普通建筑材料_07建筑鋼材

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,?#?,,,單擊此處編輯母版文本樣式,第二級,第三級,第四級,第五級,單擊此處編輯母版標(biāo)題樣式,第七,章,章,建筑,鋼,鋼材,基本,要,要求,7.1,概述,7.2,基本,知,知識,7.3,技術(shù),性,性質(zhì),7.4,冷加,工,工和,時,時效,7.5,技術(shù),標(biāo),標(biāo)準(zhǔn),及,及選,用,用,目,錄,錄,基,本,本,要,要,求,求,本章,學(xué),學(xué)時,講課,3,實驗,0.5,主要,內(nèi),內(nèi)容,建筑,鋼,鋼材,的,的特,點,點、,分,分類,及,及應(yīng),用,用,建筑,鋼,鋼材,的,的拉,伸,伸性,能,能、,沖,沖擊,韌,韌性,及,及冷,彎,彎性,能,能,建筑,鋼,鋼材,的,的冷,加,加工,及,及時,效,效強,化,化,常用,建,建筑,鋼,鋼材,的,的標(biāo),準(zhǔn),準(zhǔn)及,選,選用,重點,建筑,鋼,鋼材,的,的拉,伸,伸性,能,能、,沖,沖擊,韌,韌性,及,及冷,彎,彎性,能,能,常用,建,建筑,鋼,鋼材,的,的標(biāo),準(zhǔn),準(zhǔn)及,選,選用,Back,基,本,本,要,要,求,求,§7.1,概,述,述,定義,分類,特點,應(yīng)用,意義,,,,,,,,,,,,,Back,指用,于,于工,程,程建,設(shè),設(shè)的,各,各種,鋼,鋼材,，,，包,括,括：,型鋼,鋼板,鋼絲,鋼筋,定義,,鋼筋,型鋼,,鋼板,鋼絲,Back,概,述,述,分類,金屬,材,材料,有色,金,金屬,黑色,金,金屬,銅、,鋁,鋁及,合,合金,鋼,結(jié),結(jié),構(gòu),構(gòu),鋼,筋,筋,生鐵,(c>2.06%),按化,學(xué),學(xué)成,分,分可,分,分為,:,黑色,金,金屬,和,和有,色,色金,屬,屬,Back,優(yōu)點,比強,度,度高,塑性,好,好、,韌,韌性,好,好,能承,受,受沖,擊,擊和,振,振動,荷,荷載,加工,性,性好,特點,缺點,易銹,蝕,蝕,維護,費,費用,大,大,Back,建筑,鋼,鋼材,可,可用,于,于,:,大跨,度,度結(jié),構(gòu),構(gòu),多層,及,及高,層,層結(jié),構(gòu),構(gòu),受動,荷,荷載,作,作用,的,的工,業(yè),業(yè)廠,房,房,應(yīng)用,鋼橋,Back,建筑,鋼,鋼材,是,是建,筑,筑中常用,的,的材,料,料,鋼材,的,的品,種,種多,，,，性,質(zhì),質(zhì)差,別,別大,，,，為,了,了掌,握,握鋼,材,材的,合,合理,使,使用,，,，應(yīng),對,對鋼,材,材的,生,生產(chǎn),、,、組,成,成、,性,性質(zhì),和,和用,途,途等,知,知識,有,有一,定,定的,了,了解,。,。,本章,的,的重,點,點是,鋼,鋼材,的,的技術(shù),性,性質(zhì)（主,要,要是,抗,抗拉,性,性能,）,）、技術(shù),標(biāo),標(biāo)準(zhǔn)和選用。,意義,Back,§7.2,基本,知,知識,鋼材,的,的冶,煉,煉過,程,程及,其,其對,鋼,鋼材,質(zhì),質(zhì)量,的,的影,響,響,冶煉,原,原理,爐種,的,的影,響,響,分類,按化,學(xué),學(xué)成,份,份分,按質(zhì),量,量分,按結(jié),構(gòu),構(gòu)用,途,途分,Back,將熔,融,融的,生,生鐵,水,水或,焦,焦炭,及,及鐵,礦,礦石,加,加入,煉,煉鋼,爐,爐中,精,精煉,，,，使,炭,炭及,其,其它,雜,雜質(zhì),氧,氧化,而,而揮,發(fā),發(fā)或,變,變成,氧,氧化,物,物進,入,入渣,內(nèi),內(nèi)，,降,降低,炭,炭及,其,其它,雜,雜質(zhì),的,的含,量,量。,冶煉,原,原理,鋼材,的,的冶,煉,煉過,程,程,及其,對,對鋼,材,材質(zhì),量,量的,影,影響,Back,過程,焦炭,鐵礦,石,石,生鐵,,高爐,熔融,生鐵,,精煉,氧化,還原,鋼,,鑄錠,鋼錠,建筑,鋼,鋼材,,圖,7.2.1,鋼材,的,的冶,煉,煉過,程,程,爐種,的,的影,響,響及,氧,氧化,程,程度,爐種,的,的影,響,響及,氧,氧化,程,程度,見,見表,7.2.1,和表,7.2.2,。,表,7.2.1,爐種,的,的影,響,響,爐型,原料,吹入,氣體,冶煉時間,鋼材,質(zhì)量,成本,應(yīng)用,氧氣轉(zhuǎn)爐,熔融鐵水,氧氣,15-30,分鐘,好,低,優(yōu)質(zhì)碳素鋼及合金鋼,平爐,生鐵、鐵礦石等,空氣,5-12,小時,好,高,同上及特殊用途的鋼,,電爐,廢鋼、,生鐵,空氣,短,最好,高,同上,冶煉,中,中為,除,除去,雜,雜質(zhì),而,而進,行,行的,氧,氧化,部分,鐵,鐵不,可,可避,免,免的,被,被氧,化,化,使,鋼,鋼,錠,錠,內(nèi),內(nèi),生,生,成,成,許,許,多,多,氣,氣,泡,泡,降,低,低,了,了,鋼,鋼,的,的,質(zhì),質(zhì),量,量,為,了,了,使,使,FeO,和,Fe,2,O,3,還,原,原,為,為,Fe,,在,煉,煉,鋼,鋼,的,的,后,后,階,階,段,段,必,必,須,須,脫,脫,氧,氧,。