Homogenization of Precipitation Hardening Nickel Based Superalloys

Allvac 718 Plus and Haynes 282 are relatively new precipitation hardening nickel based superalloys with good high temperature mechanical properties. In addition, the weldability of these superalloys enhances easy fabrication. The combination of high temperature capabilities and superior weldability is unmatched by other precipitation hardening superalloys and linked to the amount of the γ’ hardening precipitates in the materials. Hence, it is these properties that make Allvac 718 Plus and Haynes 282 desirable in the manufacture of hot sections of aero engine components. Studies show that cast products are less weldable than wrought products. Segregation of elements in the cast results in inhomogeneous composition which consequently diminishes weldability. Segregation during solidification of the cast products results in dendritic microstructure with the segregating elements occupying interdendritic regions. These segregating elements are trapped in secondary phases present alongside γ matrix. Studies show that in Allvac 718Plus, the segregating phase is Laves while in Haynes 282 the segregating phase is not yet fully determined. Thus, the present study investigated the effects of homogenization heat treatments in eliminating segregation in cast Allvac 718 Plus and Haynes 282. Paramount to the study was the effect of different homogenization temperatures and dwell time in the removal of the segregating phases. Experimental methods used to both qualify and quantify the segregating phases included SEM, EDX analysis, manual point count and macro Vickers hardness tests. Main results show that there is a reduction in the segregating phases in both materials as homogenization proceeds hence a disappearance of the dendritic structure. In Allvac 718 Plus, plate like structures is observed to be closely associated with the Laves phase at low temperatures and dwell times. In addition, Nb is found to be segregating in the interdendritic areas. The expected trend of increase in Laves as a result of the dissolution of the plate like structures at the initial stage of homogenization is only detectable for few cases. In Haynes 282, white and grey phases are clearly distinguished and Mo is observed to be segregating in interdendritic areas.

Förståelse, bedömningar och hjälpinsatser : Socialarbetares arbete med män som våldsoffer

This report outlines the background to, and presents the results from the Crime Victim Compensation and Support Authority funded project "Social Workers' understanding of men as victims of crime". The project aimed at describing and analyzing how social workers understand and work with male victims of violence. More precisely, the research has focused on how social workers describe men's vulnerability and how they understand men's needs for assistance, what assistance that is provided and the way the constellations of perpetrators and victims of different gender and contexts in which the violence occurs in affect the understanding of male victims of violence. The study has also been devoted to the question of whether the Support Centers for young crime victims in Sweden provide different types of and different amount of help to young men and women afflicted of violence. The project was conducted in three substudies. The results from substudy 1 show that more young men than women seek support from the Support centers studied. Men predominate in number of cases and in the different categories of crime. The results also show that young men on average receive less assistance over a shorter average duration than young women. This applies irrespective of the category of offense that the vulnerability applies to. Furthermore, the young men, compared to the women, proportionally receive fewer interventions characterized as support and a greater proportion of interventions in the form of information. The results also show that the young men are referred on for further action to a lesser extent than is the case for women. The results from substudy 2 show that social workers tend to focus on whether, and to what extent, young men who are victims of violence themselves have behaved provocatively before the violence incident and if they have put themselves in a social situation that could be interpreted as having contributed to an escalation of the violence they have been subjected to. The results from substudy 2 also show that social workers talk about the men as active in the violent situations they have been involved in and dwell on the extent to which the young men's own actions have contributed to the violence. The results also show that young men who are victims of violence are described as "reluctant" victims who are trying to cope with their situation on their own without the involvement of professional or other helper. The young men are also described as reluctant to talk about their feelings. The results of substudy 3 show that social workers believe that young men, when they become victims of violence, risks losing their sense of autonomy, initiative and decisiveness, that is, attributes that are often linked to the dominating cultural image of masculinity. Furthermore, the results show that social workers estimate that men's practicing of their masculinity, but also the response that men who are traumatized get from society, creates difficulties for them to get help. The results from substudy 3 also shows that attributes and actions that can be connected to the masculinity of young men's, as well as a lack of such attributes and actions are considered to be adequate explanations for the violence the men has suffered. When it comes to violence in public places it is the masculinity that explains the violence and its escalation. When it comes to domestic violence it is the lack of expected male attributes and actions that are used as explanations for the violence that have occurred. The discussion is devoted to the question of how the results should be understood based on the concepts of self-performance, interpretation, negotiation and categorizations, and the consequences the results obtained should have for gender sensitive social work given to abused men.