構(gòu)造對熱處分后的構(gòu)造和性能的影響主要闡揚(yáng)在如下幾方面
(1)鍛件廠家不行改善的構(gòu)造缺陷:奧氏體和鐵素體耐熱不銹鋼、高溫合金、鋁合金、鎂合金等在加熱和冷卻過程中,沒有同素異構(gòu)轉(zhuǎn)變的質(zhì)料,以及少許銅合金和鈦合金等,在鑄造過程中發(fā)生的構(gòu)造缺陷用熱處分的辦法不行改善。
(2)能夠得到改善的構(gòu)造缺陷:在一般過熱的布局鋼鍛件中的粗晶和魏氏構(gòu)造,過共析鋼和軸承鋼由于冷卻不當(dāng)惹起的輕細(xì)的網(wǎng)狀碳化物等在鍛后熱處分時,鍛件熱處分后仍可獲取寫意的構(gòu)造和性能。
(3) 正常的熱處分較難消弭的構(gòu)造缺陷:比方低倍粗晶、9Cr18不銹鋼、H13的孿晶碳化物等需用高溫正火、反復(fù)正火、低溫剖釋、高溫分散退火等錯失才氣得到改善。
(4)用一般熱處分工藝不行消弭的構(gòu)造缺陷:緊張的石狀斷口和棱面斷口、過燒、不銹鋼中的鐵素體帶、萊氏體合金工具鋼中的碳化物網(wǎng)和帶等使熱處分后的鍛件性能下降,乃至分歧格。
(5)在熱處分時將會進(jìn)一步發(fā)展的構(gòu)造缺陷:比方,合金布局鋼鍛件中的粗晶構(gòu)造,要是鍛后熱處分時未得到改善,在碳、氮共滲和淬火后常惹起馬氏體針粗大和性能分歧格;高速鋼中的粗大帶狀碳化物,淬火經(jīng)常惹起開裂。
(6) 要是加熱不當(dāng),比方加熱溫度過高和加熱時間過長,將會惹起脫碳、過熱、過燒等缺陷。
(7)鍛后冷卻過程中,要是工藝不當(dāng)可能惹起冷卻裂紋、白點(diǎn)等,在熱處分過程中開裂。
自由鍛件廠家哪家好,就找唐山盛通鍛造有限公司。
The influence of the structure on the structure and performance after heat treatment is mainly explained in the following aspects
(1) Structural defects that cannot be improved by forgings manufacturers: austenitic and ferritic heat-resistant stainless steels, high-temperature alloys, aluminum alloys, magnesium alloys, etc., during heating and cooling, there is no homogeneous transformation of the material, and a little copper Alloys, titanium alloys, etc., the structural defects occurring during the casting process are not improved by heat treatment.
(2) Improved structural defects: coarse grain and Wei's structure in general overheated layout steel forgings, superfine eutectoid steel and bearing steel due to improper cooling caused by light and fine mesh carbides, etc. At the time of disposition, the forged piece can still obtain freehand construction and performance after heat treatment.
(3) The normal heat treatment is difficult to eliminate structural defects: for example, low-magnification coarse crystal, 9Cr18 stainless steel, H13 twinned carbide, etc., need to use high-temperature normalizing, repeated normalizing, low-temperature interpretation, high-temperature dispersion annealing, etc. Improved.
(4) Structural defects that cannot be eliminated by the general heat treatment process: tight stone fractures and facet fractures, over-burning, ferrite belts in stainless steel, carbide nets and belts in Leysite alloy tool steels, etc. The performance of forgings after heat treatment is degraded, and even divergent.
(5) Structural defects that will be further developed in the case of heat treatment: For example, the coarse-grained structure in the alloy layout steel forgings is not improved when hot after forging, and often causes Markov after carbon, nitrogen co-infiltration and quenching. Large body needles and performance differences; coarse banded carbides in high-speed steel, quenching often cause cracking.
(6) If the heating is improper, for example, the heating temperature is too high and the heating time is too long, it will cause defects such as decarburization, overheating and overburning.
(7) During the post-forging cooling process, if the process is improper, it may cause cooling cracks, white spots, etc., and crack during the heat treatment.