,。,脫,氧,氧,程,程,度,度,的,的,影,影,響,響,表,7.2.2,脫,氧,氧,程,程,度,度,及,及,鋼,鋼,材,材,質(zhì),質(zhì),量,量,鋼種,脫氧程度,冷卻情況,鋼材質(zhì)量,沸騰鋼,不充分,澆筑時有大量,CO,逸出,差,半鎮(zhèn)靜鋼,介于二者之間,,好,鎮(zhèn)靜鋼,充分,平靜冷卻，無,CO,逸出,組織致密、成分均勻、機械性能好,特殊鎮(zhèn)靜鋼,最充分,,最好,Back,碳,素,素,鋼,鋼,低,碳,碳,鋼,鋼,C<0.25%√,中,碳,碳,鋼,鋼,C=0.3,～,0.55%,高,碳,碳,鋼,鋼,C>0.6%,合,金,金,鋼,鋼,低,合,合,金,金,鋼,鋼,<5%√,中,合,合,金,金,鋼,鋼,=5,～,10%,鋼,合,合,金,金,鋼,鋼,>10%,按,化,化,學(xué),學(xué),成,成,分,分,分,分,類,類,分,類,類,表,7.2.3,碳,素,素,結(jié),結(jié),構(gòu),構(gòu),鋼,鋼,的,的,化,化,學(xué),學(xué),成,成,分,分,（,（,GB700,—,—88,）,牌號,,等級,化學(xué)成分,%,,,,,,脫氧方法,,,,C,Mn,Si,S,P,,,,,,,≤,,,,,,Q195,,0.06~0.12,,0.30,0.050,,0.045,F,、,b,、,Z,Q215,A,0.09~0.15,0.25~0.55,0.30,0.050,0.045,,0.045,F,、,b,、,Z,,B,,,,,,,,Q235,A,0.14~0.22,0.30~0.65,0.30,0.050,,0.045,F,、,b,、,Z,,B,0.12~0.20,0.30~0.70,,0.045,,,,,C,≤0.18,0.35-0.80,,0.040,,0.040,Z,,D,≤,0.17,,,0.035,,0.035,TZ,Q255,A,0.18~0.28,0.40~0.70,0.30,0.050,,0.045,Z,,B,,,,0.045,,,,Q275,,0.20~0.38,0.50~0.80,0.35,0.050,,0.045,Z,按,質(zhì),質(zhì),量,量,分,分,普,通,通,鋼,鋼,P,≯,0.045%,S,≯,0.055%,優(yōu),質(zhì),質(zhì),鋼,鋼,P,≯,0.035-0.04%,S,≯,0.04%,高,級,級,優(yōu),優(yōu),質(zhì),質(zhì),鋼,鋼,P,≯,0.025%,S,≯,0.025%,分,類,類,按,結(jié),結(jié),構(gòu),構(gòu),用,用,途,途,分,分,結(jié),構(gòu),構(gòu),鋼,鋼,各,種,種,工,工,程,程,構(gòu),構(gòu),件,件,及,及,機,機,械,械,零,零,件,件,,,屬,低,低,碳,碳,鋼,鋼,或,或,中,中,碳,碳,鋼,鋼,工,具,具,鋼,鋼,刀,具,具,、,、,模,模,具,具,特,殊,殊,鋼,鋼,不,銹,銹,鋼,鋼,、,、,耐,耐,熱,熱,鋼,鋼,、,、,耐,耐,磨,磨,鋼,鋼,Back,§7.3,建,筑,筑,鋼,鋼,材,材,的,的,技,技,術(shù),術(shù),性,性,質(zhì),質(zhì),拉,伸,伸,性,性,能,能,低,碳,碳,鋼,鋼,的,的,應(yīng),應(yīng),力,力,－,－,應(yīng),應(yīng),變,變,圖,圖,強,度,度,塑,性,性,沖,擊,擊,韌,韌,性,性,冷,彎,彎,性,性,能,能,Back,工程中,的,的鋼結(jié),構(gòu),構(gòu)和鋼,筋,筋混凝,土,土結(jié)構(gòu),中,中的鋼,材,材的基,本,本性能,有,有：,機械性,能,能,拉伸性,能,能,沖擊韌,性,性,疲勞強,度,度,工藝性,能,能,冷彎性,能,能,焊接性,能,能,Back,拉伸性,能,能錄像,拉伸性,能,能是建,筑,筑鋼材,的,的主要,性,性能,鋼材受,拉,拉后的技術(shù)性,能,能指標(biāo)可以用,低,低碳鋼,的,的應(yīng)力,—,應(yīng)變圖,來,來反映,。,。,屈服強,度,度,抗拉強,度,度,伸長率,拉伸性,能,能,低碳鋼,的,的應(yīng)力,應(yīng),應(yīng)變圖,見,見 圖,7.3.1,σ,,,,,,,,,,,,,,,,,,,,,,,,,,,B,C,D,A,δ,σ,b,σ,SU,σ,P,σ,SL,ε,,,彈性階,段,段,σ/ε=E,σ,σ,p,--,彈性極,限,限,屈服階,段,段,△,△,ε,＞△,σ,產(chǎn)生塑,性,性變形,B—,上屈服,點,點,B′—,下屈服,點,點,σ,s,—,屈服強,度,度,強化階,段,段：內(nèi),部,部組織,變,變化，,恢,恢復(fù)部,分,分強度,σ,b,--,抗拉強,度,度,頸縮階,段,段：過,C,點后，,試,試件抵,抗,抗變形,的,的能力,下,下降，,變,變形集,中,中在某,局,局部進,行,行，產(chǎn),生,生頸縮,破,破壞,0,圖,7.3.1,低碳鋼,的,的應(yīng)力,應(yīng),應(yīng)變圖,Back,定義,屈服強,度,度是指鋼,材,材開始,喪,喪失隨,變,變形的,抵,抵抗能,力,力,,,并開始,產(chǎn),產(chǎn)生大,量,量變形,的,的能力,。