.10%, Nb:0.01-0.08% by weight; All the other are tempered sorbite for the metallographic structure of this weldless steel tube of Fe after modifier treatment, and the control carbon equivalent is Ceq≤0.55;

The mechanical property of the weldless steel tube of producing by above-mentioned scope is:

Weldless steel tube with the TP890C specification is an example, and at present, the main chemical ingredients of using on the market of this series products is on the basis of 20 steel, adds alloying elements such as suitable Cr, Mo, V, W, Nb, through the rolling and heat treatment mode acquisition product of routine.The use content of W calculates according to the quotation of 2012.1.20 ferrotungsten at 0.4%-0.8%.

Containing the W grade according to ferrotungsten is 0.80 calculating, and the steel pipe of the W of containing per ton increases 1100-2200 unit than the steel pipe cost that does not contain this alloy.Also to add Cr:0.5%-0.9%Mo:0.3%-0.5%Ni:0.5%-1.30% simultaneously.

Jib boom of the present invention supports uses the low-alloy weldless steel tube, according to the scope of the moity of this weldless steel tube, allots the steel grade of following examples:

Jib boom of the present invention supports and does not only use W alloy with the low-alloy weldless steel tube, but also can reduce the use of Ni, Cr, Mo alloy significantly.Use following operational path production:

Electrosmelting → ladle refining → vacuum outgas → continuous casting → strand heating → perforation → tandem rolling → sizing → aligning → modified → cold bed → aligning → flaw detection → bundling → delivery.

Through above-mentioned technology controlling and process,, still can obtain good steel tube surface quality and can obtain following mechanical property even do not contain the weldless steel tube of W element:

Adopt jib boom of the present invention to support that not only superior but also carbon equivalent are lower than the steel that use on the market with the low-alloy weldless steel tube; And can solve the problem of cost performance well; Can not only satisfy user's technical requirements like this; And because the reduction of carbon equivalent uses the user of tubing can continue to use existing weldprocedure, the quality of welding joint should be superior to the high product of carbon equivalent.

Claims (2)

1. a jib boom supports and uses the low-alloy weldless steel tube; It is characterized in that: the moity of this weldless steel tube is %:C:0.10-0.20%, Si:0.2-0.8%, Mn:0.6-1.5%, Gr:0.3-0.8%, Mo:0.2-0.6%, Ti:0.001-0.050%, Al:0.02-0.06%, Ni:0.2-0.8%, V:0.01-0.10%, Nb:0.01-0.08% by weight, and all the other are Fe.

2. jib boom according to claim 1 supports and uses the low-alloy weldless steel tube, and it is characterized in that: the metallographic structure of this weldless steel tube after modifier treatment is tempered sorbite, and the control carbon equivalent is Ceq≤0.55;

The mechanical property of this weldless steel tube is:

When tube wall thickness t≤20mm, ys:>=890MPa, tensile strength: 940-1100MPa, longitudinal extension rate %:>=14%; Impact of collision value at-40 ℃ full-scale 10 * 10: one group of sample mean>=50J, single>=45J;

When tube wall thickness t >=20mm, ys: >=850MPa, tensile strength: 940-1050MPa, longitudinal extension rate (%): >=14%; Impact of collision value at-40 ℃ full-scale 10 * 10: one group of sample mean >=50J, single >=45J.