第1部分:铬钼钢的焊后热处理裂纹研究了标准和改进的2¼Cr lMo、3Cr-1和1½Mo钢的焊后热处理（PWHT）裂纹敏感性。试验的改性钢包括三炉3Cr-1½Mo-0.1V、一炉3Cr-1½Mo-½Ni和一炉V-Ti-B改性2¼Cr-1Mo和3Cr-1Mo。用于评估焊后热处理裂纹敏感性的试验为Gleeble模拟试验和根据ASTM G-38（用于评估应力腐蚀裂纹敏感性）中所述试验改编的“C型环”试验。 试验结果表明，焊后热处理裂纹敏感性与主要和次要合金元素的成分效应密切相关。而Ti-V脆化明显依赖于晶界的热脆化（Ti-V脆化）。碳化物提取副本的透射电子显微镜得出的一般结论是，有助于MC、M2C或M4C3C型共格基体沉淀物稳定性的元素（如V、Si）会提高焊后热处理开裂的敏感性。 镍等元素的存在将促使沉淀过程更快地达到平衡，从而降低PWHT开裂的敏感性。第2部分:高强度低合金钢的焊后热处理裂纹描述了几种高强度低合金钢、压力容器和结构钢的焊后热处理（PWHT）裂纹敏感性评估。进行了Gleeble模拟试验，以获得焊后热处理开裂敏感性的初步评估。随后对三种HSLA钢进行了C形环和Y形槽试验。 C型环试验是从传统上用于评估应力腐蚀开裂敏感性的试验改编而来，并在ASTM标准G-38中进行了描述。Gleeble试验的结果表明，淬火和回火（也包括淬火和沉淀硬化）类型的钢对焊后热处理开裂的敏感性可能更高。C型环和Y型槽试验证实，与HSLA钢、A 808和A 572 Gr 50相比，HSLA钢A 710 Gr A Cl 3的敏感性可能更高。

Part 1: Postweld Heat Treatment Cracking In Chromium-Molybdenum SteelsThe postweld heat treatment (PWHT) cracking susceptibility of standard and modified 2¼Cr-lMo and 3Cr-1 and 1½Mo steels has been investigated. The modified steels tested include three heats of 3Cr-1½Mo-0.1V, a heat of 3Cr-1½Mo-½Ni and a heat each of V-Ti-B modified 2¼Cr-1Mo and 3Cr-1Mo. Tests used to evaluate PWHT cracking susceptibility were Gleeble simulation and a "C-Ring" test adapted from that described in ASTM G-38 (used to evaluate stress corrosion cracking susceptibility).The results of the tests indicate that the susceptibility to PWHT cracking is synergistically dependent on the compositional effects of major and minor alloying elements. Both the V-Ti-B heats were relatively susceptible to PWHT cracking whereas the susceptibility of the vanadium alone heats was apparently dependent on the presence of grain boundary embrittling elements (phosphorus). Transmission electron microscopy of carbide extraction replicas leads to the general conclusion that elements (such as V, Si) that contribute to the stability of coherent matrix precipitates of the MC, M2C or M4C3type lead to enhanced susceptibility of PWHT cracking. The presence of elements such as nickel that will drive the precipitation process faster towards equilibrium reduces susceptibility to PWHT cracking.Part 2: Postweld Heat Treatment Cracking In High Strength Low Alloy SteelsThe evaluation of the postweld heat treatment (PWHT) cracking susceptibility of several HSLA, pressure vessel and structural steels is described. Gleeble simulation tests were conducted to gain an initial assessment of the PWHT cracking susceptibility. This was followed by C-Ring and Y-Groove tests on three of the HSLA steels. The C-Ring test has been adapted from one that is conventionally used to evaluate stress corrosion cracking susceptibility and is described in ASTM Standard G-38. The results of the Gleeble tests indicate that steels of the quenched and tempered (also quenched and precipitation hardened) variety have a potentially greater susceptibility to PWHT cracking. The C-Ring and Y-Groove tests confirmed the potentially greater susceptibility of HSLA steel A 710 Gr A Cl 3 when compared to HSLA steels, A 808 and A 572 Gr 50.