,。,意義,是彈性,變,變形轉(zhuǎn),變,變?yōu)樗?性,性的轉(zhuǎn),折,折點,當(dāng)外力,超,超過屈,服,服點時,，,，產(chǎn)生,不,不可恢,復(fù),復(fù)的變,形,形，鋼,材,材內(nèi)部,的,的應(yīng)力,自,自動分,配,配至低,應(yīng),應(yīng)力部,位,位,所以說,，,，屈服,點,點是確,定,定鋼結(jié),構(gòu),構(gòu)容許,應(yīng),應(yīng)力值,的,的依據(jù),屈服強,度,度,公式,屈服強,度,度,σ,s,－屈服,強,強度,Fs,－屈服,應(yīng),應(yīng)力,Ao,－試件,截,截面積,對屈服,不,不明顯,的,的鋼,,,規(guī)定以,產(chǎn),產(chǎn)生,0.2%,殘余變,形,形時的,應(yīng),應(yīng)力,f,02,作為屈,服,服強度,σ,02,，見,圖,7.2.3,,,,,,,,,,σ,ε,0.2%,O,圖,7.3.2,低碳鋼,的,的應(yīng)力,應(yīng),應(yīng)變圖,定義,σ,b,是指,鋼材能,承,承受的,最,最大拉,應(yīng),應(yīng)力,.,意義,當(dāng)外力,大,大于抗,拉,拉強度,時,時，鋼,材,材完全,喪,喪失對,變,變形的,抵,抵抗能,力,力而斷,裂,裂,因此，,在,在結(jié)構(gòu),設(shè),設(shè)計中,不,不能應(yīng),用,用,拉伸強,度,度,定義,σ,s,/,σ,b,反映了,鋼,鋼材的,可,可利用,率,率和安,全,全性的,大,大小,意義,屈強比,對,對鋼材,的,的可利,用,用率和,安,安全性,來,來說是,重,重要的,。,。,(,表,7.3.1,,圖,7.3.3),合理屈,強,強比：,碳素鋼,0.58—0.63,低碳合,金,金結(jié)構(gòu),鋼,鋼,0.65—0.75,屈強比,（,（,σ,s,/σ,b,）,,,,,,,,,,,,σ,b,σ,s2,σ,s1,σ,ε,圖,7.3.3,屈強比,的,的意義,Back,,σ,s,/,σ,b,低,σ,s,/,σ,b,高,可利用率,小,大,安全性,大,小,表,7.3.1,鋼材的,屈,屈強比,、,、可利,用,用率及,安,安全性,之,之間的,關(guān),關(guān)系,指鋼材,在,在外力,作,作用下,發(fā),發(fā)生塑,性,性變形,而,而不破,壞,壞的能,力,力。,定義,塑 性,伸長率,指標(biāo)和,公,公式,δ,n,—,伸長率,L,0,—the,原標(biāo)點,間,間距,L,1,—,拉斷后,標(biāo),標(biāo)點間,距,距,n=5d or 10d,d—,鋼筋直,徑,徑,δ,5,＞,δ,10,,,,,,,,,d,0,,,,L,0,,,,,,,L,1,,,,,,,,,圖,7.3.4,伸長率,的,的測定,斷面收,縮,縮率,Ψ,—,斷面收,縮,縮率,A,0,—,原斷面,面,面積,A,1,—,拉斷后斷面,面,面積,指標(biāo)和公式,指標(biāo)和公式,說明,伸長率是表,示,示鋼材塑性,變,變形能力的,重,重要指標(biāo),鋼結(jié)構(gòu)一般,在,在彈性范圍,內(nèi),內(nèi)工作,但在應(yīng)力集,中,中處，應(yīng)力,可,可能超過屈,服,服點,,,有一定的塑,性,性變形,因此,可以保持應(yīng),力,力重新分布,，,，從而避免,結(jié),結(jié)構(gòu)破壞,Back,沖擊韌性是,指,指鋼材抵抗,沖,沖擊荷載的,能,能力,定義,試驗方法,用擺錘打擊,有,有槽口的標(biāo),準(zhǔn),準(zhǔn)試件，直,到,到試件破壞,單位面積所,消,消耗的功,Back,沖擊韌性,A,k,—,試件破壞時,的,的沖擊功,A—,試件槽口處,截,截面積,公 式,Flash-,沖擊韌性試,驗,驗,沖擊韌性,α,k,與溫度有關(guān),(,圖,7.3.5),溫度較低時,，,，發(fā)生脆性,斷,斷裂的現(xiàn)象,發(fā)生脆性斷,裂,裂時的溫度,為,為脆性斷裂,溫,溫度,溫度較低時,，,，冷脆性好,冷 脆 性,沖擊韌性,,,,,,,,,韌性斷裂,脆性斷裂,T,ep,：,脆性臨界溫度范圍,T,A,k,,圖,7.3.5,脆性斷裂、,韌,韌性斷裂及,脆,脆性臨界溫,度,度范圍,指鋼材在常,溫,溫下承受彎,曲,曲變形的能,力,力,如果鋼材承,受,受彎曲變形,的,的程度大，,那,那么鋼材的,冷,冷彎性好,定義,指標(biāo),彎曲角度,α,及彎心直徑,/,（鋼板厚度,或,或直 徑,）,）,(d/a),冷 彎 性,能,能,Back,試驗,以規(guī)定的,α,和,d/a,進行彎曲,檢查受彎部,位,位,如不裂紋、,不,不起層或斷,裂,裂，則為合,格,格,,冷彎性能錄,像,像,冷 彎 性,能,能,冷彎是通過,彎,彎曲處的塑,性,性變形來實,現(xiàn),現(xiàn)的，因此,它,它也是反映,鋼,鋼材在靜荷,載,載下塑性的,一,一個指標(biāo)。,在拉伸試驗,中,中，鋼材試,件,件的塑性變,形,形則是局部,不,不均勻變形,.,冷彎試驗常,常,常能反映鋼,材,材內(nèi)部組織,的,的均勻程度,，,，存在內(nèi)應(yīng),力,力和夾雜物,等,等缺陷,因此可以用,冷,冷彎性來檢,查,查鋼材的質(zhì),量,量，如焊接,質(zhì),質(zhì)量,說明,Back,冷 彎 性,能,能,將熱軋鋼筋,用,用拉伸設(shè)備,在,在常溫下拉,長,長，使之產(chǎn),生,生一定的塑,性,性變形稱之,為,為冷拉,鋼材用拉伸,設(shè),設(shè)備拉伸后,能,能提高強度,冷拉,,,,,,,,,,,,,,,,,,,,,,,,F,圖,7.3.6,冷拉示意圖,Back,冷 彎 性,能,能,將鋼筋通過,硬,硬質(zhì)合金拔,絲,絲?？讖娦?拉,拉拔，使之,不,不僅受拉、,而,而且受擠壓,以,以提高強度,。,。每次冷拔,斷,斷面縮小應(yīng),為,為,10%,以下，可多,次,次冷拔,在這個過程,中,中，強度可,提,提高,40-60%,，效果好與,冷,冷拉,冷拔,Back,冷 彎 性,能,能,§7.4,建筑鋼材的,冷,冷加工與時,效,效,冷加工與時,效,效的定義,冷加工與時,效,效強化原理,冷加工與時,效,效強化的意,義,義,Back,冷加工,指在常溫下,對,對鋼材進行,冷,冷拉、冷拔,和,和冷軋?zhí)幚?冷加工強化,鋼材經(jīng)冷加,工,工后強度和,硬,硬度提高，,塑,塑性和韌性,降,降低的現(xiàn)象,時效,經(jīng)冷拉鋼材,隨,隨時間延長,強,強度提高,,,塑性、韌性,下,下降的現(xiàn)象,叫,叫做時效,可分為兩類,：,：分為自然時,效,效和人工時,效,效,Back,定義,時效,自然時效處,理,理,經(jīng)冷拉的鋼,材,材在常溫下,存,存放,15-20,天,其強度和,硬,硬度提高,，,，塑性和,韌,韌性降低,的,的現(xiàn)象,人工時效,處,處理,經(jīng)冷拉的,鋼,鋼材在加,熱,熱至,100-200℃,，并保持,一,一段時間,這將使時,效,效加速,定義,時效敏感,性,性,因時效而,導(dǎo),導(dǎo)致性能,改,改變的程,度,度大，導(dǎo),致,致塑性、,韌,韌性降低,。,。,故動荷載,重,重要結(jié)構(gòu),，,，敏感性,好,好。,說明,有些鋼材,即,即使沒有,經(jīng),經(jīng)過冷加,工,工處理，,長,長時間過,后,后也會出,現(xiàn),現(xiàn)時效，,但,但不如冷,加,加工后表,現(xiàn),現(xiàn)明顯。,Back,定義,冷加工時,效,效強化的,原,原理,由于鋼材,在,在加工時,產(chǎn),產(chǎn)生塑性,變,變形所至,，,，當(dāng)晶體,在,在外力作,用,用下，在,彈,彈性階段,金,金屬原子,偏,偏離平衡,位,位置產(chǎn)生,的,的變形，,在,在外里去,除,除后可以,恢,恢復(fù),---,彈性變形,；,；,當(dāng)外力繼,續(xù),續(xù)增大，,使,使晶格的,歪,歪曲程度,超,超過彈性,變,變形之后,，,，晶格產(chǎn),生,生滑移，,造,造成永久,性,性變形。,由,由于晶粒,表,表面的畸,變,變及滑動,平,平面的細(xì),小,小碎屑，,使,使晶體在,該,該平面上,繼,繼續(xù)滑動,產(chǎn),產(chǎn)生困難,，,，抵抗變,形,形的能力,增,增大，因,而,而屈服極,限,限及硬度,提,提高。,由于塑性,變,變形后鋼,材,材可能產(chǎn),生,生滑移的,區(qū),區(qū)域幾乎,均,均已滑動,，,，因此塑,性,性降低。,原 理,Back,時效強化,的,的原理,在高溫下,固,固溶在,α-Fe,中的氮和,氧,氧的原子,，,，在溫度,降,降低后溶,解,解度下降,，,，但未完,全,全析出，,在,在存放過,程,程中逐漸,析,析出并擴,散,散到晶粒,缺,缺陷處，,形,形成固體,微,微粒，阻,礙,礙晶粒發(fā),生,生滑移，,而,而提高了,對,對塑性變,形,形的抵抗,能,能力。,原 理,,,,,,,,σ,ε,O,O,1,B,D,1,C,D,C,1,K,1,K,,未冷拉,屈服點,B,冷拉,屈服點,: σ,s,變大,塑性和韌,性,性降低,時效,σ,s,, σ,ν,變大,塑性和韌,性,性降低,圖,7.4.1,冷加工和,時,時效強化,示,示意圖,建筑鋼材,的,的冷加工,與,與時效,可提高強,度,度，冷拉,后,后屈服強,度,度可提高,20-30%,，時效處,理,理后還可,使,使抗拉強,度,度提高。,可節(jié)約鋼,材,材,20-30%,。,對于受動,荷,荷載或經(jīng),常,常處于中,溫,溫條件工,作,作的鋼結(jié),構(gòu),構(gòu)，如橋,梁,梁、鋼軌,、,、鍋爐等,，,，為避免,過,過大脆性,，,，出現(xiàn)突,然,然斷裂，,要,要求采用,時,時效敏感,小,小的鋼材,。,。,意義,Back,§7.5,建筑鋼材,的,的技術(shù)標(biāo),準(zhǔn),準(zhǔn)與選用,鋼結(jié)構(gòu)用,鋼,鋼材,碳素結(jié)構(gòu),鋼,鋼,低合金高,強,強度結(jié)構(gòu),鋼,鋼,鋼筋混凝,土,土結(jié)構(gòu)用,鋼,鋼材,熱軋鋼筋,冷軋帶肋,鋼,鋼筋,冷拔低碳,鋼,鋼絲,Back,建筑鋼材,的,的技術(shù)標(biāo),準(zhǔn),準(zhǔn)與選用,建筑鋼材,包,包括：,型鋼,鋼管,鋼板,鋼絲,鋼筋,常用的鋼,材,材品種為,：,：,碳素鋼與,低,低合金鋼,二,二大類。,Back,鋼結(jié)構(gòu)用,鋼,鋼材,我國鋼結(jié),構(gòu),構(gòu)用的鋼,材,材主要有,碳素結(jié)構(gòu),鋼,鋼,低合金鋼,碳素結(jié)構(gòu),鋼,鋼,指各種鋼,結(jié),結(jié)構(gòu)中采,用,用的結(jié)構(gòu),鋼,鋼和工程,用,用熱軋鋼,板,板、型鋼,等,等。,現(xiàn)行國家,標(biāo),標(biāo)準(zhǔn)為,《,碳素結(jié)構(gòu),鋼,鋼,》,（,GB700-88,）,Back,牌號及其,表,表示方法,如,如,flash,中所示,Q235-AF:,屈服強度,是,是,235MPa,A,級,,,沸騰鋼,鋼結(jié)構(gòu)用,鋼,鋼材,請點擊右,鍵,鍵選擇“,播,播放”觀,看,看,Flash,動畫,碳素結(jié)構(gòu),鋼,鋼的技術(shù),要,要求,技術(shù)要求,包,包括：,化學(xué)成分,力學(xué)性質(zhì),冶煉方法,交貨狀態(tài),表面質(zhì)量,下面重點,介,介紹前兩,個,個性質(zhì)。,化學(xué)成分,各種不同,牌,牌號的碳,素,素結(jié)構(gòu)鋼,的,的化學(xué)成,分,分應(yīng)符合,GB700-88,的要求。,表,7.5.1,碳素結(jié)構(gòu),鋼,鋼的化學(xué),成,成分（,GB700-88,）,牌號,質(zhì)量等級,化學(xué)成分（,%,）,,,,,,,,C,Mn,Si,,S,,,,,,不大于,,,,Q195,—,0.06,～,0.12,0.25,～,0.50,0.30,0.050,,0.045,Q215,A,B,0.09,～,0.15,0.25,～,0.55,0.30,0.050,0.045,,0.045,Q235,A,B,C,D,0.14,～,0.22,0.12,～,0.20,≤0.18,≤0.17,0.35,～,0.80,0.30,0.050,0.045,0.040,0.035,,0.045,0.045,0.040,0.035,Q255,A,B,0.18,～,0.28,0.40,～,0.70,0.30,0.050,0.045,,0.045,Q275,—,0.28,～,0.38,0.50,～,0.80,0.35,0.050,,0.045,碳素結(jié)構(gòu),鋼,鋼的拉伸,和,和沖擊試,驗,驗指標(biāo)應(yīng),符,符合下表,規(guī),規(guī)定：,碳素結(jié)構(gòu),鋼,鋼的力學(xué),性,性能指標(biāo),（,（,GB700-88,）,力學(xué)性能,冷彎試驗,碳素結(jié)構(gòu),鋼,鋼的冷彎,試,試驗指標(biāo),（,（,GB700-88,）,表,7.5.2,碳素結(jié)構(gòu),鋼,鋼的力學(xué),性,性能（,GB700—88,）,牌號,等級,拉伸試驗,,,,,沖擊試驗,,,,屈服點,(N/mm),,抗拉強度,σb,(N/mm),伸長率（,%,）,,溫度 （℃）,V,型沖擊功 （縱向）,J,,,鋼材厚度 （直徑）,mm,,,鋼材厚度 （直徑）,mm,,,,,,≤16,＞,16~40,,≤16,＞,16~40,,,,,≥,,,≥,,,≥,Q195,—,(195),(185),315~390,33,32,—,—,Q215,A,B,215,205,335~410,31,30,—,20,—,27,Q235,A,B,C,D,235,225,375~460,26,25,—,20,—,-20,—,27,27,27,Q255,A,B,255,245,410~510,24,23,—,20,—,27,Q275,—,275,265,490~610,20,19,—,—,Tab.7.5.3,碳素結(jié)構(gòu),鋼,鋼抗彎試,驗,驗指標(biāo),(GB700-88),牌號,試樣方向,冷彎試驗,B=2a180°,,,,,鋼材厚度（直徑）（,mm,）,,,,,60,＞,60~100,＞,100~200,,,彎心直徑,d,,,Q195,縱,橫,0,0.5a,—,,—,,Q215,縱,橫,0.5a,a,1.5a,2a,2a,2.5a,Q235,縱,橫,a,1.5a,2a,2.5a,2.5a,a,Q255,2a,3a,3.5a,－,Q275,3a,2a,4.5a,－,各類牌號,鋼,鋼材的性,能,能,牌號與性,能,能的關(guān)系,根據(jù)國家,標(biāo),標(biāo)準(zhǔn),GB700-88,的規(guī)定，,碳,碳素結(jié)構(gòu),鋼,鋼按屈服,點,點分為五,個,個牌號,如表,7.5.1,和表,7.5.2,所示，,當(dāng)牌號增,大,大時，鋼,材,材的含碳,量,量提高，,伸,伸長率降,低,低，冷彎,性,性能也降,低,低。,質(zhì)量等級,：,：取決于,鋼,鋼材內(nèi)有,害,害雜質(zhì),S,、,P,的含量，,鋼,鋼材的質(zhì),量,量與好，,其,其焊接性,能,能和低溫,抗,抗沖擊性,能,能也提高,。,。,各類牌號,鋼,鋼材的性,能,能,碳素結(jié)構(gòu),鋼,鋼的選用,建筑鋼結(jié),構(gòu),構(gòu)中最常,用,用的牌號,為,為,Q235(,綜合性能,符,符合建筑,工,工程的要,求,求,),。,因為,Q235,鋼既有較,高,高的強度,，,，又有良,好,好的塑性,和,和韌型，,如,如：,B,、,C,、,D,等，可焊,接,接性也很,好,好，能滿,足,足一般鋼,結(jié),結(jié)構(gòu)用鋼,的,的要求。,Q235,的,C,級,和,和,D,級,鋼,鋼,，,，,其,其,S,和,P,的,含,含,量,量,低,低,，,，,所,所,以,以,主,主,要,要,作,作,重,重,要,要,的,的,焊,焊,接,接,結(jié),結(jié),構(gòu),構(gòu),。,。,尤,其,其,適,適,用,用,于,于,低,低,溫,溫,條,條,件,件,下,下,，,，,受,受,沖,沖,擊,擊,荷,荷,載,載,作,作,用,用,的,的,焊,焊,接,接,鋼,鋼,結(jié),結(jié),構(gòu),構(gòu),。,。,各,類,類,牌,牌,號,號,鋼,鋼,材,材,的,的,性,性,能,能,碳,素,素,結(jié),結(jié),構(gòu),構(gòu),鋼,鋼,的,的,選,選,用,用,Q195,及,Q215,：,強,強,度,度,低,低,，,，,但,但,塑,塑,性,性,和,和,韌,韌,性,性,好,好,，,，,易,易,冷,冷,加,加,工,工,，,，,在,在,軋,軋,制,制,、,、,焊,焊,接,接,加,加,工,工,成,成,受,受,沖,沖,擊,擊,、,、,偶,偶,然,然,荷,荷,載,載,等,等,情,情,況,況,下,下,，,，,能,能,保,保,證,證,安,安,全,全,使,使,用,用,。,。,Q255,及,Q275,：,強,強,度,度,高,高,，,，,但,但,塑,塑,性,性,和,和,韌,韌,性,性,差,差,，,，,可,可,焊,焊,接,接,差,差,，,，,不,不,易,易,冷,冷,加,加,工,工,；,；,可,可,用,用,作,作,砼,砼,配,配,筋,筋,和,和,鋼,鋼,結(jié),結(jié),構(gòu),構(gòu),中,中,的,的,構(gòu),構(gòu),件,件,及,及,螺,螺,栓,栓,（,（,在,在,機,機,械,械,零,零,件,件,及,及,工,工,具,具,中,中,常,常,用,用,之,之,）,）,。,。,選用鋼材，,主,主要根據(jù)工,程,程結(jié)構(gòu)的重,要,要性、荷載,類,類型、焊接,要,要求及使用,環(huán),環(huán)境溫度等,條,條件選擇。,Back,定義,在碳素結(jié)構(gòu),鋼,鋼的基礎(chǔ)上,，,，添加少量,的,的一種或幾,種,種合金元素,，,，合金元素,的,的總含量小,于,于,5%,的結(jié)構(gòu)鋼。,常用的合金,元,元素有：,Si,、,Mn,、,Ti,、,Nb,、,V,和,C,等。,牌號及其表,示,示方法,現(xiàn)行國家標(biāo),準(zhǔn),準(zhǔn),《,低合金結(jié)構(gòu),鋼,鋼,》,（,GB1591-94,）共有,5,個牌號：,Q295,、,Q345,、,Q390,、,Q420,、,Q460,。,低合金高強,度,度結(jié)構(gòu)鋼,Back,牌號由以下,四,四部分組成,(,如,flash,所示,),低合金高強,度,度結(jié)構(gòu)鋼,請點擊右鍵,選,選擇“播放,”,”觀看,Flash,動畫,低合金高強,度,度結(jié)構(gòu)鋼,低合金高強,度,度結(jié)構(gòu)鋼的,化,化學(xué)組成,(GB1591-94),如表,7.5.4,所示。,低合金高強,度,度結(jié)構(gòu)鋼的,力,力學(xué)性能,(GB1591-94),如表,7.5.5,所示。,如表,7.5.5,所示，,低合金鋼的,強,強度大大高,于,于碳素結(jié)構(gòu),鋼,鋼，并且具,有,有良好的塑,性,性和韌性、,耐,耐磨性、耐,蝕,蝕性及耐低,溫,溫性也好于,碳,碳素鋼，其,生,生產(chǎn)工藝和,成,成本都與碳,素,素鋼相近。,比采用碳素,結(jié),結(jié)構(gòu)鋼節(jié)省,鋼,鋼材，而且,可,可以減輕自,重,重，延長使,用,用壽命，,尤其適用于,大,大跨度結(jié)構(gòu),和,和橋梁工程,等,等。,低合金高強,度,度結(jié)構(gòu)鋼,表,7.5.4,低合金高強,度,度結(jié)構(gòu)鋼的,化,化學(xué)成分（,GB1591-94,）,牌號,,質(zhì)量等級,,化學(xué)成分（,%,）,,,,,,,,,,,,,,C,≤,Mn,Si,P,≤,S,≤,V,Nb,Ti,Al,≥,Cr≤,Ni≤,Q295,A,,B,0.16,,0.16,0.80,～,,1.50,0.80,～,,1.50,0.55,,0.55,0.045,,0.040,0.045,,0.040,0.02,～,,0.15,0.02,～,,0.15,0.015,～,0.060,0.015,～,0.060,0.02,～,0.20,0.02,～,0.20,—,,—,,,續(xù)表,Q345,A,,B,,C,,D,,E,,0.02,,0.02,,0.20,,0.18,,0.18,1.00,～,1.60,1.00,～,1.60,1.00,～,1.60,1.00,～,1.60,1.00,～,1.60,0.55,,0.55,,0.55,,0.55,,0.55,0.045,,0.040,,0.035,,0.030,,0.025,0.045,,0.040,,0.035,,0.030,,0.025,0.02,～,0.15,0.02,～,0.15,0.02,～,0.15,0.02,～,0.15,0.02,～,0.15,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,—,,—,,0.015,,0.015,,0.015,,,續(xù)表,Q390,A,,B,,C,,D,,E,0.20,,0.20,,0.20,,0.20,,0.20,1.00,～,1.60,1.00,～,1.60,1.00,～,1.60,1.00,～,1.60,1.00,～,1.60,0.55,,0.55,,0.55,,0.55,,0.55,0.045,,0.040,,0.035,,0.030,,0.025,0.045,,0.040,,0.035,,0.030,,0.025,,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,—,,—,,0.015,,0.015,,0.015,0.30,,0.30,,0.30,,0.30,,0.30,0.70,,0.70,,0.70,,0.70,,0.70,續(xù)表,Q420,A,,B,,C,,D,,E,0.20,,0.20,,0.20,,0.20,,0.20,1.00,～,1.70,1.00,～,1.70,1.00,～,1.70,1.00,～,1.70,1.00,～,1.70,0.55,,0.55,,0.55,,0.55,,0.55,0.045,,0.040,,0.035,,0.030,,0.025,0.045,,0.040,,0.035,,0.030,,0.025,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,—,,—,,0.015,,0.015,,0.015,0.40,,0.40,,0.40,,0.40,,0.40,0.70,,0.70,,0.70,,0.70,,0.70,Q460,C,,D,,E,,,0.20,,0.20,,0.20,1.00,～,1.70,1.00,～,1.70,1.00,～,1.70,0.55,,0.55,,0.55,0.035,,0.030,,0.025,0.035,,0.030,,0.025,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.015,～,0.060,0.015,～,0.060,0.015,～,0.060,0.02,～,0.20,0.02,～,0.20,0.02,～,0.20,0.015,,0.015,,0.015,0.70,,0.70,,0.70,0.70,,0.70,,0.70,表,7.5.5,低合金高強,度,度結(jié)構(gòu)鋼的,力,力學(xué)性能（,GB1591-94,）,牌號,,質(zhì)量等級,,拉伸試驗,,,,,,,,180°,彎曲試驗,,d=,彎心直徑,,a=,試驗厚度,,（直徑）,,,,,屈服點,(MPa),,,,抗拉強度,,σ,b,Mpa,伸長率,,δ,5,%,沖擊功,（縱向）,,（,J,）,,,,,,厚度,,（直徑、邊長）,,mm,,,,,,,,,,,≤,15,＞,16~35,,,,+20,℃,,0,℃,,鋼材厚度,,(,直徑,),（,mm,）,,,,,≥,,,,,≥,,,,≤,16,＞,16~100,Q295,A,B,295,295,,275,275,390~570,390~570,23,23,34,,d=2a,d=2a,d=3a,d=3a,Q345,A,B,C,D,E,345,345,345,345,345,325,325,325,325,325,470~630,470~630,470~630,470~630,470~630,21,21,22,22,22,34,,,34,d=2a,d=2a,d=2a,d=2a,d=2a,d=3a,d=3a,d=3a,d=3a,d=3a,Q390,A,B,C,D,E,,390,390,390,390,390,370,370,370,370,370,490~650,490~650,490~650,490~650,490~650,19,19,20,20,20,34,,,34,d=2a,d=2a,d=2a,d=2a,d=2a,d=3a,d=3a,d=3a,d=3a,d=3a,續(xù) 表,Q420,A,B,C,D,E,420,420,420,420,420,380,380,380,380,380,520~680,520~680,520~680,520~680,520~680,18,18,19,19,19,34,,34,d=2a,d=2a,d=2a,d=2a,d=2a,d=3a,d=3a,d=3a,d=3a,d=3a,Q460,C,D,E,460,460,460,420,420,420,550~720,550~720,550~720,17,17,17,,34,d=2a,d=2a,d=2a,d=3a,d=3a,d=3a,續(xù) 表,鋼筋混凝土,結(jié),結(jié)構(gòu)用鋼材,可以分為：,熱軋鋼筋,冷拉鋼筋,冷拔低碳鋼,絲,絲,鋼絞線,Back,包括熱軋光,圓,圓鋼筋,(Tab.7.5.6),及熱軋變形,鋼,鋼筋。,熱軋鋼筋按,屈,屈服強度及,抗,抗拉強度分,為,為四個等級,。,其品種、牌,號,號、力學(xué)性,能,能及其應(yīng)用,見,見下表,7.5.7,。,熱 軋 鋼,筋,筋,Back,表,7.5.6,建筑用低碳,熱,熱軋圓盤條,力,力學(xué)性能及,工,工藝性能,牌號,力學(xué)性能,,,冷彎試驗,180℃,d,＝彎心直徑,a,＝試樣直徑,,σ,s,（,MPa,）,σ,b,（,MPa,）,δ,10,（％）,,,≥,,,,Q215,Q235,215,235,375,410,27,23,d,＝,0,d,＝,0.5a,Tab.7.5.7,熱軋鋼筋力,學(xué),學(xué)性能及工,藝,藝性能表,（,（,GB/T701-1997,、,GB1499-1998,）,牌號,公稱直徑,（,mm,）,屈服強度,σ,s,,（,MPa,）,抗拉強度,σ,b,（,MPa,）,伸長率,δ,5,(%),冷彎試驗,180℃,d,＝彎心直徑,a,＝試樣直徑,,,≥,,,,HRB335,6,～,25,28,～,50,335,490,16,d,＝,3a,d,＝,4a,HRB400,6,～,25,28,～,50,400,570,14,d,＝,4a,d,＝,5a,HRB500,6,～,25,28,～,50,500,630,12,d,＝,6a,d,＝,7a,應(yīng) 用,HRB335,和,HRB400,主要用于非,預(yù),預(yù)應(yīng)力和預(yù),應(yīng),應(yīng)力混凝土,。,。,HRB500,主要用于預(yù),應(yīng),應(yīng)力混凝土,。,。,Back,冷軋帶肋鋼,筋,筋,冷軋帶肋鋼,筋,筋主要力學(xué),性,性能和工藝,性,性能如表,7.5.8,所示。,Back,級別代號,抗拉強度,σ,b,(MPa),不小于,伸長率不小于,(%),,冷彎,180°,D,－彎心直徑,d,－鋼筋公稱直徑,應(yīng)力松馳,σ,com,=0.7σ,b,,,反復(fù)彎曲次數(shù),,,δ,10,,δ,100,,,,,,,,,,1000h,≮(%),10h,≮(%),,CRB550,CRB650,CRB800,CRB970,CRB1270,,550,650,800,970,1170,8,－,－,－,－,－,4,4,4,4,D=3d,D=3d,D=3d,D=3d,D=3d,－,8,8,8,8,－,5,5,5,5,－,3,3,3,3,表,7.5.8,冷軋帶肋鋼,筋,筋主要力學(xué),性,性能和工藝,性,性能,級別代號,抗拉強度,σ,b,(MPa),不小于,伸長率不小于,(%),,冷彎,180°,D,－彎心直徑,d,－鋼筋公稱直徑,應(yīng)力松馳,σ,com,=0.7σ,b,,,反復(fù)彎曲次數(shù),,,δ,10,,δ,100,,,,,,,,,,1000h,≮(%),10h,≮(%),,CRB550,CRB650,CRB800,CRB970,CRB1270,,550,650,800,970,1170,8,－,－,－,－,－,4,4,4,4,D=3d,D=3d,D=3d,D=3d,D=3d,－,8,8,8,8,－,5,5,5,5,－,3,3,3,3,表,7.5.8,冷軋帶肋鋼,筋,筋主要力學(xué),性,性能和工藝,性,性能,Back,這是一類冷,加,加工鋼筋。,將直徑為,6.5-8,㎜,㎜,的碳素結(jié)構(gòu),鋼,鋼的,Q235,或,Q215,盤條，通過,拔,拔絲機進行,多,多次冷拔而,成,成。,冷拔低碳鋼,絲,絲分為甲、,乙,乙兩級。,甲級冷拔鋼,絲,絲主要用作,預(yù),預(yù)應(yīng)力筋；,乙,乙級冷拔鋼,絲,絲可用作普,通,通鋼筋（非,預(yù),預(yù)應(yīng)力筋）,，,，也可用于,焊,焊接網(wǎng)、焊,接,接骨架、箍,筋,筋和構(gòu)造鋼,筋,筋等。冷拔,低,低碳鋼絲的,力,力學(xué)性能要,求,求見下表,7.5.9,。,冷拔低碳鋼,絲,絲,Back,Tab.7.5.9,冷拔低碳鋼,絲,絲的力學(xué)性,能,能,(GBJ204-83),鋼絲級別,,直徑,mm,抗拉強度,N/mm,2,（,Kgf/cm,2,）,,,伸長率,（,標(biāo)距,100,mm,）,,（,%,）,,反復(fù)彎曲,(,180,°),,應(yīng)用,,,,Ⅰ,Ⅱ,,,,,,,,≥,,,,,,,,甲級,5,4,650,（,65,）,,700,（,70,）,,,600,（,60,）,,650,（,65,）,,3,2.5,4,,預(yù)應(yīng)力筋,乙級,3,～,5,550,（,55,）,,,,2,4,,非預(yù)應(yīng)力筋,Chapter 7,THE